Effect of Fertilizer on Cucumber (Cucumis sativus L.) under Greenhouse Conditions

Cucumber (Cucumis sativus L.) is regarded as an important vegetable crop in the tropics and it is one of the widely consumed member of Cucurbitaceae family. It ranks fourth after tomato, cabbage and onion in Asia. However, like any crop, cucumber requires appropriate nutrient and water management for proper growth and good yield, thus, the need for fertilizer application to achieve high yield is crucial. Therefore, the primary objective of this study was to examine the effect of fertilizer [CAN (CaCO3 + NH4NO3)] levels on the growth and yield potential of cucumber under greenhouse conditions. Cucumber (variety: Ashely) and different levels of fertilizers [CAN (CaCO3 + NH4NO3)]; zero (T1), low (T2), medium (T3) and full strength (T3) were applied. Consequently, fertilizer levels exhibited higher plant growth for treatments (T2, T3, and T4) than the control (T1). Highest number of flowers were registered in T4 (32.33) followed by T2 and the lowest number of flowers for T1. . Relatively, while treatment T1 (control) had the least germination percentage (86.66%), treatment (T2) scored the highest germination percentage (94.6%) followed by treatment T4 (93.3%) and T3 (92.0%). Surprisingly, T2, T3, and T4 showed notable increase in fruit length, fruit diameter and dry weight. Comparatively, T2 had better performance in term of crop growth, development and yield, T4 was not recommended since it was not cost-effective to use high level of fertilizer. Additionally, the results also revealed that the lower level of fertilizer had significant impact on various growth stages of cucumber. It was clearly noted that although soils in South Sudan are fertile, there is need to apply, depending on soil health, minimum doses of fertilizer to improve crop performance. The result of this research showed that lower level of [CAN (CaCO3 + NH4NO3)] fertilizer and drip irrigation especially for off-season production had positive effect on growth and yield of cucumber obtained per unit area.