Maize is one of the worlds three primary cereal crops. It occupies an
important position in world economy and trade as food, feed and industrial grain
crop. It is one of the most popular food crops on the domestic markets in Ghana
and is grown in all the agro-ecological zones of the country. It is the basis
of several food preparations and the main feedstuff for poultry and other livestock.
A total area of 954,000 ha was cultivated under maize in 2009 with a total production
of 1.62 million metric tons mainly by small scale farmers who use a low level
of technology with an average yield of 1.7 mt ha-1 (Ministry
of Food and Agriculture, 2010). The policy of the Ministry of Food and Agriculture
of Ghana is to promote and encourage increased production through intensification
rather than land expansion (Ministry of Food and Agriculture,
In general, maize planted on good soils need at least 500-700 mm of well distributed
rainfall during the season (Taba and Twumasi-Afriyie, 2008;
Department of Agriculture, Forestry and Fisheries, 2008).
For the past decade, at least one of the seasons in the bimodal rainfall pattern
exhibited in the Forest-Savannah transition zone of Ghana has experienced shortfalls
(less than 500 mm) in rainfall amounts coupled with poor distribution. The introduction
of drought tolerant maize varieties in this zone was therefore imperative to
increase maize production and subsequently alleviate hunger and poverty of farmers.
The Maize Breeding Programme at Crops Research Institute (CRI), Ghana, in collaboration
with the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria,
identified high yielding and drought tolerant open-pollinated and hybrid maize
varieties in their regional variety trials. Therefore, there was the need for
further on-farm evaluation and eventual release to farmers. Considering the
fact that the ultimate beneficiaries of these promising varieties were farmers
it was necessary to have them involved in the evaluation and selection of suitable
materials under their circumstances. The mother-baby trial model adopted for
this project consisted of researcher-managed mother trial comprising of promising
new varieties and farmer-managed baby trials which contained few varieties from
the mother trial (De Groote et al., 2002). It
is a decentralized approach to on-farm research that greatly improves the timeliness
of sowing, trial supervision and contact with farmers (Banziger
and de Meyer, 2000). Research costs can be reduced and adoption rates increased
if farmers are allowed to participate in variety testing and selection (Yadaw
et al., 2006). Researchers necessarily discard many varieties during
evaluation and selection process because of traits considered undesirable; however,
these seemingly undesirable traits could be of interest to farmers (Bellon,
2002). This illustrates the communication gap between researchers and farmers.
The importance and complex nature of agricultural research demands coordinated
effort among biological scientists, extension agents and farmers in order to
ensure that appropriate technology is developed and promoted (Rao
et al., 2004).
The objectives of the project were to: (1) involve farmers in the evaluation and selection of drought tolerant open-pollinated and hybrid maize varieties by the use of mother-baby model approach to on-farm research and (2) provide data to support the Maize Breeding Programme of CRI, Ghana for the eventual release of these varieties to farmers.
MATERIALS AND METHODS
One mother trial each of early and medium maturing maize varieties and five or six baby trials each were planted in the major season of 2009 in farming communities at Techiman, Wenchi and Kintampo in the forest-savannah transition zone of Ghana. The early and medium maturing maize varieties take 90-95 and 105-110 days to reach harvest maturity, respectively. The early maturing mother trial contained four varieties namely, 2004 TZE-W Pop STR C4, 2004 TZE-Y Pop STR C4, TZE-W Pop STR QPM C0 and Farmers variety. The medium maturing mother trial contained five entries namely, DT-SR-W C0 F2, IWD C2 SYN F2, DT-SYN-1-W, Mamaba and Farmers variety. The experimental design for the Mother trial was a randomised complete block with three replications per site. Each plot consisted of six rows, 75 and 80 cm apart for early and medium varieties, respectively. Each row was 6 m long and the distance between plants within a row was 40 cm for both maturity groups. Baby trials were not replicated and contained two drought tolerant varieties and Farmers variety with 20 m by 20 m plot size each. Varieties used in the baby trials were selected by farmers from the mother trials. Data on plant establishment and days to 50% anthesis and silking were taken and grain yield was calculated at 15% moisture content and at 80% shelling percentage.
Farmer field days were organised at various mother trial sites about one week prior to harvest. Representative farmers who were invited to the field days were requested to select their preferred varieties and rank them based on their own selection criteria with due consideration of the following parameters in the order of importance (e.g., grain type, maturity group and variety reaction to biotic and abiotic stresses). Genstat 5 Release 3.2 (PC/Windows 95) was used for all statistical analyses.
