Determination of potential productivity of Red clover varieties under different enviromental conditions

To determine potential productivity of Red clover varities, an experiment was carried out with six treatments and four replications using RCBD, under different environmental conditions in 2002–2004. Results showed that there was a significant difference (p<0.05) between Red clover varities for fresh and dry forage yield over years and locations. Karaj with 87.99 tha-1 fresh yield and 15.5 t ha-1 dry forage yield produceed the highest yield and Shahr-e-Kord with 38.14 tha-1 fresh yield and 8.76 tha-1 dry forage yield produced the lowest yield. Mean comparison of fresh and dry forage yield of Red clover varities over years and locations showed that the best adapted varieties for different locations as follows: in Karaj and Sharh-e-Kord Redquin and Kulubara; in Sanandaj and Gorgan; Redquin and Bosa, in Kermanshah and Arak Redquin, Tolidi-e-FAO and Tolidi-e-Karaj Results also showed that years and locations significantly affected on potential productivity of Red clover varities. Fresh forage yield varied between 91.8-40.2 tha-1 and dry forage yield varied between 9.02-16.42 tha-1. In all locations, forage yield of Red clover varities followed a decreasing trend from the first to the third year, forge yield potential of Red clover varities was the highest in the first year and the lowest in the third year, respectively. Kulubara was more tolerant, and Tolidi-e-FAO the most sensitive to powdery mildew, respectively. The final results showed that although in each locations there were more adapted variety, but Redquin and Kulubara are recommended as wide adapted varieties for all locations.