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J.B.O. Ogola is a Professor of Agronomy with special research interest in resource use in legume-based cropping systems and integrated soil fertility management systems. He obtained his PhD from the University of Reading, UK in 1999. Prof. Ogola has over 28 years of teaching experience at the tertiary level and is a member of several professional societies including the Annals of Applied Biologists, African Crop Science Society, South African Society of Crop Production, and European Society of Agronomy.
Poor soil fertility caused mainly by low and declining soil organic carbon is one of the major constraints limiting crop productivity in tropical and subtropical regions of South Africa. We evaluated the effect of macadamia husk compost (MHC) on selected chemical and physical properties of a sandy loam soil in NE South Africa in two successive seasons. The treatments, laid out in randomised, complete block design and replicated four times, were: (i) zero control, (ii) inorganic fertilizer (100:60:60 NPK Kg ha−1), (iii) MHC at 15 t ha−1, and (iv) MHC at 30 t ha−1. Soil bulk density; water holding capacity; soil pH; electrical conductivity (EC); organic carbon; total N; and available P, K, Ca, Mg, Al, Zn, and Cu were determined at 0–15 cm soil depth. Macadamia husk compost application decreased bulk density and increased water holding capacity. MHC and inorganic fertilizer increased soil pH, organic carbon, total N, C:N ratio, available P, exchangeable cations, and micronutrients but the effect was more pronounced under MHC treatments in both seasons. The positive effect of MHC on soil physicochemical properties was associated with an increase in soil organic carbon due to MHC application; hence, MHC may offer a sustainable option of increasing soil productivity, particularly in areas characterised by low SOC.
Dembe Maselesele; John Ogola; Romeo Murovhi. Macadamia Husk Compost Improved Physical and Chemical Properties of a Sandy Loam Soil. Sustainability 2021, 13, 6997 .
AMA StyleDembe Maselesele, John Ogola, Romeo Murovhi. Macadamia Husk Compost Improved Physical and Chemical Properties of a Sandy Loam Soil. Sustainability. 2021; 13 (13):6997.
Chicago/Turabian StyleDembe Maselesele; John Ogola; Romeo Murovhi. 2021. "Macadamia Husk Compost Improved Physical and Chemical Properties of a Sandy Loam Soil." Sustainability 13, no. 13: 6997.
Soil amendments such as biochar and biofertilizers may improve chickpea productivity but there is limited information on whether this response could be through an increase in soil pH and nodulation. We aimed to determine whether the previously observed positive effects of biochar and rhizobium inoculation on soil pH and chickpea nodulation would result in similar improvements in the proportion of radiation intercepted by the crop canopy, biomass accumulation, and grain yield of three desi chickpea genotypes. Field experiments were carried out in clay and loamy sand soils in two successive years. Biochar application and rhizobium inoculation increased biomass accumulation, chlorophyll content, the proportion of intercepted radiation, and decreased chlorophyll a/b ratios which suggests that biochar and rhizobium inoculation increased biomass accumulation by increasing antenna size and canopy cover. Although rhizobium inoculation increased grain yield of all genotypes, the increase was greater in the best performing genotype, Acc#6. Biomass was highest at 10 t ha−1 and 20 t ha−1 biochar in the clay and loamy sand soil, respectively, suggesting that the lighter soils require higher biochar rates compared to the heavier soils for optimal biomass accumulation.
J. B. O. Ogola; Patricia J. Macil; J. J. O. Odhiambo. Biochar Application and Rhizobium Inoculation Increased Intercepted Radiation and Yield of Chickpea in Contrasting Soil Types. International Journal of Plant Production 2021, 15, 219 -229.
AMA StyleJ. B. O. Ogola, Patricia J. Macil, J. J. O. Odhiambo. Biochar Application and Rhizobium Inoculation Increased Intercepted Radiation and Yield of Chickpea in Contrasting Soil Types. International Journal of Plant Production. 2021; 15 (2):219-229.
Chicago/Turabian StyleJ. B. O. Ogola; Patricia J. Macil; J. J. O. Odhiambo. 2021. "Biochar Application and Rhizobium Inoculation Increased Intercepted Radiation and Yield of Chickpea in Contrasting Soil Types." International Journal of Plant Production 15, no. 2: 219-229.
Patricia J. Macil; John B. O. Ogola; Jude J. O. Odhiambo. Response of Soil pH and Nodulation of Three Chickpea Genotypes to Biochar and Rhizobium Inoculation. Communications in Soil Science and Plant Analysis 2020, 51, 2377 -2387.
