Decolonising continuing teacher professional development in the teaching of physical science through improvisation in rural areas

Calls for the decolonisation of higher education in the world and South Africa in particular, has gained momentum since the student protests in 2015 and 2016. This takes place after some efforts have been made to transform and democratise the higher education landscape. Efforts made include: National Commission on Higher Education, White Paper 3 1997, The Higher Education Act of 1997 and the South African Qualifications Authority (SAQA) Act of 1995 which led to the creation of National Qualification Framework (NQF). The policies had promises on issues of access, equity, equality, inclusivity and social justice. After 20 years of democracy, students started to question the progress or lack thereof in the transformation of higher education in South Africa. They started to make demands for access, free education, decolonisation of the curriculum, changes in the pedagogy and epistemic practices. They also demanded the removal of certain statues on some of the campuses. The protests jolted some academics to start debating and writing about the decolonisation of higher education in South Africa. This was done by picking up different aspects that were made points of focus in terms of decolonisation. Consequently, some academics focused on the decolonisation of the curriculum, some on the higher education system whilst others focussed on teacher education. In this article, we intend to contribute to the debate by focusing on Continuing Teacher Professional Development (CTPD) that is an aspect within teacher education. The focus on CTPD was prompted by the fact that not much has been done on the decolonisation of CTPD in South Africa. Furthermore, this is a critical area, because unless teachers are empowered and reskilled to drive the decolonisation process, they may resist and ultimately render the whole process unworkable. It is based on the study that was conducted, focusing on CTPD in the teaching of physical sciences in some of the rural schools in Limpopo Province. The choice of physical sciences was because physical sciences is a gateway subject and most physics sciences teachers in Limpopo Province are based in rural areas. Generally, these schools do not have the appropriate facilities and equipment to teach physical science. Physical sciences teachers also face many challenges such as negative perception about the subject, lack of resources, limited room for professional development, poor teacher training, and inadequate support from within the school and the Provincial Department of Education.This study focussed on creativity and teacher empowerment by enabling physical sciences teachers to reflect on their implementation of science inquiry. Physical sciences teachers were empowered to be creative in handling scientific inquiry especially in the absence of the necessary scientific equipment. The study was conduct at a Higher Education Institution (HEI) in Limpopo Province where teachers, from rural schools, are specifically invited to the university for the National Science Week, which included a component of ongoing Continuing Teacher Profession Development (CPTD). During the National Science Week physical sciences teachers attend an in-service workshop on Improvisation in Science. Ninety (90) physical sciences teachers participated in this study. Data were generated by using a questionnaire and unstructured interviews. The findings of the study revealed that the success of CTPD is not so much in spending more funds in CTPD programmes, but it is in the approach that is used to prepare teachers to respond appropriately to the needs and the demands of the classroom environment. The article argues that the decolonisation process should prioritise the CTPD programmes at universities. This is due to the fact that teachers as agents of change need to be empowered and reskilled, so that they can be in the forefront of the decolonisation process. This can be achieved by adopting a transformative approach that encourages improvisation in science teaching. This approach to CPTD demands that teachers’ professional development should shift from the traditional approach to an approach that empowers teachers to be able to make a meaningful contribution to the classes that they teach

Reduced atrazine doses combined with sorghum aqueous extracts inhibit emergence and growth of weeds

Combining low doses of herbicides with allelopathic plant extracts subject weeds to different mechanisms of action, which reduces herbicide resistance. The effects of reduced atrazine doses combined with sorghum aqueous extracts (sorgaab) from sorghum accessions IS9456, IS22320 and Mahube on emergence and growth of Bidens pilosa and Eleusine indica were evaluated in a greenhouse experiment at the University of Zimbabwe in 2017. Two experiments were set up as a 3 ˟ 5 factorial arrangement in a completely randomized design testing sorghum varieties as sources of sorgaab, and five atrazine-sorgaab mixtures (100% sorgaab, 10% of the label recommended dosage (LRD) of atrazine for maize + 90% sorgaab, 30% LRD atrazine + 70% sorgaab, 100% LRD atrazine, and untreated check). Percent emergence, height, and total chlorophyll content in leaves significantly decreased (P<0.001) as influenced by sorghum variety in the order IS22320>Mahube>IS9456, for B. pilosa and E. indica. Sorghum variety significantly (P<0.001) affected dry weight of B. pilosa similarly to other parameters but did not significantly (P>0.05) affect dry weight of E. indica. Percent emergence, height, total chlorophyll content and plant dry weight significantly (P<0.001) decreased in the order untreated control>100% sorgaab>10% LRD atrazine + 90% sorgaab>30% LRD atrazine + 70% sorgaab>100% LRD atrazine. There were significant (P<0.05) effects of sorghum variety as source of sorgaab ˟ atrazine-sorgaab mixture interactions on B. pilosa emergence and height and E. indica height. There is potential to exploit sorghum allelopathy using aqueous extracts alone, and in mixture with reduced doses of atrazine in controlling certain weeds. However, the allelopathic efficacy of sorgaab was dependent on sorghum variety. The sorghum variety IS9456 possibly produces high amounts of water soluble allelochemicals, making it a suitable candidate for use in integrated weed management

