Prolonged inability of yam tubers to sprout/germinate is associated with the expression of tuber dormancy, and the start of dormancy in tubers is linked to the onset of tuber formation. Although the plant hormone, abscisic acid (ABA) is known to regulate the onset and maintenance of dormancy in tubers, there are no known method(s) of inducing shoot growth (sprouting) on seed yam tubers that are harvested at 240 days after vine emergence or earlier. Therefore, this study was conducted to: (1) determine whether the absorption of fluridone, a reputed ABA inhibitor, prior to or during early seed yam tuber formation would induce sprouting, and (2) determine the effect of fluridone on early shoot growth. The study was a 2×4 factorial experiment arranged in a Completely Randomized Design (CRD) with eight treatment combinations replicated three times. Two species of yam with long dormancy durations were used: D. rotundata var TDr 131 and D. alata var TDa 98/01166; and three concentrations of fluridone were tested (30, 50, 100 µM). Young plants (69 days after vine emergence) of TDr 131 and TDa 98/01166 were grown in a coco coir medium hydroponics system using Hoagland's Nutrient Solution, with or without the test fluridone concentrations. In all fluridone treatments, most leaves of both species of yam had 30–90% of their surface bleached while the stems appeared purplish. In both Controls, all the newly formed seed tubers that were harvested at 90 and 104 days after vine emergence were dormant (devoid of any new shoots/sprouts). In contrast, over 70% of the seed tubers that developed in 30 and 100 µM fluridone had at least one new shoot, particularly in TDa 98/01166. The fluridone treatments did not significantly affect tuber weight or vegetative growth parameters like dimensions and number of leaves. This study has shown that the duration from vine emergence of the old tuber to sprouting of the new tuber can be reduced by more than half if young plants absorbed fluridone during early tuber development.

Gene flow from herbicide-resistant rice (Oryza sativa L.) cultivars can affect the biodiversity of Oryza spp. and can result in the lack of opportunity to control weedy rice through selective herbicides. The aim of the present study was to quantify the outcrossing rate from the herbicide-resistant red rice and rice cultivars carrying three different ALS (acetolactate synthase) alleles using a single plant pollen donor approach. A field experiment was performed using the encircle population combination technique. The main plots comprised the pollen-receptor IRGA 417 cultivar or a susceptible biotype of weedy rice, and the subplots comprised the pollen-donor inbred cultivars IRGA 422 CL and PUITÁ INTA CL, the hybrid SATOR CL or a resistant biotype of weedy rice. Among the pollen-donors, the outcrossing rate for pollen receptor susceptible weedy rice and the IRGA 417 cultivar was 0.0344% and 0.0142%, respectively. Rice cultivars carrying the ALS gene mutations Ala122Thr, Ser653Asn and Gly654Asn showed a similar outcrossing rate of 0.0243%. The outcrossing rate decreased over a distance of up to 3.5 m from the pollen-donor and was not affected by the wind cardinal direction. The risk of gene flow of herbicide resistance from rice to weedy rice should be reduced through the development of new strategies to contain and mitigate gene flow and of the elimination of weedy rice escapees.

In order to identify factors that constrain or favour adoption of five crop or forage related and six animal husbandry technologies promoted by government to small-scale dairy farmers, a field survey was conducted with 115 farmers. A binary logistic regression model was fitted to identify socioeconomic and farm variables explaining the technology adoption. Factors that favoured technology adoption were based on perceived usefulness, productivity and benefits to the farm, farmer's skills and farm characteristics; moreover farmers were more willing to use technologies which required low levels of investment such as de-worming, vaccines, and data recording. Constraints were related to economic restrictions, lack of knowledge, lack of land, herd size, lack of extension advice, lack of information about government programmes, requirements associated with applying for government financial support, and technologies considered to be of little or no importance to the farm such as herbicides, artificial insemination (AI) and milking machines. Adoption of crop or forage related and animal husbandry technologies was significantly associated (p < 0.05) with socioeconomic (farmer's education, farmer's experience, farmer's wealth status) and farm characteristics (herd size, cows in production, milk yield, total hectares and technological level). It is concluded that the approach implemented in this study enables identification of key factors together with the communication approaches that have been successful.

