Open Access Original Research Article

Diversity of Ralstonia solanacerum Strains in Solanaceous Crops Production Regions of Central Kenya

E. K. Kago, Z. M. Kinyua, J. M. Maingi, P. O. Okemo

Journal of Experimental Agriculture International, Page 1-12
DOI: 10.9734/JEAI/2017/32547

Aims: Bacterial wilt disease is a very serious yield limiting problem in crops in the solanaceae family grown in regions of Kenya. The very much encouraged field sanitation and use of clean planting materials have been inadequate in combating this challenge. This has seen increased need for understanding the genetic and biochemical diversity of Rastonia solanacerum stains common to these areas as a basis for better strategies in their control.

Methodology: A field survey accompanied by samples collection was conducted covering: Nyeri, Nyahururu, Kirinyaga, Kiambu, Nakuru Murang’a and Embu Counties exclusively for solanaceae crop farms. Purposeful sampling was employed.

Results: A total of 160 samples of bacterial wilt symptomatic plants were collected, 120 isolates were confirmed as R. solanacearum using biochemical tests. They were further subjected to biovar tests using sugars and alcohols, (Cellobiose, Lactose, Maltose, D-Ribose, Salacin, Dulcitol, Mannitol, Trehalose and Sorbitol). Dextrose and Salacin were used as positive controls while sterile distilled water was used as negative control respectively. The results enabled mapping of R. solanacearum biovar in these regions. Biovar 2 was the most prevalent in the study area with biovar 2T showing high prevalence in both highlands and lowlands; biovar 2A was common in lowlands. Other biovars identified were 1 and 3.

Conclusion: This survey findings indicated that R. solanacerum, biovars present in Kenyan Highlands and Lowlands included biovars 1, 2 and 3. These biovars are highly pathogenic on solanaceae crops throughout the world. The findings of the present study will be useful for designing the study of the population structures of R. solanacearum using the molecular approaches with special emphasis on its integrated management.

Open Access Original Research Article

Determination of Effect of Cold Stratification Temperature and Duration on Germination of Spruce (Picea smithiana Wall. Boiss) under Laboratory Conditions

Javeed Ahmad Mugloo, Naseer A. Mir, P. A. Khan, Gowher Nabi Perray, K. N. Kaisar

Journal of Experimental Agriculture International, Page 1-10
DOI: 10.9734/JEAI/2017/31780

Aim: The natural regeneration of Picea smithiana is generally slow and almost negligible due to a number of factors e.g. presence of undecomposed raw humus on forest floor, low germinative capacity of seed and long interval between good seed years (5-6 years). Therefore the present investigation was carried out to find the effect of stratification temperatures and duration on the germination of Picea smithiana under laboratory conditions.

Area of Study: The germination study was carried out in laboratory at Faculty of Forestry, Sher-e-Kashmir University of Agriculture Science and Technology of Kashmir, Benhama, Ganderbal, Jammu and Kashmir during 2010-2011 to investigate the effect of different stratification temperature and durations on germination of Picea smithiana under laboratory conditions.

Methodology: For germination tests the species seeds were subjected to different stratification temperatures i.e. 0±1°C, 4±1°C, ambient temperature (room temperature) and durations i.e. (15, 30, 45, 60, 75, 90, 105 and 120 days) on germinability of spruce (Picea smithiana Wall. Boiss) seeds so that it can be propagated. The experiment was laid out in a completely randomized design with twenty-four treatments combinations replicated three times.

Results: It was observed that stratification temperature 0±1°C (T1) for a period of 75 days (P5) resulted in higher germination of 60.62% and germination capacity of 69.62%, which declined to 46.37% and 56.37% at the end of 120 days stratification period. Similar trend was observed for the other germination parameters viz. germination energy, germination value and germination speed.

Conclusion: The germination results indicated that Picea smithiana seeds do possess inherent dormancy which increases with storage. Pre-chilling or cold stratification for 75 days at 0±1°C effectively overcame dormancy in Picea smithiana.

