Beninese smallholders associate food crops and cash crops with immature oil palms to reduce field maintenance costs and gain income before the palms reach productive phase. Little is known about the effects of these crops on the nutritional status and growth of the palms in their immature phase even though the yield of adult palms can be affected by the management practices during this phase. The objective of this study was to evaluate the most common oil palm-based intercropping systems found in southern Benin in terms of nutritional status and growth of the palm. Within 15 oil palm farms, we compared 15 immature oil palm fields where the crop succession associated with the oil palms was dominated by maize, cassava, tomato, and pineapple. The nutrient concentrations in the soil and the palm leaves, and growth indicators were measured at the end of the immature phase. We found that the palm growth indicators were the lowest in the successions with pineapple. N and P nutrition of the immature palms was satisfactory but K was deficient in all systems, especially in those with pineapple. The K levels in the soils and palm leaves were correlated. Rough field budgets comparing the amounts of N and K applied to the crop successions with their N and K exports from non-returning products indicated that soil indigenous K supply would be particularly depleted in the systems with pineapple. We concluded that the young oil palms were affected by the competition for K exerted by the crop successions with pineapple even though they were the most fertilized in the region. The high profitable crop is therefore associated with the lowest growth rates of the immature palms. The mineral fertilizer management in these oil palm temporary intercropping systems should be improved.

The potential of winged bean as a multipurpose legume cover crop was shown in field trials by its abundant vegetative growth throughout the growing period of two years. Protein contents of the dry matter of the whole plant, vegetable pods, seeds and tubers were in the range 22–34, 25–30, 32–38 and 16–19%, respectively. In a comparison of two cultivation methods, significantly higher yields were obtained from staked plants than from those grown without supports; protein contents, however, remained constant.

Population pressure has diminished the role of the traditional bush fallow system in restoring the fertility of depleted soils following several years of cultivation in the derived savanna of southwest Nigeria. The search for alternative fallow systems led to the development of alley cropping using Leucaena leucocephala and cover cropping using Pueraria phaseoloides. These soil-conserving systems also embody the principles of sustainability by ensuring stable crop yields in spite of an increase in land-use intensity. Simulating smallholder farm conditions and based on a split-plot experiment with the three fallow systems as the main plots and four different land-use intensities (LUI) as the subplots, simple direct observation and record keeping were used to collect data on labour use in all farm operations including fuelwood cutting and stacking in alley cropping systems with fallow phases. Data collection covered a period of four years (1993–96), corresponding to one out of the three phases (or complete cycles) of the trial. Partial budget analysis was used to estimate profitability of cassava (Manihot utilissima)–maize (Zea mays) under each LUI. Results based on crop production indicate that each of the cassava-maize enterprises was profitable but the level of profit varied from 10 819 to 50 289 Naira ha−1. Production under cover cropping has a net benefit advantage of 4–25% (over that under bush fallow) and 25–60% (over alley cropping). Profitability increased as the LUI decreased, depicting the overall importance of fallow periods on soil fertility restoration. Results based on crop production plus fuelwood operations indicate that production with cover cropping has a net benefit advantage over that of both bush fallow and alley cropping under both zero-fallow and one-year fallow LUIs. However, results from two- and three-year fallows indicate that fuelwood yield generated sufficient revenue to put alley cropping at a net benefit advantage of 29–42% over bush fallow and 26–37% over cover cropping. From these results, cover cropping is recommended, especially to farmers in areas where, although land shortage is a problem, fuelwood and the other sources of domestic energy are still cheap and easily accessible. However, in areas with abundant land and where farmers can still wait for fallow periods of at least two years, alley cropping is recommended since, in addition to soil fertility improvement, substantial revenue is obtained. However, considerations of yield variability, labour scarcity, as well as risk-aversion behaviour among farmers may alter their technology choice.

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.