Wheat grown under zero tillage (ZT) and raised-bed following a legume crop may have a variable N requirement compared with conventionally-tilled flat-sown crop. A field experiment was conducted for two years during 2005–07 to study the effect of varying tillage (conventional and zero), crop establishment (flat and raised-bed sowing) and N fertilization (0–160 kg N ha−1) on wheat grown after greengram at New Delhi, India. Rainy-season greengram performed equally well under flat and raised-bed planting, but the seed yield was 25.9% lower under ZT than conventional tillage (CT) conditions. Wheat following greengram during winter season also showed better growth and yield under CT than ZT, as well as under flat sowing than furrow-irrigated raised-bed (FIRB) system. The grain yield was highest under CT-flat, and decreased by 5.4–9.4% under FIRB system. Nitrogen fertilization up to 120 kg N ha−1 under CT and 160 kg N ha−1 under ZT increased grain yield, and the optimum doses were worked out to be 147.1 and 154.2 kg ha−1, respectively. Nitrogen-use efficiency decreased with N levels but remained more or less similar under tillage and crop establishment practices. Maximum returns and B:C ratio were obtained under CT-flat, followed closely by ZT-flat.

Continuous rice–wheat (RW) cropping in an area of 13.5 million ha with intensive tillage has resulted in over exploitation of resources, decline of the factor productivity, loss of soil fertility and biodiversity and decline of resource use efficiency in the Indo-Gangetic plains (IGPs) of South Asia. This has led to unsustainability of agriculture in the region. Replacement of a cereal-cereal system with a legume–cereal system may prove beneficial for long-term sustainability of the system. A field experiment was conducted with soybean–wheat (SW) rotation in the IGP of India during 2009–10 and 2010–11 to assess the suitability of conservation tillage versus conventional tillage (CT) and crop-establishment techniques, namely bed (B) planting versus flat (F) planting. The study revealed that the zero tillage (ZT) for soybean during rainy and for wheat during winter season either in flat or in bed system performed equally good with CT. The maximum system productivity (7.06 t ha−1 in 2009–10 and 8.48 t ha−1 in 2010–11) was obtained with combined application of wheat + soybean residue. The maximum net returns of ₹46.98 and ₹65.08 thousands and B:C ratio of 2.35 and 3.08 were recorded in the SW system with zero tillage-flat (ZT─F) during 2009–10 and 2010–11, respectively. The minimum energy of 64.67 and 63.01 ×103 MJ ha−1 was utilized as input energy with zero tillage-bed (ZT─B) while the maximum energy use efficiency of 4.10 and 5.14 was obtained with ZT─F and ZT─B for the SW system during 2009–10 and 2010–11 respectively. The gross output energy was maximum with wheat + soybean residue (241.6 and 265.7 ×103 MJ ha−1) contrary to this the net energy (194.4 and 213.4 ×103 MJ ha−1) and energy use efficiency (9.03 and 10.96) was maximum with control (no residue) in the SW system. In wheat there was 37.85% improvement in irrigation water use efficiency (WUE) in raised bed planting than flat planting and 28.57% of irrigation water was saved. The study suggested that ZT either bed or flat planting to both the crops can successfully adopted along with application wheat + soybean residue together with full recommended dose of NPK fertilizers to the system for improving productivity, profitability, soil health and sustainability of SW system in the IGPs of South Asia.

