Effect of Sheep Manure and Phosphorus Fertiliser on Productivity of Snap Bean (Phaseolus vulgaris L.) in Northern Rwanda

Aims: Snap bean (Phaseolus vulgaris L.) productivity is low in Rwanda. Investigations were carried out to assess the productivity of Snap bean using pot experiments.

Methodology: The experiment was laid out in a completely randomized design with seven (7) treatments: Compost (T0), Cow manure (T1), Sheep manure (T2), Compost with diammonium phosphate (DAP), DAP alone (T3), Cow manure with DAP (T4), Sheep manure with DAP (T5) and control (T6) on Andisol and Oxisol replicated three (3) times.

Results: The results showed that the pod yield was the highest in Andisol (2.39 tha-1) and the application of sheep manure significantly (P<.001) increased the leaf area, the number of leaves (P = .01) and the plant height (P= .01). The number of pods, the pod weight and the total pod yield were also significantly (P<.001) different between the fertilizer treatments and the soil types. Treatments with DAP (T3, T4 and T5) showed better development of the leaf area (231.50 cm2, 221.30 cm2 and 231.80 cm2 respectively), increased the number of leaves (9.67, 9.83 and 10.17 per plant respectively), the plant height (270.80 cm, 266.70 cm and 271.70 cm respectively), the number of pods (11.17, 11.33 and 13.33 per plant), the pod weight (10.68, 10.98 and 12.11 g plant-1) and the total pod yield (2.44 tha-1, 2.51 tha-1 and 3.31 tha-1 respectively). Agronomic efficiency (AE) was the highest in Andisol (5.17 kg of snap bean pod yield per kg nitrogen applied) and in pots that received sheep manure combined with DAP (6.52 kg of snap bean pod yield per kg nitrogen applied).

Conclusion: Use of sheep manure and DAP could be a potential option for fertilisation of snap bean in Northern Rwanda.