Variation and Selection for Cooking
time in Drought tolerant Canning Beans
(Phaseolus vulgaris)
Warsame, A. O., P. M. Kimani, and J.W. Mwangi
Department of Plant Science and Crop Protection, College of Agriculture and Veterinary
Sciences, University of Nairobi
First Bio-Innovate Regional Scientific Conference
United Nations Conference Centre (UNCC-ECA)
Addis Ababa, Ethiopia, 25-27 February 2013
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Contents
Introduction
Materials and Methods
Results &Discussion
Conclusions
Acknowledgements
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Introduction
Common beans is one of most import crops in eastern Africa (Pachico,
1993; Kimani, 2001)
Cooking time of dry bean is an important trait related to its utilization
(Iyer et al., 1980; Miles and Sonde, 2004; Elia, 2003).
Bean cooking time can vary from ½ hour to 8 hours (Miles and Sonde,
2004).
In Kenya, traditional bean varieties need 2-3 hours to cook (Kimani,
2001).
Cooking time is import for both canning industry and household
consumption.
For processors, long cooking is associated with higher energy
requirements and lower processor yields (Van Loggerenberg, 2004).
Urban consumers spend more money on expensive fuels.
Rural households use large quantities of firewood and spend time in
searching it.
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Continued……
Thus, faster-cooking bean cultivars would:
 save energy and deliver higher processor yield for canning industry
 save money spent on kerosene, charcoal, electricity, and natural gas
for or rural and urban consumers.
 Save forests.
However, at present there is a little information on fast cooking bean
varieties in the region.
Processing industry in Kenya depend on single variety (Mex-142)
which is highly susceptible to rust and anthracnose, and is low
yielding.
Therefore, there is need for new faster cooking bean varieties which
combine other important traits like disease resistance, drought
tolerance and other agronomic traits, and also meet consumer
preferences for seed colors.
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Objectives
The objective of this study was to evaluate the
cooking time of advanced canning bean lines
previously selected for drought tolerance, resistance
to diseases and other agronomic traits
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Material and Methods
Bean seeds used in this study were obtained
from Grain Legume Research Program of the
University of Nairobi, which fall in 7 market Market class Number of
classes. lines
Mex142 was used as check Red mottled 22
155 Bean lines of diverse market classes were Red kidneys 23
grown and selected at Kabete Field station, Speckled Sugars 22
University of Nairobi during the 2012 long-rain
season season. Pintos and Cariocas 22
Seeds were soaked for 16 hours and cooked
using Matson Bean cooker (Matson, 1946) and Small reds 22
trial was repeated three times. Navys 24
Analyses of variance (ANOVA) appropriate to a Mixed Colors 20
randomized complete-block design was
performed using GenStat 13.3 (VSN
International Ltd., UK.) at significance level Total 155
(0.01).
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Continued….
Small red
Selection
Red
in the
mottled
field
Pinto
Red Soaking
kidney Carioca
Matson
Speckled Yellow Bean
sugar Cooker
Tan
Navy
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Results
Analysis of variance showed that
there were highly significant (P<0.01)
genotypic differences for cooking
time within and among market
classes.
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Fig 1. Cooking time of advanced Red Mottled canning bean lines
selected at Kabete Field Station, 2012
50
46.3
45 42.9 41.9 42.1 41.9 43
40.7 40.7 41.6
38.9 38.3
40
36.1 35.8 36.3
34.3 34.9 34.4
35 33.1 33 32.2
31.8 31.4 30.6
Minutes
30
25
20
15
10
5
0
0
Genotype
Mean 37.48
LSD (0.05) 2.801
SE 0.567
CV (%) 1.5
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Fig 2. Cooking time of advanced Red Kidney canning bean lines
selected at Kabete Field Station, 2012
55
48.8
50 46.3
45 43 42.4
41.6 40.9 41.4
39.1 39.5 38.7 38.7
40 36.6 37.8 35.6
35.2
35 32.6 32.1 32.1
31.3 31.1 31.8
29.6
27.8
Minutes
30 27.1
25
20
15
10
5
0
Mean 36.77
Line
LSD (0.05) 2.973
SE 0.265
CV (%) 3.7
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Fig 3. Cooking time of advanced speckled sugars
canning bean lines selected at Kabete Field
60
Station, 2012
51.53 50.83
50
43.27
41.1 41.73
39.03 38.7 39.7
40 34.87
37.6
35.27 36.1
35.3 34.73
Minutes
33.4 33.73
32.43 32.17
30.4 31 30.43
29.67 30.13
30
20
10
0
Mean 36.66
LSD (0.05) 3.797 Line
SE 0.033
CV (%) 2.1
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Fig 4. Cooking time of advanced Navy Bean lines selected at Kabete
Field Station, 2012
60.0
49.8 48.9 48.9
50.0
43.3
41.7 41.3 42.0
40.5
39.3 39.3
40.0 37.9
35.3 35.9 36.3 36.4
34.0 34.6
Minutes
33.8
32.2 31.8 32.0
30.4 29.6
30.0
24.4
20.0
10.0
0.0
Mean 37.21
LSD(0.05) 3.836 Line
SE 2.337
CV(%) 1.5
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Fig 5. Cooking time of advanced Small Red canning bean lines
selected at Kabete Field Station, 2012
60.0
52.4
50.0
41.8 42.3
40.8 39.6 40.5
38.7 38.3
40.0 36.9
35.4 35.4 35.3 35.1
Minutes
33.7 32.5 34.5
31.6 32.0 31.2
28.7 29.8 30.6
30.0 27.1
20.0
10.0
0.0
Mean 37.21 Line
LSD(0.05) 3.836
SE 2.337
CV(%) 1.5

Conclusions
Results of this work showed significant variation in cooking
among bean lines across market classes.
More than 60 lines from different market classes cooked
faster than the industry standard Mexican-142.
This genetic variation for cooking time, can combined with
drought tolerance, resistance to diseases and other
agronomic traits.
Such lines will save time, energy for rural and urban poor in
cities and processors.
A broad range of Consumer preferences can be met.
Increased utilization of beans and income for farmers.
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Acknowledgements
The University of Nairobi
Bio-Innovate-Africa program
Beans for Climate Change Consortium
Supervisors
Bean Program Technical staff-UON
Governments of Kenya, Sweden-Sida and Somalia
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THANK YOU
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