Influence of planting density per hole drip irrigation on selected nutrient elements in indigenous leafy vegetablewild cucumber (Cucumis myriocarpus)

Abstract

Increasing planting density/hole drip irrigation (HDI) could improve vegetative growth of indigenous leafy vegetables at the expense of nutrient elements due to intra-specific competition. The objective of the study was to determine the influence of planting density/HDI on selected immobile (Ca, Mg) and mobile (K, P) nutrient elements in wild cucumber (Cucumis myriocarpus Naude.) indigenous leafy vegetable. A field trial was setup over two seasons using 0.6 m intra-hole drip tubes, with inter-row spacing at 1.0 m. Treatments were arranged in a randomised complete block design, with eight replications. At 56 days after transplanting, Ca, Mg, K and P in leaf tissues over planting density/HDI exhibited quadratic relations, with Ca and Mg each suggesting strong seasonality effects, which were not observed in K and P. Optimisation suggested that nine plants/HDI resulted in intensive intra-specific competition for the four nutrient elements. In conclusion, findings in the planting density of C. myriocarpus per HDI suggested some seasonal effects on Ca and Mg, without any such effects on K and P, with strong intra-specific competition, necessitating further empirically-based trials to establish the fertiliser requirements for C. myriocarpus in the proposed planting density system.