The use of date palm (Phoenix dactylifera L.) has been closely connected with the survival of people in arid areas given their fruits´ high concentration of energy, fibre, minerals, vitamins and 16 amino acids. The arid climate and sandy or clayey loam soils in many parts of Pakistan are ideal for the cultivation of date palm, which contributes to feeding the country's rapidly growing population. To fill knowledge gaps on the effects of cultivar diversity and cultivation sites on the nutritional properties of dates, the present project studied dates and related physical and chemical soil properties across six districts in four provinces of Pakistan: Jhang, Muzaffargarh and Bahawalpur in Punjab; Dera Ismail Khan (D. I. Khan) in Khyber Pakhtunkhwa (KPK); Khairpur in Sindh and Panjgur in Baluchistan. To this end, during 2012–2013, a total of 170 households (HHs) were selected using a snowball sampling approach. Thirty-nine different date palm cultivars with diverse nutritional properties are grown in the study area. In these total soluble solids (TSS) were highest in Muzawati and Koharba cultivars, while cultivars and site conditions significantly affected TSS, minerals (calcium and magnesium), acidity, and firmness of dates. Concentration of CaCO3 and bulk density (BD) of soils varied widely, while hydraulic conductivity (HC) was similar across sites (p = 0.128). Mean soil pH was highest in Panjgur (8.3) and lowest in Muzaffargarh (7.6), soil organic matter content was highest in Jhang (0.8%) and lowest in D. I. Khan (0.6%) and plant available phosphorous (P) was highest in Muzaffargarh (7.8 mg kg−1) and lowest in Panjgur (6.0 mg kg−1). As indicated by correlation analysis BD and cation exchange capacity of soils seemed to affect TSS, whereas concentration of CaCO3 and available P were correlated with calcium concentration of dates. HC and electrical conductivity, however, seemed to have little effect on dates´ nutritional properties.

The shoot regrowth vigour of sugarcane varieties having contrasting phosphorus (P) efficiency was evaluated under varying soil P availability. The P-inefficient (IAC91–1099 and IACSP94–2101) and -efficient (IACSP94–2094 and IACSP95–5000) sugarcane varieties were grown under low (25 mg P kg−1 soil) or high (400 mg P kg−1 soil) P supply at planting. After 90 days (first cycle of growth), the shoots were harvested and regrowth was studied 70–75 days later by evaluating photosynthesis, leaf area formation, biomass production and P uptake. The shoot dry matter (DM) of sugarcane regrowth subjected to a low P supply was genotype-dependent, with the P-efficient varieties exhibiting greater values than the inefficient ones. This result was explained by the greater efficiency of IACSP94–2094 and IACSP95–5000 in acquiring P rather than P utilization efficiency for shoot biomass production. The root P stored during the first cycle of growth would represent only a minor fraction (< 20%) of the total P content in the shoots at the end of the regrowth period. Thus, we argue that the improved shoot P uptake of the P-efficient varieties was related to their ability to sustain P acquisition after harvesting rather than to the remobilization of root P reserves. Moreover, our data revealed that net CO2 assimilation per leaf area was not associated with differential performance among varieties under P deficiency, suggesting a more critical role of total leaf area in photosynthate supply for sugarcane regrowth. In conclusion, sugarcane regrowth is improved in P-efficient varieties under P deficiency conditions, a finding of practical relevance as such ability might benefit the productivity and the longevity of sugarcane ratoons in low P tropical soils.

