Black substance on onions and garlic: Welcome back to “Science For Everyone”, ABP Live’s weekly science column. Last week, we explained what materials transition is, and how this can help ensure a net-zero future. This week, we discuss what the black material found on the surface of onions and garlic is, if such vegetables can be consumed, and how the condition can be managed.
Before peeling onions and garlic, almost everyone must have noticed a black substance on the vegetables. But have you ever wondered what that material is? Is it soil? Is it dirt? Well, the answer is that the black material is a fungus or mold called Aspergillus niger. Black mold is commonly found in the soil, and to prevent mold from growing on harvested onions, they must be stored in the refrigerator for at least two months.
How does Aspergillus niger infest onions and garlic?
According to the University of California Agriculture & Natural Resources, Aspergillus niger is first detected on onions and garlic as an area covered with a black sooty mass. This sooty mass is made up of microscopic spores, and can be found on the neck or outer scales of the vegetable. An opening on the skin of the vegetable caused by an injury, disease, or toppling of foliage is the reason why the black sooty mass settles on it.
Spores of Aspergillus niger may develop between dry, dead outer scales, and the first inner fleshy scales of the onion or garlic bulb. The scales of the vegetables that have been invaded become water-soaked. The fungal spores are often seen in a streaking pattern along the veins.
In some cases, the interior parts of the bulb may also be affected with grey or black discolouration. When conditions are dry, diseased scales dry and wither, and the black masses of the spores of Aspergillus niger are visible between outer scales.
Soft rot bacteria may invade the parts of the onion or garlic affected by spores of Aspergillus niger. As a result, the whole bulb may deteriorate into a watery soft rot.
Under what conditions does black mold develop on onions and garlic?
The black sooty mass formed by Aspergillus niger, or black mold, is a postharvest condition, and while it occurs on both onions and garlic, it is more of a concern in onion crops.
Not all onion and garlic crops are infested with black mold, but the ones grown under warm conditions often become covered with black spores of Aspergillus niger. For instance, India and the desert areas of California are warm regions, as a result of which black mold often develops on the onion and garlic crops grown in these areas.
Black mold disease develops when moisture is present on the bulb for six to 12 hours. If bulbs are damp when stored, or if condensation accumulates on the bulbs between the outer dry scales when the onions and garlic are sent to be stored, and brought out of storage, black mold disease may occur.
All fungi live on decaying organic substrates such as plant debris. However, Aspergillus niger is a weak pathogen that usually does not affect uninjured bulbs. This fungus is widely distributed among soil environments.
Some fungicidal control programmes used for foliar diseases may reduce the incidence of black mold, but no fungicides can directly control black mold. The fungicides used to control Peronospora parasitica, the fungus that causes downy mildew, cannot reduce the incidence of black mold.
How can black mold infestation be controlled and managed?
One can culturally manage black mold by following steps such as storing and transporting bulbs at temperatures below 59 degrees Fahrenheit or 15 degrees Celsius, and at low humidity to slow down the growth of Aspergillus niger.
Other measures include reducing bruising and injury during harvest, handling, and transport to minimise the opening of the skin. This is because open spots may serve as invasion sites for Aspergillus niger.
Onions should be promptly harvested, and drying must not be delayed. Heated air must not be used for drying.
During the transport of onions and garlic, stable temperatures must be maintained. This should also be done when the bulbs are going into and coming out of storage.
When there are wide temperature fluctuations, condensation occurs on the bulbs, and between the outer dry scales, promoting the development of black mold.
According to the US Department of Agriculture, mold growth can be discouraged by rinsing small amounts of the black mold on the outer scales of the onion under cool, running tap water, or chopping off the affected layers. People can use the unaffected parts. Also, those who are allergic to Aspergillus niger must not use onions infested with black mold.
Black substance on onions and garlic: Welcome back to “Science For Everyone”, ABP Live’s weekly science column. Last week, we explained what materials transition is, and how this can help ensure a net-zero future. This week, we discuss what the black material found on the surface of onions and garlic is, if such vegetables can be consumed, and how the condition can be managed.
Before peeling onions and garlic, almost everyone must have noticed a black substance on the vegetables. But have you ever wondered what that material is? Is it soil? Is it dirt? Well, the answer is that the black material is a fungus or mold called Aspergillus niger. Black mold is commonly found in the soil, and to prevent mold from growing on harvested onions, they must be stored in the refrigerator for at least two months.
How does Aspergillus niger infest onions and garlic?
According to the University of California Agriculture & Natural Resources, Aspergillus niger is first detected on onions and garlic as an area covered with a black sooty mass. This sooty mass is made up of microscopic spores, and can be found on the neck or outer scales of the vegetable. An opening on the skin of the vegetable caused by an injury, disease, or toppling of foliage is the reason why the black sooty mass settles on it.
Spores of Aspergillus niger may develop between dry, dead outer scales, and the first inner fleshy scales of the onion or garlic bulb. The scales of the vegetables that have been invaded become water-soaked. The fungal spores are often seen in a streaking pattern along the veins.
In some cases, the interior parts of the bulb may also be affected with grey or black discolouration. When conditions are dry, diseased scales dry and wither, and the black masses of the spores of Aspergillus niger are visible between outer scales.
Soft rot bacteria may invade the parts of the onion or garlic affected by spores of Aspergillus niger. As a result, the whole bulb may deteriorate into a watery soft rot.
Under what conditions does black mold develop on onions and garlic?
The black sooty mass formed by Aspergillus niger, or black mold, is a postharvest condition, and while it occurs on both onions and garlic, it is more of a concern in onion crops.
Not all onion and garlic crops are infested with black mold, but the ones grown under warm conditions often become covered with black spores of Aspergillus niger. For instance, India and the desert areas of California are warm regions, as a result of which black mold often develops on the onion and garlic crops grown in these areas.
Black mold disease develops when moisture is present on the bulb for six to 12 hours. If bulbs are damp when stored, or if condensation accumulates on the bulbs between the outer dry scales when the onions and garlic are sent to be stored, and brought out of storage, black mold disease may occur.
All fungi live on decaying organic substrates such as plant debris. However, Aspergillus niger is a weak pathogen that usually does not affect uninjured bulbs. This fungus is widely distributed among soil environments.
Some fungicidal control programmes used for foliar diseases may reduce the incidence of black mold, but no fungicides can directly control black mold. The fungicides used to control Peronospora parasitica, the fungus that causes downy mildew, cannot reduce the incidence of black mold.
How can black mold infestation be controlled and managed?
One can culturally manage black mold by following steps such as storing and transporting bulbs at temperatures below 59 degrees Fahrenheit or 15 degrees Celsius, and at low humidity to slow down the growth of Aspergillus niger.
Other measures include reducing bruising and injury during harvest, handling, and transport to minimise the opening of the skin. This is because open spots may serve as invasion sites for Aspergillus niger.
Onions should be promptly harvested, and drying must not be delayed. Heated air must not be used for drying.
During the transport of onions and garlic, stable temperatures must be maintained. This should also be done when the bulbs are going into and coming out of storage.
When there are wide temperature fluctuations, condensation occurs on the bulbs, and between the outer dry scales, promoting the development of black mold.
According to the US Department of Agriculture, mold growth can be discouraged by rinsing small amounts of the black mold on the outer scales of the onion under cool, running tap water, or chopping off the affected layers. People can use the unaffected parts. Also, those who are allergic to Aspergillus niger must not use onions infested with black mold.
