INFLUENCE OF AGRONOMICPRACTICES ON SEED QUALITY AND LEAF YIELD OF JUTE MALLOW (Corchorus olitorius) IN THE NORTH RIFT REGION, KENYA

Abstract

Production of Jute mallow (Corchorus olitorius) in Kenya has been low due to many reasons, some of them being poor production agronomic practices by farmers such as poorly spaced plants, incorrect fertilizer rates, incorrect seed harvesting stage and poor quality seeds. The result is that the yield has remained low, 2-4 tons/ha as compared to potential yield of 5-8 tons/ha. Observations from the Jute mallow growing areas showed that as much as 7 kg/ha instead of 5 kg/ha of seed is being used, which is required for a density of 250,000 plants/ha. This is 40% extra seed. The objective of this study was to discern effect of agronomic practices on seed quality and leaf yield of Jute mallow germplasm, in the North Rift region, Kenya. A seed collection from Kenya Seed Company, Iten, Eldoret, Kapsabet, Kitale and Kapenguria was done and information from the farmers collected using questionnaire and data analyzed using descriptive statistics. The collected seed germplasm were taken for seed quality tests on analytical purity, germination and vigour as per International Seed Testing Association. Pure seed sub-samples were then planted in green house and morphological characterization done and seed harvested and planted at two sites of Eldoret and Kitale over one season under three spacings (20 cm x 30 cm, 30 cm x 30 cm, 40 cm x 30 cm) and three fertilizer rates (0, 60, 120 kg/ha) treatments. Data was collected and analyzed using GENSTAT. Seed was then harvested at three different maturity stages of green, tan and black pod and seed taken to laboratory for quality tests on analytical purity, germination and vigour. The survey results showed 86% farmers growing Jute mallow for seed were of middle and old age and 98% were female. Only 14% farmers were trained on vegetable seed production and agronomy. Education level showed 54% had not attended school. Seed quality analysis showed 98% purity and 59% germination which is below quality standard of 60%. Morphological characterization results at green house showed two morphotypes based on colour (Green and Brown) and two based on height (Short and Tall). Plant height results showed morphotypes green short being 28.3 cm and morphotypes brown short at 29.0 cm, while morphotypes green tall being 93.0 cm and brown tall at 84.0 cm. Pod count per plant was lowest on morphotypes green short with 14 pods and highest on green tall with 19 pods. Field results showed Jute mallow responded best to wider spacing of 40 cm x 30 cm and high fertilizer rates of 120 kg/ha on GLMT and BLMT morphotypes with plant height of 91.67 cm and 93.00 cm at site 1 and 2 respectively; highest number of branching of 8 and 9 branching per plant at site 1 and 2 respectively; highest pods of 23 and 24 pods per plant at site 1 and 2 respectively and highest leaf yield of 99.2 g and 96.3 g per plant respectively. Harvesting stage maximizing on quality seed attribute of germination were at tan stage on morphotype GLMT (94.5%) and BLMT (94.25%). It is concluded that most farmers have low education, are aged and not trained in Jute mallow seed and agronomic aspects, plant own saved seed or from neighbours where storage was in plastic containers. For high quality seed and leaf yield, it is recommended spacing of 40 cm x 30 cm coupled with higher fertilizer rates of 120 kg/ha be used and seed be harvested at tan stage.