Scientists in Bangladesh have developed the country's first biotech rice variety giving farmers an answer to the difficulties they face in harvesting the staple with machines.

Stems of BRRIdhan-86, the variety that got release approval yesterday, are strong and stout and easy to reap by mechanical harvesters. This will come handy to farm owners, who have dearth of labourers and also find it difficult to use harvesters.

BRRI breeders told UNB that the new variety, with half a tonne of extra yield potential per hectare over the country's most produced rice variety BRRIdhan-28, is derived from Iranian rice variety Niamat through application of a biotech tool called anther culture.

Anther culture, applied for the first time in rice science in Bangladesh, is a biotech plant culturing technique where immature pollens are made to divide and grow into tissues either on solid and liquid medium.

The scientists at the Bangladesh Rice Research Institute (BRRI) have also developed a new rice variety with the highest ever zinc (27.6 mg/kg) content. BRRIdhan-84 also got approval along with three more new rice varieties yesterday.

In 2013, Bangladesh released the world's first biofortified zinc-rich rice variety BRRIdhan-62 with 19 mg/kg of the micronutrient. Since then countries scientists at BRRI and Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU) have, so far, developed six zinc-rich rice varieties with the yesterday's one richest in zinc content.

BRRI scientists told UNB that BRRIdhan-84 is also moderately enriched with another key micronutrient, iron.

Zinc deficiency causes stunting, while iron deficiency is a leading cause of anaemia. More than one-third of under-five children in Bangladesh are stunted, while more than 43 percent women of reproductive age are anaemic.

A meeting of the National Seed Board (NSB) held in the city yesterday with the agriculture ministry secretary in the chair also gave nods to short-duration transplanted Aus variety BRRIdhan-82, broadcast Aus variety BRRIdhan-83 and a rice variety that can withstand stagnant water BRRIdhan-85.

Talking to UNB, BRRI Research Director Tamal Lata Aditya said both the biotech rice and the zinc-rich rice would be good supplements to Boro-season mega variety BRRIdhan-28. Both of the new ones have higher yield potentials of varying degrees compared to BRRIdhan-28.

The new varieties come at a time when two of the country's most common rice varieties -- BRRIdhan28 and BRRIdhan-29 released in 1994 -- are losing potential due to ageing.

The prospect of higher rice yield through the release of the new varieties also comes against the backdrop of diminishing returns from the country's rice fields.

A recent International Food Policy Research Institute (IFPRI) report says Bangladesh's rice production growth slowed down to just 0.7 percent in five years (2012-16), whereas the growth was as high as 4.8 percent in the preceding five years (2007-11).

Akhter Ahmed, the country head of the Washington-based food research think tank IFPRI, said, "Rice production more than tripled since the country's liberation [in 1971], but the [agricultural] growth is slowing down."

He observed that the most popular rice varieties in Bangladesh are old and they require better replacements so that farmers could reap more yield from less land and go for agricultural diversity by growing other high-value crops.

Akhter put emphasis on the agricultural extension service's role in demonstrating and popularising the new potential rice varieties among farmers. As a third of Bangladesh's total farm households are of pure tenants, who work on land owned by others, it is very crucial for the state to take extension services to them, he added.

Sazzadur Rahman, a prominent young rice scientist, explained to UNB that application of biotech tool helped the BRRI scientists to come up with a potential rice variety, which otherwise could have taken longer.

With the five varieties that got approved yesterday, the number of BRRI-developed rice varieties now stands at 91. Among them, one is biotech rice, six are hybrids while the rest are high-yielding inbred varieties (HYVs).

BRRI-developed rice varieties are cultivated on more than 80 percent of the country's land where paddy is grown. These varieties account for more than 91 percent of the country's total 35 million tonnes of rice production.

The farm sector contributes about 17 percent to the country's Gross Domestic Product (GDP) and employs more than 45 percent of the total labour force.

Currently, nearly 75 percent of the total 7.84 million hectares of arable land is being used for producing rice, thanks to land scarcity and people's rice-centric dietary habit.