AMA StylePatricia J. Macil, John B. O. Ogola, Jude J. O. Odhiambo. Response of Soil pH and Nodulation of Three Chickpea Genotypes to Biochar and Rhizobium Inoculation. Communications in Soil Science and Plant Analysis. 2020; 51 (18):2377-2387.
Chicago/Turabian StylePatricia J. Macil; John B. O. Ogola; Jude J. O. Odhiambo. 2020. "Response of Soil pH and Nodulation of Three Chickpea Genotypes to Biochar and Rhizobium Inoculation." Communications in Soil Science and Plant Analysis 51, no. 18: 2377-2387.
Heat and drought stresses are two abiotic factors that often occur simultaneously and are predicted to increase, consequently hampering plant growth. Response of different species to either stresses is well documented but information on the response of the same genotypes to both stresses in chickpea is limited. We aimed to determine whether previously noted heat stress tolerant genotype (Acc#7) is drought tolerant and the heat sensitive (Acc#8) is drought sensitive, and whether intermittent moisture supply at vegetative stage would induce priming effect to later drought at flowering. At vegetative stage, plants were divided into three groups, non‐stressed (watered to 75% field capacity (FC), severe water stress (moisture‐withholding for 14 days) and treated to 40% FC throughout the experiment (mild‐stress), with recovery for the severely stressed plants after which they were stressed (double‐stress) at flowering. Drought treatments at vegetative and flowering growth stages decreased physiological parameters and biomass accumulation in both genotypes except low water supply at 40% FC that decreased biomass in Acc#7 but not Acc#8. Double drought stress resulted in priming effect in Acc#7, having higher biomass, chlorophyll fluorescence, stomatal conductance, net photosynthesis, and relative water content in comparison to the introduction of stress only at flowering growth stage, as well as in comparison to Acc#8. These results showed that both Acc#7 and Acc#8 are sensitive to drought whereas after priming Acc#7 is better acclimated to drought than Acc#8 associated with osmotic adjustment on leaf relative water content (RWC) and higher capacity to protect photosynthetic activity, making Acc#7 potentially ideal for areas associated with intermittent drought spells. This article is protected by copyright. All rights reserved
Givemore M. Makonya; Ochanda Ogola; A. Muthama Muasya; Olivier Crespo; Sipho Maseko; Alex J. Valentine; Carl-Otto Ottosen; Eva Rosenqvist; Samson B.M. Chimphango. Intermittent moisture supply induces drought priming responses in some heat‐tolerant chickpea genotypes. Crop Science 2020, 60, 2527 -2542.
AMA StyleGivemore M. Makonya, Ochanda Ogola, A. Muthama Muasya, Olivier Crespo, Sipho Maseko, Alex J. Valentine, Carl-Otto Ottosen, Eva Rosenqvist, Samson B.M. Chimphango. Intermittent moisture supply induces drought priming responses in some heat‐tolerant chickpea genotypes. Crop Science. 2020; 60 (5):2527-2542.
Chicago/Turabian StyleGivemore M. Makonya; Ochanda Ogola; A. Muthama Muasya; Olivier Crespo; Sipho Maseko; Alex J. Valentine; Carl-Otto Ottosen; Eva Rosenqvist; Samson B.M. Chimphango. 2020. "Intermittent moisture supply induces drought priming responses in some heat‐tolerant chickpea genotypes." Crop Science 60, no. 5: 2527-2542.
Rhizobia is a group of gram-negative soil-borne bacteria with several beneficial strains for biological nitrogen fixation in legume crops. Rhizobium strains are found native in the soil but where they are absent, commercial strains are inoculated on crops. We assessed the availability of native rhizobia in chickpea fields at two sites, with contrasting soil types, in NE South Africa. Serial dilutions were used to identify bacteria from soil samples and chickpea nodules sampled before sowing and at flowering, respectively. Our results indicated the absence of rhizobia strains at both sites. Burkholderia cenocepacia, Klebsiella variicola, Bacillus subtilis and Ochrobactrum spp, which are not important in agriculture but are often reported in clinical environments, were identified. Therefore, inoculating chickpea with compatible rhizobia strains may be necessary in some soils in this region.
J. B. O. Ogola; P. J. Macil; E. Ramabulana; J. J. O. Odhiambo. Native rhizobium strains are lacking in some agricultural soils in NE South Africa. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 2020, 70, 406 -408.
