natural pest predators). Gianessi and Williams (2011) contend that herbicide use, in particular, remains a major unexploited means of increasing yields and saving labor on SSA farms.

In their global analysis, Zhang, Jiang, and Ou (2011) found that only 3 percent of global pesticide consumption came from Africa while 2 percent of all pesticide consumption came from South Africa alone, leaving only 1 percent for the remainder of the continent. In their review, Abate, van Huis, and Ampofo (2000) find that most pesticide use in SSA is on commercial export crops—coffee, cotton, cocoa—which means most pesticide use in the region is predicted to be used for fighting migratory pests like locusts not the larger set of possible yield inhibitors. Because most analysis of this sort relies on official government estimates using outdated data and given even limited household-level evidence showing a steady increase in pesticide use over time (Williamson, Ball, Pretty 2008) and findings that households source pesticides from unregulated and informal markets (Williamson 2003), these figures might dramatically understate pesticide use in Sub-Saharan Africa.

Again, the statistics provided by FAOSTAT represent, to the best of our knowledge, the only cross-country comparable evidence of low agro-chemical use. Even then, data are inconsistently available across years and is over a decade old for several countries. Table 3 provides the most recently available data by country. Because of inconsistently collected data, we are unable to provide a regional average estimate for any year in the recent past. Comparing use rates to those found in large-scale household surveys provides a great challenge. In studies with the largest and most recently collected data that we found, only the percentage of households using agrochemicals was provided. Those numbers, where available, are included in Table 3 as a reference and comparison.

Table 3: Total agro-chemical use per hectare of cultivated land

||FA<br>|OSTAT<sup>~~1~~</sup> (va<br>|riousyears)–<br>|average appli<br>|cation rate(kg<br>|/ha)<br>|Literature review<sup>~~2~~</sup><br> <br>|
|---|---|---|---|---|---|---|---|
||Year|Pesticides|Insecticides|Herbicides|Fungicides|Total|%hh using<br>Source|
|Ethiopia|2001|0.003|0.012|0.039|0.001|0.055|21<br>Taffesse (2008)|
|Malawi|2009|0.028|-|-|-|0.028|3<br>Zezza et al. (2007)|
|Niger|2010|0.001|0.001|-|-|0.002|-<br>-|
|Nigeria|-|-|-|-|-|-|10.5<br>Akramov (2009)|
|Tanzania|1997|0.001|0.002|0.002|-|0.005|-<br>-|
|Uganda|1995|0.001|0.006|0.001|0.004|0.013|3<br>Okoboi(2010)|

Sources:<sup>~~1~~</sup> FAOSTAT. Data presented from most recently available year. Many different types of agro-chemicals categorized into four categories by authors. Cultivated land defined as arable land plus land under permanent crop. See more details at FAOSTAT.<sup>2</sup> From review of literature. See Appendix 1 for other studies and details.

Some argue that increased use of pesticides in SSA should not be applauded given the many negative environmental and health externalities that farmers often do not consider (Wilson and Tisdell 2001). Also, because overuse of pesticides can exacerbate the problem of unwanted pests by encouraging the growth of resistant pests, incorrect application practices can spur increased pest pressure and reliance on stronger and more dangerous chemicals over time. Because of this, the academic literature has mostly focused on the negative health and environmental context surrounding often unregulated pesticide use (e.g., Antle and Pingali 1994) instead of garnering a better picture of who is using pesticides and the possible correlation of agro-chemical use with other variables. A larger set of integrated pest management techniques is often suggested as an alternative (Grzywacz et al. 2013).

6