by Miseda Victoria Onyango, Wanyera Ruth, Muthamia Japhet and Owuoche James
Original Research
Stem rust (Puccinia graminis f.sp tritici) of wheat (Triticum aestivum L.) is a major threat to wheat production. The objective of the study was to determine the effects of fungicide on the development of stem rust infection. Kwale cultivar was grown in the field at KALRO-Njoro in a Randomized Complete Block Design (RCBD) split-plot arrangement for main-rain (June to November, 2014) and off-rain season (February to May, 2015) by applying three treatments of Fosphite 53 SL (Monopotassium + dipotassium 530 g a.i. L-1) (5L ha-1, 7.5L ha-1, 10L ha-1), untreated plot and a standard check (Folicur 25 EW at 2.5L ha-1) at three different growth stages of the wheat cultivar Kwale. Evaluation of disease severity was based on the modified Cobbs scale and expressed in terms of Area Under Disease Progress Curve (AUDPC). Data on yield and yield components were taken at harvest and analyzed using Statistical Analysis System (SAS) and the mean comparisons based on Least Significant Difference (LSD) at 5% probability for the separation of season, growth stage and fungicide rates. There was significant (P≤0.05) effect (season × crop stage) for AUDPC-YR and (P≤0.001) for plant height. Main-rain season, 2014 had higher values for AUDPC-SR and AUDPC-YR at 40.579% and 36.777% and lower values for plant height, tillers, spike length, spikelet per spike, TKW, biomass and yield by 17.127%, 36.874%, 19.543%, 1.27%, 3.26%,39.263%, and 40.148%, respectively compared to off-rain season, 2015. Tillering stage had lower values for AUDPC-SR and AUDPC-YR by 3.41% and 17.617% and high yield and grain weight as compared to stem elongation and heading stage. Of all the tested rates of Fosphite 53 SL (Monopotassium + dipotassium 530 g a.i. L-1) only the rate of 0.5L ha-1 showed significant reduction in the disease pressure and positive influence in the yield and grain weight. The results suggest that spraying of Fosphite 53 SL at 0.5L ha-1 at tillering stage is effective in controlling stem rust hence, the adoption of effective fungicides to control stem rust pathogen and their application at the right stage of the crop can be used in reducing stem rust severity and increase yield of susceptible wheat cultivars in stem rust occurring areas.
World Journal of Agricultural Research. 2016, 4(6), 183-187. DOI: 10.12691/wjar-4-6-5
Pub. Date: November 09, 2016
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by Kariithi Samuel Ngure, Abwao Stephen Indieka, Ndung’u John and Njau Peter
Original Research
Wheat is an important cereal crop in most diets thus its nutritional content is crucial in addressing microelement deficiencies. This study focused on Zn, Fe, phytic acid and resistant starch content and their effect on rheological and organoleptic properties for whole meal flour from Kenyan wheat varieties. Zn and Fe levels ranged from111 to 305 ppm and 26 to 91 ppm, whereas phytic acid and resistant starch levels ranged from 2.66 to 5.05 ppm and 0.37 to 6.03%. Variety and site significantly (p<0.05) influenced iron and resistant starch content, whereas variety and variety × site influenced zinc and phytic acid. Protein and gluten levels ranged between 11.96 to 14.53% and 7.81% to 19.60% respectively. All the varieties recorded high water absorption levels ranging from 72.2% to 80.8%, while DDT ranged from 4.00 to 9.83 minutes. P and L values ranged between 21 to 79 and 16 to 51 mm, external loaf characteristics ranged between 2.2 to 4.3 and 2.13 to 3.70 for taste and aroma. Zinc and protein positively correlated (r=0.69, p<0.05), stability and P (r=0.69 p<0.05) and DDT and stability (0.71 p<0.05). Phytic acid and crust colour (r=0.66 p<0.05), zinc and shape (r=0.78 p<0.05), zinc and acceptability (r=0.77 p<0.05), DDT and shape (r=0.74 p<0.05), aroma and shape (r=0.67 p<0.05) were positively correlated. The results obtained indicate varieties tested contained considerable levels of zinc, iron, resistant starch, low levels of phytic acid and they had no adverse effect on rheological and organoleptic parameters of whole meal flour.
World Journal of Agricultural Research. 2016, 4(6), 173-182. DOI: 10.12691/wjar-4-6-4
Pub. Date: October 10, 2016
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by Nour Ibrahim, Salah F. Abou-Elwafa, Hamdi Mahrous, Abdel-Azeem A. Ismail and Ezzat E. Mahdy
Original Research
Cotton is an important commercial crop of Egypt. The present study was carried out to study the possibility of selection of elite high yielding plants characterized by the same fiber properties of the superior cultivar Giza 90. To attain this goal two cycles of selection for single trait selection for lint yield/plant and 14 selection indices (desired genetic gain index) were achieved. Average observed genetic gain of the ten selected families after two cycles of selection indicated that LY/P ranged from insignificant (16.57%) for index 2 (LY/P and BW) to 21.63% (P ≤0.01) for index 7 (NB/P and NS/B). Index 2 increased BW by 9.27% (p ≤ 0.05) and UHM length by 2.23% (p ≤ 0.01). Index 7 showed significant genetic gain of 20.26, 21.63, 3.16, 5.44 and 2.785 for SCY/P, LY/P, SI, PI, and UHM length, respectively. Index 3 showed significant genetic gain of 19.71, 21.36, 3.61, 7.82, and 2.65% for SCY/P, LY