• Wednesday, Nov 13, 2019
  • Last Update : 11:11 am

Wheat that can withstand the heat

  • Published at 12:12 am July 7th, 2019
Wheat-Bigstock
Photo: Bigstock

Bangladeshi scientists develop heat tolerant wheat variety at a time when wheat output is dwindling largely due to shorter winters, higher temperatures

With the gradual rise in temperatures and shorter winters in Bangladesh, growing wheat in warmer weather appears to be increasingly challenging.  Bangladesh’s dependence on imported wheat, the second most important food crop after rice, is increasing year on year.  

Only the development of a heat tolerant variety can come to the rescue. And the breakthrough has just been achieved!

Scientists at the Bangladesh Wheat and Maize Research Institute (BWMRI) have developed a high yielding wheat variety – WMRI Gom 01 – which can withstand warmer weather and mature early. 

The National Seed Board recently approved the release of the heat tolerant and early maturing variety of wheat, that also a high yield potential of upto 5 tons a hectare compared to a national average wheat yield of 3 tons per hectare.  

This is a welcome development given the fact that Bangladesh currently grows a little over one million tons of wheat on 0.35 million hectares of land a year, compelling public and private importers to buy  six million tons of wheat internationally to meet increasing domestic demand. Bangladesh spends upto USD 1.5 billion a year to foot the wheat import bill.  

Domestic wheat production hit a record high of 1.9 million tons in fiscal 1998-99. But thanks to shorter winters as a fallout of climate change, and farmers switching over to more high value crops such as maize, potatoes, and vegetables, the production of wheat has dwindled over the years.

Bangladesh is a subtropical country where only spring wheat is grown in short winters. The spring wheat grown in this region is exposed to chronic heat stress at certain growth stages. Thanks to land scarcity and high cropping intensity, up to 80 percent of wheat in Bangladesh is grown after monsoon rice is harvested, and hence wheat seeding is often delayed. 

Late planting exposes the wheat to higher temperatures in its grain filling phase, causing significant yield loss. 

And as Bangladesh has a cropping intensity of nearly 300% (meaning, on average, crop land is harvested thrice a year) , one of the highest in the world, wheat has to compete with winter rice, maize, potato, and other crops, for farmland.  

The new heat tolerant variety would come to the rescue of thousands of wheat growers. They would be able to plant late and harvest the grain long after winter is gone. The WMRI Gom 01 wheat strain would be able to tolerate high March temperatures, explained one of the country’s preeminent wheat scientists, Dr. Naresh Chandra Deb Barma.

Dr Barma, who oversaw the Wheat Research Centre’s transformation into an institute, the Bangladesh Wheat and Maize Research Institute (BWMRI), as its first director general, told Dhaka Tribune that the WMRI Gom 01 is a hybrid of two popular wheat varieties, Shatabdi and Prodip. 

“It was initially named BAW 1194, selected from various wheat strains in diverse environments. This breeding line produced a 20-25% higher yield than the trial varieties in different nurseries and yield trials. This variety has been proven high yielding and heat tolerant,  successively for three years in research trials and farm fields,” said Dr Barma.

Back in 1983 the Wheat Research Centre developed and released a highly productive semi-dwarf wheat variety called Kanchan. In subsequent years varieties like – Kanchan, Shatabdi, Prodip – became hugely popular with wheat farmers. But eventually some of the earlier varieties degenerated and became susceptible to various diseases.

National Seed Board officials say the newly released variety is not only early maturing and heat tolerant, but also resistant to leaf blight and leaf rust diseases. 

Wheat scientists say heat stress is becoming an issue in the Rabi season of Bangladesh due to global warming and shorter winters. They say the newly released wheat variety, WMRI Gom 01, needs rapid expansion to boost wheat yields and farmer incomes. 

They said where many traditional wheat varieties take up to 120-125 days to mature, WMRI Gom 01 can be harvested in 105 to 110 days,  and farmers can plant till as late as mid-December and can withstand the hotter March temperatures.   

About its features BWMRI scientists said, the variety is 90 to 100cm tall with 4 to 5 tillers in each plant having broad and dark green leaves. The spike is long, with 45-50 grains in each spike.  The grains are white, shiny, and bold, with a thousand kernels weighing 52-60 grams.