Yield and Yield Attributes of Tomato as Influenced by Organic Fertilizer

A field experiment was established at the Botswana University of Agriculture and Natural Resources to evaluate the effects of organic fertilizer on yield and yield attributes of tomato from October 2014 to March 2015. The experiment was laid out in a randomised complete block design (RCBD) with four treatments being varying levels of organic fertilizer; 0 kg m-2, 5 kg m-2, 7.5 kg m-2 and 10 kg m-2 each replicated three times. The growth attributes measured were plant height, stem thickness, canopy diameter, number of leaves, fruits and fruit weight. Organic fertilizer application rates of 7.5 and 10 kg m−2 showed significantly (P = .05) taller plants from weeks 4 to 6 compared to other treatments. A highly significant difference in plant canopy was observed across the four application rates from weeks 1 to 5. Canopy spread was overall higher in the 10 kg m-2 application rate across all the weeks. A highly significant treatment effect was observed on leaf number with plants in the 10 kg m-2 application rate exhibiting the highest number of leaves. Stem thickness showed significance differences across treatments with the 10 kg m−2 application rate having thicker stems. A highly significant treatment effect was observed on number of harvested fruits with the 7.5 kg m-2 application rate showing higher yields between the first and fourth harvest and 10 kg m-2 application rate from fifth to sixth harvest. Organic fertilizer had a significant effect on fruit weight from first to third harvest with the 10 kg m-2 application rates having the heaviest tomato fruits. The 10 kg m-2application rate outperformed the lower rates for most measured parameters. The organic fertilizer is recommended to small-scale vegetable growers because it is affordable and abundant in Botswana.