Effect of triazoles foliar application and calcium silicate on canola (Brassica napus L.) dryness tolerance

Due to reduction the crops yield and yield components in water stress condition, a factorial experiment was conducted in a randomized complete block design with three replications to evaluate the effect of water deficite stress and growth improver materials on canola (Brassica napus L.) yield and yield components in research greenhouse of Agricultural Faculty of TarbiatModares University. Treatments includes water deficit stress {Control (50% discharged available water) (S1), average stress (65% discharged available water) (S2) and sever stress (80% discharged available water) (S3)} and foliar application {Control (F1), distilled water (F2), calcium silicate (F3), Hexaconazole (F4), propiconazole (F5), and penconazole (F6)}. Results showed the highest of yield was related to S1F6 that showed 2.1 gr higher than S2F1. Also S1F6 and S3F1 With more than 2-fold difference were the highest and the lowest of thousand seed weight. Also in S2, control and foliar application of F4 were the highest and the lowest of oil percentage respectively with 34.4% difference. S1 and S2 with no significant difference were lower than control with a significant difference proximately 5.8 µmol co2 m-2 Leaf s-1 in photosynthesis rate. S1F2 and S3F1 were the highest and lowest stomatal conductivity with 0.154 mol H2O m-2s-1 difference. Also S1F1 was the highest amount of intercellular Co2 concentration with 229 µmol CO2 mol air -1 difference with S3F2. So foliar application of triazoles (penconazole) and calcium silicate somewhat reduces the water deficit stress damages. So foliar application of triazoles (penconazole) and calcium silicate somewhat reduces the water deficit stress damages.