Brassica napus Growth with Limited Water.

Spring canola cv. Hyola 357 Magnum is grown for oil used in cooking and as bio-diesel fuel. Field trials were conducted in the Nebraska Panhandle limiting irrigation to determine effect on plant growth and seed yield of spring canola at Scottsbluff (SB) and Sidney (SY) in 2007. Four irrigation schemes, 0, 10, 20, and 30 cm were applied, with supplement rainfall, and replicated three-fold. Plant growth was measured at 4½, 6, 8, 10, and 12 weeks after planting (WAP) at SB and 4½, 6, 9, and 12 WAP at SY. Canopy height peaked at 9-10 WAP at SB, and at 12 WAP at SY. Canopy fresh weight reached maximum at 8-9 WAP at SB, and at 12 WAP at SY. Maximum dry weight was increasing at 12 WAP at both sites. Vegetative growth required 28-30 cm precipitation. Seed yield was harvested 14-15 WAP and reached maximum at Sidney. To reach maximum yield, 20 cm of irrigation for a total of 50 cm of precipitation was needed. The change in soil moisture from planting to harvest showed that water was lost from soil until total precipitation reached 50 cm. This agreed with the yield data analysis. In both trials, the highest irrigation treatment increased seed oil content by 1%. Spring canola seed yields at all irrigation levels indicated good potential as an economical crop under limited irrigation, but spring canola needed 8 cm more water than spring Camelina sativa cv. Cheyenne for comparable results.