Production Practices and Quality Assessment of Food Crops. Vol. 1

178 Chris A. Shisanya
equation 3). The Rhizobia capable of nodulating TB in the soils of SE-Kenya was
1.0 × 10 2 cells per gram of soil.
2.9.2. Nodulation status and dry weight of TB in greenhouse experiment
There were significant differences (P ≤ 0.05) in nodule number and hence nodule
dry weight between the treatments (Table 4). Treatment R3254 had the highest
number of nodules and hence nodule dry weight. At harvest, no significant differences
in root and shoot dry weights between N and R3254 treatments were observed.
However, these treatments differed significantly in the two parameters from the other
treatments (Table 4).
Table 4. Effectiveness of rhizobia strains in nitrogen fixation in tepary bean during greenhouse
experiment.
Treatment Nodule number Nodule dry Root dry Shoot dry
(plant –1 ) weight weight weight
(mg plant –1 ) (g plant –1 ) (g plant –1 )
Nitrogen (N*) 03 c 02.8 d 0.7 a 5.6 a
Control 00 d 00.0 e 0.2 c 1.5 c
TB + R3254 40 a 17.8 a 0.8 a 5.8 a
TB + R446 10 b 07.1 b 0.5 b 4.2 b
TB + RTB 14 b 10.5 b 0.6 b 4.3 b
TB + R578 04 c 03.0 d 0.5 b 3.8 b
TB + R579 07 c 06.1 c 0.6 b 4.0 b
Means (n = 7) followed by the same letter down the column are not significantly different (P ≤ 0.05)
by Duncan’s multiple range test.
* Nitrogen medium incorporating 5 mM Ca(NO 3) 2 4H 2O in the solution.
(Source: after Shisanya, 2002)
2.9.3. The LR season field results
The total amount of rainfall received during the growing season was 223 mm.
There were significant differences (P ≤ 0.05) in nodule number and the corresponding
nodule dry weight between treatment R3254 and the rest of the other
treatments (Table 5). Treatment R3254 had the highest number of nodules at this
stage of growth. The rest of the treatments had the same number of nodules.
However, no significant differences in total plant dry weight between the different
treatments, 21 DAE, were observed (Table 5).
The pattern observed 21 DAE was similar to that at 42 DAE, except for the
pod dry weight and plant dry weight (Table 6). Treatment R3254 had significantly
(P ≤ 0.05) higher pod numbers per plant and hence pods dry weight. There was
no significant difference (P ≤ 0.05) in plant dry weight between the N and R3254
treatments. The other treatments had similar plant dry weights (Table 6). At final
harvest, the R3254 treatment had significantly (P ≤ 0.05) higher pod dry weight,
plant dry weight, 100 seed weight, seed weight per plot and grain yield (Table 7).