Field performance of spider plant (Cleome gynandra L.) under different agronomic practices.
Field experiments were carried out at Kaguvi Vocational Training Centre located in the Midlands province of Zimbabwe, to determine the effect of planting date and fertilizer types in enhancing the productivity of spider plant, an indigenous leafy vegetable. The experimental design was a split-plot arranged in a randomized complete block design (RCBD) with three blocks. The planting date was the main plot with three levels (15/10/12, 30/01/13 and 15/02/13) and the fertilizer treatments as the subplots with seven levels including a control (no fertilizer applied), 20 t/ha cattle manure, 30 t/ha cattle manure, 5 t/ha poultry manure, 10 t/ha poultry manure, 300 kg/ha Compound D +100 kg/ha ammonium nitrate and 300 kg/ha Compound D +150 kg/ha (ammonium nitrate). Growth parameters, vitamin A and C, crude protein, iron content, fresh and dry yield were significantly (p<0.05) increased by use of organic and inorganic fertilizers across all planting dates compared to the control where no fertilizers were added. The October 2012 planting date, combined with high rates of organic and inorganic fertilizers had the best response with regards to the variables measured, including the duration of the harvest period which was nine weeks, compared to the January and February planting dates where harvesting was for six weeks. The inorganic fertilizers provided readily available nutrients for uptake by the plants while the long production period for the October 2012 planting date enabled the organic manures (cattle and poultry manure) adequate time to release the nutrients for uptake, compared to the January 2013 and February 2013 planting dates. It can be concluded that there is merit in staggering the planting dates while using organic and inorganic fertilizers as the practice results in an extended harvest period. High rates of both inorganic and organic fertilizers are recommended for the different planting dates as follows; 30 t/ha cattle manure, 10 t/ha poultry manure, 300 kg/ha Compound D +100 kg/ha ammonium nitrate and 300 kg/ha Compound D +150 kg/ha ammonium nitrate.