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

Effect of Phosphate Solubilizer Biofertilizer and Phosphorus Fertilizer on Response of Agronomic Traits, Yield and Yield Components of Pumpkin (Cucurbita pepo L.)

This research was carried out to investigate the response of agronomic traits, yield and yield components of pumpkin (Cucurbita pepo L.) to phosphate solubilizer biofertilizer at different levels of phosphorus (P) fertilizer. The experiment was factorial, based on randomized complete blocks design with three replications. Treatments included two levels of phosphate solubilizer biofertilizer (inoculation of seeds and non-inoculation) and P fertilizer at four levels (25, 50, 75 and 100% of recommended level based on soil test), which were performed at Educational and Research Farm of Bu-Ali Sina University, Hamadan, Iran, in 2011. Results of the flowering stage showed that application of 75% P fertilizer produced maximum number of leaves per plant (21.86), leaf dry weight (27.75 g/plant) and plant dry weight (49.66 g). At the stage of fruit production, maximum number of branches and leaf dry weight per plant were achieved in inoculation treatment. With increasing P fertilizer application, the number of fruits per plant was increased. Application of P fertilizer up to 50% of recommended level along with using biofertilizer increased seed yield. This result could be due to increased efficiency of bacteria, which dissolve phosphate in lower rates of P fertilizer