Open Access Original Research Article

Occurrence of Bacterial Leaf Blight of Cocoyam and Characterisation of the Causal Organism in Northern Nigeria

A. Abdullahi, S. E. L. Alao, O. O. Banwo, O. Alabi, S. Lu, R. Bandyopadhyay

International Journal of Plant & Soil Science, Page 1-13
DOI: 10.9734/ijpss/2019/v27i230070

Aim: To determine the occurrence of bacterial leaf blight of cocoyam and to characterize isolates of the causal organism in Northern Nigeria.

Place and Duration of Study: The study was conducted in cocoyam farmers’ fields in Kaduna and Kano States, Department of Crop Protection, Ahmadu Bello University, Zaria, Nigeria and the Mississippi State University, USA in 2015.

Methodology: Field surveys were conducted in Kaduna and Kano States of northern Nigeria to determine occurrence of bacterial leaf blight of cocoyam. Sampling was done using quadrat. Incidence and severity of the disease was assessed on the field. Bacterial isolates obtained from the diseased samples were used for pathogenicity and hypersensitive reaction (HR) tests. Biochemical tests such as Gram, catalase, oxidase, pectolytic, amylolytic and production of acid from glycerol were carried out on the isolates. A nearly full length of the 16S rDNA gene of selected isolates was PCR amplified using 16S rRNA primers. The resulting amplicons were sequenced using Sanger sequencing. The 16S rDNA gene sequences were aligned along with other Xanthomonas sequences imported from the NCBI database using muscle tool from MEGA6.

Results: The results showed Kaduna State had higher incidence and severity (50.2%, 13.5%) than Kano State (20.5%, 5.1%) and that bacterial isolates induced blight symptoms on cocoyam and elicited HR reactions on tobacco. Isolates were Gram negative, catalase positive, oxidase negative, amylolytic, pectolytic and produced no acids from glycerol. BLAST search of sequenced genes showed 98-100% homology to Xad. Maximum likelihood phylogenetic trees constructed for the 16S rDNA gene sequences revealed isolates were identical to the Xad reference strains KP247494, KM576803 and EU203153. Generally, all the isolates obtained were Xad.

Conclusion: Bacterial leaf blight of cocoyam occurred in Kaduna and Kano States and the bacterial isolates were identical to Xanthomonas axonopodis pv. dieffenbachiae.

Open Access Original Research Article

Effect of Maize –Legume Intercrop and Fertilizer on Weed Suppression and Maize Performance in South Eastern, Nigeria

Akpa, Ogonnaya Esther, Udensi Ekea Udensi, Omovbude, Sunday, Orluchukwu, Joseph Amadi

International Journal of Plant & Soil Science, Page 1-15
DOI: 10.9734/ijpss/2019/v27i230071

Maize is one of the most commonly cultivated arable crops in the rain forest zone of South Eastern Nigeria. Globally soil fertility and weed pressure are the most important constraints limiting increase productivity of Maize especially in Sub Saharan Africa (SSA). Unavailability and cost of inorganic fertilizer as well as cost of labour for weeding have engendered low productivity of maize. Hence this trial was conducted to evaluate the efficacy of maize-legume systems on weed suppression and maize performance. The trial was carried out at the Teaching   and Research  Farm of Faculty of Agriculture, University of Port Harcourt, Nigeria located within latitude 04°54’N and longitude 6°55E). The trial was conducted between April 4th and July 5th, 2017. The experiment was a 3 x 3 factorial arrangement fitted into a randomized complete block design (RCBD) consisting of 3 types of legume systems (Mucuna pruriens, Lablab purpurens and No legume) and three levels of NPK 15:15:15 fertilizer (0, 15, and 30 kg NPK/ha). The 9 treatment combinations were replicated thrice to give 27 plots.  Data collected were on maize yield and yield components, weed and legume parameters at 4, 8 and 16 weeks after sowing (WAS). Result showed that legume significantly reduced weed biomass when compared to the natural fallow. The effect of weed biomass reduction was Mucuna 34.8% >Lablab 29.2%. The legume system significantly suppressed weed compared to natural fallow and the weed suppression ability average 56% and 30% respectively for Mucuna and Lablab whether or not they received NPK. Result of this trial also revealed that within 8 weeks after sowing legumes (8 WASL) 26% N and 22% N can be harvested by integrating this legume cover in cropping system and that NPK application has little or no effect in the performance of these legumes. Mucuna was not sensitive to fertilizer application while Lablab responded to fertilizer application. Maize was sensitive to Mucuna due to early integration; hence, it is recommended that these legumes be integrated at six weeks after sowing maize.

