Caught off guard: folk knowledge proves deficient when addressing invasive pests in Asian cassava systems

Abstract

Farmers’ knowledge, attitudes, and beliefs are of paramount importance in shaping the on-farm adoption and diffusion of integrated pest management (IPM). In particular, for invasive pests, this (gendered) knowledge base can dictate how fast and effective farmers respond to emerging threats. In this study, we employ qualitative and quantitative methods to assess agro-ecological knowledge and pest management behavior of small-scale cassava growers in rural Vietnam and Laos, when faced with two new biotic threats, i.e., the invasive cassava mealybug Phenacoccus manihoti and cassava witches broom disease. Despite their pronounced impact on crop yields, farmers overall had limited knowledge of recent invaders and regularly ascribed their appearance to “climate change". Growers were largely unaware of preventative tactics for pest control, and resorted to curative measures (e.g., unguided pesticide sprays) at the P. manihoti invasion front. Farmers’ attitudes toward invasive pests were highly context- and locality-dependent, and knowledge scores differed between households positioned along a gender continuum. Though women assumed a minor role in IPM decision-making and possessed comparatively deficient knowledge, they favored agro-ecological approaches and took on key tasks in the selection of propagation material. Gender roles in cassava crop protection are equally context-dependent, yet women may be well-positioned to promote IPM practices such as the use of disease-free planting material. Future extension should thus pay attention to (a) strengthening (women) farmers’ knowledge base, to empower them as change agents and drive IPM adoption, and (b) transferring local innovations between sites, eventually through visual educational aids. Given the increasing importance of invasive pests in many developing countries, our work emphasizes how adult education and (adaptive) co-learning should become core components of mitigation programs.