Effects of Plant Population and Harvesting Interval in the Growth and Leaf Yield of Slenderleat(Crotalaria Brevidens) in Kisii County, Kenya

Abstract

Slenderleaf (Crotalaria brevidens), also known as rattle pod, is a prominent species of Crotalaria used as a vegetable in Kenya. It is a highly nutritious leafy vegetable, good sources of provitamin A, Vitamin C, carotenoids, iron protein, and calcium. At an average of 3 tons per hectare production of slender leaf in Kenya is low compared to an average potential of 11 tons per hectare. Previous studies done evaluated the influence of nitrogenous and phosphoric nutrients on slenderleaf growth. Notwithstanding, but no work has been carried out in Kenya on the effect of plant population and fresh leaf harvesting interval on the yields of the slenderleaf. One of the major limitations of slender leaf production is the inadequate comprehensive technical production package. The aim of the study was to determine plant population and harvesting interval effects on the fresh leaf yield and grain seed yield of the slender leaf with the aim of increased growth and yield. The experiment carried out from July to December 2018 at Kisii Agricultural Training Centre (KATC) in Kisii County. An experiment of Randomized complete block design (RCBD) comprising of three repetitions was carried out with the following treatments; three different levels of plant population (S1 = 30 cm x 30 cm, S2 = 30 cm x 20 cm and S3 = 30 cm x 15 cm) and four levels of leaf harvesting intervals (H1 = 7, H2 = 28 days, H3 = 49 days and H4 at maturity). Data on plant height, number of branches, fresh leaf weight, dry leaf weight, number of pods, and seed weight was collected and analyzed using the SPSS 21.0.Analysis of Variance(ANOVA) was done to identify the significant means between treatments and Post hoc test using Least Significant difference(LSD) was used to separate at P≤0.05. The results indicated that fresh leaf yield is depended upon the harvesting interval (intensity) and spacing (p<0.05). Harvesting interval was significant and had a greater effect on fresh leaf yield (p<0.05) as opposed to plant spacing which had no significance (p= 0.985).The highest fresh leaf yield was achieved under treatment 30 cm x 20 cm and 28 days harvesting interval which gave 11,358 kg/ha. Plant population had a great significant on plant growth (plant height and number of branches).Spacing 30 cm x 20 cm at maturity harvesting interval yielded the tallest plants while highest number of branches were realized in spacing 30 cm x 30 cm at maturity harvesting interval. Harvesting interval and plant spacing was significant in pod formation and seed weight per plant where treatment 30 cm x 30 cm and at maturity harvesting interval yielded the highest number of pods. The dry seed yield was greatly influenced by both spacing and harvestings interval with 30 cm x 20 cm and at maturity, producing the highest seed yields of 3,500kg/Ha. It is recommended that by adopting optimum combination of plant population and harvesting interval of 30 cm x 20 cm and 28 days harvesting interval the slenderleaf vegetable can be grown to achieve optimum fresh leaf yields.