Ecosystem services in cassava intercropping: a global synthetic review

Intensification and extensification of agriculture are eroding the integrity of tropical ecosystems. As global land comes under increasing anthropogenic management, considering the impacts of management practices on ecosystem services (ES) is essential. Cassava (Manihot esculenta Crantz) cultivation has expanded dramatically in the tropics, currently representing over 25 million hectares managed by millions of smallholders (Fig. 1). Diversification is often cited as a strategy for augmenting the functioning of ES in agricultural landscapes (Brooker et al., 2015; Kremen & Miles, 2012). Despite this, attempts to comprehensively evaluate diversification practices in cassava from an ES perspective remain rare. We conducted a systematic literature review of intercropping in cassava cultivation systems, and employed the concept of ES bundles to evaluate the impacts of diversification on a key set of ES

On-farm diversity offsets environmental pressures in tropical agroecosystems: A synthetic review for cassava-based systems

Peer Revie

Linking up: The role of institutions and farmers in forage seed exchange networks of Southeast Asia

In Southeast Asia, access to improved forages remains a challenge for smallholder farmers and limits livestock production. We compared seed exchange networks supporting two contrasting livestock production systems to identify bottlenecks in seed availability and determine the influences of the market, institutions, and cultural context of seed exchange, using interview-based methods for ‘seed tracing’ and network analysis. Government agencies were the primary sources of high-quality genetic materials, with secondary diffusion in the Philippines dairy case being dominated by key individuals in active cooperatives. In the Vietnamese beef-oriented production context, farmer to farmer dissemination was more substantial. In both cases, formal actors dominated where botanical seed was exchanged, while farmers frequently exchanged vegetatively propagated materials among themselves. To improve access to forage seed in these contexts, government agencies and development actors should coordinate quality seed production upstream while supporting the creation of appropriate training, structures, and incentives for seed exchange network improvement downstream

Susceptibility of cassava varieties to disease caused by Sri Lankan cassava mosaic virus and impacts on yield by use of asymptomatic and virus-free planting material

Cassava (Manihot esculenta Crantz) is a rainfed, smallholder-produced crop in mainland Southeast Asia, and is currently facing a serious challenge posed by the introduction of cassava mosaic disease (CMD). This study assessed the susceptibility of popular Asian varieties to CMD, yield penalties associated with the disease, and the efficacy of selecting clean or asymptomatic plants as seed for the following season. Field experiments evaluated agronomic management practices (ie, fertilizer application, use of symptomatic and asymptomatic seed stakes) in Cambodia with six to nine popular varieties over three seasons under natural disease pressure. Popular cassava varieties KU50 and Huaybong60 showed superior CMD tolerance, with consistently fewer symptomatic plants, lower disease progress measures, and higher yields. Plants demonstrating symptoms at early stages of development, ie, 60 days after planting, yielded significantly less than those developing symptoms later (ie, 270 DAP) or not at all. Plants grown from clean stems yielded on average 20% to 2.7-fold higher than those grown from symptomatic planting material. A yield decline of~ 50% was recorded with symptomatic planting materials of susceptible varieties (eg, SC8,~ 25 t ha− 1) over successive years. The findings emphasize that farmers could use positive selection by choosing asymptomatic plants to significantly reduce yield losses

Cassava rapid stem multiplication tunnel: Construction manual

This manual will teach you how to build a rapid stem multiplication tunnel based on CIAT’s experiences in Colombia and Lao PDR . These tunnels have been developed by CIAT and tested in South America and Asia, proving to be practical solutions for rapid production of clean planting materials