There are many prerequisites for potato production to meet its full potential as a food security crop for subsistence farmers in Sub-Saharan Africa. One of these is the introduction of improved varieties. Traditionally, the introduction of new varieties is by government agencies or Non-Governmental Organizations (NGOs). To understand the diffusion of seed tubers (seeds) of new potato varieties in farmer networks, we analysed social factors influencing the sharing of seed of improved potato varieties amongst farmers in Chencha, Ethiopia. We interviewed 166 farmers and analysed 146 seed transactions. We used seed flow mapping to visualize seed sharing amongst farmers. We found that the social networks of farmers are differentiated by wealth, gender and religion, and that this differentiation affects the dispersion of new varieties through the farming communities: Wealthier farmers shared seed tubers most frequently and poor farmers did not share seed at all. Seed sharing was influenced by, but not restricted to, gender and religion categories. Most sharing was with relatives (as gifts) and neighbours (in exchange for labour). There weas no equal access to seed for all households because of (i) the targeting of the better off farmers by the NGO (ii) differences in frequency of sharing and (iii) terms and motivation of the transactions. Our results show that wealthy farmers most effectively multiply and share the seed of new varieties with medium wealthy and poor farmers. This study shows that for the introduction of new technologies into a community, its dynamics of social differentiation need to be understood.

Understanding crop water use in mixed crops over sole cropping is vital for developing optimum water management systems for crop production. In this study, a two-year field experiment with typical maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] relay strip intercropping (2:2 maize-to-soybean rows; 200 cm bandwidth) was carried out in the 2013 and 2014 growing seasons. The quantitative effects of various planting patterns on the water-use efficiency (WUE) and water distribution were investigated. Our results indicated that soil volumetric water content and soil evaporation in the intercropping systems showed decreasing trends in the order: maize row (MM) < maize-to-soybean row (MS) < soybean row (SS). The highest leaf transpiration (1.91 and 2.07 mmol m−2 s−1) for the intercropped maize was measured in each of the two years in the 20 cm maize narrow-row planting pattern and decreased thereafter. Opposite trend was observed for the intercropped soybean; the highest soybean leaf transpiration (7.01 and 6.80 mmol m−2 s−1 for 2013 and 2014, respectively) was recorded in the 70 cm. The WUE of maize and soybean intercrops was lower than that of sole crop counterparts. However, the maximum group water use efficiency (GWUE) of 26.08 and 26.20 kg ha−1 mm−1 in the 40–50 cm maize narrow-row planting pattern was, respectively, 39.6% and 23% higher compared with that of sole crops. The water equivalent ratio (WER) values ranged from 1.60–1.79, suggesting better crop water use in the intercrops over sole cropping. Planting patterns provided by 40–50 cm maize narrow-row spacing were considered the most efficient in terms of maximum total yields, GWUE and WER. These results suggest that an appropriate reduction in the spacing of narrow maize row with wide soybean row could be an efficient crop management method to achieve optimal WUE and homogeneous water distribution in maize–soybean intercropping systems.

Soil quality indicators (SQI) can be used as a synthetic tool for the assessment of the sustainability of agricultural systems. In this study, we developed SQI using minimum data set (MDS) and determined the response of SQI to long-term tillage systems. Field pea (Pisum sativum L.) and spring wheat (Triticum aestivum L.) were grown in alternate years at northwestern China, and soil attributes and crop productivity were measured 6 years after the initiation of the experiment. The MDS used to develop the SQI included soil physical (aggregate, bulk density, capillary porosity, field capacity), chemical (soil organic matter, total nitrogen, available phosphorus, available potassium) and biological (microbial count, microbial biomass, and the activities of catalase, urease, alkaline phosphatase, and invertase) properties. All the property variables were measured in each of the 0–5, 5–10 and 10–30 cm depths and those variables that contributed significantly to the SQI were selected to be included in the MDS. Amongst the measured variables, bulk density and microbial counts occurred in the MDS of all the three depths, suggesting that these two properties are highly affected by the tillage treatments. In the long-term field experiment, the no-till with stubble covering the soil surface treatment received the greatest SQI score and achieved the highest crop yield. Soil quality under tillage systems can be assessed adequately using MDS measured at the top soil (0–5 cm) layer in rainfed agro-ecosystems.

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.