Following preliminary work in the previous year, further field trials were carried out with strains of the pearl lupin (Lupinus mutabilis Sweet) at Oxford, England. Two strains originating in Argentina and one in Bolivia were considered to show promise for development as crop plants in England if toxic alkaloids can be bred out of them. The seeds harvested had a crude protein content from 38·6 to 41·8% and an oil content from 13·1 to 14·4%. Advice is given, based on these trials, on sowing date and spacing.

In order to measure the effects of new agricultural technologies on labour productivity in sub-Saharan Africa, on-farm trials are usually conducted using small plots. Farmers who keep no records have to be interviewed frequently to minimize the effect of memory loss on the accuracy of the data collected. In this paper, results are reported of experiments in the forest zone of Nigeria and the semi-arid Sahel of Niger. They show that if researchers can take steps to fix events in the memory of farmers, accurate labour use data can be collected in interviews as long as three months after the events being recalled. A range of plot sizes, with a minimum of 350 m2 in the forest zone, needs to be used to measure accurately labour use per hectare and to take into account the effect of economies of size on crop production.

Recopilacón de datos significatiaos sobre el use de mano de obra en estudios realizados en fincas del sub-Sahara africano

This research set out to find ways to increase wheat production in Bangladesh. The approaches were (1) to increase the area planted to wheat, concentrating on developing a suitable management system for the very hot, often saline and hitherto largely untested fallow lands of the south; and (2) to increase economic and sustainable yield of wheat in the traditional rice-wheat zones. Five mechanized reduced tillage and planting systems were compared. They were used to enable 200 co-operating farmers at 11 locations to plant on time and avoid the reduction in yield that accompanies delays, found in this study to average 2 % d−1. Methods that placed seeds in rows were zero tillage, full or strip surface shallow till, and raised beds. A partially mechanized version of the traditional manual system called New Conventional, in which seeds and fertilizers were broadcast, was also tested. Farmers' wheat yields averaged more than 3.5 t ha−1 for the two seasons of the study. Farmers in the untested lands averaged more than 2.5 t ha−1 on their farms, well above the 0.5 t ha−1 needed to cover all costs and equal to normal production levels in traditional wheat areas. Surprisingly, full and strip till did not produce higher yields overall than New Conventional in either season. Reasons for the lack of difference are discussed in relation to other aspects of management and variation between the farmers themselves. Farmers had varying opinions and mixed success with zero till and beds. The economic consequences to farmers of using the different systems are also discussed with the suggestion that the low-tech New Conventional method will be preferable for novice wheat farmers in the historically fallow lands where the study indicated potential production is 1 million tonnes.

Hesperaloe funifera (Agavaceae) is an experimental fibre crop which produces strong, fine fibres with potential uses in the specialty-paper industry. Hesperaloe's agronomic potential was evaluated in two long-term studies. The plant is a perennial with a rosette habit. Growth occurred by production of new leaves from the primary rosette until Year 3 and from secondary rosettes from Year 3 on. Rates of biomass growth increased over the five years studied. High-density stands (27 000 plants ha-l) produced 190 t fresh weight ha-1 after five years. Plots harvested once, after Year 5, produced more biomass than plots harvested twice, after Years 3 and 5. Increased biomass production can be achieved by improved stand establishment and nutrient management.

The North China Plain (NCP) is an important agricultural area, where conventional tillage (CT) is used year-round. However, long-term CT has damaged the soil structure, threatening agricultural sustainability. Since 2002, we have conducted a long-term tillage experiment in the NCP to explore the effects of different types of tillage on soil and crop yield. As part of long-term conservation tillage, we conducted a 2-year study in 2016/2017 to determine the impact of no tillage (NT), subsoiling (SS), rotary tillage (RT) and CT on soil aggregate distribution, aggregate-associated organic carbon (AOC), aggregate-associated microbial biomass carbon (AMBC), and maize yield. Compared to CT, NT increased the content of macro-aggregates (+4.8%), aggregate-AOC (+8.3%), and aggregate-AMBC (+18.3%), but decreased maize yield (−11.5%). SS increased the contents of macro-aggregates (+5%), aggregate-AOC (+14.7%), and aggregate-AMBC (+16%); although the yield increase was not significant (+0.22%), it had the highest economic benefit among the four tillage measures. RT had no significant advantage when considering the above soil variables; moreover, it reduced maize yield by 16.1% compared with CT. Overall, SS is a suitable tillage measure to improve soil macro-aggregate content, carbon content, yield, and economic benefit in the NCP area.

