Leaf area index assessment for tomato and cucumber growing period under different water treatments

Abstract

The aim of this study was to assess the leaf area index (LAI) of tomato and cucumber using an AccuPAR-LP-80-ceptometer to find the influence of irrigation. LAI was also determined by destructive sampling for comparison. The research was conducted at the Liaoning Water Conservancy Institute, North China in 2016. A randomized block design was used to test the influence of four treatments corresponding to field water capacity. Full irrigation (W_1.0), 15% (W_0.85), 25% (W_0.75) and 35% (W_0.65) water deficit were applied using the drip system. Regression model was developed to estimate LAI in response to irrigation. The results show that there is no difference between the two methods. The highest LAI obtained for tomato and cucumber was 5.21 and 3.21 m²/m², respectively, with W_0.85 at 70-days after transplanting, which corresponds with destructive results. This result was found 11% higher and equal compared with W_1.0 for tomato (4.62) and cucumber (3.21), respectively. For both crops, LAI was found significantly influenced at 50-days after transplanting. It also indicated that LAI significantly influenced (by 15%) deficit irrigation for both crops and methods that achieved the highest yield. The predicted LAI was obtained best-fitting with the observed values, which indicated that the AccuPAR-ceptometer is suitable to be used.