Effect of yellow rust disease on agronomic and physiological characteristics of winter and facultative bread wheat (Triticum aestivum L.) cultivars

To investigate the effect of yellow rust disease on some agronomic and physiological characteristics of bread wheat cultivars, two field experiments were conducted in Agricultural Research Station of Miandoab in West Azerbaijan, Iran, in 2013-2014 and 2014-2015 cropping seasons. Experimental treatments were arranged as factorial in randomized complete block design with three replications. Treatments included; non-sprayed and sprayed of Tilt fungicide with six winter and facultative bread wheat cultivars (Zarrin, Alvand, Pishgam, Oroum, Zareh and Mihan). Environmental conditions was inductive and yellow rust disease occured naturally in both cropping seasons. The results showed that Zarrin and Alvand cultivars had the highest disease infection (63% and 57%, respectively) in the non-sparyed treatment. However, Pishgam, Orum, Zareh and Mihan cultivars were resistant to yellow rust disease. Yellow rust decreased grain filling duration in sausceptible cultivars (Zarrin and Alvand) by 10 days. Leaf chlorophyll content of susceptible cultivars decreased in non-sprayed treatment from the milky to hard dough stage with a steepy slope. However, in the sprayed treatment leaf cholorophyll content decreased with slower rate. Yellow rust disease in non-sprayed treatment caused the highest proportion of reserved carbohydrtaes remobilization in Zarrin and Alvand by 30%, but 1000 grain weight loss in susceptible cultivars was about 26%. Despite of 29% increase in grain yield of susceptible cultivars in the sprayed treatment, the higher grain yield was obtained from resistant cultivars, Pishgham and Mihan (7877 and 7593 kg.ha-1, respectively). It can be concluded that integrated disease management by using resistant/ moderately resistant cultivars and fungicide application would be the best crop management practice to control yellow rust disease and reduce environmental pollution by application of less fungicide and reducing production costs.