https://hdl.handle.net/13049/90 2026-04-29T03:03:38Z https://hdl.handle.net/13049/660 Effects of plant density on growth parameters and yield of sugar bean (Phaseolus vulgaris L.) in Swaziland Zwane, S. T.; Ossom, E. M. Field bean (Phaseolus vulgaris L.) consumed in Swaziland is mostly imported. Small- scale farmers can grow this crop in the country and obtain good yields if the correct planting density is identified. A field study was conducted during the growing season of 2004/2005 to determine the influence of different planting densities on growth parameters and yield of field bean. The experiment consisted of a randomised complete block design, with four replications. There were five planting densities (400,000; 200,000; 133,333; 100,000 and 66,667 plants/ha studied for 11 weeks. Results showed that Absolute Growth Rate (AGR) was significantly (P < 0.01) higher in the lower populations. The lowest population had AGR of 7.0 g/week whereas the highest plant population had AGR of 2.4 g/wk between 7 and 10 weeks after planting (WAP). At 7 WAP, the highest plant population had a significantly (P <0.01) higher leaf area index, LAI, of 4.6 while the lowest plant population had LAI of 0.7. At 400,000 density of plants/ha, though the seed yield (695.8 kg/ha) was low, however, it was 56% higher than the yield (445.5 kg/ha) of the recommended plant population. Planting density of 400,000 plants/ha is suggested. 2005-01-01T00:00:00Z https://hdl.handle.net/13049/659 Post-flowering photoperiodic and temperature effects on phonological development and yield in field-grown bambara groundnut (Vigna subterranea) landraces in a sub-tropical environment. Sesay, A. The post-flowering phonological development of two local bambara groundnut (K/gna subterranea) landraces was studied at Luyengo, Swaziland using six sowing dates between mid-October 1999 and late January, 2000. The objective was to examine the influence of variation in post-flowering photoperiod and temperature on the phonological development and pod yield of the crop. While the rate of progress from sowing to podding was influenced by both temperature and photoperiod, the rate of progress from flowering to podding (1/ (p-f), with (p-f) being the number of days from 50% flowering to 50% podding) was influenced only by photoperiod between flowering and podding (r = 0.86, p < 0.01). Pod yield was strongly and positively related to the duration of the pod­ filling period (r2 = 0.96, p < 0.01), while the duration of the pod-filling period was strongly related to thermal time accumulated during the reproductive period. Photopcriod during the reproductive period influenced pod yield indirectly, through its influence on the onset of podding. The study confirms the photosensitivity of the onset of podding in bambara groundnut, and it was concluded that in bambara groundnut, unlike in other leguminous crops, the duration of the reproductive or pod-filling period, and therefore yield, are largely influenced by environmental factors prevailing at and subsequent to the onset of flowering. 2005-01-01T00:00:00Z https://hdl.handle.net/13049/655 The heavy metal content of Gaborone secondary sewage effluent in Botswana Emongor, V. E.; Ramolemana, G. M.; Machacha, S.; Khonga, E. B.; Marumo, K. The objective of this study was to determine the heavy metal content of the Gaborone secondary effluent in Botswana before its discharged to the Notwane river. Secondary effluent water was sampled every month for one year, from a breather pipe on the pivot irrigation system at the Botswana College of Agriculture, Notwane Farm, Gaborone, using USEPA procedures and guidelines. The results showed that the heavy metals of most widespread concern to human health Hg, Cd, Pb and As were below detectable limits, 5.75, 4.83 and 5.7 parts per billion (pgL1), respectively, and were below concentrations that could pose pollution of the environment and were within the recommended limits for irrigation water by FAO and the Botswana guidelines for irrigation water. The other trace elements Be, Ti, V, Cr, Co, Cu, Ga, Ge, Se, Sr, Ba, Ce, Bi, Al, Li, Mn, Mo and Fe were all below the recommended limits for irrigation water by FAO and the Botswana guidelines for irrigation water. Most of the trace elements were in concentrations of parts per billion. The current results suggest that the Gaborone secondary effluent is suitable for unrestricted irrigation of field, fodder and horticultural crops. However, heavy metal levels should be monitored continuously either by the Gaborone City Council or any other government institution in order to make sure the treated secondary sewage effluent meets the recommendations for irrigation water, and prevent environmental pollution and reduce health hazards that may be caused by pollutants to the end users of this scarce resource. 2005-01-01T00:00:00Z https://hdl.handle.net/13049/654 Cryptosporidium infection in cattle in southern Botswana Sharma, S.P. A parasitological survey was conducted to determine the prevalence of Cryptosporidium infection in cattle in Gaborone, Lobatse, Mochudi and Molepolole veterinary districts. Faecal samples from 137 dairy and beef calves < 3 months, 38 heifers and 36 cows were examined for oocysts of Cryptosporidium species in faecal smears stained with modified Ziehl Neelsen stain. The prevalence of Cryptosporidium infection was 29. 3% in dairy calves (n=106), 22. 6% in beef calves (n=31), 15. 8% in heifers (n=38) and 8. 3% (n= 36) in cows. The infection rate was significantly more in dairy calves in comparison to cows (_2 5. 4, P < 0. 05). Prevalence rates in dairy and beef calves < 4 weeks and 4 to 13 weeks old were 37. 8% of 74 and 15.9% of 63, respectively and the difference was statistically significant (_2 7. 1, P < 0. 01).The infection rate was significantly higher in diarrhocic dairy and beef calves (64.3%) compared to that of non-diarrhoeic calves (23.6%) (_~ 8.5, P < 0. 01) indicating role of C. parvum in neonatal diarrhoea. Morphologically, the oocysts observed in the faecal smears of calves were apparently indistinguishable from those of C.parvum, while in heifers and cows, the majority of oocysts were of C. andersoni. Il is evident from this preliminary investigation that Cryptosporidium infection is fairly high in cattle especially calves which constitutes a serious risk of infection to animal handlers and HIV infected individuals who fail to wash their hands and they need to be educated on the possible dangers of their acquisition of this infection while working with these infected animals. Further studies are recommended by including more bovines and other livestock species from different parts of this country. 2005-01-01T00:00:00Z