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

Improvement of Grain Legume Production in Semi-Arid Kenya 181
Table 9. Effects of rhizobia inoculation on growth and nodulation of TB 42 DAE during the SR
season of 1999/2000.
Treatment Nodule Nodule Pod dry Pod dry Plant dry
number dry weight number weight weight
(plant –1 ) (mg plant –1 ) (plant –1 ) (g plant –1 ) (g plant –1 )
TB+N* 20 b 13.2 b 21 b 18.7 b 14.2 a
Control 19 b 13.0 b 17 b 14.4 b 09.5 b
TB + R3254 47 a 32.0 a 22 a 39.8 a 14.4 a
TB + R446 20 b 13.3 b 12 b 16.4 b 08.5 b
TB + RTB 20 b 13.0 b 20 b 15.1 b 11.3 b
TB + R578 20 b 13.2 b 32 b 15.7 b 10.0 b
TB + R579 18 b 12.8 b 15 b 17.3 b 09.5 b
Means (n = 28) followed by the same letter down the column are not statistically different (P ≤ 0.05)
by Duncan’s multiple range test.
* Nitrogen (N) fertilizer was top-dressed 10 DAE at the rate of 40 kg ha –1 of CAN (26% N) powder.
Source: After Shisanya, 2002.
Table 10. Effects of rhizobia inoculation on growth and grain yield of TB at final harvest 70 DAE
during the SR season of 1999/2000.
Treatment Pod dry Plant dry 100 seed Seed Grain
weight weight weight weight yield
(g plant –1 ) (g plant –1 ) (g) (plot –1 ) (kg ha –1 )
TB+N* 1871.4 b 518.9 b 12.2 b 1415.3 b 0978 b
Control 1437.3 b 333.3 b 11.5 b 1069.4 b 0850 c
TB + R3254 3978.0 a 755.3 a 13.3 a 3126.3 a 1576 a
TB + R446 1641.4 b 372.3 b 11.6 b 1304.3 b 0793 c
TB + RTB 1512.6 b 333.7 b 11.7 b 1133.9 b 0848 c
TB + R578 1569.0 b 329.1 b 11.5 b 1167.7 b 0792 c
TB + R579 1730.3 b 410.0 b 12.0 b 1316.0 b 0998 b
Means followed by the same letter down the column are not statistically different (P ≤ 0.05) by Duncan’s
multiple range test.
* Nitrogen (N) fertilizer was top-dressed 10 DAE at the rate of 40 kg ha –1 of CAN (26 % N) powder.
Source: after Shisanya, 2002.
teristics of Rhizobium sp. described by Vincent (1970) and Somasegaran and Hoben
(1985). The isolate from tepary bean (RTB) did not absorb Congo red at all. On
BTB medium, a colour change to yellow indicated production of acidic substances,
which diffused into the medium. A change to blue colour would have indicated
production of alkaline substances, which diffuse into the medium. This is common
with fast-growing Rhizobium sp. and slow-growing Bradyrhizobium sp., respectively
(Somarsegaran and Hoben, 1985). These tests helped in the screening of rhizobial
isolates for contamination (Gitonga et al., 1999) and enabled the rejection of impure
cultures.
From the MPN greenhouse experiment, the population of rhizobia specific to
tepary bean was 1.0 × 10 2 cells g –1 of Kiboko soil (Table 3). These numbers are