The phytosanitary status of sunflower crops оf north-eastern Forest-Steppe of Ukraine

Abstract

The high economic efficiency of sunflower growing contributed to a sharp increase in the sunflower planting acreage in Sumy region. The increase of cultivated areas under sunflower resulted in an oversaturation of crop rotations with this crop. The study of the phytosanitary status of sunflower crops was carried out in the basic farms of the phytosanitary security department of the Main Office of State Consumer Service (Derzhprodsluzhba) in Sumy region. The research methodology was commonly accepted.
 The main pests of sunflower crops were grey beet weevil (Tanymecus palliates Fabr.), larvae of common click beetle (Agriotes sputator L.), darkling beetle (Opatrum sabulosum L.), larvae of the western may beetle (Melolontha melolontha L.), leafcurl plum aphid (Brachycaudus helichrysi Kalt).
 The sunflower seedlings were damaged grey beet weevil, darkling beetle. The most widespread soil pests were the larvae of the western may beetle and larvae of common click beetle.
 Leafcurl plum aphid populated sunflower crops with 6‒8 pairs of true leaves. It continued to spread across the field during the inflorescence stage and the stage of initial blossom. The highest pest colonization was observed at the edge of the field in 2015, 2017 and accounted for 16 % of the plants. In the middle of the field, the aphid colonization was lower than at the edge.
 During the years of research, the economic threshold of sunflower pest harmfulness was exceeded only in some years. Sunflower damage by grey weevil beet, larvae of common click beetle, darkling beetle, larvae of the western may beetle was weak, and their number was insignificant.
 The increase of sunflower acreage did not lead to a significant growth of pest number, the exceeding of economic threshold of their harmfulness.