POTENTIAL FOR QUALITY PROTEIN MAIZE FOR REDUCING PROTEIN-ENERGY UNDERNUTRITION IN MAIZE DEPENDENT SUB-SAHARAN AFRICAN COUNTRIES: A REVIEW

Most cereal crops, including maize ( Zea mays L.), are deficient in essential amino acids, such as lysine and tryptophan; hence they are poor in protein quality. A mutant maize with elevated levels of lysine and tryptophan was developed by the International Maize and Wheat Improvement Centre (CIMMYT) and was called quality protein maize (QPM). Nonetheless, people in sub-Saharan Africa (SSA) continue to use normal endosperm maize (non-QPM) instead of QPM. The objective of this article was to examine the existing information on institutional arrangements, infrastructure and social systems hampering adoption of QPM and to identify opportunities for promoting the campaign for its utilisation in SSA, through innovative research for development initiatives. It is clear that QPM has superior nutritional value, both to humans and to monogastric animals compared to non-QPM. Lack of sound policies and awareness among farmers about the existence and advantages of QPM are some of major drawbacks to QPM adoption and realisation of its benefits. Most farmers hardly believe information regarding nutritional composition of varieties, without convincing visual evidence such as grain yield from demonstration plots. Many African governments have mounted campaigns geared to promote adoption of QPM varieties. Varying levels of QPM adoption have been recorded in South Africa, Burkina Faso, Uganda and Ghana with high QPM production under areas ranging from 12 500 to 71 250 ha. In order to reduce protein-energy undernutrition (PEU), SSA countries should implement policies that promote QPM adoption such as providing farmers with a premium price for the QPM grain. Results from meta-analysis community based studies revealed that QPM based diets resulted in a 12% improvement on weight and 9% increase in height in infant and young children compared to non-QPM based diets. Therefore, quality protein maize bears great potential for reducing PEU and its adoption could be high given that most SSA countries depend on maize as the major source of calories and protein.La plupart des cultures c\ue9r\ue9ali\ue8res, y compris le ma\uefs ( Zea mays L.), sont d\ue9ficients en acides amin\ue9s essentiels, tels que la lysine et le tryptophane, donc elles sont pauvres en prot\ue9ines de qualit\ue9. Un ma\uefs mutant avec des niveaux \ue9lev\ue9s de lysine et tryptophane \ue9tait d\ue9velopp\ue9 par le Centre International d\u2019Am\ue9lioration du\ua0Ma\uefs et du Bl\ue9 (CIMMYT) appel\ue9 ma\uefs \ue0 prot\ue9ine de qualit\ue9 (QPM). N\ue9anmoins, les peuples de l\u2019Afrique Sub-Saharienne (SSA) continuent d\u2019utiliser le ma\uefs \ue0 endosperme normal (non-QPM) \ue0 la place du QPM. L\u2019objectif de cet article \ue9tait d\u2019examiner l\u2019information existant sur les dispositions institutionnelles, les infrastructures et les syst\ue8mes sociaux emp\ueachant l\u2019adoption du QPM et pour identifier les opportunit\ue9s pour une campagne de promotion pour son utilisation dans les SSA, \ue0 travers la recherche innovante pour les initiatives de d\ue9veloppement. C\u2019est clair que QPM a une valeur nutritionnelle sup\ue9rieure au non-QPM, \ue0 la fois pour les hommes et les animaux monogastriques. L\u2019absence d\u2019une politique solide et de sensibilisation entre les producteurs concernant l\u2019existence et les avantages du QPM sont les quelques facteurs limitant l\u2019adoption de l\u2019QPM et la r\ue9alisation de ses b\ue9n\ue9fices. La plupart des producteurs croient difficilement les informations relatives \ue0 la composition nutritionnelle des vari\ue9t\ue9s, sans l\u2019existence d\u2019une \ue9vidence visuelle comme le rendement en grain des parcelles de d\ue9monstration. Plusieurs gouvernements africains ont mont\ue9 des campagnes pour promouvoir l\u2019adoption des vari\ue9t\ue9s QPM. Des niveaux d\u2019adoption de l\u2019QPM ont \ue9t\ue9 enregistr\ue9s en Afrique du Sud, au Burkina Faso, en Ouganda et au Ghana avec une forte production de QPM sur des superficies variant de 12500 \ue0 71250 ha. Dans le but de r\ue9duire le d\ue9nutrition prot\ue9ino-\ue9nerg\ue9tique (PEU), les pays du SSA devraient mettre en application les politiques qui favorisent l\u2019adoption des QPM telles que fournir aux producteurs des prix r\ue9duits sur les graines de QPM. Les r\ue9sultats des m\ue9ta-analyses sur la base des \ue9tudies communautaires ont montr\ue9 que les r\ue9gimes alimentaires bas\ue9s sur le QPM r\ue9sultent en une augmentation de 12% du poids et 9% en taille des enfants et des petits enfants compar\ue9s aux r\ue9gimes alimentaires bas\ue9s sur les non-QPM. Donc, les ma\uefs \ue0 prot\ue9ine de qualit\ue9 ont un grand potentiel de r\ue9duire le PEU et son adoption pourrait \ueatre forte \ue9tant donn\ue9 que beaucoup de pays du SSA d\ue9pendent du ma\uefs comme source principale d\u2019\ue9nergie et de prot\ue9ine