AMA StyleJ. B. O. Ogola, P. J. Macil, E. Ramabulana, J. J. O. Odhiambo. Native rhizobium strains are lacking in some agricultural soils in NE South Africa. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science. 2020; 70 (5):406-408.
Chicago/Turabian StyleJ. B. O. Ogola; P. J. Macil; E. Ramabulana; J. J. O. Odhiambo. 2020. "Native rhizobium strains are lacking in some agricultural soils in NE South Africa." Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 70, no. 5: 406-408.
In recent decades climate change has impacted ecosystems negatively globally with Mediterranean systems being particularly vulnerable. Changes in rainfall pattern and amounts have led to increases in flooding and droughts in certain areas of the world. Many important agricultural crops such as Aspalathus linearis (Burm.f.) R. Dahlgren, rooibos tea, rely on the Mediterranean-type seasonality in the Western Cape, South Africa. Aspalathus linearis plants, which occur naturally in the Cedarberg, grow in hot and dry summer conditions and have a root that penetrates the soil down to 2 m, yet no work has looked at the root response to drought under low rainfall environments. The objective of this study was to determine the physiological and morphological response of A. linearis plants grown at two different water regimes to drought. A potted glasshouse experiment was carried out where drought stress (withdrawing watering) was imposed on well-watered and low moisture supplied plants. The low moisture droughted plants exhibited drought tolerant mechanisms which included higher root/shoot ratios as well as thinner roots, both of which are effective for water and nutrient uptake. Overall, plants in the 30% FC treatment recorded lower Pmax, gs and E after three days in the drought conditions while 70% FC plants were only affected after five days. Furthermore, plants grown under low moisture conditions produced 50% lower biomass compared to plants grown under adequate moisture conditions. This implies that low rainfall and the occurrences of dry spells and drought, associated with climate change are likely to reduce the production of A. linearis in the Cederberg area.
Dunja MacAlister; A. Muthama Muasya; Olivier Crespo; John B.O. Ogola; Sipho Maseko; Alex J. Valentine; Carl-Otto Ottosen; Eva Rosenqvist; Samson B.M. Chimphango. Stress tolerant traits and root proliferation of Aspalathus linearis (Burm.f.) R. Dahlgren grown under differing moisture regimes and exposed to drought. South African Journal of Botany 2020, 131, 342 -350.
AMA StyleDunja MacAlister, A. Muthama Muasya, Olivier Crespo, John B.O. Ogola, Sipho Maseko, Alex J. Valentine, Carl-Otto Ottosen, Eva Rosenqvist, Samson B.M. Chimphango. Stress tolerant traits and root proliferation of Aspalathus linearis (Burm.f.) R. Dahlgren grown under differing moisture regimes and exposed to drought. South African Journal of Botany. 2020; 131 ():342-350.
Chicago/Turabian StyleDunja MacAlister; A. Muthama Muasya; Olivier Crespo; John B.O. Ogola; Sipho Maseko; Alex J. Valentine; Carl-Otto Ottosen; Eva Rosenqvist; Samson B.M. Chimphango. 2020. "Stress tolerant traits and root proliferation of Aspalathus linearis (Burm.f.) R. Dahlgren grown under differing moisture regimes and exposed to drought." South African Journal of Botany 131, no. : 342-350.
Mediterranean systems, such as in South Africa, are particularly vulnerable to the predicted increases in mean surface temperatures which will likely affect the growth and physiology of many plants and subsequently affect agricultural productivity. Aspalathus linearis (Burm.f.) R. Dahlgren (rooibos) is an important commercial, endemic crop that is produced in the Cederberg region, South Africa. This region experiences a Mediterranean-type ecosystem that is characterised by hot, dry summers (November – February) and cool, wet winters (May – August). This study assessed the effects of temperature on the growth and stress tolerant traits of A. linearis over two years. Crop biomass and selected physiological traits were determined in the field, along a temperature gradient, at four farm sites in the Cederberg during the summer and winter 2017 and summer 2018. Aspalathus linearis plants showed evidence of transpirational leaf cooling during summer and this, combined with lower chlorophyll and high phenolic content, could be considered acclimatized adaptive changes allowing the plants to mitigate the heating effects of elevated temperatures. Although changes in soil nutrients and increasing temperatures had a negative impact on crop biomass, the phenolic content, a measure of tea quality, did not vary with sites. This suggests that a shift in rooibos farming to cooler and wetter areas further south, for better growth and higher yields, would not compromise the quality of rooibos tea.
