| dc.description.abstract | A study was conducted in Machakos district to determine the importance and performance of
different grain legumes in the smallholder farms. A random survey was carried out in different
agro-ecological zones to determine the performance of different grain legumes among the
smallholder farmers to determine grain legume production systems, levels, constraints and who
makes the farming decisions. Soil samples were randomly taken at depth of 30 em to determine
the physico-chemical characteristics and for determination nodulation, dry matter accumulation
and total tissue N content in green house experiment. The treatments included seven grain
legumes (hyacinth bean, common bean, cowpea, lima bean, pigeon pea, and green gram) and soil
samples from eight different agro-ecological zones. The experiment design was randomized
complete block design (RCBD), with split plot arrangement with three replications. The field
trials were carried out at Kimutwa location, Katumani to determine nodulation levels, dry matter
accumulation, pest and disease prevalence and grain yields. The treatments consisted of two
levels of di-ammonium phosphate (D.A.P), (0 and 70 kg ha -IP20S; and 0 and 30 kg ha-1N) and
eight different food legume species. The experiment design was randomized complete block
design (RCBD), with split plot arrangement with four replications.
The per capita land size in Machakos is low at 0.4 ha. Constraints limiting grain legume
production includes low soil fertility, high incidence of the pests and diseases, limited choice of
appropriate food grain legume species, erratic and unreliable rainfall and inappropriate farming
systems. Women make farming decisions 53.1% of the households surveyed. Common bean
(Phaseolus vulgaris) is the most important grain legume species and highest yielding with a yield
of 816 kgha'. Most of the farmers practice intercropping and crop rotation of legumes with
cereals. Most areas has clay loam soil with soil pH ranging from 4.3 to 7.3, low in organic C, N,
moderate levels of P and adequate in K. The major diseases were root rot (Pythium spp,
Macrophomina spp, Rhizoctonia spp, Fusarium spp, and Sclerotium spp) and foliar blight
(Pseudomonas spp and Xatphomonas spp). The main insect pests included beanfly (Ophiomyia
spp), bollworms (Helicoverpa spp), systate beetles (Systates spp), striped bean weevil (Alcidodes
spp), foliage beetles (Ootheca spp), sucking bugs (Clavigralla spp, Anoplocnemis spp, Riptortus
spp), and legume pod borers (Maruca spp).
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Soil from different afro-ecological zone had no significant effect on nodulation and biomass
accumulation. However, inoculating with soil from agro-ecological zone UM3 induced more
root nodules with higher average dry weight per plant. A significant interaction was observed
between inoculating with soil from agro-ecological zone LM3 and cowpea in tissue N
accumulation.
DAPfertiliser had no effect on pest and disease incidences, suppressed nodulation except for onfarmtrials
during the long rains, root nodule dry weight, increased the root dry matter during the
short rains. DAP fertiliser and legume species interactions had significant affects on root dry
weight in the on-farm trials during the short rains and shoot dry weight per plant. DAP fertiliser
increased insignificantly the number of pods per plant and grains per pod Legume species by
DAP fertiliser interactions increased the yields of the food grain legume species except for the
on-farmtrials during the short rains.
It can be concluded that, balancing gender interests and participation at household level would
positively influence grain legume production, farmers should use appropriate Rhizobia strains,
implement integrated pest control strategies, intensify use of organic fertiliser and practice the
appropriate farming systems. Implementation of strategies that could increase nodulation in
common beans could lead to high yields. Use of DAP fertiliser is more beneficial to grain
legumeproductivity where soil moisture is adequate. It is recommended that more work be done
on evaluating for the most appropriate grain legume species within the different agro-ecological
zones, post harvest management of grain legumes and the development of low cost integrated
legumepest and disease management strategies. | en |
