Фітосанітарний стан основних сільськогосподарських культур органічного виробництва України в умовах змін клімату

Abstract

Climate change causes the environmental impacts on the population dynamics of insect pests, their distribution and feed. Under climate change it is especially important to assess the potential yield loss by complex of specialized pests of major organic crops in various regions of Ukraine. For increase of organic farming productivity it is necessary to improve affective control of plant pests using plant protection of organic crops. The results will also be a basis for recommendations of the best regions and the crop list for organic farming without increased risk of economic losses. The aim of the study was to determine the potential yield losses of crops for organic produce in regions of Ukraine under climate change. It was analyzed the data of pests distribution and their number in agrocenosis of Ukraine. Potential hazard of insect species was analyzed using the average economic indexes. For their calculations used ratio of actual pest quantity to the index of economic threshold of hazard. For calculation of indexes used the tables of threshold indexes of hazard of every species. The total pest damage (complex hazard) was determined by calculation the integral index of hazard. That is the sum of economic indexes of each species of harmful insect complex of crop with correction coefficient pointed out the features of plant response to damage of different pest species. Multiply index by 3% (minimal crop losses) allow estimating potential yield losses. If integrated economic index does not exceed 1, under the concept of economic threshold, crop protection against pests is not appropriate. In organic farming of Ukraine the winter wheat is a dominant cereal crop. The phytosanitary monitoring shown, that climate change had an effect on the hazard insect complex of wheat. In 1996-2004 the number of wheat fly has increased in pest complex of Forest Steppe. But a number of insects such as Hessian fly, wheat fly, corn-bug and opomyzid fly has decreased during recent years. During 2005-2011, a sharp increase of corn-bug number was recorded. But during next years, their population has decreased significantly. The transition to a state of corn-bug depression can be caused by rapid growth of cereals observed recently. By earlier harvesting a significant part of the corn-bug population does not have time to a normal physiological development and survival of the pest during the winter is reduced. Up to 2012, a number of corn ground beetles and corn bugs was more stable and varied from 0, 5 to 1, 6 individuals per square meter. In recent years the hot and dry weather and less precipitation in July – September has delayed output from diapause of corn ground beetles, decreased female fertility and caused death of eggs and larvae. The analysis allowed concluding that during the five-year period of 2011 to 2016 in conditions of climate warming a number of herbivores and the potential loss of yield of winter wheat - the main export cereal crop of organic produce of Ukraine - significantly decreased and upon the average did not exceed the threshold level. Thus, there were the favorable conditions for increase of winter wheat production using organic farming techniques without significant risk of economic losses from pests. There are risks of economic losses of organic produce of sunflower in the Vinnytsya, Kherson, Kharkov, Chernihiv, Donetsk and Kyiv regions; corn - in Kyiv, Ivano-Frankivsk, Vinnytsya, Donetsk, Luhansk, Kharkov regions; soya - in Lviv, Kharkov, Kherson, Kirovohrad, Volhynia, Vinnytsia, Ternopil, Kyiv, Dnepropetrovsk, Mykolaiv, Chernivtsi, Zaporizhzhya, Cherkasy, Rivne, Zakarpattia, Zhytomyr, Poltava regions. The organic farming of potato and cabbage requires a protection of plantations from the plant pests’ complex in all regions of Ukraine. To prevent economic losses from pests of organic crops in Ukraine the list of pesticides should check against standards of organic farming and should develop a search program of new biological agents of pest control. Keywords: climate change, organic farming, complex of plant pests, crop losses