Black substance on onions and garlic: Welcome back to “Science For Everyone”, ABP Live’s weekly science column. Last week, we explained what materials transition is, and how this can help ensure a net-zero future. This week, we discuss what the black material found on the surface of onions and garlic is, if such vegetables can be consumed, and how the condition can be managed.
Before peeling onions and garlic, almost everyone must have noticed a black substance on the vegetables. But have you ever wondered what that material is? Is it soil? Is it dirt? Well, the answer is that the black material is a fungus or mold called Aspergillus niger. Black mold is commonly found in the soil, and to prevent mold from growing on harvested onions, they must be stored in the refrigerator for at least two months.
How does Aspergillus niger infest onions and garlic?
According to the University of California Agriculture & Natural Resources, Aspergillus niger is first detected on onions and garlic as an area covered with a black sooty mass. This sooty mass is made up of microscopic spores, and can be found on the neck or outer scales of the vegetable. An opening on the skin of the vegetable caused by an injury, disease, or toppling of foliage is the reason why the black sooty mass settles on it.
Spores of Aspergillus niger may develop between dry, dead outer scales, and the first inner fleshy scales of the onion or garlic bulb. The scales of the vegetables that have been invaded become water-soaked. The fungal spores are often seen in a streaking pattern along the veins.
In some cases, the interior parts of the bulb may also be affected with grey or black discolouration. When conditions are dry, diseased scales dry and wither, and the black masses of the spores of Aspergillus niger are visible between outer scales.
Soft rot bacteria may invade the parts of the onion or garlic affected by spores of Aspergillus niger. As a result, the whole bulb may deteriorate into a watery soft rot.
Under what conditions does black mold develop on onions and garlic?
The black sooty mass formed by Aspergillus niger, or black mold, is a postharvest condition, and while it occurs on both onions and garlic, it is more of a concern in onion crops.
Not all onion and garlic crops are infested with black mold, but the ones grown under warm conditions often become covered with black spores of Aspergillus niger. For instance, India and the desert areas of California are warm regions, as a result of which black mold often develops on the onion and garlic crops grown in these areas.
Black mold disease develops when moisture is present on the bulb for six to 12 hours. If bulbs are damp when stored, or if condensation accumulates on the bulbs between the outer dry scales when the onions and garlic are sent to be stored, and brought out of storage, black mold disease may occur.
All fungi live on decaying organic substrates such as plant debris. However, Aspergillus niger is a weak pathogen that usually does not affect uninjured bulbs. This fungus is widely distributed among soil environments.
Some fungicidal control programmes used for foliar diseases may reduce the incidence of black mold, but no fungicides can directly control black mold. The fungicides used to control Peronospora parasitica, the fungus that causes downy mildew, cannot reduce the incidence of black mold.
How can black mold infestation be controlled and managed?
One can culturally manage black mold by following steps such as storing and transporting bulbs at temperatures below 59 degrees Fahrenheit or 15 degrees Celsius, and at low humidity to slow down the growth of Aspergillus niger.
Other measures include reducing bruising and injury during harvest, handling, and transport to minimise the opening of the skin. This is because open spots may serve as invasion sites for Aspergillus niger.
Onions should be promptly harvested, and drying must not be delayed. Heated air must not be used for drying.
During the transport of onions and garlic, stable temperatures must be maintained. This should also be done when the bulbs are going into and coming out of storage.
When there are wide temperature fluctuations, condensation occurs on the bulbs, and between the outer dry scales, promoting the development of black mold.
According to the US Department of Agriculture, mold growth can be discouraged by rinsing small amounts of the black mold on the outer scales of the onion under cool, running tap water, or chopping off the affected layers. People can use the unaffected parts. Also, those who are allergic to Aspergillus niger must not use onions infested with black mold.
Black substance on onions and garlic: Welcome back to “Science For Everyone”, ABP Live’s weekly science column. Last week, we explained what materials transition is, and how this can help ensure a net-zero future. This week, we discuss what the black material found on the surface of onions and garlic is, if such vegetables can be consumed, and how the condition can be managed.
Before peeling onions and garlic, almost everyone must have noticed a black substance on the vegetables. But have you ever wondered what that material is? Is it soil? Is it dirt? Well, the answer is that the black material is a fungus or mold called Aspergillus niger. Black mold is commonly found in the soil, and to prevent mold from growing on harvested onions, they must be stored in the refrigerator for at least two months.
How does Aspergillus niger infest onions and garlic?
According to the University of California Agriculture & Natural Resources, Aspergillus niger is first detected on onions and garlic as an area covered with a black sooty mass. This sooty mass is made up of microscopic spores, and can be found on the neck or outer scales of the vegetable. An opening on the skin of the vegetable caused by an injury, disease, or toppling of foliage is the reason why the black sooty mass settles on it.
Spores of Aspergillus niger may develop between dry, dead outer scales, and the first inner fleshy scales of the onion or garlic bulb. The scales of the vegetables that have been invaded become water-soaked. The fungal spores are often seen in a streaking pattern along the veins.
In some cases, the interior parts of the bulb may also be affected with grey or black discolouration. When conditions are dry, diseased scales dry and wither, and the black masses of the spores of Aspergillus niger are visible between outer scales.
Soft rot bacteria may invade the parts of the onion or garlic affected by spores of Aspergillus niger. As a result, the whole bulb may deteriorate into a watery soft rot.
Under what conditions does black mold develop on onions and garlic?
The black sooty mass formed by Aspergillus niger, or black mold, is a postharvest condition, and while it occurs on both onions and garlic, it is more of a concern in onion crops.
Not all onion and garlic crops are infested with black mold, but the ones grown under warm conditions often become covered with black spores of Aspergillus niger. For instance, India and the desert areas of California are warm regions, as a result of which black mold often develops on the onion and garlic crops grown in these areas.
Black mold disease develops when moisture is present on the bulb for six to 12 hours. If bulbs are damp when stored, or if condensation accumulates on the bulbs between the outer dry scales when the onions and garlic are sent to be stored, and brought out of storage, black mold disease may occur.
All fungi live on decaying organic substrates such as plant debris. However, Aspergillus niger is a weak pathogen that usually does not affect uninjured bulbs. This fungus is widely distributed among soil environments.
Some fungicidal control programmes used for foliar diseases may reduce the incidence of black mold, but no fungicides can directly control black mold. The fungicides used to control Peronospora parasitica, the fungus that causes downy mildew, cannot reduce the incidence of black mold.
How can black mold infestation be controlled and managed?
One can culturally manage black mold by following steps such as storing and transporting bulbs at temperatures below 59 degrees Fahrenheit or 15 degrees Celsius, and at low humidity to slow down the growth of Aspergillus niger.
Other measures include reducing bruising and injury during harvest, handling, and transport to minimise the opening of the skin. This is because open spots may serve as invasion sites for Aspergillus niger.
Onions should be promptly harvested, and drying must not be delayed. Heated air must not be used for drying.
During the transport of onions and garlic, stable temperatures must be maintained. This should also be done when the bulbs are going into and coming out of storage.
When there are wide temperature fluctuations, condensation occurs on the bulbs, and between the outer dry scales, promoting the development of black mold.
According to the US Department of Agriculture, mold growth can be discouraged by rinsing small amounts of the black mold on the outer scales of the onion under cool, running tap water, or chopping off the affected layers. People can use the unaffected parts. Also, those who are allergic to Aspergillus niger must not use onions infested with black mold.
