Farmer participation in agricultural research can improve the efficiency and impact of the research. This functional component of participatory research includes the identification of traits that guide crop breeders' work. Participatory research can also lead to farmer empowerment, although when carried out by research organizations, direct empowerment is often limited to relatively few farmers. Farmer empowerment is, therefore, best carried out by development organizations whose longer-term interaction with farmers is likely to ensure that greater numbers of farmers benefit. Hence, research organizations ought to focus on the functional components of participatory research along with the empowerment of intermediate/partner organizations rather than the direct empowerment of large numbers of farmers.

In most cotton-growing regions of West and Central Africa where rainfed conditions prevail, cropping conditions are highly diversified since the crop is planted over an extended period. We studied production and development patterns in 10 cotton (Gossypium hirsutum) varieties to determine the most efficient strategies that could be transformed into breeding traits. Four trials were carried out between 2002 and 2003 in two cotton-growing areas in Benin to compare the 10 varieties at three stand densities and two planting dates. The parameters monitored were the mean first flower opening date (FF), effective flowering time (EFT), plant height at harvest (HH), height to node ratio (HNR), length of fruiting branch (LFB), number of vegetative branches (NVB) and average boll retention at the first position of the fruiting branches (RP1). We identified two ideotypes that yielded better than the others: (i) Mar 88-214 performed well under late planting–high stand density conditions and was characterized by low vegetative growth and early flowering onset, a short flowering period and low RP1; (ii) H 279-1 performed especially well under early planting–low stand density conditions and was characterized by high vegetative growth, late flowering, long EFT and high RP1. We propose a breeding strategy for both ideotypes based on seven indicators with high heritability (FF, HH, HNR, and LFB) or medium heritability (NVB, EFT, and RP1).

Intercropping cereals with legumes for forage or food production is extensively used as a cropping practice in many parts of the world. A 2-year field study was conducted using common vetch (Vicia sativa), winter wheat (Triticum aestivum), triticale (× Triticosecale), barley (Hordeum vulgare) and oat (Avena sativa) sole crops as well as common vetch intercrops with each of these cereals in a 35:65 cereal:common vetch ratio based on seed numbers, to determine their ability to compete with sterile oat (Avena sterilis spp. sterilis). At nine weeks after planting, fewer sterile oat plants emerged in common vetch sole crop than in cereal sole crops. Intercropping of cereals with common vetch generally did not affect sterile oat stem number and biomass compared with cereal sole crops. At harvest, cereal sole crops provided greater total dry biomass (DB) than the common vetch sole crop. However, triticale and oat produced more DB than winter wheat and barley. In most cases intercropping reduced total DB compared with cereal sole crops. The results of this study indicated that intercropping of the four winter cereals with common vetch did not provide any significant competitive advantage against sterile oat. However, common vetch sole crop showed the greatest suppressive ability against sterile oat among the sole crops or intercrops studied.

Striga hermonthica is a parasitic weed that attacks maize, sorghum and other staple cereal crops and has long been considered one of the greatest biotic constraints to cereal production in Africa. Use of resistant or tolerant maize varieties, a maize–legume rotation using trap crops that stimulate suicidal germination of Striga and the application of nitrogen fertilizer are all effective in reducing infestation and damage. This paper reports on the use of a participatory research and extension approach in assessing the performance and scaling-up of integrated Striga control packages in three agro-ecological zones in Borno State, Nigeria. The participatory process which encourages close interaction between research, extension and farmers, involved 30 local communities and 228 farmers representing 193 farmer groups in identifying their own problems and seeking solutions to them. Results showed not only effective Striga control but productivity increases of over 200%. The involvement of local farmers and groups in the evaluation process, firstly, helped to confirm that Striga control can best be achieved using soyabean followed by Striga-resistant maize together with productivity-increasing management practices and, secondly, promoted farmer-to-farmer extension. A participatory adoption assessment exercise indicated widespread adoption of new varieties and management practices, despite the need for increased labour. Great potential exists to scale out the results to similar areas of Guinea and Sudan savannas in the West Africa region.

