Environment

Does India Need Transgenic Mustard?

Indian researchers can and will eventually develop high-yielding mustard hybrids through non transgenic means. Still, India will need transgenic mustard as an alternative.

A mustard flower. Credit: prince_tigereye/Flickr, CC BY 2.0

A mustard flower. Credit: prince_tigereye/Flickr, CC BY 2.0

A previous story on The Wire explored the safety of transgenic mustard for consumers and the environment. But there is another key question that opponents of transgenic mustard often raise: does India need transgenic mustard at all? If supporters of the technology believe it will help dent India’s massive edible-oil import bill by ramping up mustard-oil production, opponents say we could do the same without any help from transgenics.

How tenable are either of these arguments? And is transgenic mustard, with its promised yield of around 30% more than that of pure varieties of mustard, going to solve India’s edible-oil woes? The answer isn’t straightforward.  

First, Indian farmers will need a lot more than transgenics to really ramp up oil production. The real problem with mustard productivity in India today is yield gaps: the difference between the potential yield of mustard crops under ideal circumstances and the yields that farmers are able to realise on their fields. This difference exists because Indian farmers are unable to follow good practices of cultivation such as irrigation, seed replacement and fertiliser use. The new transgenic mustard is likely to be plagued by the same problems, and this means it may not really be a game-changer.

But there is more to the transgenic mustard, called DMH-11, than high yields alone. The genetic engineering used to create DMH-11 provides plant breeders with a new method of hybridising mustard. It may now be possible to create hybrids that were tough to make with conventional methods, such as hybrids that are resistant to drought and disease. Each of these traits could potentially change farm economics the way Bt Cotton’s pest resistance did. It is here that the true promise of transgenic mustard lies.

Can we replicate the yellow revolution through protectionism?

India has a big edible-oil problem. It imports over 60% of what it consumes at a cost of around $10 billion each year, a huge drain on its forex reserves. This is because we aren’t very competitive in growing oilseeds, with mustard productivity lagging some way behind world averages. Ramping up mustard production will bring down mustard oil prices, increase its consumption among price-sensitive users, and dent the edible-oil bill to some extent.

But opponents of transgenic mustard say that DMH-11, the hybrid developed by Delhi University professor Deepak Pental, isn’t required to hike mustard production. As evidence of this, they point to a period between 1986 and 1994 called the ‘yellow revolution’, when India boosted edible-oil production through policies that favoured farmers.

Dismayed by India’s massive import bill, the then prime-minister Rajiv Gandhi launched the Technology Mission on Oilseeds, under which farmers were provided with extension services. New, high-yielding crop varieties were developed and a high minimum support price (MSP) was offered to farmers to encourage them to grow oil seeds. Moreover, India put edible oil on the negative list, meaning nobody could import it except state agencies. These policies worked their magic and the country increased edible-oil production from 12.2 million tons in 1986 to 21 million tons in 1995, turning from a net importer to an exporter during this period.

The era’s end was heralded 1994, when India’s commitments to the World Trade Organisation forced it to lower trade barriers, and the tables were turned again. Low-cost palm oil began flooding India from southeast Asian nations and the resulting crash in market prices pushed farmers out of oilseeds. Today, we are back to an edible-oil deficit. The question then is: if India raised import tariffs on edible oil again and incentivised farmers to grow oilseeds, could we get back to the golden age of edible-oil surpluses?

This argument doesn’t hold water because it ignores an unfortunate side-effect of the yellow revolution, says Amarendra Reddy, an agricultural economist who studies oilseeds at the Indian Agricultural Research Institute, Delhi. Much of the increase in production during this period was driven by an increase in cultivated farmland – not just by an increase in productivity. In fact, a World Bank report argued that the protectionism had diverted land that would have been more profitably used for productive crops to oilseeds, in which India did not have a comparative advantage. “What happened was that, even though we were not competitive in edible oil, and our cost of production was very high, we were still producing a lot. We didn’t have the required technology or natural resources,” says Reddy.

The high cost of production drove up prices for consumers. As a result, oil consumption in India hardly grew during this time, inching up by about 0.5%, with the poor being worst hit by the high prices. It was only when India began dropping import barriers in 1994 that cheap imports brought some relief to consumers. This is why, according to Reddy, there are two things to keep in mind while deciding on trade policy: “Farmers should get a remunerative rate but consumers should also get oil at a reasonable rate.”