Open Access Original Research Article

Soybean (Glycine max L.) Response to Lime and Vermicompost Amelioration of Acidic Nitisols of Assosa, North Western Ethiopia

Tigist Adisu, Lemma Wogi, Tesfaye Feyisa

International Journal of Plant & Soil Science, Page 1-18
DOI: 10.9734/ijpss/2019/v27i230072

Acidic soils limit the production potential of crops because of low availability of basic cations and excess of hydrogen (H+) and aluminium (Al3+) in exchangeable forms. In the western part of the country such as Assosa and Wellega, soil acidity is a well-known problem limiting crop productivity. A field study was conducted to assess the effects of lime, vermicompost and their combinations on selected soil physico-chemical properties and responses of soybean grown on acidic Nitisols of Assosa area during 2016 and 2017 main cropping seasons. Soil samples were collected from the experimental site before planting and from plots after harvesting. The collected samples were analysed following the standard methods for soil physico-chemical analysis. The treatments were factorial combinations of four levels of lime (0, 1.62, 3.62 and 4.90 t ha-1) and four levels of vermicompost (0, 1.50, 3.00 and 4.50 t ha-1). The results revealed that soil pH increased from 5.31 – 5.86 pH while exchangeable acidity decreased from 5.46 - 2.85 cmol (+) kg-1 with levels of lime and vermicompost (3.26 with 3 and 4.90 with 4.5) t ha-1 respectively, which resulted in improved soil physico-chemical properties. The combined application of lime and vermicompost also significantly improved the yield related parameters of soybean. The maximum grain yield (1.95t    ha-1) was obtained from the combined application of 4.90 ton lime and 3.00 ton vermicompost ha-1 followed by combined application of 3.26 ton lime with 3.00 ton vermicompost ha-1 with non-significant variation. Therefore, the combined application of 3.26 ton lime and 3.00 ton vermicompost ha-1 is a promising alternative amendment for amelioration of acidic Nitisols of Assosa (Amba-12 Kebele) and other similar agro-ecologies for the improvement of soybean production.

Open Access Original Research Article

Altering Growth Characters and Seed Cotton Yield under Foliar Application of Boron

Md. Tasdiqur Rahman, M. Moynul Haque, Md. Gazi Golum Mortuza, Md. Sadek Hossain, Md. Shah Newaz Chowdhury

International Journal of Plant & Soil Science, Page 1-5
DOI: 10.9734/ijpss/2019/v27i230073

The experiment was conducted at Central Cotton Research Farm, Sreepur, Gazipur during cotton growing season of 2009-2011. Cotton variety cv. CB-10 was used under experiment. Eight levels of boron (0.0, 0.25, 0.50, 0.75, 1.0, 1.25, 1.50 and 1.75, g L-1 water) were sprayed at reproductive stage of cotton as treatment. The design of the experiment was randomized completely block design (RCBD) with three replications. Result revealed that, foliar application of boron has significant influence on different traits of cotton. Foliar application of boron may improve the performance of cotton plant by reducing the percentage of boll shattering and increasing the growth of square for better quality fiber. 

Open Access Original Research Article

Carbon Stock as Related to Fallow Age in the Sudano-Guinea Savannahs of Ngaoundere, Adamawa, Cameroon

Adamou Ibrahima, Platini Nguilandi Saolo, Chimène Abib Fanta

International Journal of Plant & Soil Science, Page 1-14
DOI: 10.9734/ijpss/2019/v27i230074

Aim/Objectives: In order to assess the fallow contribution on the carbon cycle and soil organic matter restoration, a study of the carbon dynamics was undertaken in fallow systems of 1, 2, 5 and 20 years old in the Ngaoundere savannahs of Cameroon.

Methodology: Carbon stock was estimated in 100 m2 plot for shrubs, in 1 m2 plot for understorey, litter and earthworm casts, and 0.0625m2 plot for fine roots and soil. The experimental design was randomised complete block with three replicates. The age of fallows was the mean treatment whereas the plots were the replicates.

Results: The results showed that the phytomass increased with fallow age, except that of shrubs. Soils and earthworm casts were the mean carbon sinks in the four fallows, with more than 55.61% and 26.24% of the total carbon stock respectively in the soil and earthworm casts. The total carbon stock increased with fallow age, from 34.54 in the young fallows to 154.52 tC.ha-1 in the old fallows. In the same way, vegetation and soil carbon increased with fallow age except that of shrub. The results showed that the carbon stock was influenced by floristic composition and spatial distribution of the vegetation, which related to fallow age.

Conclusion: These preliminary results will contribute to the understanding of the impact of fallow age on the global carbon cycle and awareness in the conservation of fallows for the environment protection.