Volume 6, Issue 1

Seed Potato Production Practices and Quality of Farm Saved Seed Potato in Kiambu and Nyandarua Counties in Kenya
Original Research
Potato production in Kenya is mainly constrained by limited supply of quality seed potato tubers. The objective of this study was to determine seed potato handling practices and quality of farm saved seed potato. A survey involving 79 farmers was conducted in potato production areas in Kiambu and Nyandarua Counties to collect information on seed potato production practices including sources of seed tubers, seed selection, seed tuber storage, pests and diseases. Samples of seed potato were collected from farmers and evaluated for quality parameters such as tuber size, weight, stout sprout length and infection with diseases. Factors affecting potato production included limited quality seed supply, pests and diseases. Shangi was the main potato variety grown by majority (62.8%) of farmers and all the farmers used own farm saved seed. Most (45.5%) farmers recycled the seed for four seasons and 44.1% of farmers stored seed potato for three months. Freeness from seedborne diseases was the main seed quality preference by farmers. The main pest reported was cutworms (42.6% of farmers) while potato late blight and bacterial wilt were the major diseases reported by 87.1% and 86.7% of the farmers respectively. All farm saved seed potato samples were infected with Fusarium coeruleum, 51.2% with Rhizoctonia solani, 53.3% with Fusarium sambunicum, 33.3% with Fusarium solani and 48.3% with Aspergillus niger. Over 69% of the farm saved seed samples were infected with Ralstonia solanacearumwhile 40.1% were infected with Potato Virus S, the most dominant. Due to poor post-harvest handling practices, farmers incurred seed quality and quantity losses in storage. Farm saved seed is contaminated with multiple seed borne diseases. Farmers should be sensitized on appropriate seed potato handling practices and there should be increased supply of certified seed potato.
World Journal of Agricultural Research. 2018, 6(1), 20-30. DOI: 10.12691/wjar-6-1-5
Pub. Date: February 11, 2018
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Effect of Maturity Stage of Donor Plant on Propagation of Diploknema butyraceathrough Branch Cuttings
Original Research
Diploknemabutyracea an important multipurpose species owing to its great economic and medicinal value is facing threat as the exploitation levels have reached all time high. The species is failing to regenerate in spite of reasonable seed production. Therefore, in order to augment the natural regeneration, special attention needs to be given for its propagation. Thus, vegetative propagation is a better option, as it ensures purity of clonal or true-to-type propagation of elite tree. The present investigation was conducted to study the effect of maturity stage of donor plants on rooting of branch cuttings of Diploknema butyracea. Mature and juvenile branch cuttings of 2-3 cm diameter and 16-20 cm length classes were planted in the non-mist propagation chambers for sprouting and rooting of cutting. Maximum 92.20% sprouting was observed in juvenile cutting which got reduced to 37.20% in mature donor plants. The maturity stage of the donor plant had significant effect on the mean length and mean number of sprouts per cutting. Maximum (3.63) mean number of leaves was recorded in juvenile cuttings. Percent rooting decreased as age of the donor plants increased. Maximum (66.70%) rooting was observed in juvenile branch cuttings which decreased to (4.40%) in cutting collected from mature donor plants. Juvenile branch cuttings showed significant survival percentage (87.80%) and survival percentage during hardening (77.80%) than mature ones. Maturity stage had a significant effect on the mean number and mean length of roots per cutting after 64 days of planting.
World Journal of Agricultural Research. 2018, 6(1), 15-19. DOI: 10.12691/wjar-6-1-4
Pub. Date: January 22, 2018
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Spatial Assessment of Heat Stress Impact on Rice Production in Two Districts of Andhra Pradesh, India
Original Research
Physiological studies have provided clear evidence of heat-induced spikelet sterility in rice, which can cause significant yield reductions. However, it is rather difficult to evaluate such yield losses in real world situations in farmers’ fields, especially across large areas. State-of-the-art technologies, such as remote sensing and crop modeling, can offer solutions for evaluating the heat-induced yield penalty in rice across a spatial area. Remote-sensing technologies, especially Synthetic Aperture Radar (SAR), can provide spatial detection of the start of the rice-growing season. This information, combined with time-series temperature data, can be assimilated into a crop simulation model, which can provide a thorough assessment of any heat-induced yield penalty over a specific geographic region. In this paper, we demonstrate how SAR can be used to assess the effects of heat stress in rice in two districts of Andhra Pradesh, India, during the 2017 rabi (dry) season. The accumulated data suggest that 53,623 and 21,436 ha of rice fields in Nellore and West Godavari districts, respectively, had yield losses due to heat stress. Rice fields in Nellore suffered higher yield and production losses due to heat stress because of steeper trend of increasing temperatures during the rice plants’ reproductive stage.
World Journal of Agricultural Research. 2018, 6(1), 10-14. DOI: 10.12691/wjar-6-1-3
Pub. Date: January 15, 2018
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Evaluation the Toxicity of Honey Bee Venom on Achroia grisella Developmental Stages
Original Research
The common control method used to control the lesser wax moth A. grisellawas fumigation with toxic gases; however, many insect pests of honey bees have developed resistance to the conventional control methods. This study aimed to study the toxicity of crude bee venom on developmental stages of A. grisella as safer alternative and replacement of these chemicals.The bee venom was collected by placing the electric bee venom collector device at the entrance of the beehive. Newly deposited eggs of A. grisella were assayed to evaluate the crude honey bee venom effect on the viability of eggs. Dried crude honey bee venom was diluted with pure acetone to concentrations of 50, 25, 12.5 and 6.25 µg/µl. Egg hatchability was significantly (p<0.05) affected by the treatment. The corrected mortality of the treated eggs was 50.54% in the higher concentration of 50µg/µl with average unhatched eggs of 17.5 eggs per total of 25 eggs with the median lethal concentration (LC50) of 52.89 µg /µl. The topical application of crude honey bee venom was applied on 3rdinstar larvae with concentrations of 0, 6.25, 12.5, 25, 50 µg. The calculated mortality percentages for all treatments were 8% at the lower concentration and 52% at the high concentration. The calculated lethal median concentration LC50 was 38.27 µg /µl.
World Journal of Agricultural Research. 2018, 6(1), 5-9. DOI: 10.12691/wjar-6-1-2
Pub. Date: January 05, 2018
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Can Fucoidan Decrease the Mortalities Caused by Columnaris Disease in Nile Tilapia?
Original Research
Columnaris disease is a serious disease in warm water fish. It is caused by Flavobacterium columnare, a Gram-negative bacterium. In this work, fucoidan was tested for its efficacy in decreasing the mortalities caused by Columnaris disease in Nile tilapia. Consequently, naturally-infected Nile tilapia with Flavobacterium columnare, showing eroded fins, rigid body figure, and ulcerated body surface, was treated with fucoidan (8 gm/kg ration) for 17 days. Flavobacterium columnare infection was confirmed by isolation on selective medium (cytophaga agar), from the skeletal muscle, tails fins, and gills, giving the typical rhizoid shape. It was also confirmed by Flavobacterium columnare specific PCR using selective primers for Flavobacterium columnare 16S ribosomal DNA. Fucoidan caused decreased the mortalities to nil and cured the eroded fins, the ulcerated body surface, and the rigid body figure. Fucoidan also decreased the tissue damage score to reach the normal histological score.
World Journal of Agricultural Research. 2018, 6(1), 1-4. DOI: 10.12691/wjar-6-1-1
Pub. Date: December 29, 2017
6411 Views1927 Downloads