harvest management of alfalfa cultivars evaluation within and between different growing season under khouzestan warm and dry condition

to assessment alfalfa cultivars research project this research has been fulfilled in 2011 at khouzestan agricultural and natural resource research center in southwest of ahwaz in khouzestan province (iran) by position 31º20′ n, 48º40′ e. at first section for evaluation wet forage yield cultivars such as “baghdadi”, “mesasersa”, “yazdi”, “bami”, “nikshahri”, “synthetic” (main factor) and two cutting time (sub factor) according harvest time in four experiment by statistical plane of split plot based randomized complete block design in four replication was conducted. in summer cutting cultivar at 5% flowering stage, autumn cutting at 6-8 cm height of crown buds, winter cutting at 10-12 cm height of crown buds and spring cutting cultivars harvested at 15% flowering stage. second section was conducted according statistical plane was mentioned expect sub factor include four level. result showed baghdadi, mesasersa and synthetic were superior to another cultivars and harvest time on forage yield and also interaction effect of factors on all traits expect stem diameter and number of stem in square meter were significant at 1% probability level. because of climate factors in summer and spring cutting 25-30 day was best period for growing season. in autumn and winter cutting according low flowering it possible use growing degree days and period of received sunshine hours, their values in order 300-350 and 400-450 hours (enough time), as well as baghdadi, mesasersa and synthetic cultivars were superior in all cutting.