Where the ANOVA showed significant differences (p<0.05) of variables (e.g., days to 50% anthesis and silking, grain yield, etc.) between treatments (varieties), the Standard Errors of Differences of means (SED) were used to compare between treatments. The relations between grain yields of the best improved variety of the two maturity groups and Farmers variety across different environments were investigated by regression analysis.
Early maturing drought tolerant mother and baby trials: Significant (p<0.05) differences were observed between varieties in Days to 50% Anthesis (DFA) and Days to 50% Silking (DFS) (Table 1). Anthesis and silking in the farmers variety were late at 57 and 60 days after planting, respectively, while the improved drought tolerant early maturing varieties took 48-50 and 53-55 days, respectively, to reach mid-anthesis and mid-silk across locations. The lateness of the farmers variety in anthesis and silking and subsequently in maturity did not translate into higher yield as expected. Surprisingly, the early maturing drought tolerant variety TZE-W Pop STR QPM C0 (4266 kg ha-1) out-yielded the farmers variety (3479 kg ha-1) by 23% across locations (Table 1). The other two improved varieties, 2004 TZE-W Pop STR C4 (3951 kg ha-1) and 2004 TZE-Y Pop STR C4 (3804 k ha-1) also out-yielded the Farmers variety by 14 and 9%, respectively.
In the baby trials which were managed by farmers the improved drought tolerant maize varieties again out-yielded the Farmers variety in all the four locations at Kintampo and Wenchi (Table 2). Here also, the Farmers variety (1793 kg ha-1) was late in silking (61 d) as compared to the drought tolerant varieties of 53 d. However, TZE-W Pop STR QPM C0 (3400 kg ha-1) and 2004 TZE-W Pop STR C4 (2827 kg ha-1) out-yielded the Farmers variety by as much as 90 and 58%, respectively. Plant stand establishment of the farmers variety was however lower than the improved variety (Table 2).
Medium maturing drought tolerant mother and baby trials: In the mother
trial, significant (p<0.05) differences were observed between varieties in
DFA, DFS and in grain yield (Table 3). The highest yielding
variety IWD C2 SYN F2 (4839 kg ha-1) out-yielded the Farmers variety
(3532 kg ha-1) and the released hybrid variety, Mamaba (3733 kg ha-1)
which was used as the standard check by 37 and 30%, respectively, across locations
||Grain yield (kg ha-1), days to 50% anthesis (DFA)
and days to 50% silking (DFS) of three early maturing drought tolerant maize
and farmers varieties tested across three locations in the mother
||Days to 50% silking (DFS), plant density and grain yield (kg
ha-1) of early maturing maize Baby trials planted at Kintampo
and Wenchi Farming communities
The other two drought tolerant varieties DT-SR-W C0 F2 (4077 kg ha-1)
and DT-SYN-1-W (4231 kg ha-1) also significantly (p<0.05) out-yielded
the farmers variety but not Mamaba.
In the baby trials the improved drought tolerant maize varieties DT-SR-W C0
F2, IWD C2 SYN F2 and Mamaba produced significantly (p<0.05) higher yields
than the Farmers variety in eight locations in the Techiman, Kintampo and Wenchi
farming communities (Table 4, 5). The farmers
planted full season or late maturing varieties which took 63 and 70 d to tassel
and silk as compared to the medium maturing improved varieties of 53-57 and
60-62 d, respectively (Table 5). The Farmers varieties
were also taller and therefore were more prone to lodging (21%) than the improved
varieties (5%). Plant stand establishment of the Farmers variety (3.716
plants m-2) was significantly (p<0.05) better than the improved
variety DT-SR-W C0 F2 (3.386 plants/m2 at Kintampo and Techiman but
did not translate into higher grain yield of the former variety (Table
4). Plant density of the Farmers variety at Wenchi was however lower than
the improved varieties (Table 5).
