Highlights • Drought stress across all stress levels resulted in a reduction in dry matter production, leaf area index, number of seeds per plant, number of pods per plant, seed size and finally grain yield. • The highest WUE was found in the treatment which was irrigated on fortnightly bases from 36 DAP. The results suggest that drought stress towards the end of the growing season may not cause serious harm in grain yield. • The results suggest that drought stress can be practiced in dry bean production in areas where there is a challenge of irrigation water with consideration of the growth stage of the crop. • The results of the study indicate that drought stress effects on photosynthetic rate were highly significant. • Chlorophyll fluorescence was also affected by drought stress.

Recent trends in soil microbiology suggest that fungal inoculants such as Trichoderma harzianum or arbuscular mycorrhizal fungi (AMF) have the potential to improve yield and fruit quality of crops. The purpose of this study was to investigate the effect of inoculating tomato (Solanum lycopersicum L.) with T. harzianum and the AMF (Glomus mosseae) on yield and nutrient content of tomato fruit. A factorial experiment (3 × 3) with three application timings for each of T. harzianum and AMF, namely uninoculated control, inoculated before sowing and two weeks after sowing, giving nine treatment combinations was conducted in a greenhouse. Both T. harzianum and AMF increased total yield and marketable yield of tomato (P >0.05). Inoculating tomato with AMF before sowing significantly increased the percentage of extra-large fruit, while inoculation with T. harzianum two weeks after sowing lowered the Ca and Mg contents of tomato fruit. Trichoderma harzianum and AMF inoculation increased the lycopene content, but did not affect the antioxidant activity, total flavonoids or vitamin C of the tomato fruit. Results of this study suggested that T. harzianum and AMF have the potential to influence yield and nutrient content of tomato in a greenhouse.

The effect of nursery inoculation of tomato (Solanum lycopersicum L.) with Trichoderma harzianum and arbuscular mycorrhizal fungi (AMF) Glomus mosseae on fungal root colonization, plant growth, yield and quality of field-grown tomato was investigated. The four treatments included T. harzianum, AMF, T. harzianum'AMF, and uninoculated control. At mid-harvest, 84 days after transplanting, no interactive effect of the fungi on the external mycelium growth was observed. Inoculation with AMF alone or in combination with T. harzianum increased dry shoot weight by 35% and 30%, respectively, during the first season, and by 30% and 21%, respectively, during the second growing season. Trichoderma harzianum increased the percentage of large fruit by 76% in 2008Á2009, whereas AMF increased the percentage of extra-large fruit by 44% in 2009Á2010. Similarly, AMF increased total soluble solids by 10%. Inoculated tomato seedlings with T. harzianum and/or AMF significantly increased early yield of tomato, by 10%, 65% and 70%, respectively, during 2008Á2009, and by 27%, 36% and 37%, respectively during the 2009Á2010 growing season. In conclusion, results of the study suggested that T. harzianum and AMF have the potential to improve growth, early yield and fruit quality of field-grown tomato.

Ginger species play an important economic role as medicinal plants, food flavourings, and dietary supplements. Products from ginger, including oil and fresh and dried rhizomes can be used to treat malaria, asthma, headaches, and act as anti-inflammatory and anti-microbial agents. The cultivation of wild plant species can alleviate the pressure from harvesting from the wild. Under cultivation, the major constraints on crop yield and quality are water availability and plant nutrition. Therefore, the impact of water stress on commercial and African ginger was assessed in the rain shelter study. Irrigation treatments were based on the maximum allowable depletion (MAD) levels of plant available water in the root zone (T1: 20–25% MAD, the control; T2: 40–45% MAD; T3: 60–65% MAD; T4: 80–85% MAD). As water stress decreased, the plant height and number of stems per plant of both plant species were positively affected. The number of open stomata was higher for well-watered and less stressed treatments in both ginger species. Higher fresh and dry rhizome yields were recorded for commercial ginger at all water treatments as compared to those from African ginger. In general, water use efficiency (WUE) of fresh and dry rhizome yield was higher for commercial ginger as compared to the indigenous African ginger, while moderately stressed treatments generally resulted in the highest WUE for both species.

