DEGREE OF DAMAGE OF PEAR VARIETIES (PYRUS COMMUNIS L.) AND CONTROL ERIOPHYES PYRI PGST. (ACARI: ERIPPHYOIDEA) IN THE FOMIN BOTANICAL GARDEN

Abstract

In 2018-2020, a study was conducted on the territory of the Academician A.V. Fomin Botanical Garden on the settlement and damage of Eriophyes pyri (Pgst.) pear leaves. The leaves of the studied varieties were selected four times during the growing season, starting from mid-May to early August. All varieties were divided into five groups, depending on the degree of colonization (score) of leaves with mites: I - very low (1 point; <5% are covered with galls), II - low (2-3 points; 5-25% are covered with galls); III - medium (4-5 points; 26-50% are covered with galls), IV - high (6-7 points; 51-85% are covered with galls), V - very high (8-9 points; > 85% are covered with galls). It was found that among the twenty-four varieties of the most damaged (8-9 points) E. pyri were three winter varieties: «Beurré Kyivskaya», «Dekanka winter», «Crymskaya winter» and Willow pear Pyrus salicifolia Pall. Three varieties «Yellow Mlievskaya», «Royal Winte»r, «Tayushchaya» were evaluated in 6-7 points of infestation of pear leaves of E. pyri, and the least damaged (1 point) were four summer varieties – «Williams Rouge Delbara», «Williams summe»r, «Ilyinka», «Clapp's Favorite». All other varieties of Pyrus communis were characterized by a weak or medium degree of E. pyri population. The most significant damage to the leaves of all studied varieties was recorded in late July. The test results of the drugs showed high efficiency of acaricides of biological origin: Fitoverm (DR aversectin C), 5% k.e. and Vertimek (d.r. abamectin), 018 k.e. This will not only inhibit the development of phytophagous, but also save predatory mites. An important problem is the development of parameters necessary for accurate calculation of the sum of effective temperatures at which the spring migration of mites from the buds. This is necessary to accurately determine the time of protective treatments against Eriophyes pyri.