Sugarcane Seventeenth to eighteenth week practices

• Irrigation should be given in this week.

Grassy Shoot Disease:

Symptoms:

• The disease is characterized by the production of numerous lanky tillers from the base of the affected shoots. Leaves become pale yellow to completely chlorotic, thin and narrow. The plants appear bushy and ‘grass-like’ due to reduction in the length of internodes, premature and continuous tillering. 

Management:

Cultural Control:

Fresh sowing is done after 3-4 years with seed-setts from resistant varieties. Uproot and destroy the affected clumps. Growing resistant varieties viz., Co 86249, Co G 93076 and Co C 22. 

Physical Control: 

Treat sets with hot air 54°C for 8 hours to inactivate the casual Virus. Hot Water Treatment (HWT) of sets at 520C for 30 min OR Aerated Steam Therapy (AST) at 500C for 1 hr.

Chemical Control:

Control vector by spraying Dimethoate 30% EC @2ml/lit. of water OR Methyl -Demeton 25% EC @ 2 ml/lit. of water for controlling aphids/leaf hopper.

Whitefly:

Symptoms:

• Neonate nymphs are pale yellow in color, flat and oval in shape, and later turn shiny black. There is a “T‟ shaped white marking on the thorax, which splits at the time of adult emergence. Adult Pale yellow body with hyaline wings dusted with waxy bloom, exhibit brisk fluttering movements.
• Whiteflies damage sugarcane by extracting large quantities of phloem sap from leaves. Large colonies of Aleurolobus barodensis nymphs suck the sap from the under surface of the leaves which turn yellow; in severe cases of infestation the leaves show pinkish discoloration.

Management:

Cultural control:

Clipping of infested leaves. Avoid water stress and waterlogged conditions. Avoid planting in low land areas. Synchronization of sugarcane planting and harvesting may be adopted zone wise. 

Mechanical Control:

Detrashing the puparia bearing leaves and immediately disposing by burning or burying to prevent emergence of adult white flies. Installation of yellow sticky traps@6-8 in Nos. for white fly. 

Biological Control: 

Release of natural enemies such as Encarsia sp, Eretmocerus spp @4-5 cards/acre. 

Chemical Control: 

Foliar sprays with Quinalphos 2 ml/lit. of water. Thiamethoxan 25% WG @ 50g/acre, 250-300 liter of water.