Regression of the grain yield of the most promising early TZE-W Pop STR QPM C0 and medium IWD C2 SYN F2 varieties on to the Farmers variety (Fig. 1, 2) was significant (p<0.01) with R2 of 0.76 and 0.65 for TZE-W Pop STR QPM C0 (early) and IWD C2 SYN F2 (medium), respectively. The regression coefficients of the two drought tolerant varieties were 0.78±0.204 and 0.82±0.242, respectively (Fig. 1, 2).
||Relation between grain yield (kg ha-1) of drought
tolerant variety TZE-W Pop STR QPM Co and Farmers variety
||Relation between grain yield (kg ha-1) of drought
tolerant variety IWD C2 SYN F2 and Farmers variety
Farmers perception about the varieties: An average of 25 farmers
attended each field day at the mother trial sites. The parameters of most interest
to the farmers were grain yield, grain size, cob size, grain colour, grain texture,
earliness, plant height, drought tolerance and marketability. These parameters
were ranked in all three locations in a 1-9 scale of importance, 1 being the
most preferred and nine the least preferred (Table 6). The
mean scores from the three locations indicated that the three most important
selection criteria for the farmers were grain size (2), grain yield (3) and
cob size (3.7). The parameters of intermediate importance were seed texture
(5), marketability (5.3) and earliness (6). Seed colour (6.3), drought tolerance
(6.7) and plant height (7) were less important to the farmers as selection criteria.
Selection or ranking of varieties were done on a scale of 1-4 for early maturing varieties and 1-5 for medium maturing varieties, 1 being very good and 4 or 5 being poor. In the early varieties, 2004 TZE-W Pop STR C4 was ranked highest (1) and selected by more farmers, followed by 2004 TZE-Y Pop STR C4 (2). The variety TZE-W Pop STR QPM C0 (4) was least selected by farmers (Table 7). However, the variety which was least selected by farmers (TZE-W Pop STR QPM C0) was ranked first (1) by researchers and the Farmers variety last (4).
In the medium maturing varieties, IWD C2 SYN F2 was ranked highest (1) by both
researchers and farmers, followed by DT-SR-W C0 F2 (2).
||Grain yield (kg ha-1), days to 50% anthesis (DFA)
and days to 50% Silking (DFS) of four medium maturing drought tolerant maize
and farmers varieties tested across three locations in the transition
zone of ghana
||Days to 50% silking (DFS), percent of plants lodged, plant
density and grain yield (kg ha-1) of medium maturing maize baby
trials planted in Kintampo and Techiman farming communities
||Days to 50% anthesis (DFA), days to 50% silking (DFS), plant
density and grain yield (kg ha-1) of medium maturing maize baby
trials planted in Wenchi farming communities
The variety DT-SYN-1-W was least (5) selected by both farmers and researchers
and the Farmers variety (4) was last but one (Table 8). In
this maturity group, farmers variety preferences were surprisingly in perfect
agreement with those of the researchers.
The rainfall figures for Techiman during the crop growing period was 356.1 mm and was obtained over a very short period of 25 days which was inadequate for good crop growth and development (Table 9). However, rainfall figures and distribution for Kintampo and Wenchi of 515.0 mm (41 days) and 516.1 (40 days), respectively, were just enough for good maize growth and development (Table 9).
On-farm testing of promising crop varieties identified on-station is an essential
stage in the development and eventual release of suitable varieties to farmers.
Generally, farmers responded positively in the assessment of the new varieties
they evaluated based on grain yield and other non-reproductive parameters. Most
of the improved varieties had been appreciated by both researchers and farmers.
In the early set mother trials, farmers rankings of varieties were quite different
from those of researchers, however, in the medium set variety trials both actors
ranked the varieties in the same order (Table 7, 8).
Abebe et al. (2005) in a similar investigation
observed that farmers preferences in some cases coincide with the breeders
selection. The present investigation also confirms the observation by Bellon
(2002) that farmers perception about crop varieties are not always
the same as breeders and if given the opportunity, farmers are able to express
their preferences differently. For instance, in the early set mother trials,
the variety TZE-W Pop STR QPM C0 was ranked first (1) and Farmers variety
last (4) based on grain yield by researchers (Table 7). However,
TZE-W Pop STR QPM C0 was the least preferred (4) by farmers but 2004 TZE-W Pop
STR C4 was their best choice (1). In the medium maturing varieties, IWD C2 SYN
F2 was ranked highest by both researchers and farmers and the farmers variety
was last but one.