Trials in Kenya have shown that yields of tea clones can be increased significantly by grafting onto suitable rootstocks, with the best combinations giving profitable yield increases compared to straight cuttings. However, stock × scion interactions were significant, and not all clones gave useful responses to grafting even onto the best rootstocks, so combinations must be tested individually before commercial planting is considered. The effect of grafting was to increase the number of shoots harvested, with little change in mean shoot weight. Grafting had little or no effect on quality of the tea produced. Attempts to find a method of identifying good rootstocks without testing them in grafting trials were inconclusive.

A growth analysis study involving monthly excavation of Dioscorea esculenta plants revealed that the root system developed fully in the period before tuber initiation, and extended radially for a distance between 2.3 and 4.3 m. Primary roots initially remained in the top 10 cm of the soil profile, but descended to approximately 30 cm near their full extension. Tuber number increased from initiation around 21 weeks after planting (WAP) until maximum vine growth was reached around 33 WAP, but tuber dry weight continued to increase throughout the senescence period of the vine, to 45 WAP. Tubers lost dry matter but not fresh weight during dormancy in the soil, to 55 WAP. The results indicate that a distance of at least 4.5 m is required to separate experimental fertilizer treatments, and that post-establishment burial of fertilizers around the mound or ridge risks damage to roots near their base, while inter-row application is accessible to roots and may be preferable.

A series of experiments was conducted on rice seedlings in a nursery seedbed and after transplanting in order to understand root and shoot characteristics, and their contribution to the production of tillers and dry matter. At the nursery stage, the seedlings' were studied at varying densities (high and low) and fertilizer treatments (with and without nitrogen) at 12 and 24 days after sowing (DAS) in wet or dry seedbeds. After transplanting, the effects of seedling age at the time of transplanting (12 and 30 days), method of raising seedlings (dry or wet seedbed) and water regimes (flooded or non-flooded) were studied. The overall aim was to understand the benefits, if any, of this system of rice intensification (SRI) management practices over conventional methods. The study revealed that in a nursery at 12 DAS, rice seedlings raised in a dry seedbed, irrespective of seeding density and fertilizer application, showed accelerated growth with better shoot and root characteristics in terms of greater leaf number, plant height, lateral root formation and elongation, and dry mass compared to seedlings grown in a wet seedbed. At 24 DAS, a significant interaction between seeding density and fertilizer application was found for dry-seedbed plants compared to those grown in a wet seedbed. Poor shoot and root growth was seen in older seedlings grown without fertilizer. Seedling age was found to be the most important factor affecting both shoot characteristics after transplanting (number of tillers, plant height, dry matter production) and root characteristics (root length density, root weight density). Younger seedlings performed better than older seedlings transplanted into either flooded or non-flooded soils with greater uptake of nitrogen and manganese than older seedlings. These results indicate that many of the constraints previously associated with non-flooded rice cultivation may be alleviated by transplanting younger seedlings that have been raised by SRI methods.

This paper assesses farmer adoption of rice varieties and new genotypes introduced through participatory varietal selection (PVS) in villages which represent submergence- and drought/submergence-prone villages in eastern Uttar Pradesh, India. It focuses on the involvement of women farmers in participatory research for screening improved varieties for areas which suffer from abiotic stresses. It further assesses the impact on the decision-making authority (or women's empowerment) on rice varietal choice, seed acquisition and disposal, and crop management after participating in PVS trials. It suggests strategies to empower women farmers in making sound and timely decisions on farm-related matters and to enhance their roles in accelerating the adoption of new varieties.

Few references are available on collaborative monitoring and evaluation, that is, how diverse organizations promoting similar innovations can together assess their efforts. We examined the experience of 30 organizations in working together in western Kenya, from 1999 to 2003, assessing their impact in helping farmers to adapt and adopt two soil fertility practices. While the collaborative process improved the flow of information among organizations, it did not reduce monitoring costs, but rather increased them. The process increased participating organizations' awareness of farmer innovations and the number being promoted. The process also contributed to the formation of a consortium among the participating organizations. We viewed the benefits of the collaborative approach as greater than the costs, but recognize that the resources for implementing such exercises may often not be available.

