Abstract:
Snap bean (Phaseolus vulgaris L.) ranks first among vegetables produced for the export market in Kenya. All Snap
beans were planted in different treatments containing various levels of Nitrogen of Calcium Ammonium Nitrate
(CAN) Treatments T1- T2 had IgN,1.5gN, 2.0gN, 2.5gN, 5gN, 10gN and 15gN respectively while T8 was inoculated with
Rhizobium. The control T9 lacked nitrogen. All were supplied with equal amounts of phosphorus fertilizer (5.5g)
single super phosphate per plant. The effects of different levels of nitrogen were determined on the vegetative
growth, seed and pod production and nodulation. It was found that an increase in nitrogen application increased
vegetative growth, dry matter production, seed and pod production. Increased Nitrogen application had a negative
effect on nodulation. T1 which had the least level of nitrogen application managed to modulate moderately and also
had high yields and dry matter production as compared to the control. However, inoculation alone had best
nodulation but seed production, vegetative growth and dry matter production was low compared to the treatment
with least nitrogen indicating that the nitrogen fixed through nodules was not enough for maximum production.
From this study, it can be recommended that 22kg N/ha would be economical for snap beans production.
