Galina Patamanska and Ivanka Mitova
Institute of Soil Science, Agro-Technology and Plant Protection, Agricultural Academy, Sofia 1331, Bulgaria
Patamanska, G. & Mitova, I. (2023). Fruit yield, water and nitrogen use efficiency of tomato under drip irrigation in unheated greenhouse. Bulg. J. Agric. Sci., 29(4), 690–696
This study aimed at investigating the effects of two irrigation regimes (full and deficit irrigation), combined with four different fertilizer rates on fruit yield, irrigation water and fertilizer use efficiency of tomato (Solanum lycopersicum), grown in unheated greenhouse under mulched drip irrigation and fertigation. For two consecutive years (2019–2020), experiments were conducted on the experimental field in Chelopechene of ISSAPP „Nikola Pushkarov“, in Sofia, Bulgaria. Two irrigation rates (100% and 60% of crop evapotranspiration (ETc)), under four fertilizer rates (unfertilized, 80% NPK, 100% NPK, 120% NPK), have been served as a treatment. The results showed that greater fruit yields were obtained in fully irrigated treatments. Application of the highest fertilizer rate (120% NPK) results in highest average total yield, both in fully irrigated (104.37 t ha-1) and deficit irrigation (78.02 t ha-1) treatments. Irrigation water use efficiency was higher under deficit irrigation and its maximum value (34.87 kg m-3 for 2020 ) was obtained with the highest fertilser rate trough fertigation. The highest nitrogen use efficiency (672.14 kg kg-1) was obtained in the fully irrigated treatment with the highest fertilizer rate. The experimental results obtained in both years indicated that drip fertigation technology with appropriately selected levels of irrigation and fertilization could improve fruit yield and water and nutrient use efficiency of greenhouse tomatoes.