Chaika O. Agroecological substantiation of the system spring barleyseed crops protection against diseases under the conditions of Polissya

The thesis studies the spread, harmfulness and agents depending on the ecological factors under the conditions of Polissya as well as the improvement of the system of spring barley seed crops protection against of spring barley mildew, leaf spotting and root rot under the conditions of Polissya. The dependence of the above diseases development on the hydrothermal coefficiend (HTC) level has been established. Mildew, lesf spotting and root rot development depending on the elements of fertilizer application and soil cultivation systems has been investigated and spring barley varieties which are most resistant to the above diseases have been revealed. The author determines the most efficient seed trearers (Sumi 8 FLO, suspension concentration (sc) - 1.7 l/t and Rostok, ec - 1 l/t), fungicides for crops treatment (Reх, sc/ - 1 l/ha and Impact 25 SC, sc - 0.5 l/ha combined with the biopreparation (Micosan H, 3% v.r.k., 4 l/t and Micosan B, 3% v.r.k., 5 l/ha) against mildew, leaf sporring and root rot. The possibility of reducing fungicide doses owing to the inclusion of biopreparations in the protection system has been proved. On the basis of the tradional system improvement the agroecologically feasible system of spring barley seed crops protection against mildew, leaf spotting and root rot has been developed. Its biological effectiveness against the above diseases and influence on some groups of soil biota, grain yield increase and its quality improvement have been shown. The energy and economic feasibilite of the above system application has been substantiated.