Appendix 3.6: Statistics for the importance of maize in Katumba ward
4.3 Results
4.3.8 The quality of maize stored using roof and sack storage methods .1 The incidence of insect infestations in grains at harvest .1 The incidence of insect infestations in grains at harvest
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4.3.8 The quality of maize stored using roof and sack storage methods
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whereas 20.7 % of the improved varieties were infested by S. zeamais only. These findings show that in Katumba ward a large number of farm households faced insect infestation of maize prior to storage, and that S. zeamais is the main insect pest in the ward, followed by S. cerealella.
Whether the agricultural extension staff members in Katumba ward are aware of the extent of these infestations is not known because the extension staff members were not interviewed.
Likewise, efforts to contact the Vulnerability Assessment Programme in Tanzania were not successful, whether they are aware of the infestations or whether they are implementing any mitigation strategies is not known.
4.3.8.2 The incidence of insect infestations in the maize samples that were collected after five months of storage
About 93.1 % of the maize samples collected from the farm households after five months of storage were infested by either S. zeamais or S. cerealella or both. The infestation ranged from 0- 210 insects per 120 maize kernels. About 43 % of the maize samples were infested by both S.
zeamais and S. cerealella and 50 % were infested by S. zeamais only. The mean for the number of insect pests per 120 maize kernels was 80 insect pests, standard deviation was 51.44. A greatest proportion of the maize samples were infested by more than 50 insect pests per 120 maize kernels (Table 4.20).
The findings also showed that 68.5 % of the maize samples were became infested during storage.
Thus, the percentage of infested maize samples increased from 24.6 % for the maize samples that were collected from freshly harvested maize to 93.1 % after the five months of storage.
Furthermore, after five months of storage, the number of insects in the maize samples collected from the same farm households where the 33 maize samples that were found to be infested at harvest were collected had increased tremendously (Figure 4.2). The mean quantities of insect pests from the maize samples that were collected at harvest was two insect pests per 120 maize kernels, amounting to 39 insects per kg of maize, and the average number of insect pests per 120 kernels of maize which was collected after five months of storage period was 80, amounting to 1569 insects per kg of maize. This implies that most of the insect infestation of maize took place during storage, and for the maize that was infested by the insect pests prior to storage the infestation intensified during storage. Through performing a Chi square test (Appendix 4.2) it
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was found that 88 % of the maize samples that were infested by insect pests were also infected by moulds.
Table 4.20: Levels of insect infestations per 120 kernels of maize which was collected after five months of storage period
Total number of insects per 120 maize kernels
Percent of infested maize samples (n = 130)
0 7.9
<10 7.7
11-50 15.4
51-100 33.1
101-200 34.6
>200 2.3
Total 100
Figure 4.2: Comparison of levels of insect infestation on maize samples infested prior to storage with that of maize collected from the same farm households after five months of storage
It seems that the extension services in Katumba ward have not paid attention to the problem of maize infestation during storage. Consequently, this creates room for fungal infection of maize, and maize losses to occur, which can lead to the vulnerability of the farm households to hunger, undernourishment and disease.
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4.3.8.3 The percentage ofinfested maize in relation to maize variety
It was found that 93.4 % of the indigenous varieties were also infested by the insect pests, while 92 % of the improved varieties of maize samples were also found to be infested by the insect pests. The infestation ranged from 0 - 210 insects per 120 kernels for the local varieties and 0 - 184 per 120 kernels for the improved varieties.
Moreover, 39.5% of the infested indigenous varieties were infested by S. zeamais only and 55.8
% were infested by both Sitophilus zeamais and S. cerealella. Out of the infested maize samples of the improved varieties, 55.2 % were infested by S. zeamais only and 36. 8 % were infested by both S. zeamais and S. cerealella. The mean number of insects per 120 maize kernels in the maize samples of the indigenous maize types was 91.26 and standard deviation was 52.69. The mean number of insects per 120 maize kernels in the maize samples of the improved varieties was 74.37 and standard deviation was 50.22. For both the landraces and the improved varieties of maize, more than 50 % of maize samples had more than 50 insect pests per 120 kernels. (Table 4.21). T - tests results showed that there was no significant difference between the means for the maize samples for the improved varieties and landraces (Appendix 4.6).
Table 4.21: The Level of infestation of the maize samples in relation to the types of seeds
Levels of insect s
Frequency Local varieties(n=43)
Frequency
Improved varieties(n=87) Total
0 4.7 8.0 12.7
1-10 2.3 10.3 7.7
11-50 16.3 14.9 15.4
51- 100 34.9 31.0 32.3
101-200 37.2 35.6 36.2
>200 4.7 0.0 1.5
Total 100 100 100
4.3.8.4 Effect of storage facilitieson percentage of maize infestation
About 90 % of the maize samples that had been collected from the roof storage facilities were infested by insect pests, 95 % of the maize samples collected from the sack storage facilities were also found to be infested by the insect pests. The number of insects in the maize samples from the roof storage facilities ranged from 0 - 203, while the number of insects in the maize samples from
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the sack storage facilities ranged from 0 - 210. The mean number of insects on maize samples from the roof storage facilities was 80.18, and standard deviation was 49.34. The mean number of insects on maize samples from the sack storage facilities was 79.67, and standard deviation was 55.24. The high infestation rate of maize stored using the two most popular storage methods in Katumba ward imply that the farm households are vulnerable to food insecurity. Furthermore, 42
% of the maize samples collected from the roof storage facilities were infested by both S. zeamais and S. cerealella and 50 % were infested by S. zeamais only. Also 45.2 % of the maize samples that were collected from the sack storage facilities were infested by both S. zeamais and S.
cerealella and 50 % of the maize samples collected from the sack storage facilities were infested by S. zeamais only. T-test results revealed that there was no significant difference between the mean number of insect pests in the maize samples from the roof and sack storage facilities (Appendix 4.5). Other details regarding the number of infested maize samples in relation to the storage facilities from which they were taken are as shown in Table 4.22.
Table 4.22: The level of infestations of the maize samples in relation to the storage facilities (n=130)