Black substance on onions and garlic: Welcome back to “Science For Everyone”, ABP Live’s weekly science column. Last week, we explained what materials transition is, and how this can help ensure a net-zero future. This week, we discuss what the black material found on the surface of onions and garlic is, if such vegetables can be consumed, and how the condition can be managed.
Before peeling onions and garlic, almost everyone must have noticed a black substance on the vegetables. But have you ever wondered what that material is? Is it soil? Is it dirt? Well, the answer is that the black material is a fungus or mold called Aspergillus niger. Black mold is commonly found in the soil, and to prevent mold from growing on harvested onions, they must be stored in the refrigerator for at least two months.
How does Aspergillus niger infest onions and garlic?
According to the University of California Agriculture & Natural Resources, Aspergillus niger is first detected on onions and garlic as an area covered with a black sooty mass. This sooty mass is made up of microscopic spores, and can be found on the neck or outer scales of the vegetable. An opening on the skin of the vegetable caused by an injury, disease, or toppling of foliage is the reason why the black sooty mass settles on it.
Spores of Aspergillus niger may develop between dry, dead outer scales, and the first inner fleshy scales of the onion or garlic bulb. The scales of the vegetables that have been invaded become water-soaked. The fungal spores are often seen in a streaking pattern along the veins.
In some cases, the interior parts of the bulb may also be affected with grey or black discolouration. When conditions are dry, diseased scales dry and wither, and the black masses of the spores of Aspergillus niger are visible between outer scales.
Soft rot bacteria may invade the parts of the onion or garlic affected by spores of Aspergillus niger. As a result, the whole bulb may deteriorate into a watery soft rot.
Under what conditions does black mold develop on onions and garlic?
The black sooty mass formed by Aspergillus niger, or black mold, is a postharvest condition, and while it occurs on both onions and garlic, it is more of a concern in onion crops.
Not all onion and garlic crops are infested with black mold, but the ones grown under warm conditions often become covered with black spores of Aspergillus niger. For instance, India and the desert areas of California are warm regions, as a result of which black mold often develops on the onion and garlic crops grown in these areas.
Black mold disease develops when moisture is present on the bulb for six to 12 hours. If bulbs are damp when stored, or if condensation accumulates on the bulbs between the outer dry scales when the onions and garlic are sent to be stored, and brought out of storage, black mold disease may occur.
All fungi live on decaying organic substrates such as plant debris. However, Aspergillus niger is a weak pathogen that usually does not affect uninjured bulbs. This fungus is widely distributed among soil environments.
Some fungicidal control programmes used for foliar diseases may reduce the incidence of black mold, but no fungicides can directly control black mold. The fungicides used to control Peronospora parasitica, the fungus that causes downy mildew, cannot reduce the incidence of black mold.
How can black mold infestation be controlled and managed?
One can culturally manage black mold by following steps such as storing and transporting bulbs at temperatures below 59 degrees Fahrenheit or 15 degrees Celsius, and at low humidity to slow down the growth of Aspergillus niger.
Other measures include reducing bruising and injury during harvest, handling, and transport to minimise the opening of the skin. This is because open spots may serve as invasion sites for Aspergillus niger.
Onions should be promptly harvested, and drying must not be delayed. Heated air must not be used for drying.
During the transport of onions and garlic, stable temperatures must be maintained. This should also be done when the bulbs are going into and coming out of storage.
When there are wide temperature fluctuations, condensation occurs on the bulbs, and between the outer dry scales, promoting the development of black mold.
According to the US Department of Agriculture, mold growth can be discouraged by rinsing small amounts of the black mold on the outer scales of the onion under cool, running tap water, or chopping off the affected layers. People can use the unaffected parts. Also, those who are allergic to Aspergillus niger must not use onions infested with black mold.
Black substance on onions and garlic: Welcome back to “Science For Everyone”, ABP Live’s weekly science column. Last week, we explained what materials transition is, and how this can help ensure a net-zero future. This week, we discuss what the black material found on the surface of onions and garlic is, if such vegetables can be consumed, and how the condition can be managed.
Before peeling onions and garlic, almost everyone must have noticed a black substance on the vegetables. But have you ever wondered what that material is? Is it soil? Is it dirt? Well, the answer is that the black material is a fungus or mold called Aspergillus niger. Black mold is commonly found in the soil, and to prevent mold from growing on harvested onions, they must be stored in the refrigerator for at least two months.
How does Aspergillus niger infest onions and garlic?
According to the University of California Agriculture & Natural Resources, Aspergillus niger is first detected on onions and garlic as an area covered with a black sooty mass. This sooty mass is made up of microscopic spores, and can be found on the neck or outer scales of the vegetable. An opening on the skin of the vegetable caused by an injury, disease, or toppling of foliage is the reason why the black sooty mass settles on it.
Spores of Aspergillus niger may develop between dry, dead outer scales, and the first inner fleshy scales of the onion or garlic bulb. The scales of the vegetables that have been invaded become water-soaked. The fungal spores are often seen in a streaking pattern along the veins.
In some cases, the interior parts of the bulb may also be affected with grey or black discolouration. When conditions are dry, diseased scales dry and wither, and the black masses of the spores of Aspergillus niger are visible between outer scales.
Soft rot bacteria may invade the parts of the onion or garlic affected by spores of Aspergillus niger. As a result, the whole bulb may deteriorate into a watery soft rot.
Under what conditions does black mold develop on onions and garlic?
The black sooty mass formed by Aspergillus niger, or black mold, is a postharvest condition, and while it occurs on both onions and garlic, it is more of a concern in onion crops.
Not all onion and garlic crops are infested with black mold, but the ones grown under warm conditions often become covered with black spores of Aspergillus niger. For instance, India and the desert areas of California are warm regions, as a result of which black mold often develops on the onion and garlic crops grown in these areas.
Black mold disease develops when moisture is present on the bulb for six to 12 hours. If bulbs are damp when stored, or if condensation accumulates on the bulbs between the outer dry scales when the onions and garlic are sent to be stored, and brought out of storage, black mold disease may occur.
All fungi live on decaying organic substrates such as plant debris. However, Aspergillus niger is a weak pathogen that usually does not affect uninjured bulbs. This fungus is widely distributed among soil environments.
Some fungicidal control programmes used for foliar diseases may reduce the incidence of black mold, but no fungicides can directly control black mold. The fungicides used to control Peronospora parasitica, the fungus that causes downy mildew, cannot reduce the incidence of black mold.
How can black mold infestation be controlled and managed?
One can culturally manage black mold by following steps such as storing and transporting bulbs at temperatures below 59 degrees Fahrenheit or 15 degrees Celsius, and at low humidity to slow down the growth of Aspergillus niger.
Other measures include reducing bruising and injury during harvest, handling, and transport to minimise the opening of the skin. This is because open spots may serve as invasion sites for Aspergillus niger.
Onions should be promptly harvested, and drying must not be delayed. Heated air must not be used for drying.
During the transport of onions and garlic, stable temperatures must be maintained. This should also be done when the bulbs are going into and coming out of storage.
When there are wide temperature fluctuations, condensation occurs on the bulbs, and between the outer dry scales, promoting the development of black mold.
According to the US Department of Agriculture, mold growth can be discouraged by rinsing small amounts of the black mold on the outer scales of the onion under cool, running tap water, or chopping off the affected layers. People can use the unaffected parts. Also, those who are allergic to Aspergillus niger must not use onions infested with black mold.
