An Empirical Examination of the Dynamics of Varietal Turnover in Indian Wheat

The productivity gains associated with improved cultivated varieties (cultivars) tend to break down over time as they lose the genetic advantages conferred by breeding. Cultivar depreciation, in turn, can increase the vulnerability of resource-poor households to risks associated with biotic and abiotic stresses. Efforts to address this challenge through plant breeding efforts tend to fail if varietal turnover rates are low — a problem that is particularly acute among smallholders in many developing countries. This paper addresses the challenge of increasing the rate of varietal turnover to prevent depreciation of improved cultivars over time. It examines the supply of and demand for improved cultivars of wheat in India to illustrate this challenge in a unique manner, combining national-level data on breeder seed production with primary data on cultivar adoption. The analyses show that the rate of varietal turnover for wheat has slowed in India from an average of 9-10 years a decade ago to 13-14 years in 2010. By focusing on a sample of farmers and villages in Haryana, where seed and information networks are relatively well developed, the study finds that wheat farmers still prefer cultivars that were released 9-10 years ago. The results indicate that while wheat breeding and seed delivery systems may be the primary causes of this slowdown in varietal turnover, many social and economic factors at the household and village levels further slow turnover. This finding suggests that many of the constraints to technology adoption and wheat productivity growth identified 40 years ago during the Green Revolution persist today. In the face of emerging production risks ranging from new pathogens to climate change, greater investment is required to accelerate varietal turnover at the farm level as a means of sustaining wheat yield growth, reducing losses to various stresses, and protecting rural livelihoods