بررسي اثر اسيديته آب روي كارايي حشره‌كش‌هاي اسپيروتترامات و ايميداكلوپرايد عليه پسيل معمولي پسته Agonoscena pistaciae در شرايط صحرايي

The effect of water pH on efficiency of spirotetramat and imidacloprid against Agonoscena pistaciae under field conditions

يكي از مسائل مهمي كه روي كارايي حشره‌كش‌ها بر عليه پسيل معمولي پسته،Agonoscena pistaciae Burckardt and Lauterer (Hemiptera: Aphalaridae) مهم‌ترين آفت از گروه آفات درجه اول پسته ايران، موثر است، اسيديته آبي است كه براي سم‌پاشي استفاده مي‌شود. در ‌اين پژوهش اثر حشره‌كش‌هاي اسپيروتترامات (مونتو®SC 10%) و ايميداكلوپرايد (كنفيدور®SC 35%) به‌همراه تركيبات كاهنده اسيديته آب (ركتيفاير® و سيترال pH ®)، بر كاهش انبوهي جمعيت تخم و پوره‌ي پسيل معمولي پسته در قالب طرح بلوك‌هاي كامل تصادفي در چهار تكرار بررسي شد. نمونه‌برداري يك روز قبل و 3، 7، 14، 21 و 28 روز پس از سم‌پاشي انجام شد. نتايج نشان داد كه اضافه نمودن سيترال pH و ركتيفاير، تاثير معني‌داري بر افزايش كارايي حشره‌كش‌هاي اسپيروتترامات و ايميداكلوپرايد، براي كاهش جمعيت تخم نداشت و تنها در هفت روز بعد از سم‌پاشي، تركيب ايميداكلوپرايد + ركتيفاير (91/58 درصد كاهش جمعيت تخم) سبب افزايش معني‌دار كارايي آن شد. نتايج تاثير تيمارهاي مختلف روي جمعيت پوره پسيل معمولي پسته نشان داد كه در تمام زمان‌هاي نمونه‌برداري ميزان تاثير حشره‌كش‌ به‌همراه مواد كاهنده اسيديته بيش‌تر از ميزان تاثير كاربرد حشره‌كش به‌تنهايي بود، اما تاثير آن‌ها معني‌دار نبود و فقط در سه و هفت روز بعد از تيمار، تركيب ركتيفاير توانست تاثير حشره‌كش‌ ايميداكلوپرايد را به‌طور معني‌داري افزايش دهد، به‌طوري‌كه درصد كاهش جمعيت پوره در تيمار ايميداكلوپرايد + ركتيفاير در روزهاي مذكور نمونه‌برداري 90/13 و 93/23 درصد ثبت شد.

Background and Objectives Water pH is one of the most important factors that affects the inefficiency of insecticides against the common pistachio psyllid, Agonoscena pistaciae Burckardt and Lauterer (Hemiptera: Aphalaridae), as the most important pest in Iran's pistachio orchards. Materials and Methods In this study, the effect of insecticides including spirotetramat (Monvento® SC 10%) and imidacloprid (Confidor® SC 35%) and pH reducing agents, such as Rectiphier® and Citral pH®, on the reduction of population density of eggs and nymphs of common pistachio psyllid were investigated under field conditions. The experiment was carried out as randomized complete block design with four replications. The samplings were done one day before and 3, 7, 14, 21 and 28 days after spraying. Results The results indicated that adding Rectiphier and Citral pH to the insecticides had no significant effect on increasing the efficacy of spirotetramat and imidacloprid on eggs population of pistachio psyllid, and only on 7 days after spraying, adding of Rectiphier to imidacloprid significantly increased the efficiency of the insecticide, and reduced the amount of oviposition of A. pistaciae (91.58%). The results of the effect of different treatments on nymphs population density of A. pistaciae showed that the effect of insecticides + pH reducing agents was more than application of insecticides alone, but their effect was not significant, and only on 3 and 7 days after spraying, Rectiphier significantly increased the effect of imidacloprid. The reduction of nymphal population densities in imidacloprid + Rectiphier treatment were 90.13% and 93.23%, on those sampling dates, respectively. Discussion PH reducers (Rectifier and Citral pH) could have the potential to increase the efficacy of spirotetramate and imidacloprid or other insecticides to control A. pistaciae and produce healthy crops, reduce costs, environmental hazards and side-effects on natural enemies and to minimize application of chemical insecticides. However, more research is needed with regard to the effect of different compounds of pH reducer, different concentrations of those compounds and also the effect of these compounds on different water pH.