Drought is considered as the major environmental stress affecting coffee production, and high phosphorus (P) supply may alleviate the drought effects on crop metabolism. Here, we hypothesized that high P supply would mitigate the impacts of drought on Arabica coffee physiology, morphology, and biomass accumulation. Potted Arabica coffee plants were grown under two P levels: the recommended P fertilization (P), and twice the recommended fertilization (+P), and two water regimes: well-watered and water withholding for 32 days. Leaf, stem, and root P concentrations were increased under +P, with plants showing higher photosynthesis and growth than the ones receiving the recommended P dose. Higher plant growth under high P supply seems to upregulate leaf photosynthesis through the source–sink relationship. Under the water deficit, the reduction of leaf photosynthesis, stomatal conductance, transpiration, water use efficiency, carboxylation efficiency, chlorophyll content, number of plagiotropic branches, plant leaf area, and vegetative biomass production was similar comparing plants fertilized with the recommended P to those supplied with +P. However, Arabica coffee trees under high P supply and water deficit presented morphological and physiological traits similar to plants under well-watered and recommended P fertilization.

Genotype by environment interaction is a common phenomenon in crop production and remains an important issue in genotype evaluation and recommendation. However, no detailed multi-environment evaluation of Ethiopian white lupin has been undertaken so far. Thus, this study was undertaken with the objectives to evaluate the performance and stability of white lupin landraces in six locations; and characterize white lupin growing environments in Ethiopia. Twelve white lupin landrace collections of Ethiopia were evaluated across six different locations in Ethiopia during the 2014/15 main growing season using a randomized complete block design with four replications. The genotype main effect plus genotype by environment interaction (GGE) biplots analysis was used to visualize the patterns of the interaction components. The results depicted that the tested landraces had differential performances across locations implying the presence of crossover interaction. The first two principal components (PC1 = 41.6% and PC2 = 21.8%) of the GGE explained 63.4% of the GGE sum of squares. All test locations were found to be representative with different degrees of reliability whereby Finote Selam and Dibate were found to be most representative. In addition, all test locations, except Mandura and Injibara, had generally similar and good discriminating power. Finote Selam and Dibate were found to be the most representative and discriminating environments and are characterized as most desirable test locations for white lupin improvement in northwestern Ethiopia. G2 was found to be the highest yielding and most stable landrace across the test environments, and hence identified as most desirable genotype recommended for production.

Effects of cutting lengths on tuber yields and vine production of Missus and Madam sweet potatoes, as influenced by two different fertilizer regimes, were studied on Njala upland soils of Sierra Leone. Cuttings 61 cm. long gave significantly the highest tuber yields for both early-maturing cultivars when fertilized with 336 kg. sulphate of ammonia, 112 kg. basic slag, 448 kg. sulphate of potash, 841 kg. lime and 340 kg. sulphate of magnesium per ha. in two split applications a month apart. Fertilized with 502 kg./ha. sulphate of ammonia per application for 4 applications, 61 cm. long cuttings again gave the highest vine production. The lower the vine/tuber ratio, the higher the tuber yield.

