Replanting Indian cotton

Replanting Indian cotton

Context

Researchers say it is time India moves on from hybrids

What has happened?

Pink bollworm infestation in Bt cotton in India has turned the spotlight on an important question: has hybrid cotton lived up to its promise? India was a pioneer in this technology in the 1970s; today, it is the only country that exclusively grows cotton hybrids.

High productivity

By 2011, over 95% of cotton in India was under hybrids, from less than 50% before 2002. Bt cotton’s insecticidal traits helped raise Indian yields further

Productivity plateaued

India’s average yield is around 500 kg of lint per hectare, about a fourth of Australia and Turkey which plant OP varieties

Reasons for low productivity

Going overboard with the number of hybrids approved after Bt cotton arrived

Genetic Engineering Approval Committee (GEAC) simplified the process for hybrid approval leading to poor quality hybrids in the market

• An unsuitable hybrid: What was the problem with an inadequately tested hybrid? Sometimes the seeds were of poor quality, sometimes the hybrids didn’t express enough Bt toxin, and sometimes hybrids meant for one agro-climatic zone were approved in other zones. For example, many hybrids that were meant for irrigated farmlands ended up in areas with no irrigation, a recipe for disaster
• Indian hybrids couldn’t be planted in high densities: Many were designed to be tall and bushy, unlike OP varieties which are short and straight. This meant that hybrids could not be planted in large densities — one of the contributors of high yields in Australia and Brazil.
• Low harvest index: Some of these hybrids also had a low harvest index, meaning that the mass of their seeds and lint was low compared to the mass of the rest of the crop, like shoots and leaves

Can OP varieties save the day?

• Some cotton researchers believe that it is time to ditch hybrids and return to OP varieties, at least in rain-fed regions
• Varieties are compact and can be selected for resistance against pests like whiteflies
• When planted at high densities, they can rival hybrid yields