A study that aims to assess the impact of the interaction between soil macrofauna and soil fertility management methods on runoff, was conducted in the north-sudanian zone of Burkina Faso on a Lixisol with an average slope of 1.5%. Runoff was measured using a runoff plot of 1.04 m2 and crop yields were measured on the effective area of the elementary plot. Biocide treatments used to control the population of macrofauna have eliminated 95% to 99% of soil macrofauna. Except for urea treatment, the results showed that the presence of macrofauna has led to the reduction of runoff in the other treatments. The absolute contribution of macrofauna to runoff varied between 24.58% and 30.74%. Runoff reduction was higher on soil management based on sorghum straw + urea (71.24% in 2008 and 78.80% in 2009) in the presence of soil macrofauna. We concluded that in cropping systems with low external inputs, stimulating the activity of macrofauna by burying material with high ratio of carbon to nitrogen reduces runoff and thus maintains the potential of farm land.

The resource conservation technologies (RCTs), being advocated for countering the threat to the sustainability of wheat–rice cropping system (RWCS) in the north–west (NW) Indo-Gangetic Plains (IGP) of India, have been evaluated mostly for the individual crops, without depicting the impact of these technologies on the succeeding or preceding crop. A study was thus conducted during 2012–2014 in NW India to assess the land and irrigation water productivity (WPI) of RWCS under different establishment and conservation tillage techniques in a sandy-loam soil (coarse loamy, calcareous, mixed, hyperthermic Typic Ustochrept). The treatments included zero (ZTW) and conventional (CTW) tillage in wheat as main plot, establishment methods (direct seeded (DSR) and mechanically transplanted rice (MTR)) as sub-plot and tillage in rice viz. puddle (PR), dry (CTR) and zero (ZTR) tillage as sub–sub plot treatments, replicated thrice in split–split plot design. The land productivity of RWCS was significantly lower in ZTW plots than in CTW plots. The residual effect of tillage in wheat on rice productivity was distinct during the second year of study, when the CTW plots recorded significantly higher (17.5%) rice yield than the ZTW plots. The productivity of the cropping system with DSR was statistically similar to that with MTR. The WPI of RWCS increased in the order ZTW–DSR–ZTR25 < CTW–DSR–ZTR < ZTW–MTR–CTR < ZTW–DSR–PR < CTW–DSR–PR < ZTW–MTR–PR26 < CTW–MTR–PR.

Farmers who continue to grow old and obsolete varieties do not gain the benefits they could get from growing newer ones. Given the potential large scale of these foregone benefits, relatively few studies have examined the age of varieties that farmers grow. In three surveys, members of over 3300 households were interviewed to find the rice varieties they grew in 2008 and 2011 in 18 districts in the Terai, the low-altitude region of Nepal. This provided the first description of detailed geographical patterns of adoption of rice varieties and their ages that were repeated over time. There were large differences between district and individual varieties that showed specific geographical patterns of adoption. Such detailed knowledge on spatial diversity of varieties is invaluable for planning extension activities and developing breeding programmes, and cheaper ways than household surveys of collecting this information are discussed. Some of the factors considered important in determining this complex pattern of adoption were seed availability, growing environments that differed from east to west and the continued popularity of varieties once they had established markets. Rice diversity was low because a small number of rice varieties occupied large areas. In 2011, nine varieties covered at least 75% of the total rice area in western districts, just four in central districts and eight in eastern districts. Of these, most were released before 1995 resulting in a high average age of the predominant varieties – they always had an average age of over 20 years no matter which region or year was considered. Even though there were some large changes in varietal composition from 2008 to 2011, the average age of the predominant varieties remained almost the same. In a second paper in this series, we examine how these very low varietal replacement rates, that reduce yields and increase risk to farmers, can be accelerated using a participatory research for development approach called Informal Research and Development (IRD) (Joshi et al., 2012).

