Evaluating the Role of Potassium Silicate and Bordeaux Mixture in Enhancing Closer Insecticide Efficacy Against Woolly Apple Aphid (Eriosoma lanigerum)

• Mahmood mofeed al-qasimi1*, Awad jasim al-kalash2

  Author

This study aimed to field test the effectiveness of Closer insecticide with two adjuvants, potassium silicate and Bordeaux mixture, against woolly apple aphid (Eriosoma lanigerum Hausmann) on two local cultivars (Sharabi and Ibrahimi) of apple. grown in Al-Alam District, Salah al-Din Governorate, Iraq. A field experiment was laid out in a randomised complete block design (RCBD) with three replications for each cultivar. The following six treatments were evaluated: Control (Water Only), Potassium Silicate, Bordeaux Mixture, Closer insecticide (sulfoxaflor), Closer + Potassium Silicate and Closer + Bordeaux Mixture. Colony counts were done at 3, 7, 14 and 21 days after treatment. The treatment Closer + Bordeaux mixture resulted in the greatest reduction of waxy colony density at 21 days with 94.26% and 92.76% for Sharabi and Ibrahimi cultivars, respectively. Closer + potassium silicate was the next best combination with a reduction of 88.66% and 87.58% respectively as compared to 79.78% for Closer alone. The Sharabi cultivar always gave a higher response level than the cultivar called Ibrahimi. 99.83% sequence identity was obtained with Eriosoma lanigerum voucher CNC#HEM028323 (KR043025.1) using the mitochondrial COX1 gene; while the Iraqi isolate (Aw.) was identical.The sequence obtained from J-3) was and is deposited in GenBank with accession number OP776810.1. The findings indicate that the use of Closer in conjunction with Bordeaux mixture or potassium silicate was effective as strategy in the integrated pest management (IPM) programme to control woolly apple aphid (WAA) in the apple orchard

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