pests and diseases of cane cultivation: common rust

Sugarcane rust mainly attacks the leaves, destroying and / or reducing the effective photosynthetic area, which leads to a limited growth of the plant and a thinning of the stems.

It was registered in 1978 for the first time in America, in the Dominican Republic; It was identi fi ed in Venezuela in the year 1979 in the cultivar 'B-4362'. Among the affected cultivars can be cited 'C323-68', 'V78-106', 'CP74-2005', 'CC85-92', 'V98-120', 'V71-39', 'V75-6', 'CR87-339', 'My55-114', 'PR61-632', 'B80-408', 'B80-549', 'V90-14', 'CR74-250', 'SP70-1284', 'Ragnar', 'CR83-323', among others.

symptom

It is a disease that attacks the foliar system of the plant; In the beginning, the symptoms consist of the appearance of elongated yellow spots that are visible on both sides of the leaves (Figure 2);

the lesions turn brown with the presence of a chlorotic halo. As they develop, they form pustules that contain the structures of the fungus known as uredospores, which cause infection (Figure 3).

To recognize the presence of rust in the field, take the leaf and press both sides with two fingers, if these are stained reddish brown or orange it is in the presence of the pathogen and therefore of the disease. When it is necessary to find a considerable number of lesions that join to form extensive and irregular necrotic areas, which causes intense necrosis that results in the drying of the leaf (Figures 4 and 5), being able to observe a ferrugrous color in the leaves (Figure 6). )

Dissemination and control

The spread of spores occurs through wind, water, insects, birds, humans. The control of the disease is done through the use of resistant cultivars, crop management and in a natural way with the fungus Sphaerellopsis fi lum (= Edarluca fi lum), subdivision Of u t e r o my c o t i n a, C o e o o my c e t e, S p h a e r o p e i c e a e e, Sphaeropsidales; which acts as a biological controller.

He fungus Sphaerellopsis fi lum grows on the pustules of the Puccinia occupying the space where uredospores go to grow and develop so that they do not develop.