Background Very little has been researched about the efficacy, effectiveness, feasibility, sustainability and impact of food-based approaches on the diets and nutritional status of populations at risk of hunger and food insecurity. This study contributes knowledge about the impact of food-based approaches on the diets of populations at risk of hunger and food insecurity in four of the poorest rural communities in South Africa. The study investigated the consumption and production patterns of rural households (278 in summer and 280 in winter) in four sites in the poorest municipalities in South Africa. Methods A multistage stratified random sampling technique was applied to identify the communities and sample households for the quantitative survey and qualitative assessments. Qualitative and quantitative data were collected between 2013 and 2015 through focus group discussions (FGDs), key informant interviews and the two-round panel survey to cover both the summer and winter seasons at each site. Results Home gardening led to a significant positive increase in the consumption of white roots and tubers, dark green leafy vegetables, orange-coloured fruit and other fruit in the 24 h prior to the survey. Participation in a community garden led to significant increases in the consumption of dark green leafy vegetables and other vegetables. School gardening did not demonstrate any statistical relationships with the consumption of foods from the crop-related food groups. Crop production improved dietary diversity. Selling produce and irrigation showed a stronger improvement in dietary diversity. Seasonality affected the availability of fresh fruit and vegetables for home consumption in winter. Conclusions Producing beyond that solely for home consumption has greater benefits for dietary diversity and a consumption-smoothing effect during the post-harvest period. Politicians and the scientific community should recognise the role that household and small-scale crop production plays in supporting household consumption and the provision of essential micronutrients despite constraints and disincentives. Production and education programmes should focus on strengthening existing good consumption patterns and promoting the consumption of foods that can improve dietary diversity.

Several studies have demonstrated Si absorption in monocotyledon and dicotyledon species. Regarding Si accumulation, studies in monocotyledons have identified Si deposition around the cell wall, cuticle layer bulliform cells, silica cells and endodermal cells. In previous studies with different citrus species there were evidence of Si accumulation, however no information on Si deposition can be found. Therefore, in this study, Si was applied (0 and 1000 mg L−1) to the roots of two citrus species, ‘Delta’ Valencia (Citrus sinensis) and ‘Nules’ Clementine (Citrus reticulata). Si accumulation were investigated in new, and old leaves and roots. Si deposition was investigated through scanning electron microscopy using energy dispersive analysis X-ray, environmental scanning electron microscopy and light microscopy. Si accumulation was significantly higher in Si treated leaves comparatively to the control in both young and mature leaves. Meanwhile, Si accumulation increased with leaf age. Additionally, Si accumulation was significantly higher in roots than in leaves. With respect to Si deposition, granules were identified in the epidermal cells through SEM and ESEM studies. The light microscopy identified the presence of Si granules in the surface and around the outer cell surface forming the cuticle-silica double layer of the lower epidermis in Si treated plants. Silica deposit were not found on the abaxial leaf surface. The findings suggest a passive uptake in citrus species.

In the framework of a gene flow assessment, we investigated the natural hybridization rate between Gossypium hirsutum (AADD genome) and G. herbaceum (AA genome). The latter species, a diploid progenitor of G. hirsutum, is spontaneously present in South Africa. Reciprocal crosses were performed without emasculation between G. herbaceum and G. hirsutum. Neither examination of the morphological characteristics nor flow cytometry analysis of the 335 plants resulting from the G. hirsutum × G. herbaceum cross showed any hybrid features. Of the 148 plants produced from the G. herbaceum × G. hirsutum cross, three showed a hybrid phenotype, and their hybrid status was confirmed by SSR markers. Analysis of DNA content by flow cytometry and morphological traits clearly showed that two of these plants were triploid (AAD). The third plant had a flow cytometry DNA content slightly higher than G. hirsutum. In addition, its morphological characteristics (plant architecture, presence and size of petal spots, leaf shape) led us to conclude that this plant was AAAD thus resulting from fertilization with an unreduced AA gamete of the female G. herbaceum parent. Fluorescent In Situ Hybridization (FISH) and meiotic behavior confirmed this hypothesis. To the best of our knowledge, this is the first description of such gametes in G. herbaceum, and it opens new avenues in breeding programs. Furthermore, this plant material could provide a useful tool for studying the expression of genes duplicated in the A and D cotton genome.

Management of the biological component of agricultural soils is a vital aspect of sustainable food production systems. There is a need for soil biology metrics that producers can use as a decision support tool when it comes to managing the soil biological component of agricultural soils. We evaluated the usefulness of nematode community profiling as a soil biology monitoring tool in support of a sustainable commercial-scale tomato production system in South Africa. The objectives were to: 1) study the effects of land use change on nematode communities in the tomato production region, and 2) explore the correlation between tomato crop productivity and the nematode community metrics. The enrichment index was a sensitive indicator of land use change, but the structure index was not. Although the number and proportion of free-living and plant-parasitic nematodes increased and decreased respectively, the selective amplification of specific herbivorous genera was observed.Helicotylenchus spp. was sensitive to land use change and might serve as soil health indicator in this tomato production region. Regression analysis indicated a combination of variables associated with soil pH, free-living nematodes (notably the bacterivores) and specific plant-parasitic nematode genera (Paratrichodorus spp. and Rotylenchus spp.) predictedtomato yield (R 2 = 0.846). Despite the useful information gleaned from the nematode community metrics regarding soil food web functioning, the importance of ecologically and economically important nematode genera was re-emphasized. The results of this study highlight an important principle regarding development of soil health metrics for tomato agroecosystems: tomato crop health was not necessarily predicted solely by indicators of soil food web health and functioning.