Role of Foliar Application of Organic Liquid Fertilizers Fortified with Phosphorus and Calcium in Tomato Yield and Fruit Quality

This study was conducted in Al-Nakhil Station - Al-Najaf governorate/Iraq during the growing season of 2021. The study aimed to identify the role of foliar application with organic liquid fertilizers rich in phosphorous and calcium in some indicators of yield and fruit quality of the limited-growth hybrid tomato (OULA F1). The field trial comprised two factors represented by phosphorous and calcium fertilizers and was setup as a factorial experiment with three replications according to a Randomized Complete Block Design (RCBD). The first factor included spraying of phosphorous as NPK with three concentrations (0, 1, 2) ml.L-1, and the second factor was three concentrations of calcium spray (0, 1.25, 2.5) ml.L-1. Two-way ANOVA was performed and the averages of the treatments were compared according to the LSD test at a probability level of 0.05. The results showed the superiority of spraying treatment with organic liquid fertilizer rich in phosphorous at a concentration of (2 ml.L-1) for the measured indicators (fruit set percent, fruit number per plant, and total yield) reached the maximum average (69.37%, 36.32 fruits.plant-1, 44.37 t.ha-1), respectively, except for fruit weight was the highest (80.56 g.fruit-1) at a concentration (1 ml.L-1). Further, tomato plants sprayed with organic calcium fertilizer at (2.5 ml.L-1) resulted in the maximum average for yield parameters (fruit set 74.24%, fruit number 37.77 fruits.plant-1, fruit weight 82.38 g.fruit-1, total yield 47.88 t.ha-1), compared to the control treatment (without spray). There were significant variations between tomato treatments in terms of fruit quality indicators, where the high concentration of organic NPK fertilizer fortified with P has improved percentages of N, P, and K in tomato fruits as well as vitamin C content in fruits (1.53%, 0.43%, 2.09%, and 21.87 mg. 100 ml-1 fresh juice), consecutively, in comparison with non-sprayed plants. However, the fruit Ca and fruit firmness reached the highest average (0.80% and 2.92 kg.cm2) at the concentration (1 ml.L-1) of P fertilizer. In addition, all fruit minerals N, P, K, and Ca, as well as fruit firmness and vitamin C content were significantly enhanced when organic Ca fertilizer was applied at a concentration of (2.5 ml.L-1) and realized the highest average (1.59%, 0.41%, 2.03%, 0.83%, 3.61 kg.cm2, 25.30 mg. 100 ml-1 fresh juice), respectively, as compared to the control. Significant effects were found in most of the measured indicators for fruit yield and quality regarding the interaction between the experiment factors.