The development of two simple techniques, box storage and field clamps, which allow curing and storage of fresh cassava roots for 1 and 2 month periods, is described. Consistent and acceptable results have been obtained following storage of roots in boxes packed in moist but not wet sawdust and kept at ambient temperatures. The design of field clamps that maintain internal temperature below 40°C, to allow successful curing and storage, varies in different seasons. Storage life of roots is enhanced by the selection of roots in good condition, and any delay in placing the roots in storage results in poorer out-turns.

Three varieties in one cassava trial and five in another were planted in a systematic density experiment which showed that optimum plant density for root yield changes with plant age. Some varieties showed a pronounced optimum plant population, whilst others showed a flattopped response curve. Reduction in yield above the optimum is due to a reduced harvest index. Yields of over 50 t–ha were obtained with varieties that respond to close spacing.

Yields of sugar cane in low-silicon soils were significantly increased by the application of both calcium silicate and coral sand. Over and above the significant response to Ca and increase in soil pH, there was a highly significant response to Si. The overall response to the higher level of calcium silicate application (14·2 tons/ha.) over the control was 28·3 tons of cane per hectare. Neither calcium silicate nor coral sand influenced the sucrose content of the juice.

A series of 17 crop-loss assessments was made under simulated farmers' field conditions in the three main rice cropping seasons of Bangladesh. The main insect pests were the rice stem borers (Tryporyza incertulas, Chilo polychrysa, Sesamia inferens) and in the monsoon rice gall midge (Pachydiplosis oryzae). Disease incidence was negligible. In the winter and early monsoon yield losses averaged 4 and 6% respectively, but economic benefit was only derived from insecticide application in the monsoon season, when there was an average yield loss of 16%. An economic threshold of 5–10% damaged tillers (‘deadhearts’ and ‘onion shoots’) was indicated for early attacks of stem borers and gall midge. Possible reasons are given for the usually low incidence of insect pests and diseases in Bangladesh rice.

Salicylic acid (SA) can induce multiple stress tolerance in plants. This study investigated the relationship between SA and antioxidant enzyme activities in maize seedlings under chilling stress. Changes of endogenous SA, antioxidant enzyme activities and malondialdehyde (MDA) concentrations were assessed in two different chilling-tolerant maize inbred lines (Huang C and Mo17) under chilling stress. The results showed that both endogenous free and bound salicylic acid contents increased in roots and leaves of both lines. MDA concentrations also increased significantly in roots and leaves of both lines after chilling stress. In addition, in Huang C, chilling stress increased the activities of four antioxidant enzymes, ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR) and peroxidase, while in Mo17, only CAT and APX increased. Furthermore, a regression analysis was conducted between SA and MDA concentrations or antioxidant enzyme activities under chilling stress. The results indicated that MDA concentrations were positively correlated with total SA contents in roots (r = 0.9776, p = 0.0224) and bound SA in leaves (r = 0.9974, p = 0.0458), respectively. Total SA contents had positive correlations with APX activities both in roots (r = 0.9993, p = 0.002) and leaves (r = 0.9630, p = 0.037) and GR in leaves (r = 0.9298, p = 0.0221). Together, these results suggested that chilling stress improved the biosynthesis of endogenous SA, and lipid peroxidation and antioxidant enzyme activities could be indicated by endogenous SA contents of maize seedlings under chilling stress. Furthermore, increased activities of antioxidant enzymes, especially in roots, may contribute to the chilling tolerance of maize seedlings.

In Mozambique, the sweet potato (Ipomoea batatas) is grown in the dry season in areas with a high water table, or as an irrigated crop. It is also grown in the rainy season when short-term droughts can occur. This paper reports the results of experiments designed to evaluate the effects of water availability and vine-harvesting practices on actual crop water use (cv. TIS 2534), during two contrasting seasons in the south of the country. Rain-fed crops extracted water to soil depths (variable sandy loam) of 0.75 m, with most (90%) taken from the top 0.25 m. Well-irrigated crops apparently obtained some (10%) water from below 0.75 m, but most (75%) came from the upper 0.25 m. Total water use from well-watered crops was about 800 mm during the rains, and 550 mm during the dry season. The corresponding values for rain-fed crops were 360 and 180 mm respectively. Peak rates of water use averaged 8 mm d−1 in the rainy season, and 5–6 mm d−1 in the dry season. Water use was not modified by the frequency of vine harvests. Actual rates of evapotranspiration fell below maximum values when the soil water deficit exceeded only 20 mm. By comparison, the maximum depth of extractable water in the root zone was 80–90 mm. The crop coefficients (Kc) for each stage of growth were consistent over both seasons and estimated to be: 0.55–0.7 (crop establishment), 1.1–1.2 (mid-season), and 0.8 (end-season).

