In 2012, the grain yield performance of KK15 was best in all sites during the long rains (LR) season, while in the short rains (SR) season, KK072 had the best ...
Screening of bean varieties for adaptability in Nandi smallholder farming systems in western Kenya J.O. Ojiem, H. O. Ochieng, S.M. Kamwana, J. W. Nyongesa, J. Ambuga , & J. C. Mutai Abstract Bean productivity is low in the smallholder farming systems of Nandi, western Kenya, due continuous cropping of few bean varieties with insufficient levels of tolerance to major pests and diseases has led to a buildup of pests and diseases. Three new promising bean varieties (KK15, KK071 and KK072) were screened for adaptability in three sites in Nandi. In 2012, the grain yield performance of KK15 was best in all sites during the long rains (LR) season, while in the short rains (SR) season, KK072 had the best grain yield in all sites. In 2013, KK15 performed consistently better than that of KK071 and KK072 during LR and SR season in all sites. The results suggested varietal diversity may be a useful strategy for improving bean productivity.
Introduction
Results
Bean is the major the major source of protein for the majority of the
1.6
1.6
KK071
Bean grain yield in t/ha
and diseases has negatively affected bean production. New high yielding and root rot tolerant bean varieties are available that can improve the productivity of the Nandi smallholder systems by
1.4
KK072
1.4
soil fertility, continuous cropping, and the consequent build-up of pests
KK072
KK15 1.2 1 0.8 0.6 0.4
Bean grain yield (t/ha)
rural poor population in Nandi County, western Kenya. However, low
0.2
diversifying the production system, improving soil fertility and food
KK071 KK15
1.2 1 0.8 0.6 0.4 0.2
0 2012LR
0
2012SR
2012LR
Season
security, and providing farmers with opportunity for house hold income
Season
Figure 2: Grain yield of three bean varieties in 2012 long rain (LR) season and short rain (SR) season in Kapkerer site
1.6
performance of three new promising bean varieties in Nandi
KK071 KK072 KK15
1.4
Bean grain yield (t/ha)
smallholder systems.
1.2 1 0.8 0.6 0.4
Figure 3: Grain yield of three bean varieties in 2012 long rain (LR) season and short rain (SR) season in Kiptaruswo site
KK072 1.4
KK15
1.2 1 0.8 0.6 0.4
0.2
0.2
0
0 2012LR
KK071
1.6
Bean grain yield (t/ha)
generation. This trial was therefore conducted to assess the
2012SR
2013LR
Season
400
Koibem
350 300 250 200 150 100
KK15
1.2 1 0.8 0.6 0.4
1.6
KK071
1.4
KK072
1 0.8 0.6 0.4 0.2
0
0 2013LR
2013LR
2013SR
Figure 6: Grain yield of three bean varieties in 2013 long rain (LR) season and short rain (SR) season in Kiptaruswo site
Figure 1: Total seasonal rainfall (mm) in Kapkerer, Kiptaruswo and Koibem site
Objective To screen three promising new bean varieties for grain yield and
•
performance of 1.15 t/ha (Figure 2), while KK072 had the least grain yield of
Materials and Methods
0.55 t/ha. •
screened for grain yield and tolerance to root rot and major folia •
While KK15 had the best grain yield in Kiptaruswo in LR 2012, in the SR season 2012 KK072 had the best yield (Figure 3).
•
rains (SR) seasons of 2012 and LR and SR seasons of 2013
The grain yield performance of the varieties in Koibem (Figure 4) mirrored that of Kiptaruswo, with KK15 being the best in the LR season and KK072 the best
• Trial design was RCBD with 2 replicates per farm and 9 farms per site. Plots were 4 m2
However, in the short rains (SR) season in Kapkerer, KK15 had the least grain yield of 0.4t/ha, which was less than half the grain yield of KK071 and KK 072.
County • The trials were conducted for four seasons: long rains (LR) and short
The performance of the varieties differed by season and site. In 2012 long rains (LR) season in Kapkerer site, variety KK15 had the best grain yield
systems
diseases in three sites (Kapkerer, Kiptaruswo, and Koibem) in Nandi
Figure 7: Grain yield of three bean varieties in 2013 long rain (LR) season and short rain (SR) season in Koibem site
Results and discussion
tolerance to root rot and major folia diseases in Nandi smallholder farming
• Three new promising bean varieties (KK 15, KK071 and KK072) were
2013SR Season
Season Month
KK15
1.2
0.2
50 0
Bean grain yield (t/ha)
Kiptaruswo
KK072
1.4
Bean grain yield (t/ha)
Total seasonal rainfall (mm)
450
Figure 5: Grain yield of three bean varieties in 2013 long rain (LR) season and short rain (SR) season in Kapkerer site
KK071
1.6 Kapkerer
2013SR
Season
Figure 4: Grain yield of three bean varieties in 2012 long rain (LR) season and short rain (SR) season in Koibem site
500
2012SR
in the SR season. •
In 2012, KK15 consistently performed best in the LR season in all the sites,
• Data collected: Emergence, plants dying from root rot and bean fly,
while during the SR season, KK072 performed best in all the sites (Figure 2,
anthracnose, common bacterial blight, and aphid scores, and grain
3, & 4). In 2013, however, grain yield of KK15 was consistently better than that
yield
of KK071 and KK072 in the LR and SR season in all sites (Figure 5, 6 & 7).
Conclusion Due to the large variations in the performance of the bean varieties in different seasons and sites, a single adapted variety may not be a good strategy for improving bean productivity in the smallholder systems. Varietal diversity may be a better way of managing production risks and ensuring yield stability.