Black substance on onions and garlic: Welcome back to “Science For Everyone”, ABP Live’s weekly science column. Last week, we explained what materials transition is, and how this can help ensure a net-zero future. This week, we discuss what the black material found on the surface of onions and garlic is, if such vegetables can be consumed, and how the condition can be managed.
Before peeling onions and garlic, almost everyone must have noticed a black substance on the vegetables. But have you ever wondered what that material is? Is it soil? Is it dirt? Well, the answer is that the black material is a fungus or mold called Aspergillus niger. Black mold is commonly found in the soil, and to prevent mold from growing on harvested onions, they must be stored in the refrigerator for at least two months.
How does Aspergillus niger infest onions and garlic?
According to the University of California Agriculture & Natural Resources, Aspergillus niger is first detected on onions and garlic as an area covered with a black sooty mass. This sooty mass is made up of microscopic spores, and can be found on the neck or outer scales of the vegetable. An opening on the skin of the vegetable caused by an injury, disease, or toppling of foliage is the reason why the black sooty mass settles on it.
Spores of Aspergillus niger may develop between dry, dead outer scales, and the first inner fleshy scales of the onion or garlic bulb. The scales of the vegetables that have been invaded become water-soaked. The fungal spores are often seen in a streaking pattern along the veins.
In some cases, the interior parts of the bulb may also be affected with grey or black discolouration. When conditions are dry, diseased scales dry and wither, and the black masses of the spores of Aspergillus niger are visible between outer scales.
Soft rot bacteria may invade the parts of the onion or garlic affected by spores of Aspergillus niger. As a result, the whole bulb may deteriorate into a watery soft rot.
Under what conditions does black mold develop on onions and garlic?
The black sooty mass formed by Aspergillus niger, or black mold, is a postharvest condition, and while it occurs on both onions and garlic, it is more of a concern in onion crops.
Not all onion and garlic crops are infested with black mold, but the ones grown under warm conditions often become covered with black spores of Aspergillus niger. For instance, India and the desert areas of California are warm regions, as a result of which black mold often develops on the onion and garlic crops grown in these areas.
Black mold disease develops when moisture is present on the bulb for six to 12 hours. If bulbs are damp when stored, or if condensation accumulates on the bulbs between the outer dry scales when the onions and garlic are sent to be stored, and brought out of storage, black mold disease may occur.
All fungi live on decaying organic substrates such as plant debris. However, Aspergillus niger is a weak pathogen that usually does not affect uninjured bulbs. This fungus is widely distributed among soil environments.
Some fungicidal control programmes used for foliar diseases may reduce the incidence of black mold, but no fungicides can directly control black mold. The fungicides used to control Peronospora parasitica, the fungus that causes downy mildew, cannot reduce the incidence of black mold.
How can black mold infestation be controlled and managed?
One can culturally manage black mold by following steps such as storing and transporting bulbs at temperatures below 59 degrees Fahrenheit or 15 degrees Celsius, and at low humidity to slow down the growth of Aspergillus niger.
Other measures include reducing bruising and injury during harvest, handling, and transport to minimise the opening of the skin. This is because open spots may serve as invasion sites for Aspergillus niger.
Onions should be promptly harvested, and drying must not be delayed. Heated air must not be used for drying.
During the transport of onions and garlic, stable temperatures must be maintained. This should also be done when the bulbs are going into and coming out of storage.
When there are wide temperature fluctuations, condensation occurs on the bulbs, and between the outer dry scales, promoting the development of black mold.
According to the US Department of Agriculture, mold growth can be discouraged by rinsing small amounts of the black mold on the outer scales of the onion under cool, running tap water, or chopping off the affected layers. People can use the unaffected parts. Also, those who are allergic to Aspergillus niger must not use onions infested with black mold.
Black substance on onions and garlic: Welcome back to “Science For Everyone”, ABP Live’s weekly science column. Last week, we explained what materials transition is, and how this can help ensure a net-zero future. This week, we discuss what the black material found on the surface of onions and garlic is, if such vegetables can be consumed, and how the condition can be managed.
Before peeling onions and garlic, almost everyone must have noticed a black substance on the vegetables. But have you ever wondered what that material is? Is it soil? Is it dirt? Well, the answer is that the black material is a fungus or mold called Aspergillus niger. Black mold is commonly found in the soil, and to prevent mold from growing on harvested onions, they must be stored in the refrigerator for at least two months.
How does Aspergillus niger infest onions and garlic?
According to the University of California Agriculture & Natural Resources, Aspergillus niger is first detected on onions and garlic as an area covered with a black sooty mass. This sooty mass is made up of microscopic spores, and can be found on the neck or outer scales of the vegetable. An opening on the skin of the vegetable caused by an injury, disease, or toppling of foliage is the reason why the black sooty mass settles on it.
Spores of Aspergillus niger may develop between dry, dead outer scales, and the first inner fleshy scales of the onion or garlic bulb. The scales of the vegetables that have been invaded become water-soaked. The fungal spores are often seen in a streaking pattern along the veins.
In some cases, the interior parts of the bulb may also be affected with grey or black discolouration. When conditions are dry, diseased scales dry and wither, and the black masses of the spores of Aspergillus niger are visible between outer scales.
Soft rot bacteria may invade the parts of the onion or garlic affected by spores of Aspergillus niger. As a result, the whole bulb may deteriorate into a watery soft rot.
Under what conditions does black mold develop on onions and garlic?
The black sooty mass formed by Aspergillus niger, or black mold, is a postharvest condition, and while it occurs on both onions and garlic, it is more of a concern in onion crops.
Not all onion and garlic crops are infested with black mold, but the ones grown under warm conditions often become covered with black spores of Aspergillus niger. For instance, India and the desert areas of California are warm regions, as a result of which black mold often develops on the onion and garlic crops grown in these areas.
Black mold disease develops when moisture is present on the bulb for six to 12 hours. If bulbs are damp when stored, or if condensation accumulates on the bulbs between the outer dry scales when the onions and garlic are sent to be stored, and brought out of storage, black mold disease may occur.
All fungi live on decaying organic substrates such as plant debris. However, Aspergillus niger is a weak pathogen that usually does not affect uninjured bulbs. This fungus is widely distributed among soil environments.
Some fungicidal control programmes used for foliar diseases may reduce the incidence of black mold, but no fungicides can directly control black mold. The fungicides used to control Peronospora parasitica, the fungus that causes downy mildew, cannot reduce the incidence of black mold.
How can black mold infestation be controlled and managed?
One can culturally manage black mold by following steps such as storing and transporting bulbs at temperatures below 59 degrees Fahrenheit or 15 degrees Celsius, and at low humidity to slow down the growth of Aspergillus niger.
Other measures include reducing bruising and injury during harvest, handling, and transport to minimise the opening of the skin. This is because open spots may serve as invasion sites for Aspergillus niger.
Onions should be promptly harvested, and drying must not be delayed. Heated air must not be used for drying.
During the transport of onions and garlic, stable temperatures must be maintained. This should also be done when the bulbs are going into and coming out of storage.
When there are wide temperature fluctuations, condensation occurs on the bulbs, and between the outer dry scales, promoting the development of black mold.
According to the US Department of Agriculture, mold growth can be discouraged by rinsing small amounts of the black mold on the outer scales of the onion under cool, running tap water, or chopping off the affected layers. People can use the unaffected parts. Also, those who are allergic to Aspergillus niger must not use onions infested with black mold.
