Abstract:
The castor bean seed when cooked and fermented, is a staple food condiment in Nigeria, but its
production is low in the humid rainforest zone of Southern Nigeria. A field experiment was
conducted in the Rivers State University Teaching and Research Farm in Port Harcourt Nigeria,
to evaluate the effect of various nitrogenous soil amendments on the growth and yield of castor
bean plant (Ricinus communis). The treatments included 120kgNha-1
equivalent of urea, NPK
20-10-10, poultry droppings, piggery dung and no amendment (control). These were replicated
thrice and laid out in randomized complete block design. A Chinese improved variety of castor
bean plant (Zibocastor No 5) was planted at a spacing of 1m x 1m within and between row, at a
population of 5,000 seeds per hectare. Results showed that the various nitrogenous soil
amendments significantly affected all growth and yield parameters measured, but germination
was negatively affected. Piggery dung gave the best values of 52.6cm, 24.0, 85.0cm2
, 191.5, and
350gplant-1
for plant height, number of leaves, leaf area, number of capsules and capsule weight
respectively, when compared to the control with 24.5, 8.0, 40.0cm2
, 28.4, 153gplant-1
. Results of
the physico-chemical properties of the soil showed significant increase in total nitrogen and
available phosphorus, and a decrease in exchangeable calcium and magnesium with no
significant changes in pH; following soil amendment and cropping. Amending the soil with
piggery dung increased yield by 397.0% over the control. |