VARIABILITY IN CONDENSED TANNINS AND BITTERNESS IN SPIDER PLANT GENOTYPES

Spider plant ( Cleome gynandra L.) contributes considerably to the nutrition and medicines of communities in southern Africa. However, its utilisation is limited by its bitterness caused by condensed tannins. Unfortunately, processing options that reduce the bitterness also remove nutritionally and medicinally useful compounds. The objective of this study was to assess the genetic variability of condensed tannins and their association with bitterness in C. gynandra so as to devise variety recommendations for either direct utilisation or for breeding programmes in Zimbabwe. Total phenolic compounds and condensed tannins were quantified in five genotypes. The amount of total phenolic compounds were not significant, but quite significant (P<0.001) for condensed tannins. Genotype CGSKGP had the highest (0.49 mg g-1) and twice as much condensed tannins as CGKEX and CGSKP. Bitterness was positively correlated with the concentrations of condensed tannins (r=0.94, P<0.05), but not with total phenolics. We identified two genotypes, CGKEX and CGSKP with less bitterness (condensed tannins) that can be used in breeding for less bitterness to reduce excessive processing that lowers the nutritional and medicinal properties of C. gynandra.La plante araign\ue9e ( Cleome gynandra L.) contribue de fa\ue7on consid\ue9rable \ue0 la nutrition et \ue0 la m\ue9decine traditionnelle chez les communaut\ue9s en Afrique du Sud. N\ue9anmoins, son utilisation est limit\ue9e en raison de son go\ufbt amer caus\ue9 par la concentration en tanins. Malheureusement, le mode de transformation qui y r\ue9duit le go\ufbt amer r\ue9duit \ue9galement les nutriments et principes actifs utilis\ue9s en m\ue9decine traditionnelle. L\u2019objectif de cette \ue9tude \ue9tait d\ue9valuer la variabilit\ue9 g\ue9n\ue9tique du taux de tanins concentr\ue9 et la relation entre ce taux et le go\ufbt amer de C. gynandra, ceci pour recommander des vari\ue9t\ue9s appropri\ue9es soit pour l\u2019utilisation directe, soit pour des programmes d\u2019am\ue9lioration vari\ue9tales en Zimbabwe. Les taux globaux de compos\ue9s ph\ue9noliques et de tanins concentr\ue9s ont \ue9t\ue9 estim\ue9s dans cinq vari\ue9t\ue9s. L\u2019\ue9tude a montr\ue9 une diff\ue9rence significative pour les tanins concentr\ue9 (P<0.001), mais pas pour les compos\ue9s ph\ue9noliques. La vari\ue9t\ue9 CGSKGP avait la concentration la plus \ue9lev\ue9e (0.49 mg g-1) et \ue9tait deux fois plus concentr\ue9e en tanins que les vari\ue9t\ue9s CGKEX et CGSKP. Le gout amer \ue9tait positivement corr\ue9l\ue9 avec la concentration en tanins (r=0.94, P<0.05), mais pas avec les compos\ue9s ph\ue9noliques. Nous avons identifi\ue9s deux vari\ue9t\ue9s\ua0ayant un faible gout amer (tanins concentr\ue9s), CGKEX et CGSKP, qui peuvent \ueatre utilis\ue9es pour d\ue9velopper des vari\ue9t\ue9s am\ue9lior\ue9es ayant un faible gout amer afin de r\ue9duire les transformations excessives qui r\ue9duisent les propri\ue9t\ue9s nutritionnelles et m\ue9dicinales de C. gynandra

