Abstract

The experiment compared the use of synthetic fertilizers [Diammonium Phosphate (DAP) and urea] with organic fertilizer (goat manure) and defoliation treatments on growth and development of broccoli. The trial was conducted under rainfed conditions in Rwanda using a 2 x 3 x 3 factorial design with three replications. The results showed that synthetic fertilizers (DAP and urea) led to significant increases in various growth parameters and revenue compared to organic fertilizer (goat manure). Synthetically applied experimental plots recorded an increase on total yield, gross revenue and net revenue by 24.12, 24.11 and 23.14% more USD/ha, respectively, compared with plots treated with organic manure. Additionally, a defoliation frequency of two times resulted in increased leaf length of 0.96 cm compared to those defoliated at once and three times. Longest stem diameter of 9.93 cm was recorded on the non-defoliated plants. Furthermore, it was observed that a combination of applying synthetic fertilizers (DAP and urea) and defoliating three leaves at once increased the overall total yield, gross revenue and net revenue of broccoli. The study recommended the use of synthetic fertilizers (DAP and urea) and a defoliation practice of removing three leaves at once to maximize broccoli head size, total yield, and revenue.

Key words: Defoliation intensity, defoliation frequency, source of nutrients, Broccoli.