Bt cotton effective in controlling bollworm

Coimbatore: The field trials have clearly indicated that Bt cotton in various cotton growing states was effectively controlling the bollworm, a senior official in the Central Institute for Cotton Research (CICR) has said.

It was also observed that opening of the boll was very good in BT cotton, besides marginal improvement in quality, K Venugopal, head and project coordinator, CICR, here said.

Though BT cotton hybrids were showing daily maturity, ranging from 15 days to one month in all the states, at a few location two to three sprayings were additionally required, when bollworm crossed economic threshold level, Venugopal said.

As the approval for conducting BT trials came only in June last, trials could not be carried out in North Zone of Punjab, Haryana and Rajasthan, where sowing was completed by May 15, he said.

However, Indian Council of Agricultural Research (ICAR) took up the trials in Central Zone of Gujarat, Maharashtra and Madhya Pradesh and southern states of Tamil Nadu, Karnataka and Andhra Pradesh this year, Mr Venugopal said.

Stating that BT cotton hybrids were made available by Mahyco-Monsanto, Mr Venugopal said that trials were taken up on greater details, taking into account all aspects from agronomy plant breeding, entomology and pathology, unlike the last year’s trials only on entomology aspect.

Tested hybrids like MECH 162, 184 and 12 were efficient in controlling bollworm and the control of spotted worm was also very good during the trial, Mr Venugopal said.

During the trials conducted last year in southern states, it was found that the control of American bollworm was satisfactory, but the yield difference between BT and non-BT cotton was not very significant, though a marginal yield increase was noted for all the BT hybrids, Mr Venugopal said.

Saying that ICAR had set up separate monitoring committees for central and south zones, he said that the trials this year were being conducted as per protocol communicated.

Initial damage to the crop was reported only at one location in Nandyal in Andhra Pradesh, following excess rainfall and flooding. Otherwise, crops in all other locations were good, particularly Guntur and Dharwad, Mr Venugopal said.

Though BT hybrids would take care of damage by bollworm, for control of sucking pests appropriate control measures like seed treatment, sprayings, bio-control measures were certainly required, he said.

With clear indication of the efficacy in controlling the bollworms, the final yield data BT hybrids would only be available by the middle of this month in central zone and 15 in South zone, he said.

The detailed economics on the efficacy of BT cotton hybrid would be worked out by February end, Mr Venugopal said. It would be apt to introduce all the public breed varieties so that pest could be controlled in cotton cultivation, he said, adding that China had taken the lead by achieving 200 lints per acre, after adopting BT cotton.

— PTI