Worldwide, it has been recorded extensively that plants are subjected to severe abiotic and biotic stressors. The scientific research community has widely reported that multi-abiotic stressors cause horticultural crop losses, accounting for at least 50 to 70% of the crop yield and quality losses. Therefore, this review focused on the detrimental effects caused by abiotic stress factors occurring in single-, combined- and multi-cell stresses on horticultural plants worldwide, along with the best production systems practices for mitigation during and post-single and combined abiotic or multi-stress damages. A conclusion and recommendation could be reached using the pool of research material, which constituted research articles, reviews, book chapters, thesis, research short communications and industrial short communications from at least twenty-five years ago. Findings showed that some of the leading abiotic stresses are single- and combined abiotic stressors like water deficit, salinity, soil pH, phosphate deficiency, wounding, soil density and pot size. Established commercial and smallholder farmers are globally adapting to plant growth regulators and biostimulants as part of their production systems. However, as much as the effectiveness of biostimulants containing humic acids, algal extracts, plant growth-promoting microorganisms and phytohormones has been reported to promote plant development under multi-stress, only a few studies are focusing on organic phytohormone-based biostimulants on horticultural crops grown under adverse multi stress factoring. In conclusion, the review recommends alternative solutions for emerging South African farmers and growers who cannot afford agricultural insurance options and energy alternatives on the common single- and combined abiotic- or multi-stress-factors.

Irrigation is required to supplement rainfall to enhance the productivity of chickpea in South Africa (SA). However, the dependence on irrigation can be problematic for SA and other countries with limited natural water resources and variable rainfall. Even though access to irrigation water has been identified as one of the challenges faced when planting chickpea in the winter season in SA, irrigation management strategies for chickpea grown on soils differing in texture have not gained considerable research attention. Hence, this study aimed to assess the effects of irrigation levels on dry matter production of chickpea grown on two soils differing in soil texture under greenhouse conditions. The experiment was arranged as a 3 × 2 factorial in a completely randomized design, with 3 irrigation levels (25%, 50% and 75% of the water-holding capacity of soil (WHC)) and 2 soils differing in soil textural class (Loamy sand (LS) soil and sandy loam (SL) soil), replicated thrice. Irrigation level, soil texture and their interaction significantly affected shoot biomass (SBM) and total plant biomass (TBM). Generally, SBM, TBM and root biomass decreased correspondingly with the reduction in irrigation. The 25% WHC significantly reduced the SBM by up to 60% and TBM by up to 56% compared to the 50% and 75% WHC. The SBM and TBM were higher in SL soil than in LS soil. A significantly higher root/shoot ratio (0.45) in the LS soil than in the SL soil (0.16) indicated that the conditions of LS soil encouraged plants to allocate higher proportions of biomass into roots, possibly due to increased competition for soil resources. In conclusion, maintaining soil moisture at 50% WHC ensures better chickpea dry matter production in SL soil.

The present study was conducted to assess the effects of co-application of winery solid waste compost (WWC) and synthetic nitrogen (N) and phosphorus (P) fertilizers (SF) on maize growth and yield parameters. The field experiment was conducted during the 2017/18 and 2018/19 summer cropping seasons. The WWCs (microbially inoculated and uninoculated) and SF were combined at ratios: 0:0, 25:75, 50:50, 75:25, and 100:0 (wt/wt) to attain the amount of N and P supplied by the predicted rates of compost. The optimum SF rate (90 kg/ha P and 200 kg/ha N) for maize was used as a positive control. The non-significant (p ≤ 0.05) effect of compost type on growth and yield parameters indicated that the microbial inoculation during compost production has no effect on compost quality. Compared with control, WWC-SF combination (50:50) improved grain weight per cob by 18.6% in 2017/18. The increase in the measured yield parameters was quantitatively higher in treatment with the 50:50 WWC-SF mix ratio than in other treatments. Significant and positive correlations exist between growth and yield parameters. In conclusion, the study findings suggest that the combined application of WWC and SF has great potential to enhance the maize growth and yield attributes.

Tillage systems and compost application play important roles in improving soil conditions, nutrient availability, and crop growth and productivity. Although numerous studies demonstrating that compost application and minimum tillage (MT) systems are effective in mitigating soil degradation, their interaction effects on crop performance and soil properties at various depths remain poorly explored and require further investigation. Hence, this study assessed the effect of tillage system and compost application rate on soya bean performance and selected soil physico-chemical properties under rainfed conditions in Limpopo province, South Africa. The trial was conducted using a split-plot arrangement within a randomized complete block design with three replications. Main treatments were two tillage systems [MT and conventional tillage (CT)], while the sub-treatments were three compost rates (0, 10 and 20 t ha^− 1). The MT involved the use of chisel-plough to provide minimal disturbance of soil, whereas CT involved sequential use of chisel-plough, mouldboard-plough and a disc-harrow to pulverize and level the soil. Plant growth parameters, total biomass, grain yield and soil phosphorus (P) were affected by the tillage system and compost rate interaction. Grain yield from the CT plot (2061 kg ha^− 1) was 62% lower than that obtained from the MT plot (3348 kg ha^− 1). Higher soil organic carbon in the MT system (0.51%) than in CT system (0.43%) showed that reducing tillage intensity increases the organic matter accumulation. Tillage system, compost rate and soil depth interaction had no significant effects on selected soil properties. The results of this study indicate that while MT enhances soya bean productivity, the tillage system and compost application interaction influences grain yield and soil P, with compost application requiring careful management to prevent yield reduction.