Performance of Tomato during Moisture Stress Condition to Soil Amended with super-absorbent Polymer at Kabanyolo

Abstract

In Uganda Tomato production is mainly done during the two rain seasons, with limited production in dry conditions due to limited soil moisture. Benefits of irrigation cannot be fully realized if moisture cannot be retained by the soil due to very high temperatures during such periods or in such zones. Super-absorbent polymer (SAP) has been prescribed as moisture retainer in soils that would accelerate crop growth due to continuous moisture availability. Therefore, the aim of this study was to assess the effect of SAP application on the growth and yield components of tomatoes in a moisture stressed conditions. Three rates of SAP 5g, 7.5g, 10g o per plant alongside mulch and a control (no SAP applied) were assessed in CRD with 15 replicates. Data was taken on seedling survival rate, plant height every 14 days, fruit number and weight at harvest. Mulch exhibited the highest survival rate (93.3%) followed by SAP level 5g per plant (86.7%) and the control had the least (40%). Initially there was no significant difference in plant height (P= 0.9039). Two weeks after Planting and application of SAP there was a significant difference between height of tomato plants with different water retention methods (P= 2.11827E-06). SAP level 5g per planting hole had the highest mean height while the control had the lowest mean height. The significant difference in height was maintained even at 4 weeks (P= 0.01649). There was also a significant difference in average tomato growth at different rates of the Polymer(P=0.00671). Among treatments SAP concentration 5g achieved the highest average growth while the control had the lowest average growth. There was a significant difference in the number of fruits for the different soil water retention methods (P=0.03660) where mulch had the highest mean number of fruits (18 fruits) while the control had the lowest. Total tomato yield per plant differed significantly across the different treatments (P=0.00051) with mulch having the highest mean yield per plant. Average tomato weight per plant differed significantly at different rates of super-absorbent polymer(P=9.26E-05) where SAP level 10g achieved the highest mean tomato weight. The results indicated that SAP application significantly increased growth and yield of tomatoes under water stressed conditions by moderating the effect of water deficit on the measured parameters. The results also indicated that SAP is fairly better than mulch as means of ensuring moisture conservation under dry conditions. Application of 10g of SAP per planting hole produced the highest mean average weight of tomato and it is therefore the best SAP application rate for tomato production.