Variety Selection and Agronomic Technology to Reduce Heat, Water, and Pest Stress of Canola in Central Montana (2003)

Abstract

This paper evaluates selected canola varieties for their adaptation to field sites in north central and central Montana, determines the optimum seeding date and rate to avoid or reduce heat and water stress without risking seedling mortality due to freezing or seed decay in cold soils, and determines the optimum seeding date and rate to avoid or reduce pest damage. Fourteen varieties and breeding lines, including regular and Clear-Field canola, were obtained from Dr. Jack Brown’s canola breeding program at University of Idaho, and three Roundup-Ready canola varieties were received from Monsanto Company and Interstate Seed Company. The canola was planted at the Central Agricultural Research Center of Montana State University, Moccasin, MT on May 30, 2003 in a tilled re-cropped field. The experiment was a randomized complete block design with four replications. The seeding rate (plant density) was 67 plants m-2. Fertilizer was applied after the canola grew to two true leaves stage at a rate of 75 kgN and 25 kgP2O5 per hectare using the broadcast method. Because of the delayed seeding (seeds arrived late) in conjunction with a severe summer drought, the experiment was a disaster. The drought during flowering and seed filling stages severely reduce canola yield. The seed yield was less than 40 kg ha-1 in this study (Table 1). Due to the severe summer drought, canola yield in 2003 was much lower than in 2002. Early seeding continued to receive higher yields than late seeding.