2.3 Results
2.3.1 Bean production constraints and cropping system
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conducting the survey, all enumerators were trained on the objective of the survey and on how to conduct an effective interview. Thirty-one bean farmers per district were interviewed, giving a total of 124 respondents for the whole survey. The respondents were selected by using a random systematic technique and an accidental sampling technique, that is, the fourth household on a particular selected footpath, or the owner of a bean field with ascochyta symptoms, were selected. Interviews were carried out if the respondent was a regular bean grower and had a bean field at the time. The questionnaire involved open-ended questions that allowed the farmers to express themselves, in order to gain as much information as possible.
To assess the incidence and severity of ascochyta blight, observations were made in the farmer’s fields in the four districts, over two seasons. Fifteen bean fields per district per season were assessed, resulting in a total of 120 fields for the whole assessment. The bean fields were selected by using a non-random systematic technique, that is, the household on a particular selected footpath, or the owner of a bean field with symptoms of ascochyta, was selected. The ascochyta ratings in the field were made during the podding stage, using a one-square metre frame. This means that the plant population was determined over a one square metre area at three locations in the field, and observations were made on the leaves and pods. In addition, the general appearance of the bean field was noted. The incidence of ascochyta was scored as the average percentage in bean fields that had plants infected with ascochyta. The severity of ascochyta was scored as the average percentage of the ratings at the three locations per visited field.
2.2.3 Data analysis
Data was analysed, using the Statistical Package for the Social Sciences (SPSS) Version 16.0 statistical software. Disease data were analysed, using the Genstat computer package (Trust, 2007).
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perceptions about the importance of diseases, the high cost of input, the lack of improved seed and poor soil, with respect to bean production. However, they had different (P≤0.01) perceptions about the importance of other factors on bean production across the four districts. Diseases were the most important constraint to bean production in Burera and Musanze with means of 88.1%, and ranging between 79.9-95.8%; while in Rwamagana, pests such as the beanfly, cutworms, bruchids/bean weevils, and aphids, were said to be most prevalent. The high cost of input and the lack of improved bean seed were considered as major constraints in the Kamonyi and Rwamagana Districts. Soil erosion was considered a problem in Burera and Musanze, due to the heavy rains on steep mountain slopes, which leads to shallow soils. Infertile soil was most mentioned in Kamonyi and Rwamagana, compared to Burera and Musanze.
The lack of stakes was the main problem in Musanze and Burera, where climbing beans are more popular than in the eastern and southern regions. Bean price fluctuation was considered a problem in the Burera District, probably because this district is near to Uganda and the price of beans is also affected also by the Ugandan market.
Excessive rainfall was considered to be a major constraint for bean production in Musanze and Burera, and was said to escalate the ascochyta problem, while drought was a major constraint in Kamonyi, compared to the other districts. This could well have been because Kamonyi had received less rainfall in the previous seasons, compared to the other districts.
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Table 2.2: Percentage (%) of farmers/respondents mentioning different constraints to bean production in four districts of Rwanda (2014)
Constraints District
Overall mean
P value Burera Kamonyi Musanze Rwamagana
Diseases 91.2 85.4 95.8 79.9 88.1 0.12
Pest 68.3 79.7 71.2 80.2 74.8 0.00
Drought 34.6 98.0 28.0 93.2 63.4 0.00
High cost of input 56.2 63.2 62.3 61.6 60.8 0.09
Lack of improved
seed 57.8 61.3 57.9 60.1 59.2 0.08
Soil erosion 65.2 31.8 61.1 34.2 48.1 0.00
Poor / Infertile soil 22.5 34.1 18.5 29.1 26.1 0.11
Lack of stakes 26.7 10.4 34.3 15.0 21.6 0.00
Market price
fluctuation 22.1 18.0 14.6 19.6 18.5 0.00
Excessive rainfall 17.0 3.0 13.1 5.6 9.6 0.00
The farmers produce beans during both the long and short rainy seasons. The short rains occur from February to May, while the short rains occur from September to December. The best yield is obtained during the short rainy season, rather than during the long rains. The main activity during the bean season is weeding, which is carried out twice, just before flowering and after pod set. Only 4.3% of farmers reported that they use agro-chemicals to control insect-pests and diseases. Most of these farmers are commercial seed multipliers and bean production cooperatives. The remaining 95.7% of farmers depended on good agronomic practices, such as weeding and the clearing of plant debris, during the production season. A total of 37.9% of farmers reported that they did not use any fertilizers. However, 42.8% used organic manure, while 19.3% reported that they used both organic and mineral fertilizers.
The farmers grow beans on small land holdings and 53.2% of the interviewed farmers planted beans on less than 0.5 ha.
41 Figure 2.2: Bean intercropping with maize and bananas
The beans were planted as an intercrop by 81.2% of the farmers and as a pure stand by 18.8%
of the farmers. The farmers intercropped beans with several other crops, including maize (35.5%), bananas (25.6%), cassava (11.3%), potatoes (4.1%), sorghum (2.4%) and coffee (1.3%) (Figure 2.2 and 2.3).
42 Figure 2.3: Bean cropping systems