GROWTH RATE AND YIELD OF BRASSICA NAPUS IN RESPONSE TO ACACIA ANGUSTISSIMA LEAF BIOMASS APPLICATION - C. Musara; a; J. Chitamba; b (Journal of Animal and Plant Sciences, 2015)
Acacia angustissima is an important agroforestry tree species and its biomass can be used for soil improvement in vegetable production. The study was conducted to investigate the productivity of Brassica napus (rape) in response to different A. angustissima biomass application rates and placement methods at Bindura University of Science Education, Zimbabwe during the 2010/2011 summer season. The experiment was laid out in a randomised complete block design (RCBD) as a 2×5 factorial treatment structure, replicated thrice. Placement method (spot and broadcasting) and biomass application rate (0 t/ha, 0.5 t/ha, 1.0 t/ha, 1.5 t/ha and inorganic fertilizer) were the treatment factors with 2 and 5 levels respectively. Fresh mass yield of B. napus harvested from the experimental units was measured three weeks after transplanting and at subsequent ten-day intervals till the end of the experiment. Data on yield and vegetative parameters were subjected to analysis of variance (ANOVA) using GenStat Version 16.1 statistical package and the least significant difference (LSD) was used in separating treatment means. In both the fresh and dry yield, the results were as follows: inorganic fertilisers > A. angustissima > untreated control. Treatments showed variation (p<0.05) in the number of leaves, leaf length and leaf width. There was significant interaction (p<0.05) between the application rate and placement method which was expressed in leaf length and width. The results showed that rape yield is most closely correlated with the nutrient content of biomass, together with the quantity of biomass applied. In comparison to non-amended treatments, it was concluded that A. angustissima biomass significantly increases growth rate and yield of B. napus.
Keywords: journal article; Acacia angustissima; application rate; Brassica napus; placement method