|| Assessment of selection criteria or parameters used by farmers
in three farming communities on a ranking scale of 1-9 in order of importance
|Scale: 1 = Most important, 9 = Least important
||Ranking of early varieties according to farmers and researchers
impression on a scale of 1-4 in order of importance
|Scale: 1: Very good, 4: Poor
||Ranking of medium varieties according to farmers and
researchers impression on a scale of 1-5 in order of importance
|Scale: 1: Very good, 5: Very poor
||Rainfall figures (mm) for the crop growing period for Techiman,
Kintampo and Wenchi in 2009
|Source: Meteorological Services, Wenchi, Techiman and Kintampo,
The poor correlation between farmers and researchers ranking of the early maturing
varieties in the mother trials bears testimony to the statement by De
Groote et al. (2002). They stated that most scientists put a lot
of controlled measures in their research methodology which are often not representative
of farmers circumstances and the improvement of limited number of traits might
not represent farmers preferences. Farmers were not included in the development
of the variety TZE-W Pop STR QPM C0 and therefore did not know its inherent
good traits and rated it very low. The adoption rate of such unknown varieties
could have been low as indicated by Mekbib (2006) that
if farmers are excluded in the development process they often reject new varieties
that do not fulfil their multipurpose values. However, through this participatory
varietal evaluation farmers realised that the attributes of drought and striga
tolerance and the quality protein trait in TZE-W Pop STR QPM were advantageous
for them. This scenario agrees with the observation by Nkongolo
et al. (2008) that participatory varietal evaluation adds information
on farmers perceptions of plant and grain traits and ensures that new varieties
satisfy their preferences and suit their socio-economic situations.
The Farmers variety exhibited poor performance in both the mother and baby
trials and in the ranking of varieties by farmers and researchers in both maturity
groups. The regression coefficient of the grain yield of the most promising
early TZE-W Pop STR QPM C0 and medium IWD C2 SYN F2 varieties on to the Farmers
variety (Fig. 1, 2) of 0.78±0.204
and 0.82±0.242, respectively, is close to one indicating their increased
response to improving environmental conditions (Virk and
Witcombe, 2002). The rainfall figure (356.1) and distribution (40 days)
for Techiman (Table 9) during the crop growing period fell
short of the requirement of maize as stated by Taba and Twumasi-Afriyie
(2008) and Department of Agriculture, Forestry and Fisheries
(2008). However, the yield of the drought tolerant varieties in the drought
prone environment was still higher than the Farmers variety. The new drought
tolerant varieties, TZE-W Pop STR QPM C0 and IWD C2 SYN F2 were thus adaptable
to the sample of target environments and therefore, were ideal replacement for
the Farmers variety. Incidentally, some farmers without authorization
kept some drought tolerant seed for planting in subsequent seasons. This development
supports the findings of Mulatu and Belete (2001) that
participatory varietal selection is a means of increasing genetic diversity
and enhancing the rate of adoption through farmer to farmer seed exchange. The
two most promising varieties, TZE-W Pop STR QPM C0 and IWD C2 SYN F2 were recommended
by the Maize Breeding Programme at Crops Research Institute to the National
Variety Release Committee (NVRC) for release to farmers in 2010. However, only
TZE-W Pop STR QPM C0 was approved and released under the local name Omankwa
meaning, it gives life. One of the reasons why this variety was accepted for
release was because it is a Quality Protein Maize (QPM) which can improve malnutrition
even though it was less preferred by farmers (Table 7). Both
farmers and researchers had indicated their preference for IWD C2 SYN F2 (Table
8) and therefore it is advisable for the Maize Programme to re-submit this
variety for re-consideration by the NVRC for release due to its other important
attributes like drought and striga tolerance and high yield potential as manifested
in this investigation.
Farmers may require multiple traits from one key crop such as maize. However, plant breeders may not know the traits that are important to farmers and vice versa. Apart from the drought tolerance of the released variety TZE-W Pop STR QPM C0 it has other important traits of quality protein and striga resistance which farmers did not know and therefore ranked it very low in preference. Multiple traits have to be considered for successful dissemination of improved varieties. The importance and complex nature of agricultural research demands coordinated effort among all actors in order to ensure that appropriate technology is developed and promoted. The collaboration between biological scientists, extension agents and farmers show promise for improving the selection procedure if farmers are informed early in the breeding process.
We are grateful to IITA-CRI-DTMA Project for providing funds for this study. Our special thanks also go to Techiman, Wenchi and Kintampo farmers who participated in the on-farm evaluation of the varieties. We also thank technicians of the Maize Breeding Programme and the On-Farm unit at CRI for packaging and supervising the conduct of the trials.