It is generally accepted that the two forms of Passiflora edulis, the golden and the purple, originated on the edges of tropical rainforests in Brazil. Extensive hybridisation has since taken place between these two forms and their hybrids. The passion fruit (a vine) is now grown throughout the tropics and subtropics. A limited amount of basic, fundamental research has been published on the water relations of passion fruit. Leaf production and expansion are both sensitive to water deficits, while water stress reduces leaf and floral bud initiation. A single axillary flower bud forms at each leaf node of new growth along with a tendril. Flower bud development and fruit set are less sensitive to water stress than leaf initiation. Heavy rain during pollination prevents fertilization. Unevenness in crop distribution during the year is possibly linked to water stress and temperature variation. Potential evapotranspiration rates in Brazil varied between 3.5 mm d−1 and 5.8 mm d−1. The value for the crop coefficient increases from about 0.6 during apical vegetative growth up to about 1.25 during flowering and fruiting. Water productivities still need to be determined. Micro-sprinklers and drip are the most effective ways of applying irrigation water with precision to passion fruit. Opportunities exist for international cooperation in research projects of mutual interest on passion fruit water relations.

The depth to ground water is increasing in several regions of the world due to use of high-yielding, but also high water-requiring crops such as rice (Oryza sativa) and wheat (Triticum aestivum), in order to maintain food security for an ever increasing world population. There is a need not only to increase the water productivity of food crops, but also to find less water-requiring crops. Irrigated chickpea (Cicer arietinum L.), traditionally grown without irrigation, may provide an alternative crop to irrigated wheat in some regions. Two field experiments were conducted to determine the effects of irrigation on chickpea yields, yield components and grain and biomass water productivity (based on irrigation (WPI) and irrigation + rainfall (WPI+R)) grown in a loamy sand soil. In the first year, 75 mm of irrigation at the vegetative stage and at the vegetative plus podding stages resulted in a 59% and a 73% increase in grain yield, respectively, compared to no irrigation, but with little change in WPI+R. Overall yields in the second year were significantly higher due to warmer temperatures and fewer frosts during flowering and podding. Compared to no irrigation, 75 mm of irrigation at flowering or at podding resulted in a 7% and a 27% increase in grain yield, but a decrease in grain and biomass water productivity (WPI+R). Irrigation had a significant effect on the number of pods plant−1 in both the years and on 100-seed weight in the first year. We conclude that application of a single irrigation during podding to chickpea grown in a loamy sand soil will reliably increase yields and may provide a water-saving alternative to wheat in water-scarce environments.

This paper explores how and to what extent women and men have benefited from social capital build-up (the ability of men and women farmers to develop and use various kinds of social networks and the resources that thereby become available) in technology uptake, and the role of women in this process. Using a series of three case studies on ICRISAT's Groundnut Production Technology, the process of technology uptake leading to empowerment is systematically documented through three stages of the adoption pathway. The process stimulating gender-equitable change and empowerment was examined through a sequential analysis using two in-depth case studies in three villages in Maharashtra, India, and complemented by a broader quantitative study of the uptake process covering villages in surrounding districts. This analysis illustrated that social capital is important for both adoption and impact to occur. Qualitative information complemented by quantitative measures provides a holistic understanding of the long-term effects and benefits. The findings illustrated that build-up of social capital improves access to resources like credit, information and knowledge about new technology options and practices. Furthermore, it expands choices available to each household member – e.g. selecting and adopting seed technology of their choice, and alternative investment options – and influences the distribution of benefits from the technology because of the ways in which social networks and social relationships facilitate technology dissemination. Mobilizing social capital through participation of men and women in groups/networks that crossed caste, class and gender barriers mediated the successful adoption and diffusion of technology.