Dunja MacAlister; A. Muthama Muasya; Olivier Crespo; Ochanda Ogola; Sipho T. Maseko; Alex J. Valentine; Carl-Otto Ottosen; Eva Rosenqvist; Samson B.M. Chimphango. Effect of temperature on plant growth and stress tolerant traits in rooibos in the Western Cape, South Africa. Scientia Horticulturae 2019, 263, 109137 .
AMA StyleDunja MacAlister, A. Muthama Muasya, Olivier Crespo, Ochanda Ogola, Sipho T. Maseko, Alex J. Valentine, Carl-Otto Ottosen, Eva Rosenqvist, Samson B.M. Chimphango. Effect of temperature on plant growth and stress tolerant traits in rooibos in the Western Cape, South Africa. Scientia Horticulturae. 2019; 263 ():109137.
Chicago/Turabian StyleDunja MacAlister; A. Muthama Muasya; Olivier Crespo; Ochanda Ogola; Sipho T. Maseko; Alex J. Valentine; Carl-Otto Ottosen; Eva Rosenqvist; Samson B.M. Chimphango. 2019. "Effect of temperature on plant growth and stress tolerant traits in rooibos in the Western Cape, South Africa." Scientia Horticulturae 263, no. : 109137.
The degree of complementarity vis-à-vis competition amongst the component crops, which is influenced by their relative planting dates, may affect the productivity of intercrop systems. This study assessed the effect of the relative planting dates of legumes on yield and yield components of three legume species. Field experiments were conducted in two consecutive years at two sites with contrasting soil types. Grain yield and yield components were determined at harvest maturity. A 4-weeks delay in incorporating legumes caused total yield loss of cowpea at both sites, decreased chickpea yield by 82% at the clay soil site, and led to negligible yield of Bambara groundnut in loamy sand soil. In contrast, sowing legumes 2 weeks after cassava decreased grain yield of cowpea (both sites), chickpea (clay soil) and Bambara groundnut (loamy sand soil). Intercropping decreased grain yield of chickpea (year 1) and Bambara (year 2) at the clay and loamy sand soil sites, respectively, but had no effect on cowpea yield. Although planting the legumes same time with cassava gave the highest grain yield, we suggest more studies, including sowing the legumes prior to planting cassava, before making categorical recommendations.
Khutso Debra Legodi; J. B. O. Ogola. Cassava-legume intercrop: II. Effects of relative planting dates of legumes on the productivity of legumes. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 2019, 70, 158 -164.
AMA StyleKhutso Debra Legodi, J. B. O. Ogola. Cassava-legume intercrop: II. Effects of relative planting dates of legumes on the productivity of legumes. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science. 2019; 70 (2):158-164.
Chicago/Turabian StyleKhutso Debra Legodi; J. B. O. Ogola. 2019. "Cassava-legume intercrop: II. Effects of relative planting dates of legumes on the productivity of legumes." Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 70, no. 2: 158-164.
Cassava is a long duration crop which grows slowly during the early stages hence incorporation of early maturing crops may improve resource use efficiency and hence crop productivity in cassava-based cropping systems. We conducted field experiments in clay and loamy sand soils, in two consecutive seasons, to assess the response of cassava productivity to relative planting dates of 3 legume species (Bambara groundnut, chickpea and cowpea) in a cassava-legume intercrop. Root yield, determined at 10 months after planting, was greater at 4 weeks after cassava (1.7 kg plant–1) compared to when legumes were planted same time (1.2 kg plant–1) and 2 weeks after cassava (0.7 kg plant–1), and intercropping decreased cassava root yield by 40% (cowpea) and 26% (chickpea) in season I in the clay soils. Neither relative planting dates of legumes nor cropping systems affected root yield in both seasons in the loamy sand soils. Intercropping increased LER in season I by 25% to 65% in clay, and 45% to 101% in loamy sand soils. Although cassava root yield was highest with a 4 week-delay in sowing the legumes and LER greatest in cassava-cowpea intercrop, we propose further studies before making any definite recommendations.
Khutso Debra Legodi; J. B. O. Ogola. Cassava-legume intercrop: I. Effects of relative planting dates of legumes on cassava productivity. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 2019, 70, 150 -157.
AMA StyleKhutso Debra Legodi, J. B. O. Ogola. Cassava-legume intercrop: I. Effects of relative planting dates of legumes on cassava productivity. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science. 2019; 70 (2):150-157.