Black substance on onions and garlic: Welcome back to “Science For Everyone”, ABP Live’s weekly science column. Last week, we explained what materials transition is, and how this can help ensure a net-zero future. This week, we discuss what the black material found on the surface of onions and garlic is, if such vegetables can be consumed, and how the condition can be managed.
Before peeling onions and garlic, almost everyone must have noticed a black substance on the vegetables. But have you ever wondered what that material is? Is it soil? Is it dirt? Well, the answer is that the black material is a fungus or mold called Aspergillus niger. Black mold is commonly found in the soil, and to prevent mold from growing on harvested onions, they must be stored in the refrigerator for at least two months.
How does Aspergillus niger infest onions and garlic?
According to the University of California Agriculture & Natural Resources, Aspergillus niger is first detected on onions and garlic as an area covered with a black sooty mass. This sooty mass is made up of microscopic spores, and can be found on the neck or outer scales of the vegetable. An opening on the skin of the vegetable caused by an injury, disease, or toppling of foliage is the reason why the black sooty mass settles on it.
Spores of Aspergillus niger may develop between dry, dead outer scales, and the first inner fleshy scales of the onion or garlic bulb. The scales of the vegetables that have been invaded become water-soaked. The fungal spores are often seen in a streaking pattern along the veins.
In some cases, the interior parts of the bulb may also be affected with grey or black discolouration. When conditions are dry, diseased scales dry and wither, and the black masses of the spores of Aspergillus niger are visible between outer scales.
Soft rot bacteria may invade the parts of the onion or garlic affected by spores of Aspergillus niger. As a result, the whole bulb may deteriorate into a watery soft rot.
Under what conditions does black mold develop on onions and garlic?
The black sooty mass formed by Aspergillus niger, or black mold, is a postharvest condition, and while it occurs on both onions and garlic, it is more of a concern in onion crops.
Not all onion and garlic crops are infested with black mold, but the ones grown under warm conditions often become covered with black spores of Aspergillus niger. For instance, India and the desert areas of California are warm regions, as a result of which black mold often develops on the onion and garlic crops grown in these areas.
Black mold disease develops when moisture is present on the bulb for six to 12 hours. If bulbs are damp when stored, or if condensation accumulates on the bulbs between the outer dry scales when the onions and garlic are sent to be stored, and brought out of storage, black mold disease may occur.
All fungi live on decaying organic substrates such as plant debris. However, Aspergillus niger is a weak pathogen that usually does not affect uninjured bulbs. This fungus is widely distributed among soil environments.
Some fungicidal control programmes used for foliar diseases may reduce the incidence of black mold, but no fungicides can directly control black mold. The fungicides used to control Peronospora parasitica, the fungus that causes downy mildew, cannot reduce the incidence of black mold.
How can black mold infestation be controlled and managed?
One can culturally manage black mold by following steps such as storing and transporting bulbs at temperatures below 59 degrees Fahrenheit or 15 degrees Celsius, and at low humidity to slow down the growth of Aspergillus niger.
Other measures include reducing bruising and injury during harvest, handling, and transport to minimise the opening of the skin. This is because open spots may serve as invasion sites for Aspergillus niger.
Onions should be promptly harvested, and drying must not be delayed. Heated air must not be used for drying.
During the transport of onions and garlic, stable temperatures must be maintained. This should also be done when the bulbs are going into and coming out of storage.
When there are wide temperature fluctuations, condensation occurs on the bulbs, and between the outer dry scales, promoting the development of black mold.
According to the US Department of Agriculture, mold growth can be discouraged by rinsing small amounts of the black mold on the outer scales of the onion under cool, running tap water, or chopping off the affected layers. People can use the unaffected parts. Also, those who are allergic to Aspergillus niger must not use onions infested with black mold.
Black substance on onions and garlic: Welcome back to “Science For Everyone”, ABP Live’s weekly science column. Last week, we explained what materials transition is, and how this can help ensure a net-zero future. This week, we discuss what the black material found on the surface of onions and garlic is, if such vegetables can be consumed, and how the condition can be managed.
Before peeling onions and garlic, almost everyone must have noticed a black substance on the vegetables. But have you ever wondered what that material is? Is it soil? Is it dirt? Well, the answer is that the black material is a fungus or mold called Aspergillus niger. Black mold is commonly found in the soil, and to prevent mold from growing on harvested onions, they must be stored in the refrigerator for at least two months.
How does Aspergillus niger infest onions and garlic?
According to the University of California Agriculture & Natural Resources, Aspergillus niger is first detected on onions and garlic as an area covered with a black sooty mass. This sooty mass is made up of microscopic spores, and can be found on the neck or outer scales of the vegetable. An opening on the skin of the vegetable caused by an injury, disease, or toppling of foliage is the reason why the black sooty mass settles on it.
Spores of Aspergillus niger may develop between dry, dead outer scales, and the first inner fleshy scales of the onion or garlic bulb. The scales of the vegetables that have been invaded become water-soaked. The fungal spores are often seen in a streaking pattern along the veins.
In some cases, the interior parts of the bulb may also be affected with grey or black discolouration. When conditions are dry, diseased scales dry and wither, and the black masses of the spores of Aspergillus niger are visible between outer scales.
Soft rot bacteria may invade the parts of the onion or garlic affected by spores of Aspergillus niger. As a result, the whole bulb may deteriorate into a watery soft rot.
Under what conditions does black mold develop on onions and garlic?
The black sooty mass formed by Aspergillus niger, or black mold, is a postharvest condition, and while it occurs on both onions and garlic, it is more of a concern in onion crops.
Not all onion and garlic crops are infested with black mold, but the ones grown under warm conditions often become covered with black spores of Aspergillus niger. For instance, India and the desert areas of California are warm regions, as a result of which black mold often develops on the onion and garlic crops grown in these areas.
Black mold disease develops when moisture is present on the bulb for six to 12 hours. If bulbs are damp when stored, or if condensation accumulates on the bulbs between the outer dry scales when the onions and garlic are sent to be stored, and brought out of storage, black mold disease may occur.
All fungi live on decaying organic substrates such as plant debris. However, Aspergillus niger is a weak pathogen that usually does not affect uninjured bulbs. This fungus is widely distributed among soil environments.
Some fungicidal control programmes used for foliar diseases may reduce the incidence of black mold, but no fungicides can directly control black mold. The fungicides used to control Peronospora parasitica, the fungus that causes downy mildew, cannot reduce the incidence of black mold.
How can black mold infestation be controlled and managed?
One can culturally manage black mold by following steps such as storing and transporting bulbs at temperatures below 59 degrees Fahrenheit or 15 degrees Celsius, and at low humidity to slow down the growth of Aspergillus niger.
Other measures include reducing bruising and injury during harvest, handling, and transport to minimise the opening of the skin. This is because open spots may serve as invasion sites for Aspergillus niger.
Onions should be promptly harvested, and drying must not be delayed. Heated air must not be used for drying.
During the transport of onions and garlic, stable temperatures must be maintained. This should also be done when the bulbs are going into and coming out of storage.
When there are wide temperature fluctuations, condensation occurs on the bulbs, and between the outer dry scales, promoting the development of black mold.
According to the US Department of Agriculture, mold growth can be discouraged by rinsing small amounts of the black mold on the outer scales of the onion under cool, running tap water, or chopping off the affected layers. People can use the unaffected parts. Also, those who are allergic to Aspergillus niger must not use onions infested with black mold.
