農藥被用來防(fang)治作(zuo)物的(de)(de)病蟲(chong)草(cao)害問題(ti)，但一(yi)種農(nong)藥(yao)用的(de)(de)時間長(chang)了(le)就會逐漸發現藥(yao)效下降(jiang)的(de)(de)現象，這是(shi)因為病蟲(chong)草(cao)害對該種農(nong)藥(yao)產(chan)生(sheng)(sheng)了(le)抗(kang)藥(yao)性(xing)(xing)，而(er)這也就是(shi)農(nong)藥(yao)的(de)(de)“壽(shou)命”，那么看看專家是(shi)如何讓農(nong)藥(yao)抗(kang)藥(yao)性(xing)(xing)減緩發生(sheng)(sheng)的(de)(de)。
一、輪(lun)換(huan)用(yong)藥不(bu)要長期單一使(shi)用(yong)某種(zhong)農(nong)(nong)(nong)藥防治某種(zhong)害(hai)(hai)蟲(chong)，這樣就可(ke)以切斷害(hai)(hai)蟲(chong)抗藥性種(zhong)群的(de)形成過程。輪(lun)換(huan)使(shi)用(yong)的(de)品種(zhong)應盡可(ke)能選用(yong)作用(yong)機制不(bu)同的(de)農(nong)(nong)(nong)藥。如(ru)有(you)機磷(lin)農(nong)(nong)(nong)藥、擬除蟲(chong)菊(ju)酯(zhi)類農(nong)(nong)(nong)藥、氨基甲酸酯(zhi)類農(nong)(nong)(nong)藥、生(sheng)物制劑類農(nong)(nong)(nong)藥等，殺蟲(chong)原理各不(bu)相同，可(ke)交(jiao)替使(shi)用(yong)。同一類的(de)農(nong)(nong)(nong)藥品種(zhong)輪(lun)換(huan)使(shi)用(yong)應慎重(zhong)，因害(hai)(hai)蟲(chong)易獲得交(jiao)互(hu)抗性，即對某種(zhong)農(nong)(nong)(nong)藥產生(sheng)抗性后，對和該(gai)種(zhong)農(nong)(nong)(nong)藥同類的(de)其他(ta)品種(zhong)也(ye)會產生(sheng)抗性。(深(shen)度(du)分析科(ke)學使(shi)用(yong)農(nong)(nong)(nong)藥減少抗藥性)
二、混(hun)(hun)(hun)合用(yong)(yong)藥(yao)(yao)兩種作(zuo)用(yong)(yong)方(fang)式和機(ji)制(zhi)不(bu)同的農藥(yao)(yao)混(hun)(hun)(hun)合使用(yong)(yong)，可減緩害蟲抗(kang)藥(yao)(yao)性的發生速(su)度(du)，即(ji)使抗(kang)藥(yao)(yao)性已經形成(cheng)(cheng)，混(hun)(hun)(hun)合用(yong)(yong)藥(yao)(yao)也能對抗(kang)藥(yao)(yao)性起(qi)抑制(zhi)作(zuo)用(yong)(yong)。以前，混(hun)(hun)(hun)合用(yong)(yong)藥(yao)(yao)較成(cheng)(cheng)功的方(fang)案有(you)(you)(you)：菊酯(zhi)類殺蟲劑與(yu)有(you)(you)(you)機(ji)磷(lin)類殺蟲劑混(hun)(hun)(hun)用(yong)(yong)；敵百蟲與(yu)辛硫磷(lin)混(hun)(hun)(hun)合使用(yong)(yong)；機(ji)油乳劑與(yu)有(you)(you)(you)機(ji)磷(lin)殺蟲劑混(hun)(hun)(hun)用(yong)(yong)等。
必須注意的是，混配農藥(yao)也不能長期單一使用(yong)，要輪換(huan)用(yong)藥(yao)，否則，同樣(yang)有引(yin)起(qi)抗藥(yao)性的危險，甚至引(yin)發(fa)害蟲產生(sheng)多種抗藥(yao)性。
三、農(nong)(nong)藥(yao)(yao)(yao)的(de)間(jian)(jian)斷使用(yong)或停(ting)用(yong)當一種農(nong)(nong)藥(yao)(yao)(yao)已經(jing)引(yin)(yin)發了(le)某(mou)種害蟲的(de)抗(kang)(kang)藥(yao)(yao)(yao)性(xing)以后，如在一段時間(jian)(jian)內停(ting)止(zhi)使用(yong)該農(nong)(nong)藥(yao)(yao)(yao)，則害蟲的(de)抗(kang)(kang)藥(yao)(yao)(yao)性(xing)會逐(zhu)漸減退甚至消失。如某(mou)些有(you)機磷農(nong)(nong)藥(yao)(yao)(yao)引(yin)(yin)起紅(hong)蜘(zhi)蛛的(de)抗(kang)(kang)藥(yao)(yao)(yao)性(xing)，經(jing)過若干年(nian)停(ting)用(yong)后，紅(hong)蜘(zhi)蛛的(de)抗(kang)(kang)藥(yao)(yao)(yao)性(xing)可基本消失。這樣(yang)，藥(yao)(yao)(yao)劑的(de)作用(yong)仍可恢復。
四、添加(jia)增(zeng)效(xiao)(xiao)劑在(zai)農藥中加(jia)入(ru)增(zeng)效(xiao)(xiao)劑，可(ke)明顯(xian)起(qi)到(dao)活(huo)化農藥、提高藥效(xiao)(xiao)、延緩和抑制害蟲(chong)(chong)產生抗藥性的(de)作用。如在(zai)氧(yang)化樂果(guo)中加(jia)入(ru)少量柴油防治蚧(jie)殼(ke)蟲(chong)(chong)，可(ke)溶蝕蚧(jie)殼(ke)，使農藥進入(ru)害蟲(chong)(chong)體內，克(ke)服了蚧(jie)殼(ke)蟲(chong)(chong)對(dui)氧(yang)化樂果(guo)的(de)抗藥性。除油類物質外(wai)，常用的(de)增(zeng)效(xiao)(xiao)劑還有中性洗衣粉(fen)、豆漿(jiang)、植物油等。
五(wu)、多樣化(hua)的施(shi)(shi)藥(yao)(yao)(yao)方法(fa)(fa)(fa)(fa)農藥(yao)(yao)(yao)的使用(yong)方法(fa)(fa)(fa)(fa)除了常規的噴霧外(wai)，還可采用(yong)其他方法(fa)(fa)(fa)(fa)，如拌毒土(tu)、制毒餌、土(tu)壤施(shi)(shi)藥(yao)(yao)(yao)、涂藥(yao)(yao)(yao)、滴藥(yao)(yao)(yao)、煙熏等，不同的用(yong)藥(yao)(yao)(yao)方法(fa)(fa)(fa)(fa)交替進行，有助于(yu)預防和克(ke)服害蟲產生抗藥(yao)(yao)(yao)性。
