The aim of the study is to determine the influence of the irrigation rate value on the vegetative development of green beans. The field experiment was conducted in the region of Plovdiv. The following variants were tested: 1) without irrigation; 2, 3 and 4 – irrigation with 30, 70 and 100% of the rate (m), respectively. The optimum irrigation (100% of the irrigation rate) is on the basis of 80% FC for the 0-40 cm layer. Results showed that irrigation increased the plant height, number and weight of leaves. An increase of the stamp and pod weight was observed, too. All parameters gave the highest values at the optimum irrigation variant (100%m). As regarded the height development of the plants and leaf weight accumulation, the number of irrigations was more important than the irrigation rate value. The 30% reduction of the irrigation rate did not affect the fresh weight of pods, except in the years with prolonged summer droughts. The 70% reduction of the irrigation rate caused significant decreasing of the values. The relationship between the fresh weight of pods and the irrigation depth is presented by a second degree function:
Y= – 0,180×2 + 0,916x + 0,270 by R2=0,764.