Mitigating climate impacts on crop production via symbiosis.

Abstract All plants in natural ecosystems are thought to be symbiotic with mutualistic fungal endophytes that can significantly improve plant fitness by enhancing root growth, fertility, nutrient acquisition and biotic or abiotic stress tolerance. Recently, Adaptive Symbiotic Technologies developed the product line BioEnsure® comprised of fungal endophytes that confer abiotic stress tolerance (drought, temperature, salinity) to food crops (www.adsymtech.com). These endophytes communicate similarly with monocots and eudicots to enhance crop production on marginal lands and mitigate the impacts of high daytime or nighttime temperatures on crop fertilization. Yield benefits in endophyte-colonized plants are remarkable and directly proportional to stress levels with average yield increases of 3-5% above control plants under low stress and >26% under high stress. The relationship between stress and yield enhancement was best exemplified in Rajasthan, India, where BioEnsure®-treated pearl millet and mung bean seeds were provided to 400 small landholding farmers. Under the hot, dry growing conditions that are typical in Rajasthan, the average yield increases were 29% for pearl millet and 64% for mung bean compared to untreated plants. This demonstrated the power of this technology to increase food security, animal fodder, carry-over seed and revenues. Interest in the USA is growing with BioEnsure®-treated seeds planted in 300,000 acres in 2017 and 900,000 acres in 2018, and >2,000,000 acres are projected for 2019.