Black substance on onions and garlic: Welcome back to “Science For Everyone”, ABP Live’s weekly science column. Last week, we explained what materials transition is, and how this can help ensure a net-zero future. This week, we discuss what the black material found on the surface of onions and garlic is, if such vegetables can be consumed, and how the condition can be managed.
Before peeling onions and garlic, almost everyone must have noticed a black substance on the vegetables. But have you ever wondered what that material is? Is it soil? Is it dirt? Well, the answer is that the black material is a fungus or mold called Aspergillus niger. Black mold is commonly found in the soil, and to prevent mold from growing on harvested onions, they must be stored in the refrigerator for at least two months.
How does Aspergillus niger infest onions and garlic?
According to the University of California Agriculture & Natural Resources, Aspergillus niger is first detected on onions and garlic as an area covered with a black sooty mass. This sooty mass is made up of microscopic spores, and can be found on the neck or outer scales of the vegetable. An opening on the skin of the vegetable caused by an injury, disease, or toppling of foliage is the reason why the black sooty mass settles on it.
Spores of Aspergillus niger may develop between dry, dead outer scales, and the first inner fleshy scales of the onion or garlic bulb. The scales of the vegetables that have been invaded become water-soaked. The fungal spores are often seen in a streaking pattern along the veins.
In some cases, the interior parts of the bulb may also be affected with grey or black discolouration. When conditions are dry, diseased scales dry and wither, and the black masses of the spores of Aspergillus niger are visible between outer scales.
Soft rot bacteria may invade the parts of the onion or garlic affected by spores of Aspergillus niger. As a result, the whole bulb may deteriorate into a watery soft rot.
Under what conditions does black mold develop on onions and garlic?
The black sooty mass formed by Aspergillus niger, or black mold, is a postharvest condition, and while it occurs on both onions and garlic, it is more of a concern in onion crops.
Not all onion and garlic crops are infested with black mold, but the ones grown under warm conditions often become covered with black spores of Aspergillus niger. For instance, India and the desert areas of California are warm regions, as a result of which black mold often develops on the onion and garlic crops grown in these areas.
Black mold disease develops when moisture is present on the bulb for six to 12 hours. If bulbs are damp when stored, or if condensation accumulates on the bulbs between the outer dry scales when the onions and garlic are sent to be stored, and brought out of storage, black mold disease may occur.
All fungi live on decaying organic substrates such as plant debris. However, Aspergillus niger is a weak pathogen that usually does not affect uninjured bulbs. This fungus is widely distributed among soil environments.
Some fungicidal control programmes used for foliar diseases may reduce the incidence of black mold, but no fungicides can directly control black mold. The fungicides used to control Peronospora parasitica, the fungus that causes downy mildew, cannot reduce the incidence of black mold.
How can black mold infestation be controlled and managed?
One can culturally manage black mold by following steps such as storing and transporting bulbs at temperatures below 59 degrees Fahrenheit or 15 degrees Celsius, and at low humidity to slow down the growth of Aspergillus niger.
Other measures include reducing bruising and injury during harvest, handling, and transport to minimise the opening of the skin. This is because open spots may serve as invasion sites for Aspergillus niger.
Onions should be promptly harvested, and drying must not be delayed. Heated air must not be used for drying.
During the transport of onions and garlic, stable temperatures must be maintained. This should also be done when the bulbs are going into and coming out of storage.
When there are wide temperature fluctuations, condensation occurs on the bulbs, and between the outer dry scales, promoting the development of black mold.
According to the US Department of Agriculture, mold growth can be discouraged by rinsing small amounts of the black mold on the outer scales of the onion under cool, running tap water, or chopping off the affected layers. People can use the unaffected parts. Also, those who are allergic to Aspergillus niger must not use onions infested with black mold.
Black substance on onions and garlic: Welcome back to “Science For Everyone”, ABP Live’s weekly science column. Last week, we explained what materials transition is, and how this can help ensure a net-zero future. This week, we discuss what the black material found on the surface of onions and garlic is, if such vegetables can be consumed, and how the condition can be managed.
Before peeling onions and garlic, almost everyone must have noticed a black substance on the vegetables. But have you ever wondered what that material is? Is it soil? Is it dirt? Well, the answer is that the black material is a fungus or mold called Aspergillus niger. Black mold is commonly found in the soil, and to prevent mold from growing on harvested onions, they must be stored in the refrigerator for at least two months.
How does Aspergillus niger infest onions and garlic?
According to the University of California Agriculture & Natural Resources, Aspergillus niger is first detected on onions and garlic as an area covered with a black sooty mass. This sooty mass is made up of microscopic spores, and can be found on the neck or outer scales of the vegetable. An opening on the skin of the vegetable caused by an injury, disease, or toppling of foliage is the reason why the black sooty mass settles on it.
Spores of Aspergillus niger may develop between dry, dead outer scales, and the first inner fleshy scales of the onion or garlic bulb. The scales of the vegetables that have been invaded become water-soaked. The fungal spores are often seen in a streaking pattern along the veins.
In some cases, the interior parts of the bulb may also be affected with grey or black discolouration. When conditions are dry, diseased scales dry and wither, and the black masses of the spores of Aspergillus niger are visible between outer scales.
Soft rot bacteria may invade the parts of the onion or garlic affected by spores of Aspergillus niger. As a result, the whole bulb may deteriorate into a watery soft rot.
Under what conditions does black mold develop on onions and garlic?
The black sooty mass formed by Aspergillus niger, or black mold, is a postharvest condition, and while it occurs on both onions and garlic, it is more of a concern in onion crops.
Not all onion and garlic crops are infested with black mold, but the ones grown under warm conditions often become covered with black spores of Aspergillus niger. For instance, India and the desert areas of California are warm regions, as a result of which black mold often develops on the onion and garlic crops grown in these areas.
Black mold disease develops when moisture is present on the bulb for six to 12 hours. If bulbs are damp when stored, or if condensation accumulates on the bulbs between the outer dry scales when the onions and garlic are sent to be stored, and brought out of storage, black mold disease may occur.
All fungi live on decaying organic substrates such as plant debris. However, Aspergillus niger is a weak pathogen that usually does not affect uninjured bulbs. This fungus is widely distributed among soil environments.
Some fungicidal control programmes used for foliar diseases may reduce the incidence of black mold, but no fungicides can directly control black mold. The fungicides used to control Peronospora parasitica, the fungus that causes downy mildew, cannot reduce the incidence of black mold.
How can black mold infestation be controlled and managed?
One can culturally manage black mold by following steps such as storing and transporting bulbs at temperatures below 59 degrees Fahrenheit or 15 degrees Celsius, and at low humidity to slow down the growth of Aspergillus niger.
Other measures include reducing bruising and injury during harvest, handling, and transport to minimise the opening of the skin. This is because open spots may serve as invasion sites for Aspergillus niger.
Onions should be promptly harvested, and drying must not be delayed. Heated air must not be used for drying.
During the transport of onions and garlic, stable temperatures must be maintained. This should also be done when the bulbs are going into and coming out of storage.
When there are wide temperature fluctuations, condensation occurs on the bulbs, and between the outer dry scales, promoting the development of black mold.
According to the US Department of Agriculture, mold growth can be discouraged by rinsing small amounts of the black mold on the outer scales of the onion under cool, running tap water, or chopping off the affected layers. People can use the unaffected parts. Also, those who are allergic to Aspergillus niger must not use onions infested with black mold.
