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Search Results: 1 - 10 of 8618 matches for " Q Emongor "
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Surface sterilant effect on the regeneration efficiency from cotyledon explants of groundnut (Arachis hypogea L.) varieties adapted to eastern and Southern Africa
SM Maina, Q Emongor, KK Sharma, ST Gichuki, M Gathaara, SM de Villiers
African Journal of Biotechnology , 2010,
Abstract: Five groundnut (Arachis hypogea L.) varieties - ICGV-12991, ICGV-99568, ICGV-90704, CG-2 and Chalimbana - that are adapted to Eastern and Southern Africa were compared to variety JL 24 for their regeneration response in tissue culture. Sodium hypochlorite and mercuric chloride were compared for efficiency as sterilizing agents and subsequent effect on regeneration. All five varieties formed shoot buds that elongated well on shoot elongation medium. ICGV-90704 and Chalimbana performed better than the other three varieties for shoot organogenesis although all varieties produced healthy rooted plants in vitro that were successfully transferred to the greenhouse where they exhibited normal growth, flowering and seed set. Both sterilizing agents were suitable, but mercuric chloride was less harmful than sodium hypochlorite. This study established a basis for genetic engineering activities on African groundnuts in the future.
Safflower (Carthamus tinctorius L.) the Underutilized and Neglected Crop: A Review
V. Emongor
Asian Journal of Plant Sciences , 2010,
Abstract: Safflower (Carthamus tintorius L.) belongs to the family Compositae or Asteracea. It’s a multipurpose oilseed crop grown mainly for its high quality edible oil and bird seed. Initially safflower oil was used as a source of oil for the paint industry, now its edible oil is used for cooking, making margarine and salad oil. Safflower is also grown for its flowers which are used as cut flowers, colouring and flavouring foods, making dyes for the textile industry, livestock forage, vegetable, making herbal teas and medicinal purposes. In China safflower is grown as a medicinal plant for the treatment of cardiovascular diseases, male and female sterility, lowering blood cholesterol, release of retained placenta and still birth, induction of labour in expectant women, delayed, heavy and painful menstrual periods, various types of rheumatism (sciatica, thorax, arthritis), respiratory diseases (whooping cough, chronic bronchitis), gastritis, etc. Despite the many uses of safflower, it has remained a minor crop. Therefore, it is essential for the scientific community to carry out research on this crop and popularize it as a commercial crop for development of pharmaceuticals, edible oil, paint and varnishes industry, dye extraction (carthamin), source of α-tocopherol, livestock feed, vegetable and cut flower.
Gibberellic Acid (GA3) Influence on Vegetative Growth, Nodulation and Yield of Cowpea (Vigna unguiculata (L.) Walp.
V. Emongor
Journal of Agronomy , 2007,
Abstract: Two field experiments were carried out to evaluate the effects of GA3 on the growth and development of cowpea cultivars Blackeye and Tswana. Exogenous application of GA3, 7 days after emergence at 30, 60 or 90 mg L-1 significantly increased cowpea plant height, first node height, leaf area and leaf number/plant, nodulation, plant dry matter accumulation, pod length, pod number/plant, seed number/pod, 100 seed weight, harvest index and seed yield ha-1. Gibberellic acid had no significant effect on cowpea plant senescence. The results of this study suggests that exogenous application of GA3 can be used to modify growth and development of some cowpea varieties.
Evaluation of the shoot regeneration response in tissue culture of pigeonpea (Cajanus cajan [L.] Millsp.) varieties adapted to eastern and southern Africa
S de Villiers, Q Emongor, R Njeri, E Gwata, D Hoisington, I Njagi, S Silim, K Sharma
African Journal of Biotechnology , 2008,
Abstract: Seven varieties of pigeonpea (Cajanus cajan [L.] Millsp.) of varying growth durations and adapted to a wide range of environments across eastern and southern Africa were evaluated for their shoot regeneration response in tissue culture. On a standardized shoot regeneration medium, the short duration varieties (ICPV 88091 and ICPV 86012) generally responded faster and better than the medium duration (ICEAP 00554 and ICEAP 00557) and long duration (ICEAP 00020, ICEAP 00040 and ICEAP 00053) varieties. However, all the tested varieties produced healthy rooted plants in vitro that could be transferred to the greenhouse where they exhibited normal growth, flowering and viable seed set. This study established the basis for genetic engineering of African pigeonpea varieties.