In rainfed lowland rice-based systems, increasing labour scarcity due to off-farm employment is encouraging farmers to switch from transplanting to dry direct seeding (DDS). To assure stable productivity at a level comparable with or superior to transplanting, DDS management must ensure rice seedlings have access to nutrients in order to be competitive with weeds, which must also be suppressed. This paper examined farmer perceptions of DDS using a farmer survey, and used on-farm experiments to examine responses of rainfed lowland rice to integrated nutrient–weed management, based around mechanised DDS. In the survey, weeds were the biggest problem faced by farmers in using DDS (61%). In 90% of cases, farmers reported that weeds had increased under DDS, with most farmers (78%) controlling weeds by hand. All farmers said they would use DDS in the following season (100%), due to labour savings (47%), timeliness of operations, improved productivity, low investment or a combination of these (44%). In on-farm experiments, banding nutrients with the seed at sowing enhanced early dry matter of rice, while early weed dry matter was reduced. Early weed control using ducklings or hand weeding reduced weed competition and increased rice growth, with ducklings providing additional yield benefits over hand weeding. Early increases in seedling vigour of rice, and in weed suppression, carried through to greater dry matter and yield of rice at maturity. Integrated nutrient–weed management in mechanised DDS increased DDS yields, reduced DDS yield variability and contributed to sustainability of DDS rice systems.

For efficient utilisation of available farm resources and to increase the income per unit of land, seven integrated farming systems were developed and different combinations of crop, animal, fish and bird were evaluated at three locations of Eastern India, viz. Patna, Vaishali and Munger districts, to sustain productivity, profitability, employment generation and nutrient recycling for lowland situations from 2007–2008 to 2009–2010. Among the tested different Integrated Farming System (IFS) models, viz. (i) crop + fish + poultry, (ii) crop + fish + duck, (iii) crop + fish + goat, (iv) crop + fish + duck + goat, (v) crop + fish + cattle, (vi) crop + fish + mushroom and (vii) crop alone, crop + fish + cattle model recorded higher rice (Oryza sativa L.) grain equivalent yield (RGEY) (18.76 t/ha) than any other combinations, but in terms of economics, crop + fish + duck + goat model supersedes over all other combinations. The highest average net returns (USD 2655/yr) were recorded from crop + fish + duck + goat system over all other systems tested here. Higher average employment of 656 man-days/year were also recorded from crop + fish + duck + goat system because of better involvement of farm family labours throughout the year. Based on a sustainability index (SI) derived from different models, crop + fish + duck + goat system was found superior with a maximum sustainability for net returns (73.1%), apart from the addition of appreciable quantity of nitrogen, phosphorus and potassium into the system in the form of recycled animal and plant wastes. The wastes/by-products of crop/animals were used as input for another component to increase the nutrient efficiency at the farm level through nutrient recycling. Results on integration of different components with crop depending upon suitability and preferences were found encouraging, and to enhance the productivity, economic returns, generating employment for farm families and maintaining soil health of the farm, the crop + fish + duck + goat combination could be adopted in the eastern part of India than cultivating the crop alone on the same piece of land under irrigated condition. Addition of organic residues in the form of animal and plant wastes could also help in improving the soil-health and thereby productivity over a longer period of time with lesser environmental hazards. The livelihoods of small and marginal farmers could be improved by their adoption of IFS technologies on a larger scale, as they provide scope to employ more labour year-round.

A three-year study was conducted on an Ultisol to determine the water requirement, yield and fruit-quality traits of three ratoon crops (R1, R2, R3) of ‘Grande Naine’ banana (Musa acuminata Colla, AAA group) subjected to four levels of irrigation. The irrigation treatments were based on Class A pan factors ranging from 0.0 (rainfed) to 1.0 in increments of 0.25. When needed, drip irrigation was supplied three times a week on alternate days. Results showed significant (p < 0.01) irrigation treatment and crop effects on bunch weight, yield, bunch mean hand weight, weight and fruit diameter of the third and last hands, and length of fruits of the third hand. Highest marketable yield (47.9 t ha−1) was obtained from the R2 crop with water application according to a pan factor of 1.0. It was concluded that irrigating the crop according to a pan factor of 1.0 was sufficient to justify the investment of a drip-irrigation system for a farm in the mountain region.

