Economic threshold for the control of apple fruit borer 桃小食心蟲的防治標準
Economic threshold of the rice stem borer 水稻二化螟防治標準
The experiment was conducted to estimate the economic injury level ( eil ) and economic threshold ( et ) of b . tabaci 摘要研究了煙粉虱在黃瓜上的經(jīng)濟損害水平和經(jīng)濟閾值。
Preliminary study on occurring regulation of henosepilachna vigintioctomaculata in yulin area and its economic thresholds 榆林地區(qū)馬鈴薯二十八星瓢蟲發(fā)生規(guī)律及防治指標初步研究
Relationship between the population density of schizotetranychus nanjingensis with the bamboo output and the determination of economic threshold 南京裂爪螨種群密度與新竹產(chǎn)量的關(guān)系及經(jīng)濟閾值的研究
Maximum economic yield programs require research that develops economic thresholds for the need to apply disease control measures , . especially excessive amounts of tillage and the use of fungicides 最大經(jīng)濟產(chǎn)量研究中,必需為必要防病措施制定一個經(jīng)濟閥值,避免耕地次數(shù)過多或施用殺真菌劑過多。
Via investigation and analysis , it discussed relation between occurrence of wheat yellow dwarf and yield . morbidity and grades standard was determined as well as wheat dwarf economic threshold 摘要通過系統(tǒng)調(diào)查與分析,探索了小麥黃矮病的發(fā)生程度與產(chǎn)量的關(guān)系,確定了其發(fā)病程度與分級標準,研究出了小麥黃矮病的經(jīng)濟閾值。