Varietal replacement rate: Prospects and challenges for global food security

The greatest challenge to ensure global food security is sustained agriculture growth that not only helps in increased crop productivity but also caters the food and nutritional demand of burgeoning population. Development, deployment and diffusion of efficient technologies in terms of climate resilience, efficient resource utilization and high yielding varieties/hybrids are required to attain desired growth that ultimately alleviate poverty and vulnerability posed by climate change effects. Genetic enhancements made by crop improvement can be translated into higher productivity with deployment of newly developed varieties. Although new varieties are continuously being introduced into the seed chain but varietal scenario at times is dominated by few varieties having major percentage share in the total indented breeder seed/basic seed requirement. Almost in all the crops, some of the old varieties still occupy the prominent position by virtue of achieving mega variety status. Besides, various institutional, environmental, socio-economic and technical constraints are persisting, which impedes in up-scaling the varietal replacement rates in developing countries. To accelerate varietal replacement rate, several strategies such as pre-breeding, participatory plant breeding, maintenance breeding, quality seed systems and policy support are quintessential. Thus, in the review, challenges associated in hindering VRR and strategies to be deployed for increasing VRR have been illustrated. Adoption of these strategies could envisage higher varietal replacement rate and ultimately higher crop productivity among climate change. •VRR is an essential factor to have genetic gains for crop productivity.•Varietal replacement rate is hindered due to cropping pattern and varietal age.•Rapid breeding cycles and quality seed systems are essential to enhance VRR.•Interlinking and exchange of elite germplasm can enhance VRR.