Cassava whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), in sub-Saharan African farming landscapes: a review of the factors determining abundance

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a pest species complex that causes widespread damage to cassava, a staple food crop for millions of smallholder households in Sub-Saharan Africa. Species in the complex cause direct feeding damage to cassava and are the vectors of multiple plant viruses. Whilst significant work has gone into developing virus-resistant cassava cultivars, there has been little research effort aimed at understanding the ecology of these insect vectors. In this review we critically assess the knowledge base relating to factors that may lead to high population densities of Sub-Saharan African (SSA) Bemisia tabaci species in cassava production landscapes of East Africa. We focus first on empirical studies that have examined biotic or abiotic factors that may lead to high populations. We then identify knowledge gaps that need to be filled to deliver long-term sustainable solutions to manage both the vectors and the viruses that they transmit. We found that whilst many hypotheses have been put forward to explain the increases in abundance witnessed since the early 1990s, there are little available published data and these tend to have been collected in a piecemeal manner. The most critical knowledge gaps identified were: (i) understanding how cassava cultivars and alternative host plants impact B. tabaci population dynamics and its natural enemies; (ii) the impact of natural enemies in terms of reducing the frequency of outbreaks and (iii) the use and management of insecticides to delay or avoid the development of resistance. In addition, there are several fundamental methodologies that need to be developed and deployed in East Africa to address some of the more challenging knowledge gaps

Resistance To Striga Asiatica (L.) Kuntze In Sorghum: Parent Characterisation And Combining Ability Analysis