Chicago/Turabian StyleKhutso Debra Legodi; J. B. O. Ogola. 2019. "Cassava-legume intercrop: I. Effects of relative planting dates of legumes on cassava productivity." Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 70, no. 2: 150-157.
Chickpea (Cicer arietinum L.), a cool season crop is severely affected by heat stress, predicted to increase due to warming climates. Research for identifying heat tolerance markers for potential chickpea genotype selection is imperative. The study assessed the response of four chickpea genotypes to a natural temperature gradient in the field using chlorophyll fluorescence, non-structural carbohydrate, chlorophyll concentrations, gas exchange and grain yield. Field experiments were carried out in two winter seasons at three locations with known differences in temperature in NE South Africa. Results showed two genotypes were tolerant to heat stress with an Fv/Fm of 0.83–0.85 at the warmer site, while the two sensitive genotypes showed lower Fv/Fm of 0.78–0.80. Both dark-adapted Fv/Fm and Fq'/Fm’ (where Fq’ = Fm’ –F) measured at comparable high light levels correlated positively with grain yield. The two tolerant genotypes also showed higher photosynthetic rates, starch, sucrose and grain yield than the sensitive genotypes at the warmer site. However, these parameters were consistently higher at the cooler sites than at the warmer. These results were further validated by a climate chamber experiment, where higher Fv/Fm decline in the sensitive compared to tolerant genotypes was observed when they were exposed to short-term heat treatments of 30/25 °C and 35/30 °C. Tolerant genotypes had higher Fv/Fm (0.78–0.81) and grain yield plant−1(1.12–2.37g) compared to sensitive genotypes (0.74–0.75) and (0.32–0.89g plant−1) respectively in the 35/30 °C. It is concluded that chlorophyll fluorescence and leaf carbohydrates are suitable tools for selection of heat tolerant chickpea genotypes under field conditions, while the coolest site showed favourable conditions for chickpea production.
Givemore M. Makonya; Ochanda Ogola; A. Muthama Muasya; Olivier Crespo; Sipho Maseko; Alex J. Valentine; Carl-Otto Ottosen; Eva Rosenqvist; Samson B.M. Chimphango. Chlorophyll fluorescence and carbohydrate concentration as field selection traits for heat tolerant chickpea genotypes. Plant Physiology and Biochemistry 2019, 141, 172 -182.
AMA StyleGivemore M. Makonya, Ochanda Ogola, A. Muthama Muasya, Olivier Crespo, Sipho Maseko, Alex J. Valentine, Carl-Otto Ottosen, Eva Rosenqvist, Samson B.M. Chimphango. Chlorophyll fluorescence and carbohydrate concentration as field selection traits for heat tolerant chickpea genotypes. Plant Physiology and Biochemistry. 2019; 141 ():172-182.
Chicago/Turabian StyleGivemore M. Makonya; Ochanda Ogola; A. Muthama Muasya; Olivier Crespo; Sipho Maseko; Alex J. Valentine; Carl-Otto Ottosen; Eva Rosenqvist; Samson B.M. Chimphango. 2019. "Chlorophyll fluorescence and carbohydrate concentration as field selection traits for heat tolerant chickpea genotypes." Plant Physiology and Biochemistry 141, no. : 172-182.
Field experiments were conducted during summer (2013/2014) and winter (2014) in two different soil types to evaluate the effect of biochar and P fertilizer application on growth, yield, and water use efficiency of chickpea. Soil types include Rhodic Ferralsols (clay) in Thohoyandou and Leptic Cambisols (loamy sand) in Nelspruit, South Africa. Treatments consisted of a factorial combination of four biochar levels (0, 5, 10 and 20 t ha−1) and two phosphorus fertilizer levels (0 and 90 kg ha−1) arranged in a randomized complete block design and replicated three times. Biochar application at 5 t ha−1 significantly increased biomass, grain yield and water use efficiency of biomass production (WUEb) in the clay soil compared to 10 and 20 t ha−1. However, the increase was attributed to the addition of P fertilizer. Biochar application had no effect on yield components in the loamy sand soil, but P fertilizer addition increased number of seeds/pod in the loamy sand soil and number of pods/plant in the clay soil. Biochar and P fertilizer application on growth and yield of chickpea varied in soil types and seasons, as the effect was more prominent in the clay soil than the loamy sand soil during the summer sowing.
Siphiwe Lusiba; Jude Odhiambo; Ochanda Ogola. Growth, yield and water use efficiency of chickpea (Cicer arietinum): response to biochar and phosphorus fertilizer application. Archives of Agronomy and Soil Science 2017, 64, 819 -833.
