The use of trap crops in rotations for population reduction of sugar beet cyst aematode Heterodera schachtii and reduction of rotation.

Integrated management of sugar beet cyst nematode (Hererodera schachtii) using crop rotation and trap crops was catTied out in Fars and Isfahan provinces. In Fars , an experiment was perfonned under circle shape microplot (80cm d.) contained infected soil in a RCa design with 6 treatments and 5 replications. The treatments were: 1- Fallow (Control) _ 2- two years crop rotation of trap crop Sinapis alba var oleifera cv. Sirola (First year) and tomato( scond year) ,3 -Two year crop rotation of com (First year) and Sirola (Second year) ,4 - Mixture of corn and Sirola 5- Trap crop Raphanus salivus cv. Carlos _ 6- Sugarbeet (Control) . 1n Isfahan, a RCa design was also used with 8 treatments and 4 replications. The treatments were :] -Mixtured of com and Sirola , 2- two years rotation of lalhyrus spp. with wheat, 3- rotation of S. alba cv. Rinova & Torpedo, 4- Rotation of Carlos & Nemex , 5- Fallow (Control) ,6- Two years rotation of com with wheat ,7- two years rotation of Nemex with wheat , 8- sugar beet (Control). After these rotations all of the plots in both provinces were sown with sugar beet seeds in 2004. In both experiments, initial (Pi) and final popu]ation (Pr) of each plots were scored according to number of eggs and larvae of the nematode in cysts which extracts from 200 g of soil before and after planting. Reprodaction factor (RF-P_f ) were also estimated and anaJized. In addition to Rr , Pi yields of sugar beet roots in 2004 were considered for evaluation in Isfahan. In Fars province the result showed that at the end of two years crop rotation there were not any significant diffference among treatments( 4,3,5,2), but all of treatments were significantly differ nom controls (PO.OI). Reduction in nematode population were 76.8%, 77.3% , 81.8% , and 84.4% for above treatments, respectively. There were considerable differece in growth of sugar beet aniong control and the other plots in final year. 1n Isfahan, the result was nearly similar to Fars. There were not any significant difference among treatments( 1,4,2,3,5 6,7) but all of them were signiticntly differed from control (sugar beet) (PO.OI).Reduction in nemtode population were 89.2 1 74.7 , 62.] , 58,39.8, 25.6, 24.5 respectively for the above treatments .. According to yields there were observed significantly difference among crop rotation, fallow with sugar beet (control) (PO.OI)