INFLUENCE OF GRAY MOLD ON PRODUCTIVITY OF WINTER RAPE AND WINTER MUSTARD

Gray mold is a harmful disease affecting winter rape and winter mustard. The objective of the study was to determine the impact of gray mold infestation of winter rape and mustard on reduced plant productivity on leached chernozem soil in the steppe zone of the Western Ciscaucasia. The study was conducted from 2010 to 2020. The study subjects were the fungus Botrytis cinerea Pers. and winter rapeseed varieties Dragon, Elvis and Loris, and Dzhuna mustard variety. The severity of gray mold (reduced plant productivity) was calculated based on the degree of infestation. Statistical data processing was performed using the simple correlation method and Styudent’s t-test. Meteorological conditions favored for B. cinerea development in crops in the 2nd ten-day period of June in 2011, 2014, 2017 and 2020 at HTC = 1.1...2.7 in combination with high relative air humidity (63...77%). The average seed weight per pod decreased depending on the degree of plant damage by 1.1...3.1 times. The correlation between the average seed weight per pod and the damage score of winter rape and mustard by Sarepta disease is strong, linear, and inverse (negative). The simple correlation coefficients were -0.93 and -0.96, respectively, and the determination coefficients were 0.86 and 0.92. In relative terms, the disease’s damage to winter rape and mustard averaged 33.3% and 32.1%.