Farmers' practices and their knowledge of biotic constraints to sweetpotato production in East Africa

Abstract

Sweetpotato (Ipomoea batatas) is a vital crop for overcoming food insecurity in sub-Saharan Africa and its production is highest in East Africa where yields are high and the growing seasons are short. This cross-country study assessed farmers' local practices and their knowledge of the biotic constraints to sweetpotato production in Uganda, Rwanda, Kenya and Tanzania with the aim of providing empirical data that can ultimately be used to enhance sweetpotato production in these four countries. We collected data from 675 households using a standardized questionnaire integrated with a web-based mobile app. Survey results provided strong evidence that sweetpotato is valued as an important subsistence crop among smallholder farmers on pieces of land of less than 0.4 ha, and we observed that females were more involved than males in sweetpotato production. Sweetpotato was ranked as the second most important staple crop after cassava. Farmers noted an increase in sweetpotato production over the past five years in Uganda and Kenya but a decrease in Rwanda and Tanzania; the proportion of farmers who reported a decrease (33%) and an increase (36%) did not significantly differ. The main constraints to production were reported to be pests (32.6%), drought (21.6%), diseases (11.9%) and lack of disease-free planting materials (6.8%). Farmers recognized the signs and symptoms associated with sweetpotato diseases on leaves, root tubers, and whole plants, but most were unable to assign the disease type (bacterial, fungal or viral) correctly. We suggest that regional governments improve education, increase the provision of clean planting materials and strengthen breeding programs to improve disease resistance.

Keywords: Food security; Ipomoea batatas; Kenya; Rwanda; Sweetpotato; Tanzania; Uganda.

Fig. 1

Map of Rwanda, Uganda, Kenya and Tanzania showing the localities surveyed in this study. Colored circles represent sampling sites in Uganda (363 sites, green), Kenya (110, red), Rwanda (101, black) and Tanzania (101, yellow). The inset map shows the geographical positions of the four countries in Africa. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

Fig. 2

Conceptual model from data capture to analysis.

Fig. 3

Numbers of farmers surveyed by gender and country: Uganda (n = 363 surveys), Kenya (n = 110), Tanzania (n = 101) and Rwanda (n = 101).

Fig. 4

The results of the survey ranking the importance of sweetpotato as a staple crop, divided by the gender of the respondent and using a 1–5 scale where 1 is the most important and 5 the least important. Surveyed farmers were from Uganda (n = 363 surveys), Kenya (n = 110), Tanzania (n = 101) and Rwanda (n = 101).

Fig. 5

Ranking of sweetpotato as a staple crop by farmers in Uganda (n = 363 surveys), Kenya (n = 110), Tanzania (n = 101) and Rwanda (n = 101).

Fig. 6

Sweetpotato cultivated areas compared with other crops across the different agroecological zones in Kenya (KE), Rwanda (RW), Tanzania (TZ) and Uganda (UG), according to farmers in Uganda (n = 363 surveys), Kenya (n = 110), Tanzania (n = 101) and Rwanda (n = 101).

Fig. 7

Sweetpotato seedbed types reported by farmers surveyed in Uganda (n = 363 surveys), Kenya (n = 110), Tanzania (n = 101) and Rwanda (n = 101), and in all four countries combined (N = 675).

Fig. 8

Source of planting materials reported by farmers surveyed in Uganda (n = 363 surveys), Kenya (n = 110), Tanzania (n = 101) and Rwanda (n = 101), and in all four countries combined (N = 675).

Fig. 9

Most serious constraints to sweetpotato production reported by farmers surveyed in Uganda (n = 363 surveys), Kenya (n = 110), Tanzania (n = 101) and Rwanda (n = 101), and in all four countries combined (N = 675).

Fig. 10

Sweetpotato disease symptoms observed on leaves, plants and tubers as reported by farmers surveyed in Uganda (n = 363 surveys), Kenya (n = 110), Tanzania (n = 101) and Rwanda (n = 101), and in all four countries combined (N = 675).

Fig. 11

Observations associated with diseases and pests of sweetpotato plants, as reported by farmers surveyed in Uganda (n = 363 surveys), Kenya (n = 110), Tanzania (n = 101) and Rwanda (n = 101), and in all four countries combined (N = 675).