Experts suggest removal of cotton weeds to thwart pink bollworm

MULTAN: Pink bollworm has emerged as a prime threat to cotton crop and the agriculture experts have asked the growers to remove cotton weeds and plants after picking until January 31 to end the chances of pink bollworm attack.

The Punjab Agriculture Department has directed the teams of extension wing and pest warning to make tours to villages across province in this regard.

The experts of Muhammad Nawaz Sharif University of Agriculture (MNSUA) said that the Agriculture Mechanisation and Research Institute (AMRI) and MNSUA had developed a modern machine that kills pink bollworm from the remains of the cotton crop in the field. This particular machine uproots cotton sticks from the field and put them into a shredder which converts them into tiny pieces, leaving no room for the survival of pink bollworm.

The process would keep the crop safe against pink bollworm attack next year and would also increase organic material in the soil. Moreover, it will also free the cotton-sown land for in-time wheat cultivation, he added. Senior cotton scientist Dr Zahoor Ahmed observed that many pests hit the cash crop cotton but pink bollworm is its worst enemy, which not only causes loss to the crop but also affects the lint quality. The economic loss it inflicts is heavier than the impact of any other worm. Depending on the extent of infestation and weather conditions, this pest can cause about 20 to 30 per cent crop loss. It is estimated that the yearly loss from pink bollworm in Pakistan is about one million bales, he explained. In 2001, Pakistan faced difficulty in disposing of its lint in the international market as the problem had struck more than once. The government and growers must join hands to eliminate or at least minimise its impact on the crop. During active season, pink bollworm completes four generations on cotton and the larvae of fifth generation start entering diapauses when temperatures start falling. Diapause is a state in which the insect remains inactive for months due to the climatic conditions or lack of food. Its activity is a complex phenomena affected by oil contents, temperature and the day’s length, he said. Larvae do not survive if an infested fruit sheds at an early stage. It continues to feed on internal parts of the fruit and later stitches the petals together, preventing the flower from opening, a condition known as “rosette flower”, he added. He said that in green cotton bolls, larvae generally enter through the tip of 14-28-day old bolls) leaving a yellow spot on the lint at entry point. It feeds on the boll contents, including the lint near the entry point at least for 24 hours. It feeds on lint, seed coat and kernel completely before attacking the second seed, he added.