There is continued decline in per capita agricultural productivity in the drier parts of Kenya's central highlands. The declines have been linked to low and declining soil fertility, soil water, high atmospheric heat, prolonged dry-spells and erratic rainfall. Integrated soil fertility management (ISFM) technologies have been developed and tested in the region. Despite their significant impacts, high variability in local soils and climate contributes to large variations and inconsistency in research results among replications. Experimentation is expensive and limited to a few years, sites and scenarios. Crop-growth simulation models suitably complement experimental research, to support decision making regarding soil fertility and water management. This study evaluated the performance of the Agricultural Production Systems Simulator (APSIM) model. APSIM was parameterized and calibrated based on a rain-fed randomized complete block trial (2009–2012) at a research station in Machang’a, Embu County. The study further reported on long-term effects of integrated Nitrogen (N) management from organic residues (goat manure, Lantana camara, Tithonia diversifolia and Mucuna pruriens) and their combination with mineral fertilizers in maize production. The model adequately reproduced the observed trends of maize leaf area index (LAI) and yield response to the test N amendments. Long-term simulations showed that application of 0, 20 and 40 Kg N ha−1 had low inter-seasonal variations (CV = 18–33%) in yields. High yield variability (CV > 56%) was observed in the application of 60 and 80 Kg N ha−1. Application of 40 Kg N ha−1 by combining mineral fertilizer and manure showed 80% chance of harvesting more than 2.5 Mg ha−1 of maize grain yield. Maize stover mulching at 5 and 6 Mg ha−1 with the same N application increased long-term guaranteed grain harvests to 3.5 Mg ha−1. This is when complemented with 90 Kg P ha−1. This integrated N and soil water management is thus recommended. For subsistence farming, low-cost recommendations are geared towards some ‘guaranteed’ yield stability each cropping season. This recommendation underpins low-cost technologies that reduce production risks among small-holder farmers who faced with intermittent financial problems, to improve food security. However, there is need to evaluate and verify that there is a positive balance of primary nutrients such as N, P and K in such a fertility and water management option. Its effects on C:N levels ought to be evaluated as well.

Chickpea yields in Israel are usually considerably lower than wheat yields under comparable conditions. This study aimed to examine the possible yield limiting factors in chickpeas. Increasing the availability of nitrogen during seed development by a pre-sowing application of nitrate or by nitrogen top dressing at the onset of flowering led to an increase in the percentage of nitrogen in the straw but had no significant effect on seed yield. Growth analysis of chickpeas and wheat grown in two adjacent field experiments revealed that during the fruiting period these crops accumulated similar amounts of dry matter. However, the proportion of total wheat dry matter accumulated in the wheat grains was twice the proportion of total chickpea dry matter accumulated in the chickpea seeds. It was concluded that the main intrinisic factor limiting the seed yield of chickpeas is the continuation of vegetative growth during the period of seed development, which reduces the amount of assimilate allocated to the seeds.

Los factores restrictivos del rendimiento en el garbanzo

The worldwide cultivation of fig (Ficus carica L.) has achieved great economic importance, mainly, due to its important role as a food supplement. This situation has generated great interest in researching its methods of production, processing and conservation. The objective of this research was to evaluate six intensive production systems of fig in hydroponic and greenhouse conditions. The experimental phase started on November 15, 2010 and was completed in September 2011. Production systems were established by varying the number of productive stems between three and eight in each plant, with densities of 1.25 plants m−2. A completely experimental – randomized design was used with five replications, with a pot and a plant as an experimental unit. The results indicate that the highest yielding of fresh fruit was presented by eight productive stems (109.5 t ha−1), this one outperformed the seven productive stems (94.8 t ha−1) in 13.3% and six productive stems (78.6 t ha−1), at 26.8%. The handling of productive stems allowed an increase in the leaf area index, harvest index and fruit yielding. These results suggest that intensive production in hydroponic and greenhouse conditions of fig is an excellent alternative production, allowing to collect up to 20 times of fresh fruit yielding in relation to the plantations in the open field.

On-station participatory evaluation of varieties was used to identify the characteristics of pearl millet (Pennisetum glaucum L. Br.) preferred by farmers in western Niger. Large numbers of productive tillers, large grain size, plant height of about 250 cm and a crop cycle of 100 d or less were the main traits that motivated farmers' preference for ICMV IS 92222. High grain yield was of less concern to farmers than these factors. Small grain size, short or thin panicles, short or thin stalks and a crop cycle of 110 d or more are traits likely to be rejected by farmers. Evidence of gender-based trait preferences was significant only for short or thin panicles and thin stalks. There was no evidence of location-driven trait preferences. Farmer participation in the on-station varietal evaluation provided a means of identifying a wide range of traits that were valued by farmers and could provide guidance on farmer demand for use in varietal evaluations.