Open Access Original Research Article

Application of Multivariate Analysis to Access Selected Rice Germplasm Phenotypic Diversity

A. A. Shaibu, M. I. Uguru

Journal of Experimental Agriculture International, Page 1-8
DOI: 10.9734/JEAI/2017/31662

Without variability, it is not possible to conduct a plant breeding program. Germplasm is hence the critical first step in initiating a breeding program. Diversity in O. glaberrima accessions is enormous. It needs to be organized and characterized in order to facilitate its use by plant breeders. Two principal components (PRIN1) and (PRIN2) accounted for most of the variability observed in characters studied. PRIN 1 accounted for 56% of the phenotypic and morphological variation. The PRIN 1 was loaded on plant height, number of panicle, biomass wet weight, panicle wet weight and grain yield traits. PRIN 2 accounted for 23% of the variation. PRIN 2 was loaded on biomass wet weight, biomass dry weight, panicle wet weight, panicle dry weight, and harvest index traits. The test for univariate statistics described individual variable to explore pattern of response to variation showed strong statistical significantly (P<0.001) on phenotypic differences in all the variables that were measured. These traits studied are the most important contributing to the overall variability. The dendogram produced grouping that defined nine distinct clusters and minimum genetic distance between clusters varies from 0 to 5. All the selected Oryza glaberrima accessions and the Oryza sativa were distributed across the nine clusters respectively.

Open Access Original Research Article

Correlation and Path Coefficient Analysis of Yield Components in NERICA Mutant Rice Lines under Rainfed Conditions

Md. Nuruzzaman, Lutful Hassan, Shamsun Nahar Begum, Md. Monjurul Huda

Journal of Experimental Agriculture International, Page 1-8
DOI: 10.9734/JEAI/2017/32756

Morphological and yield related traits of 31 genotypes were studied to ascertain the genetic and phenotypic correlations among some morphological traits and contribution of these traits to the yield under rainfed conditions directly and indirectly in NERICA mutant rice lines. Field experiment was conducted during the winter season of 2014 at the experimental field of Biotechnology division in Bangladesh Institute of nuclear agriculture (BINA), Mymensingh. The experiment was lay in a randomized complete block design with three replications. The genotypes differed significantly for all the traits viz., days to flowering (1st, 50%, 80%), days to maturity, plant height, total tillers and effective tillers hill-1, filled and unfilled grains panicle-1, 100-seed weight (g) and yield plant-1 (g). The results indicate that plant height (0.422*and 0.426*), total tillers hill-1(0.663**and 0.669**), effective tillers hill-1 (0.734**) and filled grains panicle-1 (0.525**and 0.530**) showed positive and significant association with yield per plant under rainfed conditions at both phenotypic and genotypic levels; whereas, days to maturity (-0.554** and 0.574**) had significantly negative correlation with yield. Higher phenotypic correlation values for all traits indicated that the environmental effects on traits are high under rainfed conditions. Plant height, total tillers hill-1, effective tillers hill-1, panicle length, filled grains panicle-1 and 100-seed weight showed direct positive effect on yield plant-1 at both genotypic and phenotypic levels. Therefore, these characters would be reliable criteria for improving yield. Higher heritability and genetic advance estimates for all the traits under rainfed condition indicates that these characters can be exploited more efficiently through selection in further generations.

Open Access Original Research Article

The Growth and Tuber Yield of Cassava as Affected by Cassava Peel Compost Application

A. S. Adeyeye, W. B. Akanbi, O. O. Sobola, W. A. Lamidi, K. K. Olalekan

Journal of Experimental Agriculture International, Page 1-5
DOI: 10.9734/JEAI/2017/32048

This study was conducted to assess the effect of cassava peel compost rates on the growth and tuber yield of cassava. The treatments were prepared in six compost rates as: 0, 5, 10, 15, 20, and 25 t/ha respectively and they were applied to cassava and arranged in a randomized complete block design with three replications. Growth and yield parameters were taken from 4th weeks after planting till harvest. The data collected were subjected to analysis of variance (ANOVA) at 5% level of probability and the resulted means were separated using Duncan Multiple Range. The results showed significance differences among the treatments applied. Application of 10 t/ha compost significantly produced taller plants at all growing stages and also produced higher leaf number at  6,8 and 12 weeks after planting. Furthermore the highest tuber weight was observed from addition of 15 t/ha compost. It is concluded that compost application improves the growth and tuber yield of cassava when applied at range 10 and 15 t/ha.