The expansion of sugarcane crop to regions with lower water supply in Brazil has increased the importance of correct estimation of crop water requirements. Currently, the irrigation management is generally done using the crop coefficient (Kc) based on the FAO 56 bulletin. Kc is used to determine the potential water demand of the crop for a given period of time and is considered constant for each crop stage. However, some recent studies have shown that Kc can be significantly variable under different evapotranspiration (ETo) rates. This paper aimed to analyse sugarcane water consumption at different scales: plant (sap flow measurements by energy balance method); canopy (Bowen ratio energy balance method); and plant–atmosphere coupling (infrared gas analyser) to reduce the uncertainties on the irrigation practices. Measurements were taken at two experimental sites, where a modern Brazilian cultivar CTC 12 was grown under drip irrigation and an old main Brazilian cultivar (RB867515) was grown under sprinkler irrigation by a central pivot. The mean crop evapotranspiration (ETc) values by the Bowen ratio energy balance method were 2.92 and 3.68 mm d−1 for RB867515 and CTC 12, respectively, resulting in a mean Kc of 0.99 at the full vegetative growth stage. Kc values were dependent on ETo and varied between 0.2 and 1.7 for both cultivars. This occurred in a crop coupled to the atmosphere (Ω = 0.37) and was the same found in other coupled crops such as coffee and citrus. In conclusion, the sugarcane Kc for southeast Brazil presented temporal variability due to coupling conditions according to reference evapotranspiration, and this should be considered in irrigation management.

During growth, several cereals store significant amounts of fructo-oligosaccharides (FOS), which have important prebiotic properties. Cereal forage crops are also essential components of many Mediterranean agricultural systems, although little information is available on their dynamics of accumulation and partitioning of dry matter and FOS during growth. Oat (Avena sativa L., cv. ‘Flavia’ and cv. ‘Genziana’), emmer wheat (Triticum dicoccum Schrank, cv. ‘Giovanni Paolo’), barley (Hordeum vulgare L., cv. ‘Diomede’) and triticale (xTriticosecale Wittmack, cv. ‘Rigel’) were investigated for their synthesis of FOS, with a view to development of management approaches for harvesting high-quality forage, and to determine whether these species can be used as natural sources of FOS for commercial use. The study was conducted at Foggia (Italy) and Bella (Potenza, Italy) over two growing seasons (2008–2009; 2009–2010). Dry-matter accumulation and FOS contents were determined for plant fractions from heading to kernel-hard stages. There were large variations across these species for dry-matter partitioning and dry-matter yield (greatest for triticale: 1.24 kg m−2), and for FOS levels of total plants and plant fractions. Emmer wheat and triticale showed greater FOS production (52.0, 41.1 g m−2, respectively). Barley, emmer wheat and triticale showed higher FOS levels in total plants (4.11%, 5.93%, 4.33% dry matter, respectively). Barley, emmer wheat and triticale appear to be the most interesting species for production of forage biomass rich in FOS and as natural FOS sources for industrial use.

A 2-year field study was conducted in central Greece (Larissa) and was repeated simultaneously in northern Greece (Thessaloniki) to determine the productivity and the competitive ability against corn poppy (Papaver rhoeas L.) of six faba bean (Vicia faba L.)-barley (Hordeum vulgare L.) intercrops grown at three seeding ratios (75:25, 50:50 or 25:75% of the recommended seeding rates) and two crop arrangements (alternate or mixed rows). Faba bean and barley sole crops were also included. Corn poppy dry weights in barley sole crop or faba bean-barley intercrops were 83 to 85% or 50 to 99%, respectively, lower than that in faba bean sole crop. Total dry matter (DM) and total crude protein (CP) yields of faba bean-barley intercrops were, in most cases, not significantly affected by corn poppy competition. The results obtained in both locations indicated that intercropping faba bean with barley could be an alternative practice to that of faba bean sole crop in sustainable production systems, because of its greater productivity, balanced nutritive value and competitiveness against aggressive weeds such as corn poppy.

Gliricidia sepium features prominently as a soil replenishment tree in planted coppicing fallows in eastern Zambia. Its usual method of propagation, through nurseryseedlings, is costly and may possibly hinder wider on-farm adoption. We compared fallows propagated by potted and bare root seedlings, direct seeding and stem cuttings, in terms of tree coppice biomass production, soil inorganic N availability and post-fallow maize yields under semi-arid conditions. We hypothesized that cutting fallows initially in May (off-season) would increase subsequent seasonal coppice biomass production as opposed to cutting them in November (at cropping). The tree survival and biomass order after two years was: potted = bare root > direct > cuttings. The post-fallow maize productivity sequence was: fertilized maize = potted = bare root > direct > cuttings = no-tree unfertilized controls, across seasons. However, farmers may prefer directly seeded fallows owing to their cost effectiveness. Soil inorganic N and maize yield were significantly higher in May-cut than in November-cut fallows. Preseason topsoil inorganic N and biomass N input correlated highly with maize yields. This implies that bothparameters may be used to predict post-fallow crop yields.

