Study of temprature effects on maze different hybrids yield, yield componants and phenological stage in Jiroft region

To study of temperature effects on maize different hybrids yield, yield components and phonological stages, this study were conducted in split-plots based on RCBD with three replications in Islamic Azad University, Jiroft branch during 2004-2005. The sowing dates (including 1 and 16 July, 1 and 16 August), and hybrids (ZP434, BC404, OSSK444, BC504, KSC500, G3337, NS540, BC666, BC678, KSC704, G3393 and KSC700) were selected as main and sub-plots, respectively. Results showed that year and sowing date had not significant effects on summer maize grain yield in this region. Although, one month retarding of sowing date (16 July - 16 August) were caused the yield decreasing by 3.9%, but this effect was not significant. Hybrids had significance effects (P<0.01) on maize seed yield and BC678, BC666 (belongs to FAO600 by 11.489 and 11.404 ton/ha), KSC704 and G3393 (belongs to FAO700 by 11.253 and 11.110 ton/ha) have the highest grain yield. Effects of sowing date on yield components were not significant, while hybrid's effect were significant (P<0.01). Grains/row was significantly affected by sowing date and studied hybrids had significant effects on yield components. BC678 (37.8) and KSC704 (37.8) and KSC500 (29.5) had maximum and minimum grains/row, respectively. Required growth degree days (GDD) from sowing until tassel formation, pollination and silk appearance at 5% probability level and requisite GDD from sowing until emergence and maturity in 1% probability level were significant.