BOTANY Higher Secondary Second Year - Textbooks Online

Control measures
The most economic method of control is the cultivation of resistant,
high yielding varieties.
Seed treatment
Immersion of the seeds in 0.2 per cent solution of Kalimat B for 24
hours controlled the disease and promoted the growth of seedlings. The
seed protectants such as agrosan, cerasan and spergon have been proved
responsible for the control of disease.
Sanitation
Plant debris should be collected and destroyed. The secondary host
plants such as Digitaria marginata should be collected from paddy fields
and destroyed.
Spraying and dusting
Blast disease can be controlled effectively by spraying the fungicide,
Bordeaux mixture at least 4 times before and after flowering of the crop.
Bordeaux mixture formula is as follows:
Copper sulphate 9 Kgs.
Quick lime 9 Kgs.
Water 250 litres.
The dusting of organomercuric compounds has been suggested for
controlling blast.
Groundnut or peanut - Arachis hypogea
Tikka disease of groundnut
Pathogen Disease incited by a fungus Cercospora personata.
Systematic position The fungus belongs to class Deuteromycetes.
Symptoms
Lesions appear on the leaves, when the plants are atleast two months
old. The symptoms appear in July and continue upto maturity of the
plant. The lesions on the leaves are rounded and 1 to 6 mm in diameter.
These spots are dark brown or black and found on both surfaces of the
leaf. Yellow border develops around each such leaf spot.
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