AMA StyleSiphiwe Lusiba, Jude Odhiambo, Ochanda Ogola. Growth, yield and water use efficiency of chickpea (Cicer arietinum): response to biochar and phosphorus fertilizer application. Archives of Agronomy and Soil Science. 2017; 64 (6):819-833.
Chicago/Turabian StyleSiphiwe Lusiba; Jude Odhiambo; Ochanda Ogola. 2017. "Growth, yield and water use efficiency of chickpea (Cicer arietinum): response to biochar and phosphorus fertilizer application." Archives of Agronomy and Soil Science 64, no. 6: 819-833.
This study assessed the response of photosynthesis, chlorophyll content (CC), stomatal conductance (SC) and intercepted radiation (IR) of chickpea to biochar (0, 5 10 and 20 t ha-1) and phosphorus (P) fertilizer (0 and 90 kg ha-1) rates in Thohoyandou, South Africa in 2013/2014 summer and winter seasons. Photosynthesis, CC, SC and IR were determined at vegetative and reproductive stages. Biochar increased SC and CC by 22 - 49% and 57 – 126%, respectively. P increased CC by up to 9% in the winter sowing. IR increased with P and biochar application in both sowings. Biochar increased plant height only at 70 days after emergence and P increased plant height at all plant growth stages. Biochar and phosphorus did not affect photosynthesis in either season. Therefore the use of biochar and inorganic phosphorus fertilizer may be beneficial in chickpea cropping systems characterised by poor soils and dry winter seasons.
Patricia Jozina Macil; Ochanda Ogola; Jude Julius Owuor Odhiambo; Siphiwe Gloria Lusiba. The response of some physiological traits of chickpea (Cicer arietinum L.)to biochar and phosphorus fertilizer application. LEGUME RESEARCH - AN INTERNATIONAL JOURNAL 2017, 40, 299 -305.
AMA StylePatricia Jozina Macil, Ochanda Ogola, Jude Julius Owuor Odhiambo, Siphiwe Gloria Lusiba. The response of some physiological traits of chickpea (Cicer arietinum L.)to biochar and phosphorus fertilizer application. LEGUME RESEARCH - AN INTERNATIONAL JOURNAL. 2017; 40 (2):299-305.
Chicago/Turabian StylePatricia Jozina Macil; Ochanda Ogola; Jude Julius Owuor Odhiambo; Siphiwe Gloria Lusiba. 2017. "The response of some physiological traits of chickpea (Cicer arietinum L.)to biochar and phosphorus fertilizer application." LEGUME RESEARCH - AN INTERNATIONAL JOURNAL 40, no. 2: 299-305.
This study evaluated the effect of biochar and phosphorus fertilizer application on selected soil physical and chemical properties in two contrasting soil types: Rhodic Ferralsols (clay) in Thohoyandou and Leptic Cambisols (loamy sand) in Nelspruit, South Africa. Field experiments were conducted in summer and winter. Treatments consisted of a factorial combination of four biochar levels (0, 5, 10 and 20 t ha−1) and two phosphorus fertilizer levels (0 and 90 kg ha−1) arranged in a randomized complete block design with three replicates. Chickpea was the test crop. Soil bulk density, aggregate stability, porosity, total C, total N, C:N ratio, K and Mg were determined. Biochar (10 t ha−1) and phosphorus increased bulk density and decreased porosity at 0–5 and 15–20 cm soil depth on a loamy sand soil in both seasons. The interaction between biochar and phosphorus increased total C and total N on a clay soil in the summer sowing. However, in the loamy sand soil, biochar (10 t ha−1) increased total C, C:N ratio, K and Mg in the summer sowing. The effect of biochar was more evident in the loamy sand soil than the clay soil suggesting that the influence of biochar may be soil-specific.
Siphiwe Lusiba; Jude Odhiambo; Ochanda Ogola. Effect of biochar and phosphorus fertilizer application on soil fertility: soil physical and chemical properties. Archives of Agronomy and Soil Science 2016, 63, 477 -490.
AMA StyleSiphiwe Lusiba, Jude Odhiambo, Ochanda Ogola. Effect of biochar and phosphorus fertilizer application on soil fertility: soil physical and chemical properties. Archives of Agronomy and Soil Science. 2016; 63 (4):477-490.
