EN
The influence of tomato growing in mulch of rye, rye with vetch, rye with vetch plus crimson clover and in mulch of rape on contents of nitrate, phosphorus, potassium, magnesium and calcium in their leaves was investigated. Damage caused by Phytophthora infestans on tomato leaves was significantly smaller on plants growing on plots with cover crops mulch than on plants from plots with bare soil. Significant correlation between Ca contents in tomato leaves with the leaf area damaged by P. infestans was stated. When Ca content in tomato leaves was increased, the leaf area damaged by P. infestans decreased.