Did you say High Yield?

By Debal Deb on 14th May, 2019

In spite of all the hype and false promises, the yield of hybrid rice in India has seldom exceeded 6.5t/ha under irrigated condition on farmers’ fields.1 On marginal farms (e.g. rainfed drylands, submerged lowlands, and coastal saline farms), the yield of hybrid as well as any modern rice varieties remains abysmally poor. The reason is simple: none of the hybrids can withstand adverse environmental conditions, especially drought and salinity, on marginal farms. In contrast, there is a plethora of folk varieties (also called ‘landraces’) that are perfectly adapted to marginal farm conditions and local environmental vagaries. Many of these folk varieties evince amazing yield performance on farm fields. The table on the next page describes some yield characteristics of a few selected indigenous rice varieties grown every year on Basudha farm in West Bengal and Odisha.

The data presented here are based on the current year’s (2011- 12 Kharif) plot-wise harvest from Basudha farm. As the data indicates, the performances of these rainfed folk varieties are yet unachieved by any modern varieties (including hybrids) on two counts: (a) zero inputs of agrochemicals and (b) long term yield stability. Even on coastal saline soil of the Sunderban islands in eastern India, the grain yield of a few salt-tolerant landraces is 4t/ha – considerably higher than some of the best lowland high yielding varieties (e.g. Sabita, Lalat) introduced into the coastal districts. Conversely, no modern variety can practically survive on coastal saline farms receiving tidal waters.

The mean yield of numerous lowland landraces often exceeds the mean yield of the best modern HYVs. A good example is Bahurupi, whose average yield generally exceeds 6 t/ha in southern West Bengal. With adequate rainfall (but no irrigation), its yield can exceed the Chinese average of 6.3 t/ha – after subtracting the loss due to sterile (unfilled) grains. While Bahurupi marks the crown of yield among the highyield landraces, there exist several lowland folk varieties (Table in next page) which outperform modern high input-responsive varieties in similar environmental conditions.

One among this select group of high-yield landraces is that of Baigana Manjia of Odisha – over 5.6 t/ha, which is substantially greater than the socalled HYVs tested in Odisha under identical edaphoclimatic conditions. In the table in the following page we have compared the yield of two modern varieities released by CRRI, Cuttack. All these landraces also prove to be resistant to different insect pests and pathogens. High grain yields are generally more common among lowland folk varieties, owing to obviously greater water availability to the former than to upland varieties. However, farmers’ selection of yield-related traits, bred over generations, has produced a considerable number of upland varieties that yield reasonably high–despite zero chemical inputs. Dhankadi Deepa, an upland-adapted landrace from Tamil Nadu, is a case in point. If the rain is not too late or too scanty, this variety does not require irrigation for a moderate grain output. If the rain is timely and generous – as was the 2011 monsoon – its yield can reach up to 5.10 t/ha.

Yield characteristics of selected rice landraces

 

The examples given here are only illustrative. Basudha farm conserves a large number of similar high-yield landraces, which subverts the myth that modern HYVs are ‘high yielding’ by definition, whereas folk rice varieties are low yielding. The new frenzy with hybrid rice varieties seeks to reiterate this myth by obliterating all local landraces from the country’s farm fields. A huge number of incredibly high yielding landraces have already been lost from farmers’ fields under the impact of agricultural modernisation. In situ conservation of the remaining landraces is the need of the day to ensure the food security of the country’s poor. Furthermore, an intensive search for locallyadapted landraces is more urgent than introducing new hybrids with uncertain outputs on marginal farms.