Chicago/Turabian StyleSiphiwe Lusiba; Jude Odhiambo; Ochanda Ogola. 2016. "Effect of biochar and phosphorus fertilizer application on soil fertility: soil physical and chemical properties." Archives of Agronomy and Soil Science 63, no. 4: 477-490.
Crop productivity may be increased by manipulating management practices that enhance resource capture and utilisation during yield formation. This study aimed at assessing the effect of Rhizobium inoculation on growth, yield and radiation use of two chickpea cultivars at Thohoyandou, South Africa in winter 2011 and 2012. Nodulation was determined at flowering, crop biomass and grain yield were determined at harvest maturity, intercepted total radiation was determined by measuring photosynthetically active radiation above and below the crop canopy at 7-days intervals using an AccuPAR ceptometer, and radiation use efficiency was calculated as ratio of yield to intercepted total radiation. Number and weight of nodules per plant were greater with inoculation compared with the control. There were no significant differences in crop biomass, grain yield, harvest index, intercepted total radiation and radiation use efficiency between Rhizobium inoculation and the non-inoculated control. The low yield and non-significant effect of Rhizobium inoculation suggest that (i) the productivity of chickpea was probably constrained by factors other than nitrogen deficiency; or (ii) there was no difference in nitrogen fixation between the inoculated and non-inoculated treatments. However, further field trials should be conducted, over several seasons, before any definite conclusions can be drawn.
Ochanda Ogola. Growth and yield response of chickpea to Rhizobium inoculation: productivity in relation to interception of radiation. LEGUME RESEARCH - AN INTERNATIONAL JOURNAL 2015, 38, 1 .
AMA StyleOchanda Ogola. Growth and yield response of chickpea to Rhizobium inoculation: productivity in relation to interception of radiation. LEGUME RESEARCH - AN INTERNATIONAL JOURNAL. 2015; 38 (6):1.
Chicago/Turabian StyleOchanda Ogola. 2015. "Growth and yield response of chickpea to Rhizobium inoculation: productivity in relation to interception of radiation." LEGUME RESEARCH - AN INTERNATIONAL JOURNAL 38, no. 6: 1.
Chickpea is a relatively new crop in the NE South Africa. High incidences of plant death were observed in an experiment that was established in 2012 in Mziniti, South Africa to assess the agronomic performance of 66 elite chickpea lines from International Crop Research Institute for Semi-Arid Tropics. Infected plants showed signs of root rot. Therefore this study aimed at investigating the cause of the root rot. Roots of infected plants were sampled and incubated at 25°C until colonies of the pathogen were observed. Colonies were sub-cultured with sterile soil extract and sterile leaf blades. Isolates were stored in sterile distilled water with leaf blades in screw capped 15 ml McCarthy bottles at 18°C. The pathogen was identified as Pythium irregulare based on morphological structures and species description. The isolates were inoculated on healthy potted chickpea plants and these showed root rot symptoms similar to field observation. The pathogen was re-isolated from the inoculated plants and cultured; they showed similar characteristics to the ones observed during the first isolation. This is the first report of P. irregulare incidence on chickpea in South Africa.
Cherian Mathews; John B. O. Ogola; Wilhem Botha; Michael Magongwa; Pooran Gaur. First report of root rot caused by Pythium spp. on chickpea in South Africa. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 2015, 66, 379 -380.
AMA StyleCherian Mathews, John B. O. Ogola, Wilhem Botha, Michael Magongwa, Pooran Gaur. First report of root rot caused by Pythium spp. on chickpea in South Africa. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science. 2015; 66 (4):379-380.
Chicago/Turabian StyleCherian Mathews; John B. O. Ogola; Wilhem Botha; Michael Magongwa; Pooran Gaur. 2015. "First report of root rot caused by Pythium spp. on chickpea in South Africa." Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 66, no. 4: 379-380.
Ochanda Ogola. Assessment of factors affecting the farmer demand for seed potato in Nakuru District, Kenya. African Journal of Agricultural Research 2012, 7, 1 .
AMA StyleOchanda Ogola. Assessment of factors affecting the farmer demand for seed potato in Nakuru District, Kenya. African Journal of Agricultural Research. 2012; 7 (29):1.
Chicago/Turabian StyleOchanda Ogola. 2012. "Assessment of factors affecting the farmer demand for seed potato in Nakuru District, Kenya." African Journal of Agricultural Research 7, no. 29: 1.
Ochanda Ogola. Adaptation of cassava (Manihot esculenta) to the dry environments of Limpopo, South Africa: growth, yield and yield components. African Journal of Agricultural Research 2011, 6, 1 .