Use of Secondary Effluent in Food Production in Botswana
V.E. Emongor
Journal of Applied Sciences , 2006,
Abstract: The use of secondary effluent for irrigated agriculture offers an opportunity to conserve limited water resources and increase food production in Botswana. Effluent irrigation is a means of ecological waste water management and it`s a resource of economic development. The secondary effluent contains both macro-and micro-nutrients needed for crop growth and development. The secondary effluent contains phosphorus and nitrogen which are responsible for eutrophication of rivers and other water bodies where the effluent is discharged. The sludge that results from municipal waste water treatment processes contains organic matter and nutrients that, when properly treated, composted and applied to farmland, can improve the physical properties and agricultural productivity of soils and its agricultural use provides an alternative to disposal options, such as incineration, or landfilling. For the safety of food products and the sustainability of agricultural land, the use of waste water treatment technology that destroys all pathogens and toxic chemicals in raw municipal waste water and stringent waste water discharge requirements are important. The sewage sludge must be treated to levels that allow it to be reused. In order to minimize the potential health and environmental consequences in the use of secondary sewage effluent and sludge, the quality of the effluent for irrigation and treated composted sludge has to be monitored continuously to meet the specific set standards for the particular purpose. This study discusses the uses of secondary effluent, health-risks, reuse standards, irrigation suitability and management guidelines in the use of secondary effluent for irrigation.
Effects of Gibberellic Acid on Postharvest Quality and Vaselife Life of Gerbera Cut Flowers (Gerbera jamesonii)
V.E. Emongor
Journal of Agronomy , 2004,
Abstract: Laboratory trials were carried out to investigate the effect of gibberellic acid (GA3) on the postharvest quality and vase life of gerbera cut-flowers. Freshly cut flower stems of gerbera cultivar `Ida Red`, with two outer disc florets open were put in flower vases containing 0, 2.5, 5, or 7.5 mg L-1 of GA3. The treatments were arranged in a Completely Randomized Design with four replicates. Gerbera cut-flowers held in GA3 at 2.5, 5 or 7. 5 mg L-1 significantly delayed flower senescence by increasing the number of disc florets open, delayed petal fading and abscission. Gibberellic acid at 2.5, 5 or 7.5 mg L-1 significantly reduced dry matter content in the flower heads and stems of gerbera cut-flowers. Gerbera cut-flowers held in 2.5, 5 or 7.5 mg L-1 GA3 had significantly higher water content in the flower heads and stems, hence maintaining flower turgidity, reduction in bent neck and flower senescence and increased flower quality after 14 days of holding compared to flowers held in distilled water. Gibberellic acid at 2.5, 5 or 7.5 mg L-1 has the potential to be used as a gerbera cut-flower preservative solution.
Effect of accel on the vase life and post harvest quality of alstroemeria (alstroemeria aurantiaca l.) cut flowers
TM Mutui, VE Emongor, MJ Hutchinson
African Journal of Science and Technology , 2001,
Abstract: Freshly cut flowering stems of Alstroemeria ‘Yellow King’ and ‘Marina’ were placed in glass jars containing solutions of Accel at 0, 25, 50, 75 and 100 mg/litre BA equivalent and arranged in a completely randomised design with 3 replicates. The effect of Accel on the vase life and quality of Alstroemeria was investigated. Flowers held in Accel at 25 or 50 mg/litre BA equivalent consistently increased the number of days to full opening of primary florets and delayed the onset of flower senescence as measured by days to 50 % petal fall and days to 50 % leaf yellowing. Accel at 25mg/ litre BA equivalent significantly increased the leaf nitrogen and chlorophyll content of Alstroemeria cut flowers. High Accel concentrations of 50, 75 and 100 mg/litre BA equivalent reduced significantly the leaf water content of Alstroemeria cut flowers. Accel at 75 and 100 mg/litre BA equivalent increased leaf dry weight of Alstroemeria cut flowers. Our results indicate that Accel at 25 mg/litre BA equivalent has the potential to be used as a commercial cut flower preservative solution for delaying flower senescence, prolonging the vase life and enhancing post harvest quality of Alstroemeria cut flowers
Effect of accel, sucrose and silver thiosulphate on the water relations and post harvest physiology of cut tuberose flowers
MJ Hutchinson, DK Chebet, VE Emongor
African Crop Science Journal , 2003,
