Use of wheat cultivar blends to improve grain yield and quality and reduce disease and lodging

Cultivar blends can provide a measure of disease control due to host diversity. The diversity of cultivar blends also may be useful for improving agronomic performance and end-product quality. This paper reports on the performances of blends (0:1, 1:2, 1:1, 2:1, and 1:0) of two fall-sown hard red spring wheat cultivars, Yolo (high grain yield, low susceptibility to septoria tritici blotch and leaf rust, good lodging resistance, poor grain quality) and Serra (high grain yield, high susceptibility to septoria tritici blotch and leaf rust, high susceptibility to lodging, excellent grain quality). The blends were grown in several environments in California for 3 years. The taller Serra was more competitive than Yolo in the various blends. Spike populations of Serra often were larger in blends than expected from the proportion of seed sown. Spikes of Yolo in blends had fewer spikelets than spikes of Yolo in sole crop Yolo, while spikes of Serra in blends had more spikelets than spikes of Serra in sole crop Serra. Blends had advantages over sole crops in several respects. When disease pressure was moderate or high, blends had less leaf rust and septoria tritici blotch than sole crop Serra, but more disease than sole crop Yolo. When lodging occurred, blends had less lodging than sole crop Serra. Overall, there were no significant differences in yield among the blends and sole crops of Serra or Yolo. The blends produced grain protein and baking quality equivalent to sole crop Serra and better than sole crop Yolo. The 2:1 Yolo:Serra blend was the optimum blend and is an attractive alternative to sole crop Yolo or sole crop Serra for wheat growers in the Sacramento Valley of California.