This study was conducted to determine the most suitable irrigation frequency and quantity for the greenhouse-grown indigenous leafy vegetable, Cucumis myriocarpus, and herbage crop, Cucumis africanus. Four irrigation intervals were tested, 2, 3, 4 and 5 days, arranged in a randomised complete block design. Total irrigation quantities, plant water consumption, rate of progress towards flowering and vine length varied amongst the irrigation frequency treatments, whereas biomass partitioning to botanical fractions differed only in the roots of C. myriocarpus. The highest yields were obtained from treatments employing the middle (3 and 4 days intervals) frequencies and quantities of irrigation. Results of the study suggest that proper management strategies of irrigation amount and frequency can improve the quality and quantity of C. myriocarpus and C. africanus for sustainable rural smallholder crop production system augmentation in the Limpopo Province of South Africa.

Greenhouse studies were conducted to compare wild watermelon (Cucumis africanus) and wild cucumber (C. myriocarpus) under five irrigation frequencies. The irrigation frequencies were 0, 1, 2, 3, 4 and 5 days, where 0 day implied daily irrigation. Samples were collected at T1 (70 days) and T2 (84 days) to determine (1) relative growth rate (RGR), (2) unit leaf rate (ULR), (3) leaf area ratio (LAR), (4) leaf weight fraction (LWF) and (5) specific leaf area (SLA) using the classical growth analysis tool. Generally, when using RGR and ULR, the model suggested that C. africanus had superior growth rate than C. myriocarpus, whereas for LAR and LWF C. myriocarpus was superior, variable results for SLA. In conclusion, C. myriocarpus exhibited potential for leafiness, a trait that is desirable since the plant leaves are harvested and used as a leafyvegetable by smallholder farming communities in the Limpopo Province, South Africa.

A study was conducted during the 2009/10 summer growing season to determine the effect of varying irrigation frequencies and NPK fertilizer application rates on biomass yield and partitioning to plant fractions of Cucumis myriocarpus. The experiment was laid out in a split-plot design arrangement and replicated five times. Three irrigation frequencies, namely, 2, 4 and 6 day interval, were the main plots and sub-plot treatments were NPK fertilizer levels combined in a ratio 3:2:1 (60-40-20 kg NPK ha -1 , 120-80-40 kg NPK ha -1 and 180-120-60 kg NPK ha -1 ) and a control treatment of 0 Kg NPK ha -1 . Higher and lower total and plant fraction biomass yield were observed in the intermediate category of four day irrigation frequency, but varied among the different rates of NPK fertilizer rate. In conclusion, the results indicate that the plant can produce adequately under greenhouse conditions with moderate to limited water supply and provision of supplemental nutrients.

In South African traditional medicine the roots, stems, leaves or fruit of wild cucumber, Cucumis africanus, are used as an emetic, purgative or enema for various ailments. The fresh young leaves are eaten as a pot herb by many rural people. A study was conducted to show the effects of irrigation frequency and NPK fertilizer application rate on leaf yield characters, harvest index and resource use efficiencies of C. africanus. The experiment was laid out in a splitplot design arrangement and replicated three times. Three irrigation frequencies, namely, 2, 4 and 6 days, were assigned as main plots and Nitrogen, Phosphorus and Potassium (NPK) application rates of 0 Kg NPK ha -1 , 60-40-20 kg NPK ha -1 , 120-80-40 kg NPK ha -1 and 180-120-60 kg NPK ha -1 were sub-plots. EYR, YER, AHI and SHI were significantly (P˂ 0.05) higher in the intermediate treatment of four day irrigation frequency and 120-80-60 kg NPK ha -1 , while WUE and NUE were pronounced in the six day irrigation frequency and 180-120-60 kg NPK ha -1 . WUE was significantly (P˂ 0.05) affected by both irrigation frequency and the interaction between irrigation frequency and NPK application rate, while NUE responded to NPK level only. Keywords: edible yield rate, yield efficiency rate, harvest index, water use efficiency.

Wild-watermelon, Cucumis africanus, is among important indigenous crop plants in rural Limpopo Province of South Africa, primarily used as an ethno-botanical crop and a leafy green vegetable. An experiment laid out in a split-plot design and replicated five times was conducted at the Horticultural Research Unit, University of Limpopo, South Africa. The objective was to study the effects of irrigation frequency (2, 4 and 6 day interval) and fertilizer application rate of nutrient mixture containing nitrogen, phosphorus and potassium (NPK) (0 Kg NPK ha-1 , 60-40-20 kg NPK ha-1 , 120-80-40 kg NPK ha-1 and 180-120-60 kg NPK ha-1) on leaf and non-leaf yield characters of C. africanus. The treatment of four day irrigation interval and 120-80-40 kg NPK ha-1 application rate produced significantly higher (P ≤ 0.05) vegetative yield characters and biomass of plant fractions than the extreme treatments of short two day irrigation intervals and low 60-40-20 kg NPK ha-1 ; and long six day irrigation intervals and 180-120-60 kg NPK ha-1. In conclusion, the results of the study indicate that C. africanus can be successfully grown using conventional production methods and supply rural households with good yields of a leafy green vegetable as well as providing raw materials needed for ethno-botanical purposes.