What is the cause of brown spot of rice?

Brown spot is caused by the fungus Cochliobolus miyabeanus. Also called Helminthosporium leaf spot, it is one of the most prevalent rice diseases in Louisiana. When C. miyabeanus attacks the rice plants at emergence, the resulting seedling blight causes sparse or inadequate stands and weakened plants (Figure 1).

Where do you find Helminthosporium?

Helminthosporium, genus of fungi in the order Pleosporales (phylum Ascomycota, kingdom Fungi) that exists as asexual anamorphs and causes leaf blight, especially of grasses (e.g., bluegrass, corn, oats), in humid areas.

Which disease of rice caused Bengal famine?

Though administrative failures were immediately responsible for this human suffering, the principal cause of the short crop supply in 1943 was the epidemic of brown spot disease which attacked the rice crop in Bengal in 1942 [1].

What is Helminthosporium leaf spot?

Leaf spot / melting out is one of several Helminthosporium diseases which survive in thatch during periods that are unfavorable for disease development. These fungi are most active during periods of cool (60-65°F) and wet weather, but some are able to cause disease whenever temperatures are above freezing.

Which fungus was responsible for Bengal famine?

Cochliobolus miyabeanus (formerly known as Helminthosporium oryzae) is a fungus that causes brown spot disease in rice. This disease was the causal agent of the Bengal famine of 1943. It was considered for use by the USA as a biological weapon against Japan during World War II.

How do you treat helminthosporium?

Have helminthosporium fungicides regularly applied for disease control. Maintain a grass height of 2.5 to 3.5 inches without cutting off more than a third of the current growth. Gather and destroy infected leaves and clean the mower frequently to remove contaminants.

Why did the Bengal famine in 1943 happen?

In case of Bengal, the primary reason for the famine was shortages in Rice. A variety of factors led to the shortage, but most prominent among them was not supply shortage rather it was due to improper allocation of the available rice stocks. A relatively bad harvest in winter crop of 1942, led to supply shortages.

How is bacterial blight treated?

If you have had problems with bacterial blight, you may want to use a combination of copper and mancozeb-containing fungicides for control. Apply fungicides two to three times at seven to 10 day intervals as leaves emerge, but before symptoms develop.