Skip to content
J

Joseph P. Gweyi-Onyango

Publications (16)

Impact of Nitrogen Forms and Levels on Yield and Quality of Rice in Kirinyaga and Kisumu Counties Kenya

Ntinyari Winnie & Joseph P. Gweyi-Onyango · Asian Journal of Soil Science and Plant Nutrition · 2018

Nitrogen is one of the most limiting elements in crop production. The lack of nitrogen is even more pronounced in Sub-Saharan African as farmers are poor and cannot afford the required amount for crop production. Depending on form, nitrogen is known to affect the uptake of other...

Open access Research Article 10.9734/AJSSPN/2018/44658

Diagonal Offset Arrangement and Spacing Architecture Effect on Growth and Yield Components of Grain Amaranth in Kenya

Alice Ngetich Rotich, Joseph P. Gweyi-Onyango & Nicholas K. Korir · Asian Research Journal of Agriculture · 2017

The grain Amaranth (Amaranthus cruentus) is often referred to as the crop of the future because of its advantages both for production and consumption. However, the grain amaranth has an under-exploited potential that can contribute to food security, nutrition, health, income gene...

Open access Research Article 10.9734/ARJA/2017/35312

Plant Row Spacing Effect on Growth and Yield of Green Pepper (Capsicum annuum L.) in Western Kenya

Ocharo N. Edgar, Joseph P. Gweyi-Onyango & Nicholas K. Korir · Archives of Current Research International · 2017

Green pepper production based on the package of recommendations developed has not given the desired growth and yield performances in the world and specifically Kenya. Information is required with which to evolve the agronomic practices that will be adopted to maximize yield in gr...

Open access Research Article 10.9734/ACRI/2017/33101

Influence of Mulching Materials on the Growth and Yield Components of Green Pepper at Busia County in Kenya

Ocharo N. Edgar, Joseph P. Gweyi-Onyango & Nicholas K. Korir · Asian Research Journal of Agriculture · 2016

Aims: Green pepper (Capsicum annuum) also named the bell pepper or sweet pepper is one of the most important and remunerative vegetable crops in the world. Due to the increased pressure on land, climate change and increased demand for the crop, there is need for better agronomica...

Open access Research Article 10.9734/ARJA/2016/29909

Use of Satellite Data to Extract pH Values for Crop Planning and Management of Sorghum and Green Gram in Tharaka Nithi and Machakos Counties, Kenya

Manzi K. H., Shadrack Ngene & Joseph P. Gweyi-Onyango · Asian Journal of Advances in Agricultural Research · 2023

Soil pH is one of the most important soil properties influencing plant growth and productivity. The pH of the soil affects nutrient availability, microbial activity, and soil structure. As a result, accurate soil pH measurement is critical for effective soil management, plant gro...

Open access Research Article 10.9734/ajaar/2023/v23i3464

Effects of Arbuscular Mycorrhizal Fungal Inoculation on Growth and Yield of Two Sweet Potato Varieties

Michael Ajanja Sakha, Joyce Jefwa & Joseph P. Gweyi-Onyango · Journal of Agriculture and Ecology Research International · 2019

Arbuscular mycorrhizal fungi (AMF) represent a functionally important component of soil microbial community, being of particular significance for plant mineral nutrition in tropical agro ecosystems. The effects of AMF inoculation on growth and yield of two sweet potato varieties...

Open access Research Article 10.9734/jaeri/2019/v18i330063

Benefits of Rhizobial Inoculation and Phosphorus Application on Growth of Lucerne (Medicago-sativa) in Kenya

Mutuerandu C. Miriko, Nicholas K. Korir & Joseph P. Gweyi-Onyango · International Journal of Plant & Soil Science · 2018

Field experiments were conducted to study the effects of Phosphates on growth components of Lucerne during the long and short rain seasons of 2016-2017 at Kenyatta University farm in Kiambu County in Kenya. The experiments were laid out in split-plot arrangement in a Randomized C...

Open access Research Article 10.9734/IJPSS/2018/39789

Influence of Organic Enriched Manure and Inorganic Fertilizers on Plant Physiological Processes of Kenyan Tea Clone

Hassan Kiprotich, Nicholas K. Korir, Nyabundi Karl & Joseph P. Gweyi-Onyango · Asian Journal of Soil Science and Plant Nutrition · 2019

Tea (Camellia sinensis L.) is one of the most popular beverages consumed in the world and Kenya is the leading exporter in Africa and only 3rd worldwide after China and India. Nutrient deficiency in soils and poor fertilization are possibly two reasons for low yields and quality...

