Study Of Pathogenic And Chemical Control Of Barley Leaf Stripe

1. Symptoms and incidence of barley leaf stripe disease in several districts of Gansu province were investigated in 2008-2009.The results showed that the incidence in Shangshawo Village,JintaiCountry, was 83.33%, the disease index was 36.67,which is the most serious field.The disease caused different symptoms on different position of barley. four types of symptoms on the barley were observed: seedling blight, leaf stripe,.no-ear and white ear.The chief pathogen, according to their morphology, cultural characteristics and pathogenicity, was identified as Drechslera graminea(Rabenh.ex Schlecht.)Shoem.2.The biological characteristics of Drechslera graminea (Rabenh)Shoem., the pathogenic fungus of barley leaf stripe was studied. The results showed that the temperature, pH, culture medium, carbon sources and nitrogen sources can promote the mycelial growth. The optimal growth temperature and pH were 25℃and 7, respectively. PSA and PDA media were the suitable media. Sucrose and soluble starch were the suitable carbon sources while Glycine and NaNO3 were the optimum nitrogen sources. However, it was showed that photoperiod had no effect on the mycelial growth. No spore was observed on any medium provided in this research.3. In this study, we investigated the antiseptic effects of nine kinds of germicide against Drechslera graminea (Rabenh.ex Schlecht.)Shoem. The results showed that all of them have negative effects on the growth of pathogen,but there are differences among them. Five germicide named 10%Jinzhonglinruyou,40% Colex,10% score,12.5% diniconazole and 3% Dividend are extremely poisonous to Drechslera graminea (Rabenh.ex Schlecht.)Shoem. 15% Triadmefon,Ethylicin have less but also efficient antiseptic outcome,however, 50% Carbendazim,70% Mancozeb don,t have any effects to the Drechslera graminea (Rabenh.ex Schlecht.)Shoem. in vitro.4. In this study, the experiment showed that there is no effect on the germination percentage of barley among different dosage of different fungicides under indoor experiments. In field fungicides test to control the Drechslera graminea (Rabenh)Shoem by different fungicide treatment, the results demonstrated that Jinzhonglin could inhibite the germination percentage of Drechslera graminea (Rabenh)Shoem and improve the growth of plants, remote root length and fresh weight of barley effectely. The control effects of Dividend SC,Jinzhongling EC and Jinzhongling SC to barley leaf stripe are 88.22%, 84.48% and 86.09%, respectively.