بررسی اثر تارﻳخ کاشت بر عملکرد علوفه شبدر برسیم(Trifolium alexandrinum L.) و شبدر ایرانی(Trifolium respinatum L.)

In order to evaluation of effects of planting date on forage yield of Persian and Bersim clover cultivars in fall and spring cropping systems, a field study conducted at Mahidash agricultural research station, Kermanshah province, during 2007-2009 using a split plot model and four replications. The fall and spring experiments achieved separately and planting dates (23 August, 5 September, 23 September and 7 October in fall cropping and 16 March, 4 April, 25 April and 15 May in spring cropping) and clover cultivars namely Karaj bersim, Isfahan bersim, Kermanshah land race and Berujerd land race arranged as main and subplots respectively. According to combined analysis of data, the 15.6 and 15.1 planting dates showed highest yield in fall and spring cropping respectively. Forage yield of persian clover cvs. was higher than bersim cvs. at both cropping systems. The Kermanshah land race showed highest yield in fall and spring systems. The performance of persian cvs. was better in fall cropping contrast with spring. The bersim cvs showed highest yield in spring cropping than fall. In additiom Kermansha local race is recommendable to clover grower in fall and spring season.