Growth and Yield Response of Tomato Cultivars to Nitrogen Fertilizer and Organic Amendments and Modelling Climate Impact

Abstract

Tomato production in The Gambia is ranked second after onion in terms of production acreage and highly consumed. An agronomic trial was conducted in 2021 and 2022 at Horticulture unit in Yundum. The main objective was to enhance tomato production in The Gambia through determination of effects of organic and inorganic fertilizers as well as model climate impact on the performance of Mongal F1 and Thorgal F1 tomato varieties. The design of the experiment was split-plot design with three replications and four treatments such as Leucaena leaves, Poultry bedding, Nitrogen fertilizer and Leucaena leaves + Poultry bedding. Constant increase in temperature, wind and decrease in rainfall, an unpredictable rainfall pattern and prolonged drought are effects causing severe dropping of flowers and rotting of tomato fruits. Use of synthetic pesticide, planting of trees and fertilizers are use as adaptation strategies. Mongal F1 tomato variety had performed better than Thorgal F1. Poultry bedding and Leucaena leaves has increased soil fertility than Leucaena leaves + poultry bedding and Nitrogen. Response to growth and yield, Leucaena leaves and poultry bedding performed better than Nitrogen and Leucaena leaves +poultry bedding. The results from DSSAT (CROPGRO) model shows the existence of climate change such as unpredictable and erratic rainfall, higher temperatures etc. The model indicated that, highest amount of rainfall was recorded in September, and the lowest was in July, contrary both temperature’s solar radiations were very high in July and declined in September. In addition, days after start of simulations for tomato growth, and yield, treatments did not impacted well due to their longterm effects.