The Effect of Irrigation Intervals and Arbuscular Mycorrhizal Fungi on Chlorophyll Index, Yield and Yield Components of Grain Sorghum

This experiment was carried out to study the effect of irrigation intervals and arbuscular mycorrhizal fungi on chlorophyll index, yield and yield components of grain sorghum. A factorial experiment was done based on randomized complete block design (RCBD) with three replications at the Agriculture Research Station faculty of Agriculture, Bu- Ali Sina University in growing season of 2011. Irrigation intervals (7, 14 and 21 days) with three levels of seed inoculation (control without inoculation, inoculation with Glomus mossea and inoculation with G. intraradices) were the experimental treatments. Results indicated that the effect of irrigation intervals and mycorrhizal fungi were significant for traits of chlorophyll index, percentage of root symbiosis (PRS), number of grain per panicle, 1000 seed weight, grain yield and harvest index (HI). Maximum value for each trait was observed at G. mossea treatment. G. mossea treatment in comparison with G. intraradices and control treatment can increase the grain yield of sorghum up to 6.80 and 23.10%, respectively. Also, with increasing irrigation interval from 7 to 21 days, PRS increased up to 27.9%. Maximum value for grain yield (755 g m-2) was achieved at irrigation every 14 days and application of G. mossea treatment. But, there was no significant difference between irrigation sorghum plants every 14 days and application of G. mossea and irrigation every 7 days and application of either G. mossea or G. intraradices. In general, irrigation of sorghum plants every 14 days and supplying of G. mossea can produce the highest grain yield, while decreasing water consumption for sorghum production.