Strontium was used as a tracer to detect root activity of yam (Dioscorea alata) at distances from 0.5 to 5.5 m from the plant's crown, and at depths of 7, 15, 25 and 40 cm, in field plantings separated by plastic root barriers. Tracer bands were installed at planting, and leaves were sampled at intervals throughout the growing season. Background Sr concentrations in leaves were found to be closely related to leaf Ca concentrations, allowing the expected background Sr to be calculated from the Ca concentration in each sample. The ratio of observed to expected Sr did not alter significantly with time of sampling or leaf age for control plants providing a robust parameter for comparison across harvests. Plants at all horizontal distances from the Sr placement up to 5.5 m showed significant elevation of leaf Sr by 13 weeks after planting (WAP). The depth placement at 15 cm showed earliest Sr elevation, followed by the 7 cm placement. However, both 25 cm and 40 cm placements resulted in significant leaf Sr elevation by 13 WAP, and their final Sr concentrations at 27 WAP did not differ significantly from those of shallower placements. Three fertilizer placement options were compared with respect to Sr uptake by the treated plants and by those in adjacent rows. Placement in a ring around the crown of the seed sett resulted in high leaf Sr concentration at 5 WAP, declining considerably at subsequent samplings. Placement underneath the seed sett produced a similar pattern but at lower concentrations. Banding midway between the plant rows, 0.5 m from plants, yielded a small increase at 5 WAP increasing to 13 WAP, and ultimately attaining similar concentrations to the other two placements. Plants in adjacent rows significantly accessed all three placements by 13 WAP. The results indicate greater reach of yam roots, both horizontally and vertically, than has been previously reported, and raise concerns about the adequacy of treatment separation in previously published fertilizer experiments with yams.

A field experiment was conducted in 2002/03 (year 1) and repeated in 2003/04 (year 2) to study the competitive ability of 10 winter barley (Hordeum vulgare) cultivars against common poppy (Papaver rhoeas) and ivy-leaved speedwell (Veronica hederifolia). The phytotoxic (or allelopathic) activity of barley extracts was also determined in the laboratory using a perlite-based bioassay with barnyard grass (Echinochloa crus-galli). In the field, biomass of both weeds was reduced more (65–79%) by the competition of Alpha, Esterel, Terova or Lignee 640 barley cultivars, than with Aspen or Tersey. Biomass of ivy-leaved speedwell in competition with each barley cultivar was significantly lower than that of common poppy. In year 1, the six-row barley cultivars caused greater weed biomass reduction than the two-row, but this was not the case in year 2. Grain yield of Tersey, Aspen and Goldmarker cultivars in herbicide treatments was greater by 41, 33 and 17%, respectively, than from the corresponding herbicide untreated plots. However, grain yield of Terova, Alpha, Esterel and Lignee 640 was not significantly affected by the presence of weeds. In the laboratory, barley extracts affected the total fresh weight or root length of barnyard grass more than its germination. The germination, root length or total fresh weight inhibition on barnyard grass caused by the two six-row barley extracts was greater (43, 48 and 56%, respectively) than that caused by the eight two-row extracts (22, 34 and 43%, respectively). The results of this study indicated that barley cultivars with great competitive and/or phytotoxic ability could be used in sustainable cereal production systems in order to minimize herbicide usage.

The drought tolerance of tea clones in Kenya can be improved by grafting onto appropriate rootstocks, with more susceptible clones showing greater improvement. It appears that drought may have distinct effects on rootstock and scion, with rootstock performance correlated with xylem water potential, while scion performance was correlated with stomatal conductance. Drought tolerance is not the only requirement for a rootstock under Kenyan conditions, however, and the most tolerant rootstocks do not necessarily give the greatest overall yield increase when non-drought years are included.