Cocoa (Theobroma cacao L.) is produced in systems of varying complexity ranging from monoculture with temporary shade to highly diverse agroforests. Producers have to weigh high cocoa yields in the short to medium term in monocultures against higher total system yields in the short term and sustainable production systems in the long term in conjunction with ecosystem services in agroforestry systems (AFs). More long-term data on the comparative agronomic, economic and ecological performance of differently managed cocoa production systems is required to make sound recommendations to farmers. This paper describes the only long-term field trial worldwide comparing different cocoa production systems under conventional and organic management. The factors (i) crop diversity (monoculture vs. agroforestry), (ii) management practice (conventional vs. organic) and (iii) cultivar are being tested in a full-factorial, randomized complete block design with four replications. First, results showed significantly faster development of trunk circumferences in monocultures (+21%) compared to AFs. Cocoa yields were 47% lower in the organic compared to the conventional monoculture. In the AFs, however, the organic–conventional yield gap was less pronounced (−16%) and statistically insignificant. The cumulative yields of all products harvested were significantly higher in the AFs (+161%) compared to the monocultures. The productivity of cocoa by-crops in AFs may contribute to local food security and risk distribution in smallholder contexts.

Ten accessions of Napier grass (Pennisetum purpureum Schumach.) were evaluated for their dry matter (DM) yield and forage quality in a semi-arid lowland (Katumani) and a relatively wet highland (Muguga) over seven growth cycles from 2011 to 2013 in tropical Kenya. Three biomass yield clusters were identified from the 10 accessions as high-yielding (HYC), medium-yielding (MYC) and low-yielding (LYC) clusters for both sites. Total biomass (shoot and root) yields (t ha−1) over the seven growth cycles were 25.3 for HYC, 22.2 for MYC and 19.6 for LYC at Katumani and 40.0, 41.4 and 29.1 at Muguga. Total biomass yield averaged over the study period was DM 22.4 t ha−1 at Katumani and 36.8 at Muguga. Rainfall productivity was higher at Katumani (28.8 kg ha−1 mm−1) than 20.8 kg ha−1 mm−1 at Muguga. Neutral detergent fibre (NDF) was lower in LYC, which was more leafy than the other clusters and there was little difference in NDF between the two sites.

Seed cotton yield in Northern Cameroon has been declining since the 80s despite breeding efforts. In order to evaluate the impact of genetic improvement on this decline, we conducted field experiments in two locations with 10 widely grown cotton cultivars released in Cameroon between 1950 and 2009. The rate of genetic gain (GG) was estimated with a linear regression of the cultivar mean on its year of release (YR). Contrasts between rates of GG observed with different planting dates were estimated and tested. Our results revealed a rate of GG on fibre yield of 3.3 kg ha−1 year−1 due to increased ginning out-turn (3.9% and 6.2% in 60 years in Garoua and Maroua, respectively). There was no GG on leaf area index (LAI), radiation use efficiency (RUE), aerial biomass, harvest index and on seed cotton yield. We concluded that cotton breeding efforts in Cameroon have successfully improved cotton fibre yield but there is still some room for seed cotton yield improvement.

In order to intensify cassava production in southern Côte d'Ivoire, multiple farmers’ field trials were carried out in two important cassava-producing areas (Dabou and Bingerville). The effectiveness of an Integrated Soil Fertility Management (ISFM) approach as intensification pathway was evaluated for poor sandy soils. Overall, ISFM-based systems outperformed the local cultivation system. The average cassava yield was 14.5 and 6.5 t ha−1 and 12.6 and 5.7 t ha−1 for the ISFM and traditional systems, in Dabou and Bingerville, respectively. The average profitability of ISFM systems was ca. 2500 Euro ha−1, whereby 66% was generated by cowpea intercrop, which yielded on average 3.1 t ha−1. Taking into account the limited farmer's resource endowment and poor soil fertility, ISFM is a crucial component for sustainable intensification of cassava production and poverty alleviate in southern Côte d'Ivoire.