Black substance on onions and garlic: Welcome back to “Science For Everyone”, ABP Live’s weekly science column. Last week, we explained what materials transition is, and how this can help ensure a net-zero future. This week, we discuss what the black material found on the surface of onions and garlic is, if such vegetables can be consumed, and how the condition can be managed.
Before peeling onions and garlic, almost everyone must have noticed a black substance on the vegetables. But have you ever wondered what that material is? Is it soil? Is it dirt? Well, the answer is that the black material is a fungus or mold called Aspergillus niger. Black mold is commonly found in the soil, and to prevent mold from growing on harvested onions, they must be stored in the refrigerator for at least two months.
How does Aspergillus niger infest onions and garlic?
According to the University of California Agriculture & Natural Resources, Aspergillus niger is first detected on onions and garlic as an area covered with a black sooty mass. This sooty mass is made up of microscopic spores, and can be found on the neck or outer scales of the vegetable. An opening on the skin of the vegetable caused by an injury, disease, or toppling of foliage is the reason why the black sooty mass settles on it.
Spores of Aspergillus niger may develop between dry, dead outer scales, and the first inner fleshy scales of the onion or garlic bulb. The scales of the vegetables that have been invaded become water-soaked. The fungal spores are often seen in a streaking pattern along the veins.
In some cases, the interior parts of the bulb may also be affected with grey or black discolouration. When conditions are dry, diseased scales dry and wither, and the black masses of the spores of Aspergillus niger are visible between outer scales.
Soft rot bacteria may invade the parts of the onion or garlic affected by spores of Aspergillus niger. As a result, the whole bulb may deteriorate into a watery soft rot.
Under what conditions does black mold develop on onions and garlic?
The black sooty mass formed by Aspergillus niger, or black mold, is a postharvest condition, and while it occurs on both onions and garlic, it is more of a concern in onion crops.
Not all onion and garlic crops are infested with black mold, but the ones grown under warm conditions often become covered with black spores of Aspergillus niger. For instance, India and the desert areas of California are warm regions, as a result of which black mold often develops on the onion and garlic crops grown in these areas.
Black mold disease develops when moisture is present on the bulb for six to 12 hours. If bulbs are damp when stored, or if condensation accumulates on the bulbs between the outer dry scales when the onions and garlic are sent to be stored, and brought out of storage, black mold disease may occur.
All fungi live on decaying organic substrates such as plant debris. However, Aspergillus niger is a weak pathogen that usually does not affect uninjured bulbs. This fungus is widely distributed among soil environments.
Some fungicidal control programmes used for foliar diseases may reduce the incidence of black mold, but no fungicides can directly control black mold. The fungicides used to control Peronospora parasitica, the fungus that causes downy mildew, cannot reduce the incidence of black mold.
How can black mold infestation be controlled and managed?
One can culturally manage black mold by following steps such as storing and transporting bulbs at temperatures below 59 degrees Fahrenheit or 15 degrees Celsius, and at low humidity to slow down the growth of Aspergillus niger.
Other measures include reducing bruising and injury during harvest, handling, and transport to minimise the opening of the skin. This is because open spots may serve as invasion sites for Aspergillus niger.
Onions should be promptly harvested, and drying must not be delayed. Heated air must not be used for drying.
During the transport of onions and garlic, stable temperatures must be maintained. This should also be done when the bulbs are going into and coming out of storage.
When there are wide temperature fluctuations, condensation occurs on the bulbs, and between the outer dry scales, promoting the development of black mold.
According to the US Department of Agriculture, mold growth can be discouraged by rinsing small amounts of the black mold on the outer scales of the onion under cool, running tap water, or chopping off the affected layers. People can use the unaffected parts. Also, those who are allergic to Aspergillus niger must not use onions infested with black mold.
Black substance on onions and garlic: Welcome back to “Science For Everyone”, ABP Live’s weekly science column. Last week, we explained what materials transition is, and how this can help ensure a net-zero future. This week, we discuss what the black material found on the surface of onions and garlic is, if such vegetables can be consumed, and how the condition can be managed.
Before peeling onions and garlic, almost everyone must have noticed a black substance on the vegetables. But have you ever wondered what that material is? Is it soil? Is it dirt? Well, the answer is that the black material is a fungus or mold called Aspergillus niger. Black mold is commonly found in the soil, and to prevent mold from growing on harvested onions, they must be stored in the refrigerator for at least two months.
How does Aspergillus niger infest onions and garlic?
According to the University of California Agriculture & Natural Resources, Aspergillus niger is first detected on onions and garlic as an area covered with a black sooty mass. This sooty mass is made up of microscopic spores, and can be found on the neck or outer scales of the vegetable. An opening on the skin of the vegetable caused by an injury, disease, or toppling of foliage is the reason why the black sooty mass settles on it.
Spores of Aspergillus niger may develop between dry, dead outer scales, and the first inner fleshy scales of the onion or garlic bulb. The scales of the vegetables that have been invaded become water-soaked. The fungal spores are often seen in a streaking pattern along the veins.
In some cases, the interior parts of the bulb may also be affected with grey or black discolouration. When conditions are dry, diseased scales dry and wither, and the black masses of the spores of Aspergillus niger are visible between outer scales.
Soft rot bacteria may invade the parts of the onion or garlic affected by spores of Aspergillus niger. As a result, the whole bulb may deteriorate into a watery soft rot.
Under what conditions does black mold develop on onions and garlic?
The black sooty mass formed by Aspergillus niger, or black mold, is a postharvest condition, and while it occurs on both onions and garlic, it is more of a concern in onion crops.
Not all onion and garlic crops are infested with black mold, but the ones grown under warm conditions often become covered with black spores of Aspergillus niger. For instance, India and the desert areas of California are warm regions, as a result of which black mold often develops on the onion and garlic crops grown in these areas.
Black mold disease develops when moisture is present on the bulb for six to 12 hours. If bulbs are damp when stored, or if condensation accumulates on the bulbs between the outer dry scales when the onions and garlic are sent to be stored, and brought out of storage, black mold disease may occur.
All fungi live on decaying organic substrates such as plant debris. However, Aspergillus niger is a weak pathogen that usually does not affect uninjured bulbs. This fungus is widely distributed among soil environments.
Some fungicidal control programmes used for foliar diseases may reduce the incidence of black mold, but no fungicides can directly control black mold. The fungicides used to control Peronospora parasitica, the fungus that causes downy mildew, cannot reduce the incidence of black mold.
How can black mold infestation be controlled and managed?
One can culturally manage black mold by following steps such as storing and transporting bulbs at temperatures below 59 degrees Fahrenheit or 15 degrees Celsius, and at low humidity to slow down the growth of Aspergillus niger.
Other measures include reducing bruising and injury during harvest, handling, and transport to minimise the opening of the skin. This is because open spots may serve as invasion sites for Aspergillus niger.
Onions should be promptly harvested, and drying must not be delayed. Heated air must not be used for drying.
During the transport of onions and garlic, stable temperatures must be maintained. This should also be done when the bulbs are going into and coming out of storage.
When there are wide temperature fluctuations, condensation occurs on the bulbs, and between the outer dry scales, promoting the development of black mold.
According to the US Department of Agriculture, mold growth can be discouraged by rinsing small amounts of the black mold on the outer scales of the onion under cool, running tap water, or chopping off the affected layers. People can use the unaffected parts. Also, those who are allergic to Aspergillus niger must not use onions infested with black mold.
