The Harmful Effects of Phytophagous mite ( Tetranychus urticae Koch) on Some Botanical Characters of Grapevine Plant ( Vitis vinifera L.) and Releasing The Predatory mite ( Typhlodromips capsicum Mostafa)

摘要

This experiment was carried out under field conditions (inside cages) during the two successive seasons of2011 and 2012, to investigate some morphological, physiological and anatomical structure effects of infestationwith phytophagous mite (Tetranychus urticae Koch) and the results of releasing the predatory mite(Typhlodromips capsicum Mostafa) at two levels. Infestation of grapevine by phytophagous mite caused asignificant reduction in morphological characters, i.e., branch length, number of leaves/branch, fresh and dryweights of leaves/branch, fresh and dry weights of stem/branch as well as average leaf area compared withuninfested plants. In addition, the infestation with phytophagous mite lead to the significant decrease inphysiological characters [chlorophyll a,b and total (a+b), total carbohydrates ratio and N, P, K ratios] comparedwith uninfested plants. Also, the histological measurements of stem and leaf of grapevine plants infested byphytophagous mite, compared with uninfested plants. There was a decrease in the anatomical characters of thestem and leaf. Moreover, the highest population of all stages of phytophagous mite (adults, immatures and eggs)on infested grapevine leaves were recorded on plants without predatory mite. The numbers were decreasedespecially with level of four individuals / branch, which led to improve in botanical characters and decreasedthe harmful effects of phytophagous mite of grapevine plants.