ارزیابی خسارت سفید بالک (Neomaskellia andropogonis) بر صفات کیفی نیشکر در مزارع جنوب استان خوزستان

Sugarcane whitefly Neomaskellia andropogonis from the Aleyrodidae family is one of the important pests in sugarcane fields. This study was conducted in Debel Khozaei Agro-industry Company fields located in the south of Ahvaz, Khuzestan province in 2023. The studied cultivars included early-maturing cultivars (CP73-21 and CP57-614), mid-early cultivar (CP69-1062) and late maturing cultivar (CP48-103). In each cultivar, stems were divided into one of seven groups based on the number of infected leaves (0, 1, 2, 3, 4, 5, >6). Then, the syrup of the stems was extracted by a mill and brix, pol, percentage of syrup and extractable sugar were measured. The trend of brix and pol changes under the influence of the number of leaves infected with Whitefly has followed the quadratic function. In the cultivar CP 57, the amount of brix and pol decreased slightly from the control to 3 leaves infected with Whitefly. But the trend of brix changes from 4 to 6 infected leaves had a more downward slope. The highest reduction of brix and pol was observed in 6 leaves infected with Whitefly. In the cultivar CP 73, the trend of brix and pol changes was linear, so that with an increase of one unit in the leaves infected with Whitefly, brix and pol decreased by 1.32 and 0.15%, respectively. In CP 57 and CP 73 cultivars, the percentage of syrup decreased with the increase in the number of leaves infected with white blight. In cultivar CP 57, plants infected with 1 and 2 Whitefly leaves, their extractable sugar had slight changes compared to the control, but in treatments with more than 2 infected leaves, the extractable sugar changes increased with the increase in the number of infected leaves. The results also showed that in the cultivars CP 69 and CP 48, Whitefly had no effect on the quality of their syrup. It seems that due to the higher amount of sucrose in the early cultivars at the time of the pest outbreak, the amount of Whitefly damage was also higher in these cultivars.