A field experiment was conducted on a Zn-deficient highly-deteriorated sodic soil of the Ghabdan series to determine the effect of three rates of gypsum (G0, G25, G50% of the gypsum requirement of soil) and three rates of Zn (Zn0, Zn11, Zn22 kg Zn/ha) on rice variety PR 106. Gypsum application significantly increased yield and Zn uptake in rice because of a significant decrease in soil pH and increase in Ca and Zn supply. Zinc application alone significantly increased soil and plant Zn but yields were poorer than with gypsum application alone because of Ca deficiency/Na toxicity. The same rates of Zn applied together with gypsum markedly increased yield and Zn uptake, revealing a deficiency of both Ca and Zn. The best grain yield was recorded either at G50Zn11 or G25Zn22, indicating an economy in gypsum at higher rates of Zn or of Zn at higher rates of gypsum application.

Twenty-nine diverse genotypes of cowpea (Vigna unguiculata) were grown in approximately 30 photothermal environments in Nigeria and Niger, with mean temperatures ranging from 19° to 30°C, photoperiods from 10 to 16 h d−1 and saturation deficits from 0.5 to 3.1 kPa. Twelve of these genotypes were insensitive to photoperiod. The time of flowering of these photoperiodinsensitive genotypes showed a similar response to temperature. Time to flowering was also delayed by mean pre-flowering saturation deficits greater than 1.5 kPa. The implications of these responses to temperature and saturation deficit for phenological adaptation in West Africa are discussed.

Four components of the water budget for a growing season, namely storage, drainage, transpiration and direct evaporation from the soil surface, were estimated using a suite of techniques. The only data requirements were rainfall, neutron probe measurements of soil water content and microlysimeter measurements of evaporation from the soil. Data from four growing seasons at Kiboko, Kenya between 1990 and 1992 were used to provide examples of the estimations. Drainage was significant (about 10% of rainfall) in one season only; in the other seasons, total evaporation comprised at least 95% of the seasonal rainfall.

Drainage was determined using a relationship between unsaturated hydraulic conductivity and soil water content that was determined during the early part of the rainy season when water was penetrating to depth. This analysis made it possible to identify a critical water content at the base of the soil profile, above which there would be significant drainage. However, there are large errors associated with estimation of drainage if significant drainage occurs.

Estimates of direct evaporation from the soil surface were used as the basis of distinguishing transpiration from total evaporation. Microlysimetry was used to develop a model of evaporation from these sandy soils, which was based on the assumption that the evaporation from the soil surface following heavy rainfall is a unique function of time from rainfall, and little influenced by the presence of a sparse crop. This method showed that direct evaporation from the soil accounted for between 70 and 85% of total evaporation in seasons when total evaporation estimates ranged from 150 to 325 mm.

Farmer-managed tests of Striga hermonthica-resistant maize varieties were conducted in 1994 in a moderately intensified zone in the northern Guinea savanna of Nigeria. Field history, soil properties, current season fertility management, and crop management observations were recorded for 37 farmer-managed trials. Site averages for maize grain yield varied from 300 to 4000 kg grain ha−1. In spite of the tremendous variability observed, the grain yield was significantly higher for the striga-resistant hybrid 8321-18 compared with an improved open-pollinated variety, STR Syn-W, and the farmers' current variety. Correlation analysis and stepwise regression analysis of grain yield on measured variables suggested that maize yield was a function of plant density for all three varieties. The rate of nitrogen fertilizer application was an important variable only for the hybrid, while the day of first weeding was most important for the improved varieties. The yield of the local varieties and STR Syn-W was related to the number of emerged striga at harvest in the stepwise regression, and the yield of the local varieties was highly correlated with the striga-damage score on maize. The striga-damage score was significantly lower on 8321-18 than on the other varieties, suggesting some degree of resistance in the hybrid. The number of emerged striga was lower for the hybrid but not significantly different. Farmers were almost unanimous in ranking the hybrid as least damaged by striga and highest yielding. Besides being related to maize variety, striga-damage score was lower if crop residue was observed on the field at the time of site confirmation. Highest yields (approximately 4 t ha−1) were recorded on fields near the homestead (compound fields) where soil organic carbon values were 2.0–2.5%. Realization of maize yield potential in the absence of manure or fertilizer will only be possible on long-term compound fields. Striga-resistant maize can maintain high yields under S. hermonthica infestation.