The only way to achieve this is through extension services and technology. Extension services are necessary to close the gap between yield potential and actual yield. They would include educating farmers on and financing the use of fertilisers, and encouraging the replacement of seeds. Indian farmers are averse to buying certified seeds periodically, choosing instead to depend on saved seeds from the last season. This is a problem because the quality of seeds deteriorates after a few seasons, and anything from adverse weather to physical damage can hurt its ability to germinate and grow. But the lack of quality seeds in the market, poor awareness, and poverty keeps farmers from replacing seeds. Timely seed replacement alone could increase oilseed yields in India by about 10%, according to Sant Kumar Pandey, an agricultural economist at the National Centre for Agricultural Economics and Policy Research, Delhi.  

And yet, there is only so much extension services can do. Once the pure varieties of mustard that India grows hit their maximum yield potential, India will need hybrids that out-yield these varieties. Hybrids of genetically diverse parents tend to outperform their parents on traits such as yield, in a phenomenon known as heterosis. Much of the yield growth achieved today by the world’s largest canola (a relative of mustard) producers, Canada and Germany, has come from hybrids.

Why can’t conventional breeding give us the hybrids we need?

It is true that the new hybrids India desperately needs can be created through conventional technologies. The only problem is that such a hybrid is taking a long time coming.

Conventional hybridisation systems work like this: mustard produces perfect flowers, or flowers that have both male anthers and female pistils. This makes it difficult for breeders to hand-pollinate one mustard variety with another to make hybrids, because the proximity between the pollen-producing anthers and egg-containing pistil causes a mustard variety to fertilise itself. To overcome this problem without using transgenics, breeders turn to a gene in wild mustard that impedes pollen formation. This gene, which occurs in the cell’s cytoplasm, is transferred to cultivated mustard by repeatedly crossing both plants. The cultivated mustard, known as Brassica juncea, now stops making pollen and can act as a female parent. Next, another gene from wild mustard, which can reverse the pollen sterility caused by the first gene, is transferred to another variety of Brassica juncea, which becomes the male parent. These two are then crossed to create a hybrid of both Brassica varieties.

This cytoplasmic male sterility (CMS) system took a long time to develop because of its many challenges, says A.K. Singh, head of the genetics division at Indian Agricultural Research Institute (IARI), Delhi, and a mustard breeder. First, transferring cytoplasmic male sterility from wild species to cultivated ones is extremely difficult because wild species don’t cross easily with cultivated ones. “Therefore, approaches such as embryo rescue and tissue culture had to be used. This was a long-running research program at the IARI,” explains Singh. Even after they were crossed, the resulting male and female parents didn’t always turn out perfect. Flowers on some would be deformed and unable to attract bees for pollination while the leaves on others would be discoloured. This stalled the development of CMS systems further.

But after many years of work, Indian researchers finally overcame these challenges and four CMS systems, which borrow male sterility from various wild mustard species, are on the menu for plant breeders.  A couple of publicly-developed hybrids based on them are also in the market.

Unfortunately, these hybrids don’t make the cut.

The first of these hybrids, DMH-1 (a predecessor of DMH-11), was developed by Pental and borrows the male-sterility gene from a Brassica napus mustard variety. The gene is introduced into the female parent of DMH-11, an Indian Brassica juncea variety called Pusa Bold. Next, Pusa Bold is hybridised with an eastern European variety of mustard called EH-2, which is naturally able to reverse the sterility induced by the CMS gene. Pusa Bold and EH-2 make a good couple: when hybridised, they show high heterosis and enhance the traits of their parents. As a result, DMH-1, the progeny of Pusa and EH-2, gives between 28% and 34% more yield than pure mustard varieties.

DMH-1 could have been the hybrid Indian farmers were waiting for – except that Pental’s team is unable to produce enough seed to grow this hybrid using CMS systems. Sterility often breaks down while growing the mustard for seed production, especially in frosty weather, Pental says. When this happens, the female parent pollinates itself, short-circuiting the hybridisation process. As a result, only around 85% of the seeds produced are pure hybrid seeds. Such a low level of seed purity is unusual for hybrids, with the department of agriculture typically requiring at least 95% purity. But because mustard CMS systems struggle with this problem, the department lowered the mandated purity for mustard hybrids to 85 percent in 2014. Impure seeds mean that seed makers for DMH-1 are able to produce enough for only about a quarter of a million hectares, out of the six million on which mustard is grown in India.

The second problem with the CMS system Pental has been using is that it doesn’t work with a female parent other than Pusa Bold. “When we try to introduce other traits such as disease resistance, sterility breaks down again. This means that the possibility of improved hybrids with this CMS system is very much reduced.”  Pental believes DMH-1 is as far as his cytoplasmic male-sterility system can go, and that it is time to try transgenics. “We know that DMH 1 will remain stuck here, and we may not be able to take it forward. That is why we have been shouting from the rooftops that we need a more robust hybridisation system.”

Other researchers agree that perfecting CMS systems is a long-drawn exercise. According to Trilochan Mohapatra, who heads the Indian Council of Agricultural Research , CMS systems in mustard sometimes suffer from seed purity issues of the sort Pental is facing. “These problems can be overcome, but it needs a lot of work.”

