Abstract:

The infection cycle, damage dynamic, spatial distribution pattern and sampling technique of maize rough dwarf virus disease (MRDV) in Tonglu County of Northwestern of Zhejiang Province were studied, in order to improve the monitoring, prediction and the sustained control system for MRDV disease. Infection cycle, annual dynamic and occurrence of MRDV disease were made clearly. The positive correlation was observed between till incidence of the virus disease and annual total amounts of small brown planthopper, Laodelphax striatellus. The regression equation: y= 0.860605+0.071623x (R=0.9636**). MRDV disease of summer maize was in early infection stage from late May to early June, then in fast increase period from the middle of June to the early of July, and infection peak in the middle of July. The till spatial distribution pattern of summer maize was the assemble distribution type, when till incidence percentage was higher or lower, aggregation degree declined or uniform distribution. Based on this distribution pattern, the optimal sampling technique was single line or double line linear parallel jumping method. The theoretical sampling model was as follows: n=(1.96)2/D2(1.02728/m+0.10287), and sequential sampling model were as follows: Tn=1.02728/(D2-0.10287/n). These results provided scientific basis for sampling investigating precisely and controlling effectively MRDV disease of summer maize.