International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

To establish the influence of irrigation and mineral regime on the growth index of tomatoes, the irrigation and fertilization schedules of three genotypes of tomatoes grown in an unheated steel and glass greenhouse in an experimental field of MVCRI – Plovdiv, Bulgaria, were examined. Environmentally friendly and water-saving irrigation techniques were used. Different irrigation rates were applied starting from full satisfaction of the crop water requirements to irrigation and with 25% reduction and 25% increase in irrigation rates and three fertilization rates respectively – optimum with 25% reduction and 50% increase.
After processing the results, the growth index showed an increase in the irrigation rate by 25% above the optimum growth in all three tomato cultivars included in the experiment. At the same time, no such relationship was observed when the fertilization rates were changed. The exception was the cultivar ‘Hayet,’ in which a decrease in fertilizer rate was also associated with a higher growth index, close to that of the optimum fertilizer regime. At the same time, the combination of increasing or decreasing the irrigation rate and fertilization did not have a positive effect on growth.

In order to determine the influence of different rates of irrigation and fertilization on the growth, yield, and some yield-related characteristics of three genotypes of tomatoes, research was carried out at IVCM – Plovdiv in an unheated steel-glass greenhouse of the “Venlo” type. The experiment was carried out with three modes of irrigation: optimal – 100%, reduced – 75%, and increased – 125%, using water-saving irrigation technologies and three modes of fertilization – optimal – 100%, reduced – 75%, and increased fertilization – 150%. The amount of watering and irrigation norms, the number of waterings for the growing season of greenhouse tomatoes were determined based on soil type, and climatic conditions in the region of Plovdiv. An optimal or high irrigation rate combined with reduced or optimal fertilization leads to maximum yields in all three tomato varieties. A specific reaction of the variety was observed – in “Hayet” and “Pink rock ”varieties, maximum yields (14.1 t/ha and 8.8 t/ha) were obtained in the variants with 100%/75%, while in the “Malduo” variety, the highest yield was obtained (8.6 t/ha) in the variant with 125%/100%, irrigation/fertilizer rate. In the three studied varieties of tomatoes, the lowest yield was reported when the irrigation rate was reduced by 25%, which shows that the reduction of the irrigation rate by 25% is within the limits of the critical, while the reduction of the fertilizer rate by 25% is permissible.