Research On The Occurrence Regularity And The Control Techniques Of Leaves Moss Of HuangGuoGan

The experiment whose test materials was HuangGuoGan had be done since2010to2011in Shimian County. The test had researched on the following content:the occurrence of leaves moss of HuangGuoGan in Shimian County;meteorological factors which are Temperature, rainfall, rain days and air relative humidity and orchard environment influence on the development of leaves moss; it influences on leaf photosynthesis, photosynthetic pigment, active oxygen metabolism and the fruit quality; five drugs controlled leaves moss of HuangGuoGan in the field experiment.(1) Since2010to2011, leaves moss had came on to varying degrees in Anshun township,Wajiao township,Anjing township,Meiluo township and Zaiyang township in Shimian, the incidence of this disease is highest in Anshun township and Wajiao township which are on Dadu River, the disease percentage were98.8%,94.3%in2010, declined slightly in2011; the incidence of this disease is lowest in Zaiyang township that the incidence were all below10%, and the incidence was0on new leaves. the incidence of leaves moss of older leaves were higher than new leaves,and compared with2010, the incidence and disease index of leaf moss was a downward trend as a whole in2011.(2) There were leaves moss starting around at the end of August and early September,its incidence has risen rapidly from September to October that above50%of orchard was affected, the orchard suffered injury range of80%or more from October to November, November was the rush hour of diseases. When Temperature, total rain days and rainfall werw in certain time, air relative humidity plays a main role in development of leaves moss,and high temperature and high humidity of the environment is very conducive to the occurrence of leaves moss; leaves moss are more likely to happen in the orchard which are in canopy and leaves with dense, shade and poorly ventilation pervious and poorly excessive orchard soil drainage and poorly management level.(3) Leaves moss can make leaf photosynthesis of HuangGuoGan decline, as the degree of disease aggravating, net photosynthetic rate, stomatal conductance, transpiration rate decreased rapidly, intercellular CO2concentration rose fast, compared with healthy leaves,the Pn, Tr and Gs of leaves which are infected more severe fell64.3%,49.6%and64.3%respectively, the Ci is relatively increased by29.3%; chlorophyll and carotenoid content increased with the increase of infection severity of falling, chlorophyll a contents, chlorophyll b contents and carotenoid contents of severe disease leaves fell by33.19%,34.94%,29.7%relatively healthy leaves, the biggest drop was in chlorophyll b content.(4) Leaf active oxygen metabolism of HuangGuoGan can be damaged by Leaves moss, after infection,superoxide dismutase, peroxidase and catalase activity increased with the increase of infection severity of falling, leaves the body with ros reduced capacity, significant increase in leaf cell membrane relative permeability, malondialdehyde content also increased with the increase of infection severity increasing, membrane lipid peroxidation is more intense.(5) Leaves moss had no significant effect on fruit size and shape of HuangGuoGan, compared with healthier plant, fruit weight of HuangGuoGan whose leaf disease degree for mild, moderate, severe slightly down,fell1.07%,1.52%and1.07%respectively, but the difference is not obvious, the fruits of vertical and horizontal with no significant rise in decline; leaves moss had effects on the intrinsic quality, when the degree of disease is mild, moderate, soluble solids content, total sugar content, vitamin C had no significant change,while the infected degree is severe, soluble solids content and total sugar content and vitamin C content had fallen by15.2%,33.6%and11.7%respectively than control, compared with significant difference, but leaves moss had no obvious effect on titratable acid content.(6) The result indicated that:The five drugs which are Amobam、Cuprousoxide、 Benziothiazolinone、Dithane M-45、Streptomycin have certain control effect on leaves moss of Huangguogan. Control efficiency to the best is concentration for1500times of Cuprousoxide,85.62%for control efficiency; the treatments are concentration for 800times of45%of Amobam, concentration for1000times,1500times and2000times of Cuprousoxide of more than60%for control efficiency and without phytotoxicity; the worst of the control efficiency is Streptomycin with three kinds of concentration, and the control efficiency of them is less than20%; Cuprousoxide has a good control effect on leaves moss of Huangguogan.