Occurrence Investigation and Control Agent Screening for Congjiang Citrus Black Spot Disease
[Objective]The occurrence status and rules of Congjang citrus black spot disease were explored,and the effective control agents were screened,which provided a reference for the prevention and control of Congjiang citrus black spot disease.[Method]The occurrence situation and disease rule of Congjiang citrus black spot disease were investigated by disease census and systematic investigation methods.The control agents against black spot disease were screened through setting different agents and application methods in field.[Result]The incidence of citrus black spot disease in investigated orchards was 100% .The orchards with disease index above 50 accounted for 40% .Old orchards were heavily affected,different varieties could be susceptible to the disease,and summer rainy season and early September were the key periods for the control.The field control efficiency of two treatments,respectively three agents of 80% Mancozeb diluting 700 times,70% propineb WP diluting 1000 times and 50% fluazinam SC diluting 1 000 times using twice in turn,or 50% fluazinam SC diluting 1 000 times+Lvying mineral oil diluting 200 times,against citrus black spot was the best,which was up to 100%,followed by 50% fluazinam SC diluting 1000 times,the control efficiency reached 92.31% .[Conclusion]The incidence of Congjiang citrus black spot disease is high,among which old orchards are heavily affected,and the key periods for the control are in summer rainy season and early September.It is suggested applying 80% Mancozeb diluting 700 times,70% propineb WP diluting 1 000 times and 50% fluazinam SC diluting 1 000 times twice in turn,or 50% fluazinam SC diluting 1 000 times+Lvying mineral oil diluting 200 times to prevent and control Congjiang citrus black spot disease can achieve the obvious control effects.
citrus black spot diseaseincidencedisease indexoccurrence rulefield control efficiencyGuizhouCongjiang