Effect of Weather on Grain Quality Traits of Durum Wheat Grown in the Northern Plains of USA

The objective of this research was to determine the effect of genotype and growing environment, particularly weather, on grain quality traits of durum wheat using nine genotypes (Alkabo, Carpio, Divide, Grenora, Joppa, Maier, Mountrail, Pierce, and Tioga) grown in four years (2012-2015) at six locations in North Dakota, USA. The results of this research indicated that grain test weight, 1000-kernel weight, protein content, kernel vitreousness, and falling number were affected more by environment than by genotype. However, genotypes within an environment differed in the magnitude of their response and this difference could be used to select genotypes in a breeding program to improve quality. For a given quality trait, the magnitude of the response reflects the stability of the trait to changes in the environment. In general, the quality of durum wheat grown in the northern plains of USA was favored by warm daytime temperature, low night temperature, and low relative humidity. Growing locations with high maximum air temperature and a high number of days with temperature ≥ 30°C had a positive effect on grain protein content and falling number, while a high number of days with night time temperature ≤ 13°C were ideal for 1000-kernel weight. Low rainfall and low relative humidity promoted a high falling number and vitreous kernel content. The results of this study suggested that genotypes could be selected based on their overall quality and their stability across environments. Trait stability could be an important consideration when growers select genotypes for planting in their fields.