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Bambara groundnut (Vigna subterranean (L) Verdc) is an indigenous African crop. In South Africa, the crop is grown by rural subsistence farmers. This crop is classified as a drought-tolerant crop and it can produce good yields in poor soil conditions. However, statistics show that Bambara groundnut production is currently neglected by industries due to the lack of research on the crop focused on postharvest technologies, and agro-processing. Current research on the crop is mostly focused on agronomic and growing characteristics. Data on the physical properties and processing equipment for the Bambara groundnuts are limited. The objectives of this study were to investigate the effect of moisture contents on both Bambara groundnut seeds (shelled) and pods (unshelled). The physical properties of the pods and seeds were measured at three moisture content levels. The finding showed that axial dimensions, geometric mean diameter, sphericity, volume, and weight increase as moisture content increases. The static coefficient of friction of seeds and pods increased from 0.15 to 0.19 and 0.29 to 0.31, respectively. Simirlarly, the bulk density of shelled and unshelled groundnuts increased from 500 to 955, and 355 to 422 kg.[m.sup.-3], respectively. The results also showed that the true density of seeds rose from 994 to 1832 kg.[m.sup.-3] and for the unshelled groundnuts it increased linearly from 532 to 655 kg.[m.sup.-3]. The required forces for cracking both bambara groundnut seeds and kernels showed a declining trend as moisture increased from 6 to 20%. The cracking forces required for Bambara groundnuts kernels at 6, 15, and 20 % are 32.5 [+ or -]12 N, 29.9 [+ or -]15.3 N, and 28.9 [+ or -]9 N, respectively. As the moisture increased, the data deviation from the mean decreased from 16.30 to 10.1 N. In terms of designing agro processing eqiupment or machinary such as a shelling machine, the physical properties from the lower moisture content are recommended. Key words: cracking force, physical properties, moisture content, Bambara groundnuts, INTRODUCTION Bambara groundnut (Vigna subterranean (L) Verdc) is an African legume crop that is currently neglected by commercial farms [1, 2]. This crop serves as a cheap and high-quality protein [...]

Knowledge of the cost of a storage structure for fruits and vegetables is paramount as a decision tool when farmers consider the return on investment. The performance and economic analysis associated with using a solar-powered indirect air-cooling (IAC) combined with evaporative cooling (EC) storage structure for storage of green harvested tomatoes was investigated. This study investigated the effect of IAC+EC system and period of storage on the quality of tomatoes over a 28 day storage period. The construction, maintenance and operation costs of an IAC+EC system were also studied. Various quality attributes of tomatoes were investigated by monitoring the storage of green harvested tomato fruit over 28 days under both IAC+EC system and ambient conditions with data collated every seven days. Tomatoes stored under IAC+EC conditions had significantly (P Key words: marketability, payback period, postharvest losses, small-scale farming, air-cooling, INTRODUCTION In South Africa, most fruits and vegetables including tomatoes are produced in Limpopo province while most tropical and sub-tropical fruits are grown in Mpumalanga province [1]. These two provinces [...]

The performance of a solar energy-assisted seed storage room was evaluated through an ordinary 22-[m.sup.3] room that was retrofitted with a solar collector, inlets and chimney. The structure was made of a solar collector to heat the ambient air before entering the chimney. The chimney circulated the air inside the structure and inlets. To compare the performance of the modified storage room, a room with a similar capacity and without the retrofitted components (control storage room) was used. Twelve 8 kg bags of maize were stored in each storage room for a period of three months. Samples were taken every two weeks to determine germination rate, moisture content and seed vigour. The temperature and relative humidity (RH) was measured during storage. The RH in the control storage was significantly higher (P[less than or equal to]0.05) (60.6 [+ or -] 5.87%) than in the modified storage (40.1 [+ or -] 3.21%) during the day. However, at night, the RH in the control storage room was significantly lower (P[less than or equal to]0.05) (58.5 [+ or -] 7.32%) than in the modified storage (63.7 [+ or -] 6.28%). The RH in the modified storage room increased from 40.1% during the day to 63.7% at night. The RH in the control storage room decreased slightly from 60.6% to 58.5% during the day and night. The seed moisture content in the modified storage facility was significantly lower (P[less than or equal to]0.05) (12.6 [+ or -] 0.21%) than in the control storage room (13.3 [+ or -] 0.52%). The moisture content in the modified storage room decreased from 12.6% to 12.4%, whereas in the control room, moisture content increased from 12.6% to 13.8% in three months. The seed germination rate obtained after three months of storage in the modified storage room was significantly higher (P[less than or equal to]0.05) (98.5 [+ or -] 0.85%) than in the control storage room (96.8 [+ or -] 1.49%).The seed vigour obtained in the modified storage room was significantly higher (93.6 [+ or -] 0.35%) than in the control room (91.7 [+ or -] 2.08%) (P[less than or equal to]0.05). Seed stored in the control storage lost vigour at a faster rate, compared to the seeds stored in the modified storage room. Therefore, the modified naturally-ventilated seed storage room maintained seed quality better than the control storage room. Key words: relative humidity, temperature, natural ventilated, solar energy assisted, INTRODUCTION Seed moisture, vigour and germination are some of the most important parameters for assessing seed quality, especially, for plant breeders. To preserve the quality of seeds, proper storage facilities [...]

Atmospheric warming and extreme weather events have increasingly become major contemporary issues of global concern, yet relatively few studies have investigated recent decadal-scale climate change and variability in Zimbabwe. This study investigates spatiotemporal temperature and extreme weather events in Mzingwane catchment of southern Zimbabwe for the period 1967-2015. This is achieved through using the Non-parametric Modified Mann-Kendal trend test, while magnitudes of trends are estimated using Sen's slope estimator. Temporal and spatial trends for extreme dryness and wetness are established by using the Standard Precipitation and Evapotranspiration Index. The results for annual anomalies show a strong positive anomaly (.44 °C warmer) at all five stations for the summer months, while winter months recorded cool anomaly averaging -.28 °C. Trends in annual Tmax significantly increased (p < .05) at an average of .16 °C decade-1 at four stations, but excluding Matopos, which decreased significantly at .29 °C decade-1. The mean Tmax for the period 1897-1904 was .7 and 1.7 °C cooler than the reference average and 2000-2015 average respectively, while historic Tmin is .3 and 2.1 °C cooler. Results of extreme events indicate a significant increase (p < .05) in the occurrence of extreme dry periods since the 1980s. The findings are important for developing appropriate sustainable and adaptive strategies as climate changes. [ABSTRACT FROM AUTHOR]