Hand Weeding Rice in Africa

In Ghana, recent farmer surveys show that herbicide use by rice farmers is high. The adoption of herbicides is not due to programs being promoted by international organizations. Rather, the high adoption is simply due to farmers learning about the benefits of herbicides from other farmers.

“There was strikingly high use of herbicide in rice plots, with 84 percent of rice area treated with herbicide across all rice ecologies. Fifty-eight percent of rice area was treated with herbicide before planting, and 69 percent of the area was treated with herbicide after planting.

The yield of plots with herbicide is significantly higher than that of plots without herbicide for all rice ecologies…. For irrigated plots with fertilizer and certified seed, there was a 3.1 ton/hectare difference between plots with and without herbicide.

A simple comparison of weeding costs suggests that farmers using herbicide spend 666 cedi/hectare total in purchasing herbicide (8 liters at 8 cedi/liter) and an additional 86 person-days for manual weeding, while farmers not using herbicide spend 1,477 cedi/hectare for manual weeding for 211 person-days on average. It is apparent from this calculation that it is cheaper to purchase herbicide than to hire or use family labor for weeding.

The diffusion of herbicide seems to be wide, and farmers are learning about it from other farmers. About half of farmers reported that they knew about herbicide and its benefits from advice by or observing other farmers’ plots. …This suggests that if a technology is beneficial, it can spread quickly among farmers.”

Authors: Ragasa, C., et al.
Affiliation: International Food Policy Research Institute.
Title: Patterns of Adoption of Improved Rice Technologies in Ghana.
Source: IFPRI. July, 2013. Working Paper #35. Available at: http://www.ifpri.org/publication/patterns-adoption-improved-rice-technologies-ghana