Good management of natural resources is the key to good agriculture. This is true everywhere – and particularly in the semi-arid tropics, where over-exploitation of fragile or inherently vulnerable agro-ecosystems is leading to land and soil degradation, productivity decline, and increasing hunger and poverty. Modern crop varieties offer high yields, but the larger share of this potential yield can only be realized with good crop management. The International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), working over a vast and diverse mandate area, has learned one key lesson: that technologies and interventions must be matched not only to the crop or livestock enterprise and the biophysical environment, but also with the market and investment environment, including input supply systems and policy. Various Natural Resource Management (NRM) technologies have been developed over the years, but widespread adoption has been limited for various reasons: technical, socio-economic and institutional. To change this, ICRISAT hypothesizes that ‘A research approach, founded on the need to integrate a broad consideration of technical, socio-economic and institutional issues into the generation of agricultural innovations will result in a higher level of adoption and more sustainable and diverse impacts in the rainfed systems of the semi-arid tropics.’ Traditionally, crop improvement and NRM were seen as distinct but complementary disciplines. ICRISAT is deliberately blurring these boundaries to create the new paradigm of IGNRM or Integrated Genetic and Natural Resource Management. Improved varieties and improved resource management are two sides of the same coin. Most farming problems require integrated solutions, with genetic, management-related and socio-economic components. In essence, plant breeders and NRM scientists must integrate their work with that of private and public sector change agents to develop flexible cropping systems that can respond to rapid changes in market opportunities and climatic conditions. The systems approach looks at various components of the rural economy – traditional food grains, new potential cash crops, livestock and fodder production, as well as socio-economic factors such as alternative sources of employment and income. Crucially the IGNRM approach is participatory, with farmers closely involved in technology development, testing and dissemination. ICRISAT has begun to use the IGNRM approach to catalyse technology uptake and substantially improve food security and incomes in smallholder farm communities at several locations in India, Mali, Niger, Vietnam, China, Thailand and Zimbabwe.

Small ruminants are an integral part of mixed-farming systems throughout southern Ethiopia. Yet, they have received little research attention or institutional support. Characterizing the existing small ruminant production systems and analysing their production constraints are important tools to diagnose the status and trends of the systems, and thus to identify areas for future interventions. A survey was conducted between April and July 2004 in the Adilo and Kofele areas of the southern mixed-farming systems of Ethiopia to explore reasons for keeping small ruminants and to evaluate the existing status of and the prospects for the small ruminant sector. Additional information was obtained during discussions with key informants who had experience of small ruminant keeping. Small ruminants fill several roles in the study area. However, the principal purpose of keeping sheep and goats was to generate cash income. Sheep milk consumption was widespread around Kofele unlike most agricultural systems in the country. Nearly all respondents in Adilo reported fattening their sheep before sale, while such a practice was uncommon in Kofele. Informal insurance schemes were evolving among the sheep keepers in Adilo, and these can be considered as entry points for future interventions. The common problem identified from both individual interviews and group discussions was feed shortage. The identification of alternative feed resources and strategic feeding management might be options for development. Small ruminant disease was the major constraint in Kofele, where marshy areas are increasingly assigned for grazing in the rainy season as suitable land is more and more used for cropping. The growing demand for meat from small ruminants, the improving transportation infrastructure and the experience of farmers in small ruminant keeping are providing opportunities to enhance the contribution of the sector. A thorough monitoring of the productive and economic performance of small ruminants is required to capture the full picture of their contribution thereby directing possible intervention areas to maximize benefits to the farmers.