A common practice in some South American countries consists in moving around Capsicum chinense cultivars between regions where edaphoclimatic conditions differ notably. The purpose of this research was to compare and relate gas exchange responses with assimilate allocation patterns and flower and fruit production dynamics in a cultivar of C. chinense in three locations with different mean temperatures (19, 24 and 28 °C) along a gradient from 140–1855 m. Leaf gas exchange (leaf conductance, CO2 assimilation and transpiration rates) was measured at 60–70, 110–120 and 140–150 days after transplanting (dat) from seed beds. Dry weight per plant of leaves, stems and roots were determined at 50, 73, 96, 114 and 196 dat. Flowering dynamics and fruit production were followed weekly. A marked reduction (50%) in mean Gs was found at the site with the lowest mean temperature in relation to plants grown at the highest temperature site. Mean daily CO2 assimilation rate was higher for plants in the intermediate site and a reduction of 18 and 42% was found for sites with highest and lowest mean temperature, respectively. We report an adverse effect of low temperatures on growth of C. chinense. Flowering initiation and fruit production was delayed at lower temperatures. An increase in temperature (between 26–30 °C) led to an increase in the number of flowers; below this temperature it remained unchanged. Fruit production is drastically reduced at the lower temperature site due to a large number of aborted flowers and small fruits.

Water stress is one of the main environmental stress conditions that adversely affect growth and yield of crops. Sulphydryl (-SH) compounds have been reported to induce tolerance to abiotic stress conditions. A two-year (2010 and 2011) experiment was conducted at Bikaner, Rajasthan, India to test whether the exogenous applications of thiourea (500, 750 and 1000 mg L−1) and thioglycolic acid (200, 300 and 400 mg L−1) as a foliar spray would alleviate deleterious effects of water stress on clusterbean (Cyamopsis tetragonoloba L.). The -SH-treated plants showed higher membrane stability index, photosynthetic pigment content, photosynthetic capacity and antioxidant enzyme activities and lower lipid peroxidation compared with untreated plants. Compared with untreated plants, the -SH-treated plants had 11–18, 18–30, 17–57, 25–47, 14–22% higher membrane stability index, total chlorophyll content, antioxidant enzyme activities, net photosynthetic rate and seed yield, respectively; whereas the malondialdehyde content was 10–19% lower. These data suggest that under water deficit stress, exogenous -SH compound application improves photosynthesis by increasing photosynthetic pigment, protects plants against oxidative damage by scavenging reactive oxygen species and minimizing lipid peroxidation by elevated antioxidant enzyme activities. These results indicated the role of -SH compounds in diminishing the negative effects of water deficit on clusterbean and suggest that -SH compounds could be used as a potential bioregulator to improve plant growth and yield under water deficit conditions.

This paper investigates the determinants of the performance of family farms in Senegal using both production and profit functions. The econometric analysis is based on agricultural inputs and outputs information from a survey of 504 agricultural households, member of a farmer organization in the Saint Louis region in 2009. Our main results indicate that the size of the cultivated plots has a negative effect on crop yields, representing diseconomies of scale. This finding suggests potential for improvements in farm management and organization. We also find that the development of commercialization sectors and loans could boost agricultural inputs. In terms of profitability, our results show that yields and prices play significant and important roles for all crops. An increase in the bargaining power of farmers would be required to increase unit prices and consequently their profits.

We studied physiological traits of 12 Criollo cocoa cultivars growing in a germplasm bank in the southern region of Maracaibo Lake Basin, during the rainy (RS) and dry seasons (DS) of 2007. A further evaluation of photosynthetic responses to changes in environmental parameters was done on three cultivars: Los Caños 001 (LCA001), Sur Porcelana 010 (SP010) and Escalante 001 (ESC001) in 2009 and 2010. Leaf water potential (ΨL) of most cultivars decreased during the DS of 2007, with the exception of ESC001. Maximum photosynthetic rate (Amax), stomatal conductance and water use efficiency varied among cultivars and seasons. The CO2-saturated photosynthetic rate (ACO2sat) was higher in LCA001 and ESC001 than in SP010, with no differences in carboxylation efficiency. Light curve responses of the three cultivars were similar. In all cultivars, no evidence of chronic photoinhibition was observed, since maximum quantum yield of photosystem II was high (0.77–0.81). We conclude that ESC001 has the best physiological performance (ΨL remained unchanged, highest Amax, ACO2sat and photochemical activity), and it seems to be a promising cultivar for cocoa agroforestry systems in the southern region of Maracaibo.

