Evaluation Of Vermiculite Application Rates on Growth and Yield of Brassica Napus (Rape)

Abstract

Production of leaf vegetables requires intensive soil nutrients management. A 3-year field experiment was carried out to assess effects of vermiculite application rates on the growth and yield of Brassica napus. The experiment was conducted during the 2016/17, 2017/18 and 2018/19 summer seasons at the Marondera University of Agricultural Sciences and Technology (MUAST) farm, Mashonaland East Province, Zimbabwe. Vermiculite was applied at five levels of 0 (control), 1, 2, 5 and 10 t ha-1 in a completely randomised block design (RCBD) with 3 replicates. Basal and top-dressing fertilizers were applied using the recommended rates in the study area. The B. napus leaf width, leaf length, fresh and dry matter yield, leaf nutrient concentration and N and P uptake were measured. Analysis of variance (ANOVA) at p = 0.05 was done to compare the effects of vermiculite application rates on growth and yield of B. napus. Growth parameters and yield of B. napus significantly (P <0.05) differed among the five levels of vermiculite. Application rates of 5 t ha-1 and 10 t ha-1 improved leaf width and length, fresh and dry matter yield of B. napus. Farmers may therefore apply 5 -10 t ha-1 of vermiculite in order to increase rape leaf yields. However, there is need for further researches to determine the optimum application rates of vermiculite are essential.