Spatial variability among experimental units is a common problem in field experiments on tree crops such as tea (Camellia sinensis). Spatial variability is partly accounted for by blocks, but a substantial amount remains unaccounted for and this may lead to erroneous conclusions. In order to capture spatial variability in field experiments on tea, six commonly used spatial analysis techniques were investigated: Covariate method with pre-treatment yield as the covariate, Papadakis and the Modified Papadakis nearest neighbour adjustments, Moving means and Modified moving means methods, and Autoregressive method. The data from long-term fertilizer experiments and cultivar evaluation trials, conducted at different locations by the Tea Research Institute of Sri Lanka, were used in the study. Spatial techniques were evaluated by means of their relative efficiency at each location and year. Evaluation of the four neighbour methods analysed in conjunction with the pre-treatment yield, revealed that spatial variability due to both past and current conditions are operative, especially in experiments with large blocks, and could be captured simultaneously. Relative efficiencies averaging 141% clearly indicated that the neighbour techniques in combination with pre-treatment yield would be effective in controlling the experimental error in tea experiments with large blocks (nine plots per block or more). Experiments with small blocks were not affected by spatial variability due to past conditions and only that due to current conditions need to be addressed. Neighbour techniques, on their own, were found to be adequate to capture spatial variability due to current conditions. The modified Papadakis technique was found to be the best with an average relative efficiency of 145%. The techniques investigated in the study can easily be implemented using standard statistical software. The precision of tea experiments could be increased by using covariate analysis with pre-treatment yield and any one of the four nearest neighbour adjustments tested, when the block size is large; and modified Papadakis technique, on its own, when the block size is small.

This study examines the role, structure and effectiveness of informal seed systems in the diffusion of new barley varieties. It uses data collected by tracing farmers who received new barley varieties and other farmers who purchased seeds through farmer-to-farmer seed trade over a period of five years. The principal finding was that informal farmer-to-farmer seed dissemination was an important vehicle for the diffusion of new barley varieties, which were grow on 27% of the barley area of monitored farmers, despite a complete lack of extension support. Almost all seed exchanges were undertaken through purchases at market prices, highlighting the importance of markets in informal seed systems. The second main finding was the high concentration of seed sales among a few key seed suppliers, who established reputations as reliable sources of seed and had contacts with research organizations. The importance of market-based local seed transactions implies that farmers specializing in seed sales can invest in local seed enterprises and provide sustainable services at affordable prices. The results of this study indicate great potential for supporting local seed suppliers in order to ensure a sustainable flow of new crop varieties to smallholder farmers in the dry areas. The study also examined farmers' criteria in evaluating and eventually adopting a new variety. These criteria depend on agro-ecological zones with more complex criteria in drier areas with high rainfall variability. These findings will help plant breeding programmes to target dry and marginal areas, where access to new varieties is low, more effectively.

A study was carried out to identify the factors that contributed to the natural spread and uptake of a rainfed rice variety named Agya Amoah in the Western Region of Ghana after introduction of a small amount (0.5 kg) of seed in 1987 by a small-scale farmer. Fifteen years after its introduction over 73% of rice farmers had grown the variety in the Western Region. Initial awareness of the variety was created by information provided mainly by friends, seeing the variety grown in fields and from relatives. Seed for initial planting of the variety was purchased from other farmers by 67% of farmers, but in the most recent season 77% of farmers used their own saved seed. Annual incremental income per household from the replacement of the previously most widely grown variety with Agya Amoah was estimated to be US $282. The results show that informal systems can result in relatively fast spread and extensive uptake. Local seed systems need to be understood to design appropriate activities that are likely to lead to rapid spread and equitable distribution of introduced varieties, irrespective of characteristics such as wealth and kin.

With increasing land-use pressure in semi-arid, dryland Middle Eastern agriculture, fallow-based cereal production has given way to cropping intensification, including legume-based rotations along with conservation tillage and on-farm straw disposal. Such agronomic developments can only be biologically and economically assessed in multi-year trials. Thus, this 10-year study examined the influence of tillage systems (conventional and shallow or conservation) and variable stubble management, including compost application, on yields of barley and vetch grown in rotation. Barley yielded higher with compost applied every two or four years than with burning or soil-incorporating the straw and stubble. Barley straw and grain yields were generally higher with the mouldboard plough. Similarly with vetch, treatments involving compost application yielded significantly higher than burning or incorporating the straw and stubble. Despite yearly differences between crop yields, the pattern of treatment differences was consistent. Thus, the cereal–vetch rotation system is sustainable, while excess straw could be used as compost with benefit to the crop. Though there was no clear advantage of the shallow conservation-type tillage, the energy costs are less, thus indicating its possible advantage over conventional deep tillage in such rotational cropping systems