The Effect of Plant Height on Tan Spot on Durum Wheat in Southern Saskatchewan.
Tan spot [caused by Pyrenophora tritici-repentis (Died.) Drechs.] is the most important leaf disease of durum wheat (Triticum turgidum L. var. durum). Most of the durum cultivars in western Canada are of conventional height but development of shorter cultivars is desirable. Changes in microenvironment resulting from a height reduction might cause greater leaf spot development. The effect of plant height on tan spot of durum wheat was determined in five pairs of genotypes near-isogenic for plant height and five randomly selected populations, each with a semidwarf and a conventional height parent. These were grown in five environments in Saskatchewan (1996-1998 at Swift Current, 1997-1998 at Indian Head), and evaluated for tan spot reaction in a growth chamber. There was no difference in tan spot reaction under controlled conditions between short and tall genotype(s) in each pair or population, although there were differences within each height category. Under field conditions, short genotypes had either equal or greater disease than tall genotypes. Contrasts between all short and tall genotypes also showed that the tall had less disease in 1998 at Indian Head (9.8 for tall, 10.2 for short) and in all years at Swift Current (9.5 and 9.9 in 1996, 8.1 and 8.7 in 1997, 8.5 and 8.9 in 1998, for tall and short, respectively). However, there was genetic variability within populations, with some short having equal or less disease than tall genotypes. Some of these short genotypes also had a low tan spot lesion type under controlled conditions. We conclude that plant height could affect tan spot development in durum wheat under conditions prevalent in southern Saskatchewan, and that this is probably mediated by canopy density.
Plenty Durum wheat
Plenty durum wheat (Triticum turgidum L.) is a high-yielding, moderately late durum wheat that is eligible for the top grades of amber durum wheat. It has moderately tall, strong straw and is well-adapted to the drier areas of durum production. It is similar to other durum cultivars in disease resistance. Key words: Triticum turgidum, durum wheat, cultivar description
Long-term tillage effects on spring wheat production on three soil textures in the Brown soil zone
The adoption of reduced tillage practices has increased markedly on the Canadian prairies in recent years. Producers in the semiarid Brown Chernozemic soil zone require information on how the intensity of tillage will affect moisture conservation and grain yields in the long term. A 12-yr study was conducted in the Brown soil zone of southwestern Saskatchewan on Swinton silt loam (Orthic Brown), Hatton fine sandy loam (Orthic Brown), and Sceptre heavy clay (Rego Brown) to determine the influence of tillage on the production of hard red spring wheat (Triticum aestivum L.) (on the silt loam and clay) and durum (Triticum turgidum L.) (on the sandy loam). The study was conducted with fallow-wheat (F–W) and continuous wheat (Cont W) rotations. The tillage systems were no-tillage (NT), minimum tillage (MT) and conventional tillage (CT). On the sandy soil with its low water-holding characteristics, tillage system did not affect stored spring soil moisture (SSM), nor grain yields, nor grain N. On the silt loam an...