Abstract: This study investigated the influence of cytokinins, gibberellins, sucrose and silver thiosulphate on water relations and post-harvest physiology of cut tuberose (Polianthes tuberosa L) flowers. Tuberose flowers held in de-ionised water (DIW) had a vase life of 13 days with 63% floret opening. Addition of gibberellins (GA4+7) in the vase solution had no effect on vase life or floret opening along the spike. Pulsing of the cut flowers with 10% sucrose for 24 hr before transfer to DIW improved their vase life by 4 days and improved the floret opening by 21% above DIW controls. Addition of Benzylaminopurine (BA) at low concentrations (25-50 mg L-1) improved vase life of the cut tuberose stems while higher concentrations (75-100 mg L-1) gave no improvement. A 24 hr pulse in 10% sucrose improved the vase-life by 3.6 days and floret opening by 13%. Pulsed stems transferred to holding solutions containing various concentrations of BA improved vase life by an extra 3 days at BA concentration of 25 mg L-1. Higher BA concentrations gave no significant (P>0.05) improvement over the pulsed stems. However, floret opening was greater at 25 and 50 mg L-1 BA (P<0.05). Of all treatments, STS gave the greatest improvement of vase life at 7 days longer than the DIW control and 3.5 days longer than the sucrose-pulsed solutions. Very high (88%) floret opening was observed in cut stems held in STS. There was a general decrease in water uptake by tuberose stems over time. Lowest rates of water uptake were noted in all treatments after 8 days. Among the treatments, the lowest water uptake was recorded in the DIW control and in GA4+7 treatments. Greatest uptake was in 10% sucrose + 25 mg L-1 BA. Transpiration losses were greatest for 25 mg L-1 BA and least for 10% sucrose. Differences among treatments in transpiration losses were noted only in the first 10 days. In general, water deficit was noted in cut flowers held in DIW and in GA4+7 after day 6, while stems in BA treatments manifested symptoms from day 8. The cut flowers pulsed in 10% sucrose and held in 25 and 50 mg L-1 BA and in 2 mM STS only showed water deficit status from day 12 of their vase life. Overall results suggest that STS, BA and sucrose can help improve tuberose vase life and floret opening through improvement of the water balance. Key Words: Benzyladenine, Benzylaminopurine, chrysanthemum, gibberellins, Kenya, Polianthes tuberosa RéSUMé Cette étude a évalué l'influence de cytokinines, de gibberellines, du saccharose et le thiosulphate d'argent sur les relations entre l'eau et la physiologie après récolte de fleurs de tube rose. Les fleurs de tube rose maintenues dans l'eau de-ionisée (EDI) avaient une vie de vase de 13 jours avec 63% d'ouverture de fleuron. L'addition de gibbérellines (GA 4+7) dans le vase n'a pas eu d'effet sur la vie du vase et l'ouverture du fleuron aux alentours du spike. L'impulsion de 10% de saccharose dans des fleurs coupées pour 24 h avant le transfert de EDI avait amélioré la
Effect of Water Stress Imposed at Different Growth and Development Stages on Morphological Traits and Yield of Bambara Groundnuts (Vigna subterranea L. Verdc)
R. Vurayai,V. Emongor,B. Moseki
American Journal of Plant Physiology , 2011,
Abstract: Two greenhouse trials were carried out to evaluate the response pattern of morphological traits of bambara groundnut to short periods of water stress imposed at different developmental stages and also their recuperative ability after rewatering. The treatments consisted of watering plants to 100% Plant Available Water (PAW), withholding water to 30% PAW at vegetative, flowering and pod filling growth stages and rewatering the plants after 21 days of each stress treatment. Water stress reduced the relative leaf expansion rate, leaf number, plant height and shoot: root ration depending on the stage of development when water stress occurred. When plants were rewatered after each stress treatment, the relative leaf expansion rate of plants stressed at pod filling and flowering stages failed to recover from water stress. Seed yield in all stressed plants was reduced by water stress due to reductions in pods per plant, seeds per pod and seed weight. The highest yield amongst the stressed plants was obtained in plants stressed during the vegetative stage, followed by the flowering and lastly the pod filling stage. Bambara groundnuts reduced growth therefore reducing transpirational area thus reducing water loss under water stress. The results also showed that bambara groundnuts have the ability to recover from water stress after rainfall or irrigation and is therefore capable of producing some yield under water limited conditions.
Assessment of Effluent Quality at Glen Valley Wastewater Treatment Plant
E. Nkegbe,V. Emongor,I. Koorapetsi
Journal of Applied Sciences , 2005,
Abstract: The effluent treatment process at Glen Valley Wastewater Treatment Plant was assessed weekly in terms of efficiency over 29 weeks. During this period there were significant removals of COD, BOD5, TSS, NH3-N and TKN. Average reduction of COD, BOD5, TSS, NH3-N and TKN were, 97.7, 99, 98.2, 95.5 and 93.6%, respectively. All these levels of reduction in the final effluent met the target discharge guidelines in Botswana and the treatment plant design discharge guidelines. There was a significant removal of ortho-phosphate (81.4%) in the final effluent, however, the weekly average of 6.82 mg L-1 was higher than the expected discharge of effluent to the environment guideline of <1 mg L-1. There was an increase in NO3- level in the treated effluent (82.2%) over the influent but the final effluent load of 2.7 mg L-1 was below the expected discharge level of 10 mg L-1.
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