Abstract:
Two field experiments were carried out concurrently at the Faculty of Agriculture,
Field station farm, University of Nairobi in March-July 2000 (season I) and JuneSeptember
2000 (season II) to determine the effect of application of different
levels of phosphorous (P) fertilizer on growth and yield of snowpea (Pisum
sativum L. var. Oregon sugar pod II). The experiments were laid out in a
complete randomized block design with three replicates. Four levels of P (0, 57,
114 and 171 kg P2O5 ha-1
) were applied as TSP (46% P2O5) at planting. Plant
heights were measured at 31,38,45,58,71,84 and 97 DAS. Leaf area index and
above- ground dry mass were determined at 29, 43, 63, 77 and 94 DAS.
Harvesting of pods was done at 68, 72, 75, 79, 82, 86, 89, 93, 96 and 100 DAS.
P fertilization resulted in significant (P 0.05) increases in plant height, leaf area
index, and total above ground dry matter accumulation in both seasons. Number
of pods plant-1
showed a quadratic trend with increasing P at 68, 89 and 93 DAS
in season I. Linear and quadratic increases in number of pods plant-1 were
observed at 96 DAS and on total number of pods plant-1
. At 100 DAS, only linear
increase was observed. Pod dry mass plant-1
showed a quadratic increase at 68,
89, 93 and 96 DAS. At 100 DAS, linear increase in pod dry mass plant-1 was
observed. Linear and quadratic increases were observed in total pod dry mass
plant-1
. P application did not affect both the number of pods and pod dry mass
plant-1
in season II probably because of the low amount of rainfall. Application of
57 kg P2O5 ha-1
resulted in dry pod yields of up to 9.75 tons ha-1 which is higher
than the national dry mass averages of 5 to 6 tons ha-1
. It is therefore
recommended that judicious levels of P be applied for growth of snowpeas.
