The coffee berry borer (Hypothenemus hampei) is the most devastating insect pest of coffee worldwide with its infestations decreasing crop yield by up to 80%. Caffeine is an alkaloid that can be toxic to insects and is hypothesized to act as a defence mechanism to inhibit herbivory. Here we show that caffeine is degraded in the gut of H. hampei, and that experimental inactivation of the gut microbiota eliminates this activity. We demonstrate that gut microbiota in H. hampei specimens from seven major coffee-producing countries and laboratory-reared colonies share a core of microorganisms. Globally ubiquitous members of the gut microbiota, including prominent Pseudomonas species, subsist on caffeine as a sole source of carbon and nitrogen. Pseudomonas caffeine demethylase genes are expressed in vivo in the gut of H. hampei, and re-inoculation of antibiotic-treated insects with an isolated Pseudomonas strain reinstates caffeine-degradation ability confirming their key role.

The International Maize and Wheat Improvement Center (CIMMYT) acts as a catalyst and leader in a global maize and wheat innovation network that serves the poor in the developing world. Drawing on strong science and effective partnerships, CIMMYT researchers create, share, and use knowledge and technology to increase food security, improve the productivity and profitability of farming systems and sustain natural resources. This peoplecentered mission does not ignore the fact that CIMMYT's unique niche is as a genetic resources enhancement center for the developing world, as shown by this review article focusing on wheat.

Journal articleIFPRI3; ISIEPTDP

In order to update the available information on the main current and future constraints on wheat production and human capacity development, a survey covering nineteen developing countries, including major wheat producers, was conducted prior to the 2006 International Symposium on Increasing Wheat Yield Potential in Ciudad Obregon, Mexico. The results emphasize the substantial yield losses associated with a number of critical abiotic, biotic and socioeconomic constraints, and indicate their global prevalence. The most important constraints on wheat production are heat (aVecting up to 57% of the entire wheat area in surveyed countries), competition with weeds, and diseases (both aVecting up to 55% of wheat area). Of the socioeconomic constraints listed and evaluated by respondents, access to mechanization and availability of credit were the most often highlighted. The most-reported infrastructural constraints were insuYcient resources for Weld station operations. When evaluating the importance of research partnerships to achieve national wheat program goals, respondents from all 19 countries assigned the highest importance to partnerships with international agricultural research centers. The most desired outputs from these include development and exchange of germplasm and assistance in capacity building and knowledge sharing. These Wndings conWrm the anticipated constraints and needs over the next 10-20 years and aYrm the importance of international agricultural research centers in providing support to address them.

During the past century wheat breeders have produced a large number of genetically improved wheat lines and varieties. This activity has led to widespread adoption of improved varieties, a steady increase in average wheat yields during the past 4–5 decades and major contributions to food security and poverty reduction. The rate of generation and adoption of improved varieties, and therefore the time lag from varietal release to widespread use, varies across regions. The remarkable success of wheat improvement hinges on the decisions of millions of farmers to adopt, or replace older wheat varieties with superior material. The present paper summarizes studies on the determinants of adoption. Because adoption is a necessary but not sufficient condition for economic impact, the present paper synthesizes key assessments of impact from different farming systems in developing countries.

Agricultural research has contributed enormously to poverty reduction and increased food security worldwide. Wheat crop improvement is a good example of this contribution. Public investments in wheat research from the Green Revolution onwards led to significant productivity increases: following the widespread adoption of semi-dwarf varieties, annual yield growth rates peaked at 2·75% p.a. in the 1980s. Since then, public and private investments in crop (including wheat) research have been modest despite the potential of such research to contribute substantially to the first Millennium Development Goal (MDG) of halving hunger and poverty by 2015. Drawing on a wide spectrum of recent literature, the present paper broadens the usual frame of reference for diagnosing the adoption of improved technology and measuring impact. The adoption of improved varieties and management practices is influenced on the supply side by the nature and performance of the input delivery pathway from research to the farm (input value chains), and on the demand side by the characteristics of the farm household system and the marketing or value-adding chains from the farm to the consumer (output value chains). These three elements (input value chains, farm household system characteristics, and output value chains) can be viewed as a U-impact pathway. This pathway determines the rate and extent of adoption of improved varieties and practices, the magnitude of direct and indirect impacts, and the potential for feedback loops leading to improved functioning of the input and output value chains. The U-impact pathway provides a framework to identify an expanded set of beneficiaries from crop improvement which extend beyond the common focus on producers and final consumers; conventional surplus analysis can then be used to estimate the wider benefits to crop improvement. Additional metrics may be needed to estimate impact related to non-economic benefits, such as poverty, health and social capital. The implication of this fuller accounting of impacts is that the benefits accruing to agricultural research may be greater, and more widely distributed across the economy, than previously recognized by research managers and policy-makers. This strengthens the case for maintained or increased public and private sector investment in crop improvement.

To ensure future food security, there is an urgent need for improved co-ordination of agricultural research. While advances in biotechnology hold considerable promise, significant technology gaps exist that may reduce their impact. Examples include an incomplete knowledge of target breeding environments, a limited understanding and/or application of optimal crop management practices, and underfunded extension services. A better co-ordinated and more globalized approach to agricultural research through the implementation of Global Crop Improvement Networks (GCIN) is proposed. Such networks could underpin agricultural research and development by providing the following types of services: (i) increased resolution and precision of environmental information, including meteorological data, soil characteristics, hydrological data, and the identification of environmental 'hotspots' for a range of biotic, abiotic, and socio-economic constraints; (ii) augmented research capacity, including network-based variety and crop management trials, faster and more comprehensive diagnosis of emerging constraints, timely sharing of new technologies, opportunities to focus research efforts better by linking groups with similar productivity constraints and complementary skills, and greater control of experimental variables in field-based phenotyping; and (iii) increased communication and impacts via more effective dissemination of new ideas and products, the integration of information globally to elicit well-timed local responses to productivity threats, an increased profile, and the publicity of threats to food security. Such outputs would help target the translation of research from the laboratory into the field while bringing the constraints of rural communities closer to the scientific community. The GCIN could provide a lens which academia, science councils, and development agencies could use to focus in on themes of common interest, and working platforms to integrate novel research approaches on crop adaptation and rural development.

A survey of stored product pests, their natural enemies, grain storage and pest management approaches in northern Namibia was conducted. The survey revealed five types of crop commodities (pearl millet, sorghum, cowpea, maize, feed mixture) stored in four types of grain stores (baskets, bag stags-flat stores, concrete bin, metal containers). No synthetic pesticides or plastic sheeting was recorded. Wooden-ash natural pesticide is the only protectant used. Ten insect pest species were found affiliated to the orders of Coleoptera (Attagenus fasciatus, Callosobruchus subinnotatus, Cryptolestes ferrugineus, Oryzaephilus surinamensis, Rhyzopertha dominica and Tribolium castaneum), Lepidoptera (Corcyra cephalonica, Sitotroga cerealella), Psocoptera (Liposcelis paeta) and Blattodea (Blattella germanica). Out of these, seven species were recognized as new stored-products pests for Namibia. Although listed for southern Africa region, no storage pest-mites (Acari) and Sitophilus spp., Prostephanus sp. or Trogoderma sp. beetles were traced. We found four new species of natural enemies of storage pests recruiting from insects (Habrobracon hebetor, Cephalonomia wattersoni, Brachymeria sp.) and mites (Blattisocius tarsalis). The occurrence of natural enemies indicates a potential for pest bio-control in Namibian grain stores.