On the problem of grain damage in the form of dark spots in field conditions when cultivating rice in Krasnodar region

Federal Scientific Rice Centre, laboratory of rice quality, 350921, Krasnodar, Russia

^* Corresponding author: tngerag@yandex.ru

Abstract

The analysis of grain damage in the form of dark spots of Russian rice varieties grown in Krasnodar region in 2011-2020 has been carried out. Rice grain was damaged during the filling period, mainly in full ripeness. The high degree of damage was the reason for the deterioration of grain quality. The degree of damage varied over the years. 2011 and 2012 were characterized by a high content of damaged grains (up to 3-20%). The degree of damage to rice grain was different in different agar-landscape zones of Krasnodar region: in the Krasnoarmeysky district it was higher than in the Abinsky. On panicles of variety Rapan without stinkbugs, one caryopsis with damage was found, while on panicles with stinkbugs, their number increased to 12.4-20.3%. In variety Kurazh, damage to caryopses in the form of dark spots on panicles with stinkbugs reached 10.1-19.1%. A significant increase in the degree of damage to rice grain stored in storage began in 2011. In 2011, the content of damaged grains increased by more than 1%, in 2012 it reached 8.3% in the Slavyansky district. Since 2013, the degree of damage to rice grain in the field began to decrease. It is concluded that the damage is associated with the pathogenic effect on the plant and the caryopsis of bug insects with a piercing-sucking mouth apparatus. Damage to caryopses was insignificant in 2015-2020.