Curated Content

Onion 243 is a short-day yellow hybrid variety with high yield potential and is suitable for storage. Plants have a uniform fall over of leaves at maturity. Bulbs are globular, uniform, medium-sized, and firm. Yield is comparable to hybrid varieties which are commercially cultivated locally. The variety adapts well to onion-growing regions except in coastal areas having sandy soil.

Guidelines for Extraction of Tomato Seeds

Fluazifop-P-butyl 150 g/L is a systemic, post-emergence herbicide that can be used for the control of annual and perennial grasses. Trials carried out at the FAREI on the effect of fluazifop-P-butyl on these two types of grasses have shown that the herbicide is not phytotoxic to crops such as potato, onion, carrot, creepers, peanut, and banana, as well as non-gramineae ornamentals. Weeds turn yellow or red and weed control is usually completed within 3 to 5 weeks after application

Sorghum (Sorghum bicolor [L.] Moench) is a valuable crop in the dry regions of the world, including Namibia. Due to the intensity and recurrence of drought and heat stress in the traditional sorghum growing areas, there is a need to breed and deploy new generation farmer-preferred and climate-smart cultivars to serve the diverse value chains. Therefore, the objectives of this study were to assess the present state of sorghum production in northern Namibia and document farmers’ perceived production constraints and trait preferences in new varieties to guide drought-tolerance breeding. A survey was conducted using a participatory rural appraisal in the following six selected sorghum-growing constituencies in Namibia: Kapako and Mpungu (Kavango West Region), Eenhana and Endola (Ohangwena Region), and Katima Mulilo Rural and Kongola (Zambezi Region). Data were collected using a structured questionnaire involving 198 farmers in 14 sampled villages across the regions. Results revealed variable trends in sorghum production among respondent farmers when disaggregated by gender, age, number of households, education level, cropping systems, types of varieties grown, and perceived production constraints. An equal proportion of male and female respondent farmers cultivate sorghum, suggesting the value of the crop to both genders in Namibia. Most respondent farmers (63.6%) were in productive age groups of <40 years old. In the study areas, low-yielding landrace varieties, namely Ekoko, Okambete, Makonga, Kamburo, Nkutji, Katoma, Fuba, Dommy, Kawumbe, and Okatombo, were widely cultivated, and most of the farmers did not use chemical fertilizers to cultivate sorghum. Farmers’ perceived sorghum production constraints in the study areas included recurrent drought, declining soil fertility, insect pest damage, high cost of production inputs, unavailability of improved seed, lack of alternative improved varieties with farmers’ preferred traits, lack of organic manure, limited access to market and limited extension service. The key farmers’ preferred traits in a new sorghum variety included high grain yield, early maturity, and tolerance to drought, in the field and storage insect pests. The study recommends genetic improvement and new variety deployment of sorghum with the described farmers-preferred traits to increase the sustainable production of the crop in Namibia.

The magnitude of genotype by environment interaction (GEI) is crucial for selecting high performing and adapted genotypes for targeted breeding. The aim of the study was to determine GEI of newly-developed mutant and traditional sorghum lines for grain yield and yield related traits for drought-prone areas of Namibia. Fifty sorghum genotypes were evaluated under feld conditions using a 10×5 alpha lattice design with three replications. The experiments were carried out in four environments with two growing seasons in Namibia. Data were collected on grain yield and related traits and subjected to the Additive Main Efects and Multiplicative Interaction (AMMI) model. The AMMI model showed that 93.9% of the total genetic variation was attributed to days to 50% fowering (DF), while 94.04% of the variation was due to plant height (PH), 86.52%  to panicle weight (PW), 70.67% to thousand-grain weight (TGW), and 90.68% to grain yield (GY). The larger variations attributed to genotypic efects for PL (36.3%), TGW (33.2%) and PH (20.7%) are useful for genotype selection for yield related traits. Based on a multi-trait biplot and Best Linear Unbiased Prediction (BLUPs) analyses of the GEI data across all drought-prone testing environments, the medium maturity mutant line designated as L7P9-13 was selected as the best yielding (2 tons/ha) and recommended for drought-prone area of Namibia

Cultivated sorghum [Sorghum bicolor (L.) Moench] is an important food security crop in the semi-arid regions of the world including Asia and Africa. Its genetic diversity is contained mostly in traditional varieties and modern cultivars used by farmers. In this study, agro-morphological traits and molecular markers were used to assess genetic diversity in 22 accessions of cultivated sorghum from five countries (Botswana, Namibia, Swaziland, Zambia and Zimbabwe) in the Southern African Development Community (SADC) region. The study revealed a significant variation among 22 accessions in both qualitative and quantitative morphological traits, indicating the accessions’ promising potential as breeding material. For molecular analysis, 11 microsatellite primer-pairs were used, and generated a total of 70 alleles across 20 accessions. Analysis of molecular variance revealed a high level of genetic variation; 67 % among the accessions and 10 % among the five countries. The patterns of genetic diversity and the relationships observed in this study should provide insights for genetic resource conservation and utilization of sorghum germplasm in the SADC region.