Soil Organic Carbon (SOC) is a major indicator of soil fertility in the tropics and underlies variability in crop response to mineral fertilizers. Critical SOC concentrations that interact positively with N fertilizer for optimal crop yield are less understood. A study was conducted on a Ferralsol in sub-humid Uganda to explore the critical range of SOC concentrations and associated fractions for optimal maize (Zea mays L.) yield response to applied mineral N fertiliser. Maize grain yield response to N rates applied at 0, 25, 50 and 100 kg N ha−1 in 30 fields of low fertility (SOC < 1.2%), medium fertility (SOC = 1.2–1.7%) and high fertility (SOC > 1.7%) was assessed. Soil was physically fractionated into sand-sized (63–2000 µm), silt-sized (2–63 µm) and clay-sized (<2 µm) particles and SOC content determined. Low fertility fields (<1.2% SOC) resulted in the lowest response to N application. Fields with >1.2% SOC registered the highest agronomic efficiency (AE) and grain yield. Non-linear regression models predicted critical SOC for optimal yields to be 2.204% at the 50 kg N ha−1 rate. Overall, models predicted 1.9–2.2% SOC as the critical concentration range for high yields. The critical range of SOC concentrations corresponded to 3.5–5.0 g kg−1 sand-sized C and 9–11 g kg−1 for clay-sized C.

The response to sulphur (S) and irrigation of mustard although site-specific, is less studied across sites. Economics and greenhouse gases (GHGs) emissions are other important considerations for developing resource-efficient technologies, but hardly studied in mustard. The objectives of this study were to appraise productivity, economics and GHGs emissions under three irrigation regimes combined with four levels of S, laid out in a split plot design with three replications. Results showed that two irrigations at 30 and 60 DAS combined with 60 kg S ha−1 resulted in highest gross and net returns, which were 30.9 and 37.2% higher than that in single irrigation at 30 DAS, and 47.2 and 68.0% higher than that in single irrigation at 60 DAS without S application, respectively. Estimated GHGs emissions from common inputs (machinery, diesel, fertilizer and insecticides) of mustard were 1486.2 kg CO2 eq ha−1 with greater share (95%) of fertilizer. Econometric analysis predicts that 1% increase in irrigation and S use will lead to 10.29 and 9.98% increase in mustard yield, respectively.

Theaflavins contribute to astringency and brightness while thearubigins contribute to colour and mouth feel of black tea. Green leaf flavan-3-ols influence levels and distribution of theaflavins and thearubigins in black tea and are black tea quality precursor compounds. Caffeine also contributes to tea quality. Although location of production and nitrogenous fertilizer rates influence black tea quality, it is not known if the variations arise from the levels and distribution of the precursor compounds in green leaf or other factors. The variations and distribution of the flavan-3-ols and caffeine in young green leaves of clone TRFK 6/8 due to nitrogen fertiliser rates in seven locations within Eastern Africa were evaluated. Green leaf comprising two leaves and a bud were harvested from each plot, and subjected to HPLC analysis for caffeine, total polyphenol, dihydroxyflavan-3-ols, trihydroxyflavan-3-ols, ratios of trihydroxyflavan-3-ols to dihydroxyflavan-3-ols and total catechins levels. Results were subjected to statistical analysis using split plot design, with locations as main treatments and nitrogen rates as the sub-treatment. Caffeine and flavan-3-ols levels changed (p ≤ 0.05) with location of production, demonstrating that even with use of same cultivar and similar agronomic management quality of tea from one location cannot be replicated in another location. Caffeine levels increased (p ≤ 0.05) with rise in nitrogen fertilizer rate in all locations, but the extent depended on location. Total polyphenols and individual flavan-3-ols showed an inverse quadratic response, except EGCG that linearly decreased (p ≤ 0.05) in some locations, due to increasing rates of nitrogen fertilizer. Similar responses in the black tea quality parameters had been observed in previous studies. The black tea quality results were therefore directly influenced by the green leaf precursor compound patterns. Region specific nitrogenous fertilizer rates need development to ensure high tea quality.

