COTTON, the mainstay of our national economy, is cultivated over an area of six million acres. The produce goes to thousands of ginning factories and hundreds of textile mills which provide employment to a large number of people both in the rural and urban areas.
Cotton meets the clothing requirements of the people and vegetable oil and animal feed is produced from its seed.
In unfavourable climatic conditions, the crop is attacked by a number of viruses, insects and pests which decreases its yield.. The main virus and pests that threaten the cotton crop are the Leaf Curl Virus (CLCV) and the mealy bug which drastically reduce the yield and consequently affect the national economy adversely.
The cotton mealy bug (Phenacoccus solani) is a pest which has emerged recently and its threat is increasing rapidly. Some major cotton producing districts in Punjab such as Vehari, Lodhran, Khanewal, Bahawalpur and Rahim Yar Khan had recently suffered badly due to this menace. This growing threat has made it necessary to find measures to control it effectively. The male mealy bug is winged while the female is a creeper. Its multiplication is rapid as its nymphs are crawler which are dispersed quickly through wind, human body, birds and mechanically. As it multiplies very fast, it is difficult to control it effectively and completely.
A comprehensive research is needed to find ways to eradicate the menace permanently. It is, therefore, necessary to control this pest with a short-term strategy with efforts to eradicate it completely in the long -term. Some efforts to control this pest has been made by the entomological section of the Regional Agricultural Research Institute, Bahawalpur, during the last three years through non-chemical and chemical control measures which was found effective and is produced here so that it may help the growers in protecting their crop -
Non-chemical (off season strategy): All types of weeds especially broad-leaf weeds such as ‘It sit and Butylon’, which are the most favourite weeds for the multiplication of the pest, should be eradicated completely. Pest population on all ornamental plants especially flowers and spring crops such as sunflower and ladies fingure should be controlled to minimise the chances of infestation of the cotton crop by the pest. All types of broad-leaf weeds along the roadside, railway tracks, orchards and water channels should be pulled out to prevent its further propagation in the succeeding cotton crop.
Crop season strategy: The cotton field should be kept free of all types of weeds through out the season. The infested spots should be flagged with red cotton ribbon for monitoring. The infested plants should be covered with shopping bags up to the base of the plants and should be tightened with rubber rings at the base, so that the nymphs of the female bugs may not fall on the ground or migrate to healthy plants through any source of dispersal.
These infested plants should be removed smoothly along with the shopping bags and kept in a bigger plastic or gunny bag and burnt at open places away from the healthy crop. After pulling the infested plants their sites should be sprayed thoroughly with proper insecticides. Regular monitoring of these marked spots and the healthy crop should be done at three days interval to check reappearance of any fresh pest in the field for proper and timely treatment. The flags should be kept at the sites of such infections till the maturity of the crop.
Chemical treatment: After maintaining the standard plant population i.e 18,000 to 25,000 per acre further removal of the infested plants may not be possible. At the early crop stage, if the temperature is high (from 36 to 45 degree C) and the plant growth is suffering, use of safe insecticides which have no ill effect on the growth and fruiting parts is recommended. The following safe insecticides with the doses mentioned against each are given below:
Precautions: The growers should monitor the pest regularly twice a week from sowing up to the crop maturity period by identifying and marking the infested spots and treating them with proper insecticides.
Spraying should be done preferably with knapsack hand sprayer. These treated spots should be regularly monitored at every three-day interval to detect the presence of any pest to control the infested portion if any.
For fields which are more than 50 acres two teams should be constituted one to locate the infested plants and tagging them, and the other to treat these plants with disinfectants.
Conclusion and recommendations: From the perusal of the above mentioned control strategy, it is concluded that in the short-term strategy we must screen out the varieties which are comparatively tolerant to mealy bug to sustain cotton production till the resistant varieties are evolved. This is one of the major limiting factors which are affecting the cotton yield drastically.
To avoid proliferation of the pest, the above mentioned precautionary measures should be strictly followed well in time so that the crop can be saved from disaster.
It is suggested that the policy-maker and the government should look into the matter before the next cotton growing season so that proper message may be sent to the growers and they may follow better management practices like proper weed control, timely irrigation, proper application of fertiliser and adoption of proper pest control measures, if the problem of cotton mealy bug has appeared at the early crop stage.