Pot experiments were conducted to assess the resistance of five sorghum [Sorghum bicolor (L.) Moench] cultivars namely, DC 75, SV-1, SAR 16, SAR 19 and SAR 29 to witchweed [Striga asiatica (L.) Kuntze] infestation. These genotypes were evaluated in two separate experiments, for resistance under S. asiatica infestation, and for yield without infestation. F2 progeny resulting from a four parent half diallel cross involving SV-1 and SAR cultivars were evaluated under S. asiatica infestation. The SAR and SV-1 cultivars were also screened for witchweed seed germination stimulant production using the agar gel technique. Cultivars SAR 19 and SAR 29 supported significantly lower S. asiatica counts than DC 75, SV-1 and SAR 16. They also delayed emergence of S. asiatica by more than 10 weeks relative to DC 75, SV-1 and SAR 16. Using agar assays, SAR 19 and SAR 29 had the least witchweed seed germination distances of 5.9 mm and 6.9 mm, respectively, compared to SAR 16 which had 15.4 mm and SV-1 which had 25.6 mm. Combining ability analysis for S. asiatica counts at maximum emergence revealed that additive genetic factors were preponderant for witchweed counts. Usually, SAR 16 is regarded as a resistant cultivar though its reaction to witchweed in these experiments revealed that it is susceptible. Cultivar SV-1 was susceptible, DC 75 was tolerant and SAR 19 and SAR 29 were resistant.Des essais en pots ont \ue9t\ue9 conduits pour \ue9valuer la r\ue9sistance de cinq cultivars de sorgho [Sorghum bicolor (L.) Moench] \ue0 savoir: DC 75, SV-1, SAR 16, SAR 19 et SAR 29 \ue0 l'infestation de l'herbe magicienne [Striga asiatica (L.) Kuntze]. Ces g\ue9notypes ont \ue9t\ue9 \ue9valu\ue9s en deux essais s\ue9par\ue9s, pour la r\ue9sistance \ue0 l'infestion de S. asiatica et pour le rendement sans infestation. La descendance F2 provenant des hybrides d'un demi diall\ue8le de quatre parents comprenant des cultivars SV-1 et SAR ont \ue9t\ue9 \ue9valu\ue9s sous l'infestion de S. asiatica. SV-1 et le cultivar SAR ont \ue9t\ue9 aussi cribl\ue9s pour la germination des semences de l'herbe magici\ue8nne stimulant la production en utilisant la technique de gel agar. Les cultivars SAR 19 et SAR 29 ont support\ue9 significativement un nombre faible de S. asiatica plus que DC 75, SV-1 et SAR 16. Ils ont aussi retard\ue9 l'\ue9mergence de S. asiatica plus de 10 semaines relativement \ue0 DC 75, SV-1 and SAR 16. Utilisant des essais agar, SAR 19 et SAR 29 ont eu la moindre germination des semences de la mauvaise herbe avec des distances de 5.9 mm et 6.9 mm respectivement, en comparaison avec SAR 16 qui avait 15.4 mm et SV-1 ayant eu 25.6 mm. L'analyse de l'aptitude de combinason pour les comptes de S. asiatica \ue0 l'\ue9mergence maximale a r\ue9v\ue9l\ue9 que les facteurs g\ue9n\ue9tiques additifs \ue9taient pr\ue9ponderants pour les comptes de striga. SAR 16 est normallement consid\ue9r\ue9 comme cultivar r\ue9sistant bien que sa r\ue9action au striga dans ces essais ont r\ue9v\ue9l\ue9 qui'il \ue9tait sensible. SV-1 \ue9tait sensible, DC 75 tol\ue9rant alors que SAR 19 et SAR 29 \ue9taient r\ue9sistants

Evaluation of the Potential of Jack Beat [Canavalis Ensiformis (L.) DC.} and Velvet Bean [Mucuna Pruriens (L.) DC.] Aqueous Extracts as Post-Emergence Bio-Herbicides for Weed Control in Maize (Zea Mays L.)

The objective of the study was to evaluate the effect of jack bean and velvet bean aqueous extracts when applied post-emergence alone or in combination with half dosage rates of atrazine on goosegrass, beggarticks, and maize. Three potted experiments with fifteen treatments were laid out in a completely randomized design replicated four times and repeated once. The bio-herbicidal treatments were applied to maize at two weeks after crop emergence and on the weeds at the 3-4 leaf stage. Results showed that maize height increased significantly (p0.05) affected while chlorophyll content and dry weight were significantly (p<0.05) reduced by all treatments. All the treatments caused complete weed control at 6 and 10 DAS in beggarticks and goosegrass, respectively. It was concluded that velvet bean and jack bean aqueous extracts are phytotoxic to weeds of divergent morphology

Evaluation of the Potential of Jack Beat [Canavalis Ensiformis (L.) DC.} and Velvet Bean [Mucuna Pruriens (L.) DC.] Aqueous Extracts as Post-Emergence Bio-Herbicides for Weed Control in Maize (Zea Mays L.)

The objective of the study was to evaluate the effect of jack bean and velvet bean aqueous extracts when applied post-emergence alone or in combination with half dosage rates of atrazine on goosegrass, beggarticks, and maize. Three potted experiments with fifteen treatments were laid out in a completely randomized design replicated four times and repeated once. The bio-herbicidal treatments were applied to maize at two weeks after crop emergence and on the weeds at the 3-4 leaf stage. Results showed that maize height increased significantly (p0.05) affected while chlorophyll content and dry weight were significantly (p<0.05) reduced by all treatments. All the treatments caused complete weed control at 6 and 10 DAS in beggarticks and goosegrass, respectively. It was concluded that velvet bean and jack bean aqueous extracts are phytotoxic to weeds of divergent morphology