Phaseolus vulgaris is considered an inefficient nitrogen fixer, and therefore farmers in Mexico use large quantities of synthetic nitrogen fertilisers. The aim of this research was to evaluate the performance of native isolates of Rhizobium spp. and Bacillus spp. as biological fertilisers in northern Mexico. A first test was carried out under greenhouse conditions to analyse 15 native isolates of Rhizobium and 15 native isolates of Bacillus. Based on their effects on the bean crop, the best treatments were tested under field conditions. In the field, the combination of Rhizobium and Bacillus (Rz + Bs) produced the highest grain yield, biomass production, number of nodules per plant and dry weight of nodules, statistically surpassing (p ≤ 0.05) the control (without inoculation and fertilisation). Furthermore, compared with synthetic fertilisation, no statistical differences were found, which suggests that the combination Rz + Bs can replace synthetic fertilisation.

Phosphorus deficiency in tropical acid soils is a problem because soluble inorganic phosphorus is fixed by aluminium and iron. Organic amendments could be used to overcome phosphorus fixation in acid soils. Thus, the objectives of this study were to (i) improve soil phosphorus availability using biochar and compost produced from poultry manure and pineapple leaves respectively, and (ii) determine whether the use of biochar and compost could improve phosphorus, nitrogen, potassium, calcium and magnesium uptake and dry matter production of Zea mays L. cultivation on a tropical acid soil. Organic amendments significantly increased soil pH compared with non-organic amendments. Organic amendments also significantly reduced exchangeable acidity and exchangeable forms of aluminium and iron, and effectively fixed aluminium and iron instead of phosphorus. As a result, phosphorus availability in soil increased. Besides increasing the availability of nitrogen, potassium, calcium and magnesium in soil, organic amendments improved nutrients uptake and dry matter production of Zea mays L. Biochar and compost can be used to improve the productivity of Zea mays L. on acid soils by reducing phosphorus fixation.

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.

Tillage and use of organic manure are important agronomic practices that sustain high crop and soil productivity. Hence, a three-year (2007 to 2009) study was conducted to evaluate the effect of site, tillage and poultry manure (PM) treatments on soil and plant nutrients composition, growth and yield of cocoyam (Xanthosoma sagittifolium). The study was a 2 × 5 × 5 factorial experiment with two sites (Owo – site 1 and Obasooto – site 2), five tillage methods; manual clearing (MC), manual ridging (MR), manual mounding (MM), ploughing plus harrowing (P+H) and ploughing plus harrowing twice (P+2H) and five levels of PM (0, 2.5, 5.0, 7.5, 10.0 t ha−1). Treatments were replicated thrice. Soil OM, N, P, K, Ca, Mg and leaf nutrients reduced with increase in tillage intensity, thus MC conserved soil nutrients the most, and increased nutrient uptake. Soil and plant nutrient concentration was lowest under the P+2H treatment. The MC, MR and MM treatments led to faster growth and higher tuber yield. As PM increased from 0 to 10.0 t ha−1 soil pH, OM, soil and plant N, P, K, Ca and Mg increased. The 7.5 t ha−1 PM gave the highest leaf K, Ca and Mg values. Owo site had significantly higher yield and growth parameters of cocoyam compared with Obasooto site. Yield and growth parameters of cocoyam increased with increase in PM level up to 7.5 t ha−1. Out of all tillage cum manure treatments, MC+7.5 t ha−1 PM gave the highest values of yield and growth parameters.

