Impact of pruning severity on the mitigation the infestation of apple trees with woolly apple aphid  Eriosoma lanigerum (Hausmann ) and on the nutrients content of leaves and fruits

Samar Dayoub*(1), Rashid Kharbotli(1) and Nabil Abokaf (2)

(1). Department of Horticulture, Faculty of Agriculture, Tishreen University

Lattakia, Syria.

(2). Department of Plant Protection, Faculty of Agriculture, Tishreen University

Lattakia, Syria

(*Corresponding author: Samar Dayoub. E-mail: samardayoub17@gmail.com ).

Received: 30/03∕2024                    Accepted:11∕ 06∕ 2024

Abstract:                                                                                                                                      

The experiment was carried out on two apple cultivars Royal gala, Granny smith and the rootstock Malus sylvestris (L.) Mill fifteen years old and grafted on M. sylvestris nine years old in Kassab orchard for seedling rootstocks of agriculture and agricultural reform directorate in Lattakia province during seasons of 2020 and 2021. The Different pruning treatments that practiced on trees were (control, slight, intermediate, and intensive pruning).  In addition to  artificial infestation was made for trees in June, the percentage of aerial infestation (AI %) of woolly apple aphid (WAA) were estimated after (4) months of making infestation. The aim of this study is estimating the effect of different pruning treatments on the percentage of aerial infestation (AI %) of woolly apple aphid (WAA) and its impact on the different nutrients content of both leaves and fruit.  The results showed that the intensive pruning increased the percentage of aerial infestation for all cultivars.  The intermediate pruning treatment was the best in comparison to other treatments in achieving the lowest value of aerial infestation for all studied cultivars. the results of the statistical analysis of treatments, there were differences between all the studied treatments wich was remarkable in the trees CVRoyal gala and with the superiority of the control treatment in comparison to other pruning treatments . the highest content of studied nutrients in the intermediate pruning wich gained in the CV ” Granny smithand M. sylvestris. Whereas was in the slight pruning treatment for the CVRoyal gala”  . the intensive pruning treatment reduced the fruit content of total solids (TSS%)  and total sugars(TS%). On the contrary increased the total acidity (TA%) for all cultivars. The best  pruning treatment was the intermediate pruning wich reduced the  total acidity (TA%) in the fruit flesh and also increased (TSS%)  and (TS%).

Keywords: Royal gala , Eriosoma lanigerum, intermediate pruning, , Malus   sylvestris, total acidity.       

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