Open access Research Article 10.9734/ajsspn/2019/v5i330064

Influence of Phosphorus forms on Growth and Yield of Cowpea, Kales and Amaranth Vegetable Species

Fidelis W. Githua, Winnie Ntinyari, Nicholas K. Korir & Joseph P. Gweyi-Onyango · Journal of Agriculture and Ecology Research International · 2019

Maximum production potential of leafy vegetable is limited by phosphorous (P) deficiency in the soils. This is due to the high cost of the phosphate fertilizer and the fixed form of the available phosphorous in the soil. There is therefore, need for farmers to use alternative and...

Open access Research Article 10.9734/jaeri/2019/v19i330084

Influence of Elemental Sulphur, Oxalic Acid, and Phosphoric Acid as Acidulating Agents on Phosphorous Dissolution from Rock Phosphate

Fidelis W. Githua, Winnie Ntinyari, Nicholas K. Korir & Joseph P. Gweyi-Onyango · Journal of Agriculture and Ecology Research International · 2019

Phosphorous is a limiting mineral element in crop productivity due to its less availability and fixed form in the soil. Due to its agricultural benefit, most farmers seek for alternative method to supply phosphorous in sufficient amount in the farming systems. Although the solubl...

Open access Research Article 10.9734/jaeri/2019/v18i430067

Water Stress Effect on Total Antioxiant Activity and Total Phenolic Content of Solanum scabrum Mill and Solanum scabrum in Kiambu, Kenya

Odhiambo Peter Okello, Mildred P. Nawiri, Winfred Musila & Joseph P. Gweyi-Onyango · International Journal of Biochemistry Research & Review · 2017

Aims: The aims of this study were to investigate water stress effect on total phenolics and total antioxidants of selected African nightshades and determine any possible variations in the amount of total phenolics and total antioxidants among the accessions grown. Study Design: S...

Open access Research Article 10.9734/IJBCRR/2017/33715

Effect of Phosphorus Deficiency on Phenolics and Antioxidants Content of Two African Nightshade Varieties Grown in Kenya

Ogembo Oyaro Joel, P. Nawiri, W. Musila & Joseph P. Gweyi-Onyango · International Journal of Plant & Soil Science · 2017

Indigenous vegetables form an integral part of the Kenyan diets, most commonly consumed being the African nightshade. These vegetables contain important phenolics and antioxidants that have medicinal and good health attributes. Their production has strongly been associated with e...

Open access Research Article 10.9734/IJPSS/2017/32424

Effect of Phosphate Levels on Soil Rhizosphere Nutrient Balances and Finger Millet Yield

Wekha N. Wafula, Nicholas K. Korir, Henry F. Ojulong & Joseph P. Gweyi-Onyango · Asian Research Journal of Agriculture · 2016

Soil infertility is one of the main factors leading to low finger millet production in the semi-arid tropics of Kenya. About 50-80% of P applied as fertilizer is adsorbed by soil and the amount of P needed to achieve maintenance of its adequate status and influence on other soil...

Open access Research Article 10.9734/ARJA/2016/29606

Differential Biomass Accumulation among African Leafy Vegetables as Affected by Wastewater Irrigation in Kitui County, Kenya

Judy Mwende Wambua, Shadrack Ngene, Nicholas K. Korir, Winnie Ntinyari & Joseph P. Gweyi-Onyango · International Journal of Plant & Soil Science · 2019

Water scarcity of fresh water in Sub-Saharan has led to utilization of the wastewater in home gardening and also in commercial production of vegetables. Wastewater is associated with various substances including nutrients and heavy metals hence it is pertinent to evaluate its eff...

Open access Research Article 10.9734/ijpss/2019/v27i630095

Nitrogen and Phosphorus Uptake and Partitioning in Finger Millet as Influenced by Phosphorus Fertilization

Wekha N. Wafula, Nicholas K. Korir, Henry F. Ojulong, Moses Siambi & Joseph P. Gweyi-Onyango · Journal of Experimental Agriculture International · 2016

Finger millet (Eleusine coracana) production in Eastern Africa remains low due to a variety of factors including soil nutrient depletion. As intensive row-crop production evolves, improvements in managing soil nutrient quantity and availability of less renewable nutrients like P...

Open access Research Article 10.9734/JEAI/2016/30151

Phosphorus Influence on Plant Tissue Nitrogen Contents and Yield Attributes of Finger Millet Varieties in Semi-arid Region of Kenya

Wekha N. Wafula, Nicholas K. Korir, Henry F. Ojulong, Moses Siambi & Joseph P. Gweyi-Onyango · International Journal of Plant & Soil Science · 2016

The experiment was conducted with the aim of evaluating the effect of differential levels of P on finger millet accumulation of N and yield components. On-station experiments were conducted at the KALRO-Kiboko crops research station in Makueni County during the short and long rai...

Open access Research Article 10.9734/IJPSS/2016/29901