Improving Winter Wheat Yields in U.S. Great Plains By Development of Hybrids.

Global food production needs to be doubled to meet the calorific needs of 9.7 billion world population by 2050. Rate of yield gain in major crops need to be much higher than current rates if we expect to meet the global food demand without increasing cultivated land area, in wake of climate change. A 2.3% annual yield increase is required in wheat (Triticum aestivum L.) to meet the projected demand but it has stagnated at about 0.9% in the last two decades (Ray et al., 2013). One of the strategies to break this stagnation of yield gain could be hybrid wheat, since it offers higher yield due to heterosis, yield stability and increased tolerance to biotic and abiotic stress. To test this hypothesis, elite winter wheat lines from two large wheat breeding programs of U.S. were crossed in a 25 x 25 full diallel design; using a chemical hybridizing agent in 2015 and experimental hybrids were developed. These hybrids were planted in a modified augmented design with commercial checks in Lincoln, North Platte, and Alliance, NE and McGregor, TX in 2016 to evaluate for yield, stress response and estimate heterosis, without spraying fungicides for disease control. Preliminary analysis of data from McGregor revealed the presence of adequate heterosis to justify hybrid development. The average mid-parent, high parent and commercial heterosis were 26.2, 16.3 and 11.7, respectively. More testing across years and locations is needed to get better estimates of heterosis.