Tar'an, B. and Banniza, S. 2009. Improved sources of resistance to ascochyta blight in chickpea. Can. J. Plant Sci. 89: 107Á118. Successful chickpea production in western Canada typically requires multiple applications of fungicides to minimize the severity of ascochyta blight (AB) caused by Ascochyta rabiei (Pass.) Lab. Although planting resistant cultivars could be economical and environmentally safer than fungicide use, varieties with a high level of resistance are not available. The objective of this research was to identify potentially useful parents for breeding programs aimed at the northern Great Plains by assessing the AB reaction of 12 desi and 12 kabuli chickpea varieties for their AB reaction on leaves, stems and pods under two fungicide regimes. The experiment was conducted at Swift Current and Shaunavon, Saskatchewan, in 2004 and. Differences in AB severity on leaves, stems and pods, seed yield and 1000-seed weight occurred among varieties at all site-years tested. The variation was greater among kabuli varieties than desi varieties. Ascochyta blight severity was generally lower under the high fungicide regime. A positive correlation in AB severity on leaves, stems and pods was observed, suggesting a lack of organ-specific reaction. Several promising varieties that combined improved levels of AB resistance, high yield, and large seed size were identified. Toutes les varie´te´s ont re´agi diffe´remment al 'ascochytose, la gravite´des symptoˆmes variant au niveau des feuilles, des tiges, des gousses, du rendement grainier et du poids de 1 000 graines a`toutes les anne´es-sites. La re´action des cultivars kabuli variait plus que celle des cultivars desi. En ge´ne´ral, l'ascochytose cause moins de dommages quand on applique plus de fongicide. Il existe une corre´lation positive entre la gravite´de l'ascochytose sur les feuilles, les tiges et les gousses, ce qui laisse croire que la maladie n'affecte pas spe´cifiquement certains organes. Plusieurs varie´te´s prometteuses combinant une meilleure re´sistance a`la maladie, un rendement e´leve´et des graines de gros calibre ont pu eˆtre identifie´es.

Improved cultural practices can be used to manage ascochyta blight in chickpea (Cicer arietinum L.), a disease caused by Ascochyta rabiei (Pass.) Labrousse. Th is study examined the eff ect of planting pattern, seeding rate, and fungicide application systems on ascochyta blight severity and crop yield of chickpea at Swift Current (50°25' N, 107° 44' W), SK, Canada, in 2004 and 2005. Crop was grown in uniform row (25 cm) and paired-row spacing (25 cm within each pair and 75 cm between pairs), at 44 and 31 plants m −2 , and with 1× and 0.67× the recommended fungicide application rates. Area under disease progress curve (AUDPC) averaged 1580 units for the susceptible cultivar CDC Xena, and signifi cantly greater than 573 for the partially resistant cultivar Amit. Th e AUPDC value reduced from 750 at one fungicide application to 400 at four applications for Amit, and from 1907 to 1250 for CDC Xena. Seed yield was 2.24 Mg ha −1 with four applications and 1.73 Mg ha −1 with one application for Amit, and 1.04 and 0.18 Mg ha −1 , respectively, for CDC Xena. Paired-row spacing reduced AUDPC by 12% for Amit and 14% for CDC Xena from uniform row spacing. With paired-row spacing, blight severity did not diff er between the 1× and 0.67× fungicide application rates or between the plant densities of 44 and 31 plants m −2 . Altered planting patterns, in combination with improved fungicide application systems, can potentially enable growers to reduce fungicide rates by 30% without decreasing effi cacy of ascochyta blight control or seed yield for chickpea in northern Great Plains.