Evaluation of the effects of irrigation and fertilization on tomato fruit yield and quality: a principal component analysis

Irrigation and fertilization are key practices for improving the fruit quality and yield of vegetables grown in greenhouses. We carried out an experiment in a solar greenhouse spanning three consecutive growing seasons to evaluate the effects of irrigation and fertilization on the fruit yield and quality, water use efficiency (WUE) and fertilizer partial factor productivity (PFP) of tomatoes. Interactions between irrigation and fertilization treatments and individual factors of irrigation and fertilization significantly (p < 0.01) affected fruit yield, WUE and PFP. WUE and fruit yield and quality were more sensitive to changes in irrigation than to changes in fertilizer, but PFP showed the opposite trend. Interestingly, the treatment with moderate irrigation (W2: 75% ET (0)) and high fertilizer level (F1: 240N−120P(2)O(5)−150K(2)O kg ha(−1)) was twice ranked first after a combinational evaluation. In conclusion, the proper application of drip fertigation (W2F1) may be a good compromise for solar greenhouse-grown tomatoes with regard to fruit yield and quality, WUE, and PFP. The present study sheds light on the contributions of these practices, clarifies their impacts, and provides a basis for evaluating and selecting better management practices for growing greenhouse vegetables.