Black substance on onions and garlic: Welcome back to “Science For Everyone”, ABP Live’s weekly science column. Last week, we explained what materials transition is, and how this can help ensure a net-zero future. This week, we discuss what the black material found on the surface of onions and garlic is, if such vegetables can be consumed, and how the condition can be managed.
Before peeling onions and garlic, almost everyone must have noticed a black substance on the vegetables. But have you ever wondered what that material is? Is it soil? Is it dirt? Well, the answer is that the black material is a fungus or mold called Aspergillus niger. Black mold is commonly found in the soil, and to prevent mold from growing on harvested onions, they must be stored in the refrigerator for at least two months.
How does Aspergillus niger infest onions and garlic?
According to the University of California Agriculture & Natural Resources, Aspergillus niger is first detected on onions and garlic as an area covered with a black sooty mass. This sooty mass is made up of microscopic spores, and can be found on the neck or outer scales of the vegetable. An opening on the skin of the vegetable caused by an injury, disease, or toppling of foliage is the reason why the black sooty mass settles on it.
Spores of Aspergillus niger may develop between dry, dead outer scales, and the first inner fleshy scales of the onion or garlic bulb. The scales of the vegetables that have been invaded become water-soaked. The fungal spores are often seen in a streaking pattern along the veins.
In some cases, the interior parts of the bulb may also be affected with grey or black discolouration. When conditions are dry, diseased scales dry and wither, and the black masses of the spores of Aspergillus niger are visible between outer scales.
Soft rot bacteria may invade the parts of the onion or garlic affected by spores of Aspergillus niger. As a result, the whole bulb may deteriorate into a watery soft rot.
Under what conditions does black mold develop on onions and garlic?
The black sooty mass formed by Aspergillus niger, or black mold, is a postharvest condition, and while it occurs on both onions and garlic, it is more of a concern in onion crops.
Not all onion and garlic crops are infested with black mold, but the ones grown under warm conditions often become covered with black spores of Aspergillus niger. For instance, India and the desert areas of California are warm regions, as a result of which black mold often develops on the onion and garlic crops grown in these areas.
Black mold disease develops when moisture is present on the bulb for six to 12 hours. If bulbs are damp when stored, or if condensation accumulates on the bulbs between the outer dry scales when the onions and garlic are sent to be stored, and brought out of storage, black mold disease may occur.
All fungi live on decaying organic substrates such as plant debris. However, Aspergillus niger is a weak pathogen that usually does not affect uninjured bulbs. This fungus is widely distributed among soil environments.
Some fungicidal control programmes used for foliar diseases may reduce the incidence of black mold, but no fungicides can directly control black mold. The fungicides used to control Peronospora parasitica, the fungus that causes downy mildew, cannot reduce the incidence of black mold.
How can black mold infestation be controlled and managed?
One can culturally manage black mold by following steps such as storing and transporting bulbs at temperatures below 59 degrees Fahrenheit or 15 degrees Celsius, and at low humidity to slow down the growth of Aspergillus niger.
Other measures include reducing bruising and injury during harvest, handling, and transport to minimise the opening of the skin. This is because open spots may serve as invasion sites for Aspergillus niger.
Onions should be promptly harvested, and drying must not be delayed. Heated air must not be used for drying.
During the transport of onions and garlic, stable temperatures must be maintained. This should also be done when the bulbs are going into and coming out of storage.
When there are wide temperature fluctuations, condensation occurs on the bulbs, and between the outer dry scales, promoting the development of black mold.
According to the US Department of Agriculture, mold growth can be discouraged by rinsing small amounts of the black mold on the outer scales of the onion under cool, running tap water, or chopping off the affected layers. People can use the unaffected parts. Also, those who are allergic to Aspergillus niger must not use onions infested with black mold.
Black substance on onions and garlic: Welcome back to “Science For Everyone”, ABP Live’s weekly science column. Last week, we explained what materials transition is, and how this can help ensure a net-zero future. This week, we discuss what the black material found on the surface of onions and garlic is, if such vegetables can be consumed, and how the condition can be managed.
Before peeling onions and garlic, almost everyone must have noticed a black substance on the vegetables. But have you ever wondered what that material is? Is it soil? Is it dirt? Well, the answer is that the black material is a fungus or mold called Aspergillus niger. Black mold is commonly found in the soil, and to prevent mold from growing on harvested onions, they must be stored in the refrigerator for at least two months.
How does Aspergillus niger infest onions and garlic?
According to the University of California Agriculture & Natural Resources, Aspergillus niger is first detected on onions and garlic as an area covered with a black sooty mass. This sooty mass is made up of microscopic spores, and can be found on the neck or outer scales of the vegetable. An opening on the skin of the vegetable caused by an injury, disease, or toppling of foliage is the reason why the black sooty mass settles on it.
Spores of Aspergillus niger may develop between dry, dead outer scales, and the first inner fleshy scales of the onion or garlic bulb. The scales of the vegetables that have been invaded become water-soaked. The fungal spores are often seen in a streaking pattern along the veins.
In some cases, the interior parts of the bulb may also be affected with grey or black discolouration. When conditions are dry, diseased scales dry and wither, and the black masses of the spores of Aspergillus niger are visible between outer scales.
Soft rot bacteria may invade the parts of the onion or garlic affected by spores of Aspergillus niger. As a result, the whole bulb may deteriorate into a watery soft rot.
Under what conditions does black mold develop on onions and garlic?
The black sooty mass formed by Aspergillus niger, or black mold, is a postharvest condition, and while it occurs on both onions and garlic, it is more of a concern in onion crops.
Not all onion and garlic crops are infested with black mold, but the ones grown under warm conditions often become covered with black spores of Aspergillus niger. For instance, India and the desert areas of California are warm regions, as a result of which black mold often develops on the onion and garlic crops grown in these areas.
Black mold disease develops when moisture is present on the bulb for six to 12 hours. If bulbs are damp when stored, or if condensation accumulates on the bulbs between the outer dry scales when the onions and garlic are sent to be stored, and brought out of storage, black mold disease may occur.
All fungi live on decaying organic substrates such as plant debris. However, Aspergillus niger is a weak pathogen that usually does not affect uninjured bulbs. This fungus is widely distributed among soil environments.
Some fungicidal control programmes used for foliar diseases may reduce the incidence of black mold, but no fungicides can directly control black mold. The fungicides used to control Peronospora parasitica, the fungus that causes downy mildew, cannot reduce the incidence of black mold.
How can black mold infestation be controlled and managed?
One can culturally manage black mold by following steps such as storing and transporting bulbs at temperatures below 59 degrees Fahrenheit or 15 degrees Celsius, and at low humidity to slow down the growth of Aspergillus niger.
Other measures include reducing bruising and injury during harvest, handling, and transport to minimise the opening of the skin. This is because open spots may serve as invasion sites for Aspergillus niger.
Onions should be promptly harvested, and drying must not be delayed. Heated air must not be used for drying.
During the transport of onions and garlic, stable temperatures must be maintained. This should also be done when the bulbs are going into and coming out of storage.
When there are wide temperature fluctuations, condensation occurs on the bulbs, and between the outer dry scales, promoting the development of black mold.
According to the US Department of Agriculture, mold growth can be discouraged by rinsing small amounts of the black mold on the outer scales of the onion under cool, running tap water, or chopping off the affected layers. People can use the unaffected parts. Also, those who are allergic to Aspergillus niger must not use onions infested with black mold.
