Open Access Original Research Article

Nitrogen Fertilization Contributes to the Flexible Use of Defoliation Severity in the Management of Aruana Guinea Grass

A. A. Giacomini, K. Batista, L. Gerdes, W. T. Mattos, I. P. Otsuk

International Journal of Plant & Soil Science, Page 136-146
DOI: 10.9734/IJPSS/2015/17386

Defoliation severity and nitrogen fertilization trigger physiological and morphological responses in individual plants. The objective of this study was to evaluate the capacity of Aruana guinea grass to respond to severe defoliation and to determine whether nitrogen fertilization interferes with the biomass partitioning and nitrogen concentration of this plant. Cylinders containing plant + soil material were collected on Aruana guinea grass pasture and the experiment was conducted in a greenhouse between November 2012 and March 2013. The treatments consisted of four nitrogen rates (50, 100, 150 and 200 mg dm-3) and two defoliation severities (10 and 15 cm heights) in a randomized complete block design, with four replications in a 4 x 2 factorial arrangement. More severe defoliation (10 cm) compared to lenient defoliation (15 cm) seems to induce compensatory growth, since greater biomass accumulation in leaves, a larger leaf area and a higher leaf/stem ratio were observed at the highest nitrogen rate evaluated (200 mg dm-3). Aruana guinea grass can be managed using more severe defoliation (10 cm) as long as sufficient nitrogen is supplied to compensate for the greater removal of tissues through morphological and physiological alterations.


Open Access Original Research Article

Incidence and Severity of Viral and Fungal Diseases of Chili Pepper (Capsicum frutescens) in Some Districts in Ghana

E. Asare-Bediako, A. Addo-Quaye, B. Boakye, J. M. Sarbah, P. Asante, E. Dorm

International Journal of Plant & Soil Science, Page 147-159
DOI: 10.9734/IJPSS/2015/16830

Aims: To assess the incidence and severity of viral and fungal diseases infecting pepper in some major producing areas in Ghana and to identify farmers’ agronomic practices that influence disease incidence and severity.
Study Design: Descriptive survey involving household and field surveys.
Place and Duration of Study: Sekyere South district of the Ashanti Region, Komenda-Edina-Eguafo-Abirem district of Central Region, Kintampo South district of Brong-Ahafo Region and North and South Tongu districts in the Volta Region, between April 2013 and September 2013.
Methodology: Questionnaire with both open ended- and closed ended- questions was administered to 30 pepper farmers purposively selected from each of the selected district in each Region in order to determine the farmers’ awareness of the fungal and viral diseases and their agronomic practices which could affect the disease spread in their farms. Thirty hot pepper fields from each district were selected randomly and forty (40) plants from each of the fields were observed for disease incidence and severity. Pepper diseases assessed were pepper mosaic, phytophthora leaf blight, cercospora leaf spot, fruit rot and leaf anthracnose.
Results: There were high incidences (up to 86.3%) and severities (11.8-32.1%) of pepper mosaic disease, leaf anthracnose, anthracnose fruit rot, phytophthora blight and cercospora leaf spot in all the fields surveyed. Majority of the farmers use seeds from their own farms (30-60%), practice monocropping (50-73.7%), rotate their pepper crops with tomatoes and garden eggs (43-60%) and manage diseases in their farms using synthetic pesticides (50-70%).
Conclusion: The adoption of poor agronomic practices by the farmers was the major contributing factor for the high incidences and severities of viral and fungal diseases in their farms.

Open Access Original Research Article

Changes in the Chemical Properties of Soil Cultivated with Brachiaria ruziziensis Regarding Nitrogen Fertilization

Karina Batista, Alessandra Aparecida Giacomini, Waldssimiler Teixeira de Mattos, Luciana Gerdes, Ivani Pozar Otsuk

International Journal of Plant & Soil Science, Page 160-171
DOI: 10.9734/IJPSS/2015/17601

The present study aimed to determine the effects of nitrogen fertilization on the chemical properties of Oxissol (Red Latosol), in an area cultivated with Brachiaria ruziziensis cv. Common where crop succession system was used (“safrinha” corn (second growing season) planted in succession to soybean) in no-tillage system, regarding the combinations of nitrogen doses. The experimental treatments consisted of two doses of nitrogen applied in the planting of Brachiaria ruziziensis and four doses of nitrogen applied after the first grass cut. The treatments were arranged in 2x4 factorial design, as follows: 0.0; 0.15; 0.30; 0.45; 15.0; 15.15; 15.30 and 15.45 mg dm-3. The experimental design used was completely randomized blocks with four repetitions The soil chemical properties assessed were: pH; cation exchange capacity; base saturation; potential acidity; soil contents of organic matter, phosphorus, sulfate, potassium, calcium, magnesium, boron, copper, iron, manganese and zinc. F test was used in the comparisons between nitrogen means during planting, and regression analyzes were used for the nitrogen treatments after the first grass cut. The nitrogen fertilization does not interfere in the values of pH, organic matter, phosphorus, boron, iron, manganese and zinc of the soil cultivated with Brachiaria ruziziensis. It is necessary to monitor the contents of K, Ca, Mg and B in the soil when nitrogen is applied to Brachiaria ruziziensis. The minimum sulfate content in soil cultivated with Brachiaria ruziziensis is 4.94 mg dm-3 for the dose of 36.3 mg dm-3 of nitrogen. The non-application of nitrogen at planting associated to the application of 28.5 mg dm-3 of nitrogen after the first grass cut results in higher copper content in soil (4.14 mg dm-3). The application of 15 mg dm-3 of nitrogen at planting associated to the increase in nitrogen doses after the first grass cut led to increase in copper content.


