and Natural Resources from November to December 2016. Mature Vachellia rehmanniana seeds were collected from healthy erect trees at Butale Village, Botswana to investigate the effect of different pre-sowing treatment methods on seed germination. The experiment was laid out in a completely randomized design (CRD) with five treatments (control, mechanical scarification, boiling water, hot water and concentrated sulphuric acid (98.8%)). Boiling water had three different levels of time exposure (1, 3 and 5 min) whereas, concentrated sulphuric acid had four different levels of time exposure (15, 30, 45 and 60 min). The results revealed that seed germination percentage, germination mean time and germination index were significantly (P < 0.01) affected by pre-treatment methods. The highest significant cumulative germination percentages were recorded in seeds subjected to boiling water for 3 and 5 min, sulphuric acid for 45 and 60 min, and mechanical scarification. Based on the findings mechanical scarification and boiling water techniques are recommended for use in nurseries and by farmers because sulphuric acid is expensive and need to be handled by trained individuals. It is recommended that future research should target increasing the exposure time over five and 60 minutes for boiling water and sulphuric acid treatments, respectively for this species to increase the cumulative germination percentage.

Quality of fresh produce is the most critical issue in the economics of a vegetable enterprise. In order to investigate the effect of biochar amendment and deficit irrigation on tomato fruit quality, experimental research was conducted under a rain shelter in southern China during the 2017 and 2018 growing seasons. The experiment consisted of five treatments. Crops were irrigated to 100% of field water capacity at all growth stages as treatments T1 and T2. The other treatments received 30% less irrigation water than T2 when its soil water content reached 70% of field capacity, and were designated as treatments T3, T4 and T5, applied at the vegetative (stage I), flowering and fruit development (stage II), and fruit ripening (stage III) stages, respectively. Treatment T1 included no biochar, while the other treatments included 10% biochar by weight. The results showed that the total soluble solids (TSS) content, sugar-to-acid ratio (SAR), vitamin C (VC) content, and colour index (CI) increased in the deficit irrigation treatments depending on the phenological stage, the fruit ripening stage in particular. Meanwhile, single fruit weight was significantly (p < 0.05) reduced by water deficit at stages II and III, subsequently affecting the total fruit yield. Biochar improved soil moisture conservation and had a positive effect on fruit quality as evidenced by better single quality attributes (p < 0.05) of T2 over T1. The GRA and TOPSIS appraisal methods were used to conduct the comprehensive quality analysis. Eventually, treatment T5 ranked the best in both seasons, and this was also confirmed by the combinational evaluation method.

In recent years, the awareness of pomegranate health benefits has grown exponentially; nonetheless the existing propagation methods remain a challenge to supply adequate suitable planting materials needed for commercial production. Micropropagation can lead to mass production of plantlets and callus-mediated in vitro regeneration can open avenues for the use of genetic engineering to improve this crop. The aim of this study was to evaluate appropriate conditions for pomegranate micropropagation, callogenesis and use Simple Sequence Repeat markers to screen for somaclonal variation. Cytokinins (Benzylaminopurine, Kinetin and Thiadiazol-5ylurea) were tested for shoot induction from nodal explants while auxins (1-Naphthaleneacetic acid, Indole-3-butyric acid and Indole-3-acetic acid) were tested for root induction of in vitro regenerated shoots. 1-Naphthaleneacetic acid combined with Benzylaminopurine was assessed for their ability to induce callus from cotyledon and leaf explants. Genetic integrity between mother plant, callus and in vitro regenerated shoots were assessed using eight Simple Sequence Repeat markers. Maximum number of shoots and leaves were obtained on full strength Murashige and Skoog media with 6.9 &micro;M kinetin. The highest number of roots was achieved on half strength Murashige and Skoog media with 4.9 &micro;M Indole-3-butyric acid and the longest root was got on half strength Murashige and Skoog media with 5.3 &micro;M Indole-3-acetic acid. Leaves and cotyledons demonstrated to be potential explants for callus formation at all hormonal combination levels tested. Eight out of 13 amplified alleles were polymorphic. A wider genetic variation was found with similarity coefficient range of 0.46-0.92. More somaclonal variation was in regenerated shoots compared to callus.