Performance of Screened Latin American genotypes in drought prone
Sudan Savannah region of Nigeria
Clement Adebija1, Olalekan Akinbo2*, Emmanuel Okogbenin2, Chiedozie Egesi2, Favour Ewa2, Eunice Ekaette2 and Martin Fregene3
1Institute
of Agricultural Research (IAR), Ahmadu Bello University, Kano Outstation, Kano State, Nigeria; 2National Root Crops Research Institute (NRCRI), Nigeria
3Donald
Abstract
Cassava has been identified as hardy crop that can grow on low nutrient
and poor soil with little water. Due to expanding dry agro-ecology and
short rain for rain-fed agriculture in dry ecology, early bulking cassava
has been recognised as an important character for variety in a drought
prone agro-ecology. Five released varieties in Nigeria and 29 genotypes
from Latin America germplasm were evaluated in Mijinbir Station, Kano
State in Nigeria over three years. Randomized complete block design
was used with standard 6 X 6 plot size and a local check (Dakata). In this
trial we evaluated for the best early bulking varieties from both the local
germplasm from Nigeria and others from the centre of origin. Here we
show that AR38-8, CR14B-218, CR52A-1 of Latin America origin have
fresh root yield ranges from 20 ton ha-1 to 29 ton ha-1, dry root yield 3.8
ton ha-1 to 5.88 ton ha-1, dry matter content 50% to 61% and harvest
index 0.43 to 0.59 in the dry ecology.
Introduction
Cassava has the ability to adapt to a temporary aberration, low rainfall regions and a
permanent feature of climate. Drought originates from a deficiency or irregularity of
precipitation over an extended period of time, usually more than a season. Other
climatic factors such as high temperatures, high wind, and low relative humidity are
often associated with drought. Cassava is a perennial crop which bulking duration
ranges from 8 weeks after planting to 24 months after planting which make it a suitable
crop for drought prone region of the world. Cassava has a huge yield potential in
environments where there is no production constraints, the recorded average annual
yield worldwide are 10 ton ha-1 but it can be higher as 90 ton ha-1 been reported in
experimental trials of improved cultivars at the International Research Centers. These
gaps between the potential and the actual yields on the farmers’ fields are huge and
these potentials can be harness (El-Sharkawy, 2005). Therefore, an increase in
cassava production in marginal ecology from the use of improved drought tolerant
clones will result in increase in global production. A well adapted and poorly adapted
clones in these region is necessary for the understanding the genetic and physiological
traits that make it a drought tolerant crop. We report drought tolerant and resistant
varieties of cassava identified for the maximization of productivity potential in droughtprone agroecology of Sudan Savannah areas of Nigeria.
Danforth Plant Centre, 975 North Warson Road, St. Louis, Missouri 63132, USA; corresponding author: akinbooa@yahoo.co.uk
Table 2. Mean and ranking by selection index of the yield traits
measured from the LA clones evaluated during the 2009 to 2011
cropping seasons
Materials and methods
Mature stem cuttings was brought from National Root Crops
research Institute (NRCRI), Umudike, Nigeria where the initial
screen was conducted to select the best adapted and high CMD
resistant varieties for different agro-ecologies. The selected field
is flat, well-drained with more or less homogenous soil. A simple
randomised complete block design (RCBD) of 36 plant plots (6
X 6) and three replications were used. A local variety (Dakata)
for the Sudan Savannah region was used as a check to
compare the performance of these clones. Measurement of
agronomic traits like percentage sprouting, vigour: the plant
growth vigour was visually rated using scale of 1-7; Ekanayake
et al., 1996, number of primary and secondary stems, primary
branching height, primary branching level, Leaves scar number,
leaves scar level, number of leaves, leaves area index, and
CMD (scale: 1-5), CBB (scale: 1-5) and CGM (scale: 1-5)
severity begins at 3 months after planting, all these diseases
and pest were observed under natural environmental disease
pressure (IITA, 1990). Other traits recorded at harvest are:
above-ground biomass, harvest index, storage root fresh
weight, number of storage roots, storage root dry matter
contents. The plant vigour growth was scored visually with the
rate of 1 is where the vigour is very poor, score 3 is where the
vigour is intermediate and 5 is very vigorous (Ekanayake et al.,
1996). Selection index formula (SI) = [FRY*10]+[DRY*8]+[HI*5][CMD*5]-[CBB*8]-[CGM*8]-[PT*3];
weight
are
allocated
according to the importance of each parameter in the dry agroecology.
