Effects of Irrigation Interval and Irrigation Level on Growth, Photosynthesis, Fruit Yield, Quality, and Water-Nitrogen Use Efficiency of Drip-Fertigated Greenhouse Tomatoes (Solanum lycopersicum L.)

• Published in: Agronomy (Basel) Vol. 15; no. 5; p. 1068
• Main Authors: Zhang, Hongxin, Cao, Hongxia, Zhao, Zhiming, Dou, Zhiyao, Liao, Zhenqi, Bai, Zhentao, Li, Sien, Zhang, Fucang, Fan, Junliang
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.05.2025
• Subjects: Agricultural production; Analysis; Ascorbic acid; Crop yield; Crops; Drip irrigation; Efficiency; Evapotranspiration; Fertilizers; fruit quality; Fruits; Greenhouses; Growth; Intervals; Irrigation; Irrigation effects; Irrigation scheduling; irrigation strategy; Irrigation water; Leaf area; Leaf area index; Leaves; net photosynthetic rate; Nitrogen; Organs; Photosynthesis; Plant growth; Plants; Plants (botany); Potassium; Productivity; Stems; Sugar; Sustainable production; tomato yield; Tomatoes; Water; Water consumption; water productivity; Water resources; Water shortages; Massachusetts; China
• ISSN: 2073-4395; 2073-4395
• DOI: 10.3390/agronomy15051068

The inefficient irrigation strategy is an important factor affecting the yield and water productivity of tomatoes in greenhouses, seriously hindering the development of the cultivation industry. While the impact of irrigation level on tomato growth and yield has been extensively studied, irrigation interval, another crucial component of irrigation schedule, as well as their interaction, remain poorly explored. There were four irrigation levels (W1: 125% ETc, W2: 100% ETc, W3: 75% ETc, and W4: 50% ETc; ETc represented crop evapotranspiration) and three irrigation intervals (D1: 4-day interval, D2: 7-day interval, and D3: 10-day interval), aiming to explore the effects of different irrigation intervals and levels on the performance of tomatoes. Here, we showed that the moderate increases in irrigation level and interval promoted root growth, improved nitrogen uptake and distribution, and enhanced plant height, stem diameter, leaf area index, and aboveground biomass, thereby promoting the net photosynthetic rate of plants and fruit yield. The fruit quality indicators of total soluble solids, vitamin C, and soluble sugar decreased with increasing irrigation level but increased with decreasing irrigation interval. Higher irrigation levels increased tomato water consumption and resulted in lower water-nitrogen use efficiency. Overall, compared with W2D2 and W2D3, the yield of W2D1 increased by 8.0% and 26.1%, respectively, and the water productivity increased by 5.7% and 19.3%, respectively, and the soluble sugar increased by 7.1% and 17.5%, respectively. In addition, nitrogen uptake in tomato organs increased and then decreased with the increase of irrigation level, while it consistently increased with decreasing irrigation interval. At the harvest period, the nitrogen uptake in plant organs followed the order of fruit > leaf > stem. Taken together, W2D1 (100% ETc and 4-day interval) is the recommended irrigation strategy for this experiment, which can provide a theoretical basis and technical support for the sustainable production strategy of greenhouse drip irrigation tomatoes.