Rice productivity is limited by many pests, especially Pomacea spp. in Southeast Asia. Pomacea spp. damage to rice depends on sowing methods, flooded conditions, and snail densities in the field. Therefore, this study aims to evaluate the effect of different sowing methods, water levels, and snail density (1, 2, and 3 snails per plot) on the damage potential of Pomacea maculata and Pomacea canaliculata to rice and its yield. Both species caused complete loss of crop in direct seeding and 14 days old transplanted rice. The least damage by both species was recorded in 21 and 28 days old transplanted rice with no further damage after week five. Irrigation and snail density also influenced damage whereby highest damage was recorded in rice grown with 5 cm water level in comparison to 2 cm. At 2 cm water level, damage by various snail densities was trivial. However, in 5 cm water level, damage increased with the increasing snail density and the highest damage was observed at three snails per plot of either species. No difference in inflicted damage to various treatments was observed between two species, suggesting their equal damage potential on rice. Meanwhile, rice yields in 2 cm water level treatments were compatible with 5 cm control treatment. The least yield was recorded in treatments with three snails per plot of either species at 5 cm water level. Understanding the effect of sowing method and suitable water level is important as it can be further incorporated into rice cultivation practices to reduce damage of apple snails and ensure a high yield during harvest.

Seed-oriented planting provides a manner to influence canopy structure. The purpose of this research was to improve maize light interception using seed-oriented planting to manipulate leaf azimuth across the row thereby minimizing leaf overlap. To achieve leaf azimuths oriented preferentially across the row, seeds were planted: (i) upright with caryopsis pointed down, parallel to the row (upright); and (ii) laying flat, embryo up, perpendicular to the row (flat). These treatments were compared to conventionally planted seeds with resulting random leaf azimuth distribution. Seed orientation effects were contrasted with three levels of plant population and two levels of hybrid specific canopy structures. Increased plant population resulted in greater light interception but yield tended to decrease as plant population increased. The planophile hybrid produced consistently greater yields than the erectophile hybrid. The difference between planophile and erectophile hybrids ranged from 283 to 903 kg ha−1. Overall, mean grain yield for upright and flat seed placement increased by 351 and 463 kg ha−1 compared to random seed placement. Greater cumulative intercepted photosynthetically active radiation (CIPAR) was found for oriented seeds rather than random-oriented seeds. At physiological maturity upright, flat and random-oriented seeds intercepted 555, 525 and 521 MJ m−2 of PAR, respectively. Maize yield responded positively to improved light interception and better radiation use efficiency. Under irrigated conditions, precision planting of maize increased yield by 9 to 14% compared to random-oriented seeds.

Legumes have gained increased importance in smallholder farming systems of sub-Saharan Africa due to their contribution to household nutrition and health and their ability to grow in low fertility soils. With unpredictable and highly variable rainfall characteristics of the semi-arid areas, short-season grain types are seen as a promising option for drought avoidance. Knowledge of phenological development and, in particular, time to flowering is crucial information needed for estimating the possible production success of new accessions to new environments. The photoperiod-sensitivity of 10 promising short-season Lablab purpureus (L.) Sweet accessions (CPI 525313, CPI 52533, CPI 52535, CPI 52535, CPI 52552, CPI 52554, CPI 60795, CPI 81364, CQ 3620, Q 6880B) were evaluated for their response to varying temperature and daylength regimes in field trials in Limpopo province, South Africa and under controlled conditions in growth chamber experiments in Göttingen, Germany. Photoperiod sensitivity was quantified using the triple-plane rate model of flowering response with time to flowering expressed in thermal time (Tt, °Cd). Additionally, piecewise regression analysis was conducted to estimate the critical photoperiod (Pc) above which time to flowering was delayed significantly. Relatively high variation of time to flowering amongst and within accessions in days after planting (DAP) was observed, ranging from 60 to 120 DAP depending on sowing date or daylength/temperature regime. Furthermore, a clear positive effect of temperature on growth and development of the tested accessions was found and time to flowering expressed as thermal time were consistent for the tested accessions, ranging from 600 to 800 °Cd for daylength <13 h. Only at daylength of ≥13 h and temperatures above 28 °C, development towards flowering was delayed significantly for accessions CPI 52513, CPI 52535, CPI 52554 and CPI 60795 with vegetative growth continuing for >110 DAP. The tested lablab accessions are therefore considered photoperiod insensitive, or weakly photoperiod responsive and are classified as short-day plants (SDP). Since daylength does not exceed 13 h between the latitudes 30 N to 30 S, these lablab accessions are recommended for further testing as short-duration grain legumes.

