3.3.1 Farmers Demographics and Crop Preferences
Male vegetable farmers made up of 65.4% of the respondents whilst 34.6% were female. The majority of the vegetable farmers in Domboshava practice small scale commercial farming
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(53.8%), followed by market gardeners (30.8%) and the lowest percentage was made up of subsistence farmers (15.4%). 60% the farmers are between the ages of 45 – 60, 15% are above 60, 15% are between the ages of 19 – 25 and the remaining 10% are made up of the elderly above 61 years. The majority of the respondents have attained education levels of post secondary/high school level and primary school (70%), with the remaining 30% went up to primary education.
The respondents’ most commonly grown crop preferences are in the following order: covo, which is a member of the kale family belonging to the Brassica species, tomatoes (Solanum lycopersicum, L.), rape (Brassica napus, L.), mustard greens (Brassica juncea, L.), onion (Allium cepa, L.), pumpkins (Cucurbita maxima, Duchesne.), cabbage (Brassica oleracea, L.), spinach (Spinacia oleracea, L.), common beans (Phaseolus vulgaris, L.) and soft gourd (Cucurbita maxima, Duchesne.) (Fig 3.1).
0 10 20 30 40 50 60 70 80 90 100
Percentage of respondents
Vegetable crrop types
Figure 3.1: Preferences in crop types grown as indicated by Domboshava farmers.
According to respondents, the most commonly grown crops are rape, covo and mustard greens.
The other crop which is grown in significantly high proportions are tomatoes, whilst the lowest preferred crops were common beans and soft gourd (P < 0.05, Fig 3.1).
33 3.3.2 Frequently observed disease symptoms of the
The most commonly observed vegetable disease symptoms were plant chlorosis, wilting leaves, powdery patches, root rots, dark spots and yellow halos, yellow V-shaped lesions, drying leaves, whitish blisters, stunting and water-soaked lesions (Fig 3.2). The most significant symptoms observed were chlorosis and wilting leaves (P 0.05, Fig 3.2).
0 10 20 30 40 50 60 70 80
Chlorosis Stunting Whitish blisters Powdery patches Root roots Wilting leaves Water-soaked lesions Yellow V-shaped lesions Drying of leaves Dark Spots and Yellow halos
Percentages of observed disease symptom
Commonly occuring symptoms
Figure 3.2: Commonly observed deviation from normal plant growth (disease symptoms) according to farmers’ responses in Domboshava.
3.3.3 Farmer perceptions on seasonal disease incidence
The disease incidence and type in relation to seasonality based on farmers’ response to observed symptoms are presented in Fig 3.3. Fungal and bacterial disease incidence in the area are high at 84.6% and 73.1% respectively within a particular growing season. Most of these diseases occur during the winter season [May – July] (30.8%) and rainy season [Nov – Feb] (23.1%). The least diseases occur during the spring season [March – April] (3.8%). Fungal diseases were the biggest disease problem [84.6%], while the least were bacterial diseases [15.4%] experienced in Domboshava (Fig 3.3 – Fig 3.4).
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Figure 3.3: Farmers response disease incidence in relation to season type
Figure 3.4: Farmers response on experienced disease type and their occurrence
3.3.4 Rate of disease incidence and crop losses experienced by farmers
The varying percentage losses and disease infection rates respondents are experiencing in their cropping enterprises are shown in Fig 3.5. Our study revealed that 53.8% of the farmers, which is the largest number of respondents, indicated that they experience extreme to severe disease infection rates. The other 46.2% of the respondents’ indicated that the disease infection rates they
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incur are moderate to mild in nature. The study revealed that 30.8% of the respondents experienced major crop losses due to disease outbreaks (Fig 3.5). Whilst the remaining 34.6% of the respondents’ indicated that they incur high to very high losses as a result of disease incidence in their vegetable plots.
0 10 20 30 40 50 60
Extreme to Severe Infection Rates Moderate to Mild Infection Rates Major losses High to Very High Losses Moderate to Low Losses
Percentages of respondents Rate of disease Incidence and Crop Loss
Figure 3.5: Crop losses due disease experienced by farmers in Domboshava.
The largest population of respondents indicated that they experience ‘moderate to low’, and those experiencing ‘high to very high’ crop losses due to diseases in the area are not significantly different (P < 0.05, Fig 3.5).
3.3.5 Most common plant disease control methods practised by Domboshava farmers
Figure 3.6 is an indication of the most commonly adopted disease control methods as practised by the respondents in Domboshava. The results indicated that 96.2% of the respondents’ use chemical disease control methods in managing disease outbreaks in their vegetable plots. About 53.8% of the respondents’ rely on cultural methods to manage vegetable diseases, whilst 11.5% of the respondents’ rely on natural control methods involving living fences and distance between cropping fields. The minority 3.8% of the respondents rely on mechanical control methods.
However, none of the respondents rely on biologocal control methods involving botanical
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formulations or bio-pesticides. The differences in disease control methods existing among Domboshava farmers were significant (P < 0.05, Fig 3.6).
Figure 3.6: The most common disease control methods being practiced by farmers in Domboshava.
Cultural disease management strategies were also being implemented and these were significantly different from the natural control strategies being used by the farmers (P < 0.05). The results of this study also indicate that the adoption rate for using mechanical disease control strategies was significantly different from the other strategies (P < 0.05). However, none of the farmers used biological or bio-pesticide disease control strategies (Fig. 3.6).
3.3.6 Farmer perceptions on efficacy of chemical use and application frequency
About 65.4% of the respondents stated there has been an increase in chemical application frequency when managing vegetable diseases, with 34.6% stating there was no change in spraying frequency over the past 10 years (Fig 3.7). Furthermore, 76.9% of the respondents’ indicate that there is an increase in amount of chemicals being rotated in dealing with vegetable diseases whilst 23.1% indicate that there is no change in the number of chemicals being rotated. About 53.8% of the respondents indicated that chemical disease control methods are effective while the remaining 46.2% of the respondents indicated that chemicals are ineffective in achieving vegetable disease control. About 38.5% of the respondents indicated that they sprayed once/week, while 19.2% they
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sprayed twice/week, with the remaining 7.7% carring out disease control methods once/month.
However, 34.6% of the respondents were uncertain as to how frequent they carried out disease spraying programs in their vegetable plots (Fig 3.7)
Figure 3.7: Farmers’ Perceptions on chemical control efficacy on disease control and spraying frequencies