The productivity of a herd of Mashona cattle is described, where hand-feeding was practised in winter to prevent loss of body weight. Calves weighed about 50 lb at birth, and gained weight at the rate of 1.27 lb a day to six months of age, compared widi 1.56 and 0.87 lb a day for calves at two other sites. Young animals gained an average of ½ lb a day from weaning to maturity. Mashona steers responded to pen-feeding and produced carcasses which were satisfactory for the Smithfield market. The mature weight of breeding cows was just under 700 lb and the calving rate varied from 72 to 92 per cent. Cows which failed to calve and those whose calves were early-weaned gained almost 100 lb liveweight by the end of die grazing season. Early-weaned calves fed a complete diet were 40 lb heavier than their contemporaries at 28 weeks of age. The need to develop die breed is discussed.

In young plants of Coffea canephora, fine particle film based on calcined kaolin (KF) causes a decrease in leaf temperature (Tleaf), minimizing the damages to the photochemical apparatus, especially in summer season, but no report about the ecophysiological responses to KF over phenology is available on this species. We hypothesized that greater ecophysiological effects of KF would occur during the summer phenophase of leaf area and berry expansion (BE) compared with autumn berry maturation phase (BR), and that those benefits will have impact on bean productivity and physical quality. In this sense, the present study aimed to analyze the effects of KF on some ecophysiological parameters in the last phenophases of C. canephora biennial cycle, bean productivity, and bean size classification. During the complete phenological cycle, eight applications of KF were performed, totaling 80 kg of KF ha−1 in two years. KF applications and ecophysiological measurements occurred during the BE and BR phenophases. Firstly, we documented temporal dynamics in responses of field-grown C. canephora adult plants to KF application. KF reduced Tleaf and crop water stress index and increased the thermal index of relative stomatal conductance and relative chlorophyll content (SPAD index) observed in the autumn BR (opposite to young plants). The positive impact of KF on chlorophyll a fluorescence was proportionally similar among the observed phenophases. Secondly, KF increased bean size 16 by 50% and increased total productivity. The plants treated with KF increased productivity by 1.7 t ha− commercially useful bean mass compared to the control. The kaolin dose of 40 kg ha−1 distributed four times per year was highly effective as a protection strategy against high-light and elevated Tair.

Plant populations, nitrogen levels and the use of alpha naphthalene acetic acid (ANA) to rein-force natural flower differentiation were compared in a field experiment at Malkerns in the Swaziland Middleveld. Yield was raised by increasing plant population above 17,000 plants per acre, but reached a maximum at 23,000 plants per acre. Increased yield from denser planting occurred at the expense of fruit size and fruit set, and of sucker and slip production. Hormone counteracted the depressing effect of denser planting on fruit set and denser planting reduced sunburn damage and raised fruit acidity. 400 lb N per acre per crop increased yield over 200 lb N by increasing fruit size in the mother crop, and by increasing fruit size and set in the ratoon. Added nitrogen markedly reduced fruit acidity. ANA improved fruit set and therefore yield, without detrimental effects on fruit shape or quality. There are grounds for small increases in population above 17,000 plants per acre, for the use of ANA to reinforce natural flower differentiation and for the cautious use of the higher level of nitrogen fertilization.

Nitrogen fertilizer applied to the surface of the soil in the field did not increase the yield of Bragg soybeans, and at higher levels reduced it, but may or may not significantly reduce soybean nodulation and plant height. In a pot experiment, there was evidence that deeply applied N increased plant height and dry weight of a non-nodulating isoline of Clark soybeans 46 days after planting.