Integrated green manure management for cotton crop

Dear farmers,

Green manures play a very important role in increasing seed cotton yield. Short growing and low water requiring green manure crop like sunn hemp is found to be effective for sustainability of both soil fertility and crop productivity in winter irrigated cotton crop.

For this, the green manure seed is sown at the rate of 15kg/hectare and grown simultaneously with the cotton for a period of 45 days and then buried in the soil before flowering in the furrows and cotton is grown upto maturity. In this process green manure meets one third of the nitrogen (N) requirement of the cotton crop.

          The combined application of farmyard manure (FYM) @ 5 tonne/hectare and in situ green manure of sunn hemp produces highest seed cotton yield. It is approximately equal to recommended dose of NPK (60:13:25kg/ha) in respect of yield and associated traits but soil fertility status under it will be considerably improved in comparison to control or recommended NPK. 

Following are the advantages of green manure in the cotton crop field.

1. Higher growth and fibre yield due to steady nitrogen availability.

2. Efficient utilisation of interspaces before crop competition starts.

3. Weed suppression as it covers top soil and less pest and diseases.

4. Moisture conservation and its efficient utilisation through burying near the root zone.

5. Restoration of soil fertility and higher efficiency in nutrient use.

Integrated Pink Bollworm Management for cotton farmers

Dear farmers,

                          Pink Bollworm has now became a major pest for cotton crop. It feeds on cotton seeds hence causes considerable(10-30%) production loss. It occurs in mid and late stages of crop. Nowadays it is inducing early in the crop life (i.e. 45 to 60 days after sowing). Due to internal feeding behaviour it remains usually unrecognised.

To control pink bollworm

• Do not sow cotton crop in the month of April-May as it attracts the pink bollworm at early stages of crop life
• Destroy residual stalks and partially opened bolls
• While sowing use 20% non bt(refuge) seeds for sowing with bt seeds if provided separately
• Do not store infested cotton in houses/godowns
• Sowing should be done in the month of June with early maturing Bt varieties recommended for the region
• Install pheromone trap(5 traps per hectare) after 45 days after sowing to extract male individuals and to control moth activity
• Inspect the crop at the stages of squaring and flowering for the presence of pink bollworm larvae in flowers
• At boll formation stage, inspect the presence and damage caused by pink bollworm by plucking 20 green bolls from different plants randomly
• Collect and destroy fallen squares, flowers and bolls in the field
• One spray of Neem seed kernel extract 5%+ Neem oil 5ml/lit. May be taken upto 60 days after sowing
• In months of October-November release parasitoid tricogramma bactrie at the rate 60000/ acre whenever available
• Chemical control measures should be initiated as below when pest crossed ETL  (Economic Threshold Level) i.e. 10% damaged flowers (rossete flowers) or 10% damaged green bolls (at least 2 bolls out of 20 having white or pink larvae or exit holes) or 8 moths catch per pheromone trap per night for 3 consecutive days
• Picking of clean and infested cotton should be carried out separately
• Clean cotton should be stored or marketed and infected cotton should be destroyed
• Install light traps and pheromone traps near storage houses or godowns
• Destroy trapped moths during season or off season
• Terminate crop in December to mid January

Chemical control

Month                insecticide                        dose per

                                                                         10lit water

September        Quinolphos 20% AF          20ml

                             Thiodicarb 75% WP          20g

October             Chlorpyriphos 20% EC      25ml

                            Thiodicarb 75% WP           20g

November        Fenevelerate 20% EC         10ml

                              Cypermethrin 10% EC     10ml