Ventilation and irrigation management strategy for tomato cultivated in greenhouses

Abstract

Appropriate ventilation and water management strategy are beneficial to boost crop yield and quality in greenhouses, and their optimization is crucial for improving water use efficiency (WUE). Here, we set up three irrigation levels based on measurements of the cumulative pan evaporation (AEpan) (i.e. 0.9 AEpan, 0.7 AEpan, and 0.5 AEpan), and three ventilation modes through opening the greenhouse vents at different location (VST: open the both roof and south vents; VT: open the roof vents only; VS: open the south vents only) to reveal the effects of ventilation mode and irrigation amount on picking, yield (Y), evapotranspiration (ET), WUE and quality of tomato grown in a solar greenhouse. Nine treatments were split block design with ventilation mode as main treatment and irrigation amount as vice treatment. Each treatment was replicated three times. Results showed that harvesting time of tomato were substantially influenced by ventilation mode as a result of interior temperature differences. The VT treatment was beneficial to early maturity of tomato than the VST and VS treatments. The proportion of VT in the first three harvesting was ~36.8 % and ~26.3 % higher than of VST and VS, respectively. Irrigation amount had a marked effect on ET, Y, WUE, irrigation water use efficient (IWUE), and irrigation water compensation (Irc). Here, ET, Y and Irc of K0.9 were 51.7 % and 69.8 %, 11.0 % and 19.6 %, 7.0 % and 13.5 % higher than those of K0.7 and K0.5 treatments, respectively, while the WUE and IWUE were 13.1 % and 24.8 %, 18.6 % and 28.6 % lower than K0.7 and K0.5, respectively. However, the significant interaction between ventilation and irrigation were only found on Y, WUE and IWUE. Both ventilation and irrigation treatments had considerable effect on soluble solids (TSS), Vc and organic acid. TSS could represent the comprehensive quality of tomato, because TSS was very significantly positively correlated with the comprehensive quality scores. A better combination of ventilation and irrigation was recommended as VST × 0.7 AEpan by using the TOPSIS method based on a compromise of Y, quality and WUE.