Open Access Original Research Article

Response of Tissue Zinc to Zinc Fertilisation by Zinc Biofortifier Bush Bean Genotypes Targeted for Low Income Communities

E. Nankya, J. S. Tenywa, S. Nkalubo, L. N. Mulumba

International Journal of Plant & Soil Science, Page 172-179
DOI: 10.9734/IJPSS/2015/17144

Aim: This study investigated the influence of applied zinc on the richness and distribution of Zn in the leaves and grain of Zn dense bean genotypes.
Study Design: Treatments of this study were laid out in a completely randomised design (CRD), three replications, repeated three times.
Place and Duration: The study was conducted at National Crops Resources Research Institute (NaCRRI), in Uganda during 2011-2012.
Methodology: Two Zn biofortifier bush bean genotypes (KaboF6-2.8-27 and NUA69) and Zn rates of 0, 5, 7.5 and 12.5 mg pot-1 were considered in this study. Soil used was an Oxisol obtained from continuously cultivated bean producing soils. Data collected included leaf and grain Zn and estimations of the quantities of these bean consumable parts required to meet the thresh hold daily dietary requirements for pregnant and breast feeding mothers.
Results: There was a significant (p<0.05) interaction between Zn rates and genotypes in terms of tissue Zn. Zinc application caused a slight effect on leaf zinc in KaboF2.8-27, but had no significant effect (p>0.05) in NUA69 genotype. Both genotypes maintained a similar response pattern with respect to leaf Zn. Kabo6F2.8-27 was superior and had the highest leaf Zn at 44.3 mg pot-1. As for the grain, KaboF2.8-27 and NUA69 peaked with 43 and 35.9 mg Zn kg-1 both within the application rate of 7.5 mg pot-1.
Conclusion: The quantity of leaves required by pregnant mothers to meet their daily dietary Zn requirements is 248 g; while that of breast feeding mothers is 271 g of KaboF2.8-27 genotype. There is need for evaluation of the status of bioavailability of plant tissue Zn in order to ensure its effective and efficient utilisation by communities.

Open Access Original Research Article

Contribution of the Study of Physiological Disturbances of Wheat Triticum durum in the Presence of Nitrogen Fertilizer

Sabrina Bouchelaghem

International Journal of Plant & Soil Science, Page 180-185
DOI: 10.9734/IJPSS/2015/16331

In this work we are interested in evaluating the impact of nitrogen fertilizer urea on the roots of wheat Triticum durum. We followed the percentage of germination. Also biochemical parameters such as average water content, soluble sugar and average of chlorophyll content. The main results show that the presence of urea causes a significant increase in the average water content; there is also an activation of the synthesis of soluble sugars and inhibition of chlorophyll synthesis.
The most common effect of abiotic stress on plant physiology thus reducing growth.

Open Access Original Research Article

Influence of Phosphorus Sources on the Yield and Yield Components of Groundnut (Arachis hypogaea L.) Varieties in Sokoto, Semi-Arid Zone of Nigeria

M. Musa, A. Singh, A. I. Take-tsaba

International Journal of Plant & Soil Science, Page 186-191
DOI: 10.9734/IJPSS/2015/16850

Groundnut (Arachis hypogaea L.), is a valuable source of edible oil, cakes and livestock feeds (haulm) produced throughout the tropics. However, its production is constrained by high cost of water soluble P fertilizers that are beyond the reach of most tropical poor farmers and hence, the need to study alternative sources of P that could provide information on how to increase the yield of the crop. Thus the present study was undertaken to study the influence of phosphorus sources on the yield and yield components of groundnut varieties in the region. Two field experiments were conducted during 2007 and 2008 rainy seasons at the Dryland Teaching and Research Farm of the Department of Crop Science, Usmanu Danfodiyo University Sokoto, Sokoto State, Nigeria. Treatments consisted of factorial combination of two groundnut varieties and three phosphorus sources [Sokoto rock phosphate, single super phosphate and a control (the crop relying on soil residual P from the preceding crop's fertilizer application)]. The treatments were laid out in a randomized complete block design replicated three times. The results revealed that number of pods per plant, pod yield, kernel yield, shelling percentage and harvest index were higher in Ex-Dakar variety. The performance of the crop was not influenced by direct application of phosphorus on the crop. Thus, from the findings of this study Ex-Dakar variety could be suggested for increased groundnut production in the study area. The crop could be grown with or without direct application of phosphorus.