We report here the development of 75 SSR markers for Bambara groundnut through various sequencing approaches and the subsequent utilization of these SSR markers and other marker types (DArT Arrays) for the analysis of genetic diversity, population structure and the selection of pure lines from landraces. To assess the level of genetic diversity in Bambara groundnut landrace collections, 68 and 201 polymorphic SSR and DArT markers, respectively, were assayed against 24 single individual seed from a core collection of landraces. Polymorphic information content (PIC) ranged from 0.08 to 0.89 with an average of 0.42 across all SSR polymorphic markers, with observed (Ho) and expected (He) heterozygosity of 0.01 and 0.5 respectively. For the population structure analysis, 12 SSR markers selected as highly polymorphic from the initial screen were assayed against 123 landrace accessions. The average PIC across the 12 SSR was 0.66 with an average Ho of 0.02 and an inbreeding coefficient (f) of 0.98, suggesting that seed derived from a single plant essentially represents an unselected variety. Based on the low level of Ho and high f observed in the landrace samples, a subset of 35 genotypes derived from the landraces were advanced for field trials in Botswana and scored for 37 phenotypic traits. These 35 individual genotypes were ranked for agronomic performance based on yield component factors and other qualitative traits after field evaluation. Five genotypes with good yield potential and adaptability were recommended as potential varieties for Botswanan agro-ecology.

Sorghum is an economically important and a staple food crop for over half a billion people in developing countries, mostly in arid and semi-arid regions where drought stress is a major limiting factor. Although sorghum is generally considered tolerant, drought stress still signifcantly hampers its productivity and nutritional quality across its major cultivation areas. Hence, understanding both the efects of the stress and plant response is indispensable for improving drought tolerance of the crop. This review aimed at enhancing our understanding and provide more insights on drought tolerance in sorghum as a contribution to the development of climate resilient sorghum cultivars. We summarized fndings on the efects of drought on the growth and development of sorghum including osmotic potential that impedes germination process and embryonic structures, photosynthetic rates, and imbalance in source-sink relations that in turn afect seed flling often manifested in the form of substantial reduction in grain yield and quality. Mechanisms of sorghum response to drought-stress involving morphological, physiological, and molecular alterations are presented. We highlighted the current understanding about the genetic basis of drought tolerance in sorghum, which is important for maximizing utilization of its germplasm for development of improved cultivars. Furthermore, we discussed interactions of drought with other abiotic stresses and biotic factors, which may increase the vulnerability of the crop or enhance its tolerance to drought stress. Based on the research reviewed in this article, it appears possible to develop locally adapted cultivars of sorghum that are drought tolerant and nutrient rich using modern plant breeding techniques.

Purpose This field study evaluated the interactive effects of biochar (BC) and sewage sludge (SS) on P bioavailability and spinach yields for two seasons.

Method Treatments were combinations of biochar (0, 2.5 and 5 Mg ha-1 ) and sewage sludge (0, 6 and 12 Mg ha-1 ), or mineral fertilizer (200, 28, and 18.9 kg ha-1 ), amended in a randomized complete block design to Luvisol and Cambisol.

Results Significant (p < 0.05) yield increase of 53 and 65%, respectively occurred with increasing sole biochar doses on the Luvisol. Both applied alone and in combination with BC, the high rate of SS increased (p < 0.05) yields on the Luvisol over two seasons. Complimentary effects of 6SS+5BC on the Luvisol showed the highest yield increase for the study period. Co-application of amendments on the Cambisol decreased (p > 0.05) yields compared to sole amendments. Mehlich – 3 extractable P (M3-P) in control plots (CONT) increased between seasons, presumably due to P inputs from the irrigation water. Co-amendments on the Cambisol resulted in higher M3-P increase over mineral fertilizer than on the Luvisol in both seasons. Accumulation of M3-P in control plots confounded correlations between crop yields and available P. Higher P under BC compared to SS amended soils emphasize biochar capacity to capture P from irrigation water.

Conclusion The results suggest that combined low rates of SS and BC can have significant effects on P availability and crop yields. Biochar enhanced plant P uptake, but decrease in yields with simultaneous increase in M3-P between seasons warrants further research.

The article presents results of a survey conducted in the northern part of Botswana. The study was designed to assess the quantity of vegetable produced, production trend and constraints faced by farmers. The survey was done at Ditladi and Gulushabe in the farmer’s fields in May 2019 using a pre-tested survey questionnaire. Farmers were interviewed individually in their farms. Vegetable production and importation data was sourced from Horticultural sector and department of agricultural business promotion. Farmers (41.18%) perceived an upward production trend but data from agricultural offices indicate that production is fluctuating while generally low in all crops except cabbage. Farmers are faced with constraints such as gullies that limit the cultivable area, lack of implements, and lack of transport. The small size of fields is a bottleneck to most farmers. Prevalence of crop pests and diseases results in heavy application of synthetic chemicals. Cropping plan is neglected by more than half of the farmers interviewed. Farmers do not utilize available programs and financiers satisfactorily. They interact with government extension agents mostly on quarterly basis and are aware of climate change at the same time experiencing its consequences. There is a need for a joint effort for on-farm trials and information dissemination by the relevant stakeholders.