AMA StyleOchanda Ogola. Adaptation of cassava (Manihot esculenta) to the dry environments of Limpopo, South Africa: growth, yield and yield components. African Journal of Agricultural Research. 2011; 6 (28):1.
Chicago/Turabian StyleOchanda Ogola. 2011. "Adaptation of cassava (Manihot esculenta) to the dry environments of Limpopo, South Africa: growth, yield and yield components." African Journal of Agricultural Research 6, no. 28: 1.
Dennis Ndolo; Ochanda Ogola. Transgenic Pesticidal Crops and the Environment: The Case of Bt Maize and Natural Enemies. Pesticides in the Modern World - Risks and Benefits 2011, 1 .
AMA StyleDennis Ndolo, Ochanda Ogola. Transgenic Pesticidal Crops and the Environment: The Case of Bt Maize and Natural Enemies. Pesticides in the Modern World - Risks and Benefits. 2011; ():1.
Chicago/Turabian StyleDennis Ndolo; Ochanda Ogola. 2011. "Transgenic Pesticidal Crops and the Environment: The Case of Bt Maize and Natural Enemies." Pesticides in the Modern World - Risks and Benefits , no. : 1.
Although it is generally accepted that drought tolerance is a critical agronomic trait, efficient and predictable improvement in drought tolerance in bread wheat (Triticum aestivum L.), in varying drought stress conditions, has not been fully achieved. This study aimed at assessing the responses of bread wheat to drought, using physiological traits associated with drought tolerance. Two experiments were undertaken in 2001 and 2002. In Experiment I, 17 wheat genotypes were planted in the field in Katumani, Kenya, using a randomised complete block design. Experiment II was conducted under rain shelter (by simulating early season drought at seedling stage) at National Plant Breeding Research Centre, Njoro, Kenya. Treatments were imposed in a split-plot design with water regime (low, medium and high) as main plots and 12 wheat genotypes as sub-plots. Evapo-transpiration (ET) was determined by monitoring soil moisture content at 7 d intervals using a neutron probe, stomatal conductance (g) and instantaneous transpiration (T) rates were measured on the uppermost fully expanded leaves at booting stage using a steady-state porometer, net leaf CO2 exchange rates (CER) was measured on selected leaves using a portable Infrared Gas Analyser, fitted with Parkinson Leaf chamber, and crop biomass, grain yield and harvest index (HI) determined at harvest maturity. Water use efficiency (q), HI, stomatal conductance, and CER were identified as key control points in determining the drought resistance of tolerant genotypes. Therefore it is important to determine the heritability of these traits in order to ascertain their potential usefulness in a wheat breeding program.
P.K. Kimurto; Ochanda Ogola; M.G. Kinyua; J.M. Macharia; P.N. Njau. Physiological traits associated with drought tolerance in bread wheat (Triticum aestivumL.) under tropical conditions. South African Journal of Plant and Soil 2009, 26, 80 -90.
AMA StyleP.K. Kimurto, Ochanda Ogola, M.G. Kinyua, J.M. Macharia, P.N. Njau. Physiological traits associated with drought tolerance in bread wheat (Triticum aestivumL.) under tropical conditions. South African Journal of Plant and Soil. 2009; 26 (2):80-90.
Chicago/Turabian StyleP.K. Kimurto; Ochanda Ogola; M.G. Kinyua; J.M. Macharia; P.N. Njau. 2009. "Physiological traits associated with drought tolerance in bread wheat (Triticum aestivumL.) under tropical conditions." South African Journal of Plant and Soil 26, no. 2: 80-90.
D. N. Obonyo; Ochanda Ogola; A. W. Kamau. Effects of time of planting, fertilizer and insecticide on sorghum shoot fly, Atherigona soccata (Diptera: Muscidae), on two varieties of sorghum. African Entomology 2008, 16, 185 -195.
AMA StyleD. N. Obonyo, Ochanda Ogola, A. W. Kamau. Effects of time of planting, fertilizer and insecticide on sorghum shoot fly, Atherigona soccata (Diptera: Muscidae), on two varieties of sorghum. African Entomology. 2008; 16 (2):185-195.
Chicago/Turabian StyleD. N. Obonyo; Ochanda Ogola; A. W. Kamau. 2008. "Effects of time of planting, fertilizer and insecticide on sorghum shoot fly, Atherigona soccata (Diptera: Muscidae), on two varieties of sorghum." African Entomology 16, no. 2: 185-195.