روش هاي كنترل آفات و علف هاي هرز جهت توليد بذر از چين اول در يونجه هاي بيش از 5 سال در همدان

Study on Control Methods of Pests and Weeds for Seed Production From First Cut of Alfalfa Crop with More Than Five Years Old in Hamedan Farms

First cut of alfalfa crops with more than five years old is not economic for to produce forage production, but they are suitable for seed production. At the present alfalfa seed is produced from the second and third cuts of alfalfa crops with more than five years old, having high population of plant bugs, Lygus spp. and Adelphocoris lineolatos (Goeze). They cause flower shattering in seed production fields and unfortunately the damage is very high and seed production is not economically feasibl. Therefore, if alfalfa weevil, Hypera postica (Gyl.) and weeds can be controlled, then a suitable seed may be produced. In this regard, seven different integrated control methods of pests and weeds at first cuts of alfalfa crop were used. The treatments were including A) physical control (field blaming on 1st April), B) chemical control in early spring (1st April) + spraying at green buds stage to control Lygus bugs (spraying with insecticide), C) chemical control with herbicide (using the Gramaxone on 1st April to control weeds and destroying plant debris that contained over wintering eggs), D) applying herbicide (on 1st April) + using the insecticide in the green bud stage, E) early cutting (when alfalfa height was five cm) + using insecticide in the green buds stage, F. physical control (field blaming on 1st April + using the insecticide in the green bud stage, G. using the Gramaxone on 1st April + the insecticide in the green bud stage and H) control treatment. The experiment was carried out as random complete block design with four replications during 2006. Most of the control methods were effective in controlling pests of first cut in contrast to the control and the differences were significant in 1% probability level. Treatments F, E and G were more effective than other treatments in controlling major pests. Consequently, a proper alfalfa seed with higher yield can be produced from the first cuting of lucerne crops with more than five years of age. By bud stage controlling the alfalfa weevil and weeds, and spraying on Lygus bugs, in the green. In this condition a seed yield of about 370 grams per meter square (equal to 3700 kg per hectare), can be produced.