If Pental’s system has hit a wall, the other Indian CMS systems are yet to churn out noteworthy hybrids.

One such system is Moricandia, which borrows the sterility gene from a wild Brassica species called Moricandia arvensis. S.R. Bhat, a plant biologist at the National Research Centre for Plant Biotechnology, who helped developed it says Moricandia works smoothly and can be used with any mustard variety, unlike Pental’s system. The Indian Council of Agricultural Research has even developed a hybrid called NRCHB 506 using the Moricandia system.

But NRCHB isn’t popular in India because its yields are not as high as Pental’s DMH-1. One reason for this is that NRCHB is a hybrid of two Indian varieties of mustard that do not show as much heterosis as the varieties Pental chose. The chief developer of NRCHB, K.H. Singh at Rajasthan’s Directorate of Rapeseed-Mustard Research, also admits that they are having trouble producing enough seed for this hybrid. Experiments are now on to hybridise other more heterotic parents using the Moridcandia system. But no such hybrid is in the market yet.

Improving hybrids is a gradual and complex process, says Bhat. “It takes a lot of time. The first generation of hybrids is never the best. Once they come, there is further improvement.” He points to the example of Germany which took over a decade to perfect its CMS systems and make hybrids with them. India mustard researchers are climbing up their own excruciating learning curve today, as Germany did in the late nineties.

This is where transgenics can play a role in speeding things up. DMH-11, the transgenic hybrid developed by Pental, hybridises an Indian mustard variety called Varuna with the east European EH-2, but turns to genetic engineering to overcome the problems that plagued predecessor DMH-1. Pental says the new method is able to produce pure seed almost 99% of the time, a huge jump over DMH-1. This means the transgenic mustard can reach more farmers than its predecessor ever did.

In time, it is certain that India will launch high-yielding hybrids through non-transgenic systems such as Moricandia. But when we do, we will still be better off holding on to alternatives such as DMH-11, say researchers. When it comes to hybrids, more is always merrier. Singh points to the catastrophic attack of southern corn leaf blight, a fungal disease that destroyed large tracts of corn fields across the US corn belt in 1970, as an example of what can happen when a single CMS system is deployed over a large area. During this period, nearly 80% of the corn belt grew hybrids developed with CMS borrowed from a Texan variety of corn. But the cytoplasm that carried the male-sterility gene also carried a gene that made these crops susceptible to the blight. When the disease broke out, it wiped out much of the belt and forced breeders to stop using the Texan male-sterility system.

To depend on one or two CMS systems to create hybrids would leave us open to such disasters. This is one reason why India must keep transgenics in its arsenal, even if it has conventional options. “All said and done, transgenic mustard is an alternative system. When you can afford to have fifty different brands of cars, each with its merits and demerits, why can’t you have different varieties of crops?” asks Singh.

Will farmers use DMH-11?

All these advantages of transgenic mustard won’t amount to much if farmers do not cotton to it. Some agro-economists ask if the 30% yield hike offered by transgenic mustard will cut it for farmers. For any new hybrid to be adopted, its benefits must greatly outweigh the cost of seed and cost of inputs, both of which tend to be high for hybrids. The reason why hybrids have found favour with maize farmers, says Reddy, is because they multiply yields by between two and three times, allowing costs to be recovered. Bt Cotton hybrids were a grand success for the same reason: even though the seeds cost more, farmers were able to forego the use of pesticide against the pink bollworm, typically a big part of their expenditure.

It isn’t known yet how much DMH-11 seeds will cost, although Pental has said that the hybrid can be grown using the same fertiliser and pesticide inputs as pure varieties. Reddy says it is important that these costs remain low; else farmers may not want to make a switch because “thirty percent is not a big yield jump.” These questions can be answered only after all data on DMH-11 becomes public.

This is another issue. One of the reasons farmers did not adopt the DMH-1 or the NRCHB, mustard researchers say, is that these varieties produced small seeds. Even though the size of the seed does not affect oil content, farmers continued to irrationally favour bolder seeds. “It is a perception issue,” says A.K. Singh. “Brokers are used to buying a particular type of seed. It is not easy to change perception in the market.” Unless farmers are educated about such fallacies, they may stay away from transgenic mustard as well.

Pental sees other answers to the problem. It is possible, he says, to develop hybrids with bolder seeds using a transgenic approach because certain East European varieties of mustard do have this feature. He has already begun work on hybrids that can take yields beyond what DMH-11 can hit. “Nothing is fixed for all time to come,” he says, “If people don’t like DMH 11, they can use our system to make better hybrids then we have. Who is stopping them?”