Effect of organic amendments on tomato growth and yield under field conditions

Abstract

Tomatoes represent a crucial component of Ugandan agriculture, providing essential nutrients like vitamins A, C, and E, along with antioxidants such as lycopene. However, their growth and yield are often hampered by soil fertility issues, compounded by the limited affordability of conventional fertilizers among smallholder farmers. This study aimed to assess the impact of various organic amendments on tomato growth and yield in Wakiso District, Uganda. Conducted at the National Crops Resources Research Institute (NaCRRI) in Namulonge, Wakiso District, the study investigated the effects of organic amendments-specifically, goat manure, coffee husks, organo-yield fertilizers, and their combination--on key growth parameters and yield metrics. Bi-weekly measurements were taken for plant height, number of branches, number of leaves, fruit count, and fruit weight. Results revealed significant enhancements in plant growth attributes following the application of organic amendments. Notably, treatments with coffee husks (59.0±1.3) organo yield (70.8±3.3) goat manure (72.6±3.9) and their combination (69.5±1.5) led to a substantial increase in plant height compared to the control treatment (12.3 ± 0.8) (P<0.001). Goat manure) emerged as the most effective treatment for promoting plants height followed by organo yield and the combination treatment. Furthermore, the number of branches and leaves per tomato plant showed significant increase with treatments involving goat manure, organo yield, and their combination compared to the control group (P<0.01). The organo yield treatment exhibited the highest number of branches while all three treatments resulted in significantly higher leaf numbers compared to coffee husks and control. In terms of yield, the mean number of fruits harvested from plots treated with goat manure, organo yield, or their combination was statistically similar but significantly higher them those from coffee husks and control (P<0.01). Similarly, the mean fruit weight from plots treated with coffee husks was significantly higher than control (P<0.05), although similar to plots treated with goat manure, organo yield, or their combination.Moreover, organic amendments positively influenced nutrient uptake by tomato plants, with coffee husks notably enhancing nitrogen, phosphorus, potassium, and calcium uptake compared to other treatments.