CBB
CGM
ARCH
SCARL RTWT
RTNO
FRY
DRY
DMC
DRY
(ton ha-1)
HI
(0-1)
DMC
(%)
CW525-1
48.80
26.07
0.55
21.04
117.93 (1)
KNO1
25.21
6.75
0.45
37.34
46.26 (2)
AR9-5
31.05
11.56
0.38
26.00
44.33 (3)
CW450-75
24.33
12.22
0.41
19.68
28.08 (3)
CW451-80
20.07
7.94
0.47
26.46
26.16 (4)
CR14B-180
16.05
5.38
0.45
31.49
19.59 (5)
CR14B-218
13.10
4.81
0.51
27.59
12.84 (6)
CR20A-2
13.60
4.47
0.40
30.37
7.53 (7)
CW450-106
15.05
6.41
0.44
23.47
7.01 (8)
AR14-4
12.57
4.89
0.44
26.48
4.41 (9)
AR9-45
14.75
5.84
0.38
25.79
3.66 (10)
CW451-13
7.00
1.50
0.25
46.45
2.90 (11)
CW450-46
11.15
3.87
0.42
28.77
1.42 (12)
CW450-36
11.54
4.57
0.43
26.11
0.78 (13)
Dakata
9.88
3.22
0.38
30.62
Check
Variety
Dry spell period
Results and Discussion
Recovery stage of the LA clone
Table 1. Simple correlation matrix of trait assessed for diseases,
agronomic and yield traits in 29 LA and 8 IITA improved
genotypes in Sudan savannah of Nigeria in 2010 and 2011
cropping seasons
CMD
FRY
(ton ha-1)
Ranking by
Selection
Index
The result obtained shows that different concentration of colchicines influenced
the morphology of the cassava varieties used. Table 1 shows that high
concentration of colchicines promoted sprouting across the varieties used. The
disease status of the materials showed low degree infestation level, each having a
disease score of 1 or 2 as shown in Table 2. Table 3, Figures 1a – 1d show the
correlation coefficient of the physiological parameters as influenced by the
treatment applied. Some of the parameters were positively and significantly
influenced while others were negatively influenced. The numbers of leaves were
significantly influence with increased level of colchicines and the lengths also
increased though not significantly with increasing level of treatment. This means
that it is possible to develop cassava varieties with high vegetative cover which
provides more photosynthetic surface area as well as provide conducive microenvironment for weed control and others.
The length and breadth of leaves reduced with increased level of colchicines
showing that colchicines induction can be used to modify the physiology of
cassava at will to obtain different population density and varieties for intercropping
and maximization of resources.
Considering the individual varieties, level 4 gave the highest leave number and
highest plant height. Level 2 gave more broad leaves, while increased level of the
treatment did not influence the branches.
High yield from LA clone
References
CBB
0.82****
CGM
0.79****
0.90****
ARC
0.05 ns
0.01ns
0.03ns
SCARL
-0.05ns
-0.01ns
0.05ns
-0.2***
RtWt
0.00ns
0.00ns
0.00ns
-0.13ns 0.18**
RtNo
0.06ns
0.07ns
0.07ns
-0.20ns 0.14ns
0.64****
FRY
0.00ns
0.00ns
0.00ns
-0.13ns 0.18*
1.00****
0.64****
DRY
0.02ns
0.02ns
0.02ns
-0.05ns 0.13ns
0.93****
0.57**** 0.93****
DMC
-0.01ns
-0.03ns
-0.02ns -0.04ns -0.08ns -0.03ns
HI
-0.09ns
-0.10ns
-0.10ns -0.04ns 0.16*
El-Sharkawy MA (2005) How can calibrated research-based models be improved
for use as a tool in identifying genes controlling crop tolerance to environmental
stresses in the era of genomics – from an experimentalists's perspective.
Photosytnthetica 43:161-176.
Egesi, C.N, F.O. Ogbe, M. Akoroda, P. Ilona and A. Dixon, 2007. Resistance
profile of improved cassava germplasm to cassava mosaic disease in Nigeria.
Euphytica 155: 215-224.
IITA, 1990
-0.10ns
-0.03ns
-0.00ns
-0.50**** -0.27*** -0.50**** -0.44**** 0.01ns
Local check (yield and disease status)
Figure 1. showing yield and disease resistance
genotype from the LA clone and the local check
during the dry spell and recovery during the rainy
season in 2011
Acknowledgments
This work has been partly funded by Alliance for Green Revolution in Africa,
National Root Crops Research Institute (NRCRI). We acknowledge the
contribution made by Willy Nwakor in the establishment of the trial.