Recent years have seen increasing political interest and growing public health awareness and advocacy for diversifying diets into highly nutritious traditional vegetables, fruits and other nutrition-sensitive crops as a more viable approach to mitigate the growing scourge of malnutrition due to unhealthy and imbalanced diets. These foods contribute essential micronutrients, vitamins, antioxidants, and other health-related phytochemicals to staple-based diets and their consumption is crucial for the attainment of several Millennium Development Goals. Despite their nutritional benefits and the high farm gate values per unit of land, the production and marketing of traditional vegetables from Tanzania and other countries in sub-Saharan Africa are constrained by factors such as poor quality seeds, lack of appropriate market information and support systems, and lack of consumer awareness of their nutritional importance. This paper investigates the determinants and pathways for smallholder participation in traditional African vegetable production and identifies entry points for farmers to increase traditional vegetable production by linking nutritional awareness and promotion with potential high value markets. A primary survey of 181 traditional vegetable growers from five regions of Tanzania indicates that perceptions about the nutritional value of traditional African vegetables are a main driver of household production decisions in the sector. The results of this study provide evidence that farmers tend to grow more African traditional vegetables as compared to other crops based on their increased level of perception towards nutritional value of traditional vegetables along with other factors such as their market value, timely availability of quality certified seeds, willingness to invest in labour, required training for women and better access to credits. Farm size negatively affects growing traditional vegetables, implying that on a comparative basis, smallholders tend to grow more traditional vegetables than larger-farm operators. Thus, more attention should be given to reducing production and its associated transaction costs by ensuring timely access to quality certified seeds, ensuring optimal use of inputs and increasing labour productivity, particularly for smallholders.

This study was conducted to improve wheat production under vegetative (early season) drought stress. Hydroprimed and osmoprimed (with CaCl2) seeds of wheat cultivars Lasani-2008 (LS-2008) and Triple Dwarf-1 (TD-1), were sown in 20 (narrow), 25 (medium), and 30 cm (wider) spaced rows. Crop was grown under well-watered conditions till physiological maturity or was subjected to drought stress (50% field capacity) during vegetative phase and then grown under well-watered conditions. Drought stress caused substantial reduction in grain and biological yields, related traits, harvest index (HI) and water use efficiency (WUE). Nonetheless, planting osmoprimed seeds in narrowly spaced rows significantly improved the grain yield, HI and WUE. However, wheat planted in wider rows had bold grains. Furthermore, wheat cultivar LS-2008 produced better yield, even under drought stress, than cultivar TD-1. Economic analysis indicated that planting osmoprimed seeds of wheat cultivar LS-2008 in narrowly spaced rows under early season drought yielded maximum economic benefits. In conclusion, planting osmoprimed seeds of cultivar LS-2008 in narrowly spaced rows is a good agronomic option to improve the wheat performance under early season drought stress.

Limited information is available concerning the influence of nitrogen fertilization jointly on yield response, nitrogen use efficiency (NUE) and grain quality of durum wheat under semi-arid Mediterranean conditions. The study focused on evaluating, through a systematic study, over three seasons in southern Italy the effects of three nitrogen fertilization rates (0, 80 and 160 kg N ha−1 – N0, N80 and N160), on grain yield, yield components, nitrogen efficiency indices and grain quality characteristics of three durum wheat genotypes (‘Creso’, ‘Trinakria’ and ‘Line 25’) from different breeding eras to achieve a more sustainable fertilization management of the durum wheat crop. We found that nitrogen fertilization at 80 kg N ha−1 was able to maximize the yield performances (2.1 t ha−1 year–1) of the crop and keep NUE index at an acceptable level (16.3 kg kg−1). On the other hand, nitrogen fertilization at 160 kg N ha−1 improved grain quality measured through protein (up to 14.3%) and dry gluten concentration (up to 12.8%), but had a detrimental effect on grain yield and nitrogen efficiency. Among the genotypes studied, ‘Trinakria’ showed the greatest potential to utilize nitrogen fertilization to improve grain yield and NUE (at N80) and quality (at N160), ‘Line 25’ made good use of N80 both for yield and quality, whereas ‘Creso’ proved wholly unresponsive to nitrogen. The effect of N fertilization on grain yield and N use efficiency depends on rainfall distribution, giving the best results when about 80% of total rainfall occurred from sowing to heading. Overall, our data show that in seasons with regular rainfall in quantity and distribution, combining no more than 80 kg ha−1 of nitrogen fertilization with genotypes characterized by a more efficient response to nitrogen, is a useful tool to improve the agronomic and quality performance of the crop, ensuring, at the same time, a more environment-friendly nitrogen fertilization.

In the published article Hussain et al., (2016) the name of the last co-author was spelt incorrectly. The author's name should have read as: M. Farooq.