Cotton–wheat (CW) is an important cropping system in South Asia. Wheat yields under a conventional CW system are generally lower compared to a rice–wheat system due to delayed seeding. Relay seeding of wheat can help timely sowing, capturing residual soil moisture of last irrigation to cotton, and increase the productivity and profitability of CW system. The field experiment included two Bt-cotton genotypes having different canopy cover (RCH 776 and MRC 7017), two types of relay seeders (RSs) for cotton planted at 67.5-cm and 101-cm row spacing and four types of relay seeding methods (manual broadcast, strip rotor (SR) and zero-till double disc and conventional till). Relay planting of wheat allowed one additional boll picking, which increased seed cotton yield by 12% compared with conventional tillage wheat. Cotton genotypes and RSs had no effect on emergence and yield of wheat. The RSs with SR and zero till double disc furrow openers performed better in terms of wheat emergence and grain yield compared to zero-till tine openers. Under relay seeding, wheat sowing was advanced by 31 days, which increased grain yield by 18.8% compared with conventional tillage practice. Net returns from the CW system with relay seeding of wheat were higher by US$ 311 to 425 ha−1 compared with the conventional CW system.

In this study, the effects of HA combined with NPK fertilizer (HANPK) on root growth and leaf quality of tobacco plants were investigated in tobacco fields. Results indicated that the application of HA alone did not enhance the growth of tobacco obviously, while HANPK increased tobacco biomass by 36.9% and stimulated the growth of lateral roots significantly. The number of the second-order lateral roots was increased by 89.3% compared with the control. Furthermore, HANPK raised the ratio of root biomass in 0–20 cm soil layer over the whole soil layer and increased the proportion of fine roots over the total roots. Tobacco leaf yield, output value, and benefit of HANPK were 12.2%, 29.4% and 35.5% higher than those of the control, respectively. The above results suggest that the combined application of HA and NPK chemical fertilizer is an economical pattern for improving tobacco growth.

This article was published with an incorrect Title. The correct title should read:

‘SEED-ORIENTED PLANTING IMPROVES LIGHT INTERCEPTION, RADIATION USE EFFICIENCY AND GRAIN YIELD OF MAIZE (Zea mays L.)’

The original article has been rectified with the correct title and a footnote detailing the error has been inserted in the online PDF and HTML copies.

Soybean yields on smallholder farmers’ fields in Malawi are constrained by poor soil fertility, limited application of external inputs and poor crop husbandry. We tested crop management practices through on-farm experimentation and participatory technology evaluation. Two agronomic soybean trials were established in 2009 and 2010 in three contrasting agro-ecologies resulting in 72 replications per trial. Treatments in the first trial included several combinations of inoculation with Bradyrhizobium japonicum, inorganic fertiliser application and compost manure. In the second trial, farmers tested an improved variety, optimal weeding regime, increased plant population and chemical pest and disease control. A combination of inoculation, inorganic fertiliser (10 N, 8 P, 20 K in kg ha−1), and 6 t ha−1 compost manure increased yields from 0.86 t ha−1 under farmers’ practice to 1.56 t ha−1 and resulted in average profits of US$222 ha−1. Increased plant populations and biocide spraying also resulted in substantial yield increases. Inoculation and increased plant population resulted in an average value to cost ratio (VCR) > 2. Low investment costs make inoculants, compost manure and increased plant populations interesting options, whereas adoption of inorganic fertiliser application in soybean may be limited due to high costs and low VCR. The farmers ranked eight technologies in descending order of preference as: (i) early planting, (ii) plant population, (iii) variety choice, (iv) compost manure, (v) weeding, (vi) inoculant, (vii) fertiliser and (viii) spraying. Our participatory research approach demonstrated that there is a wide range of technologies with different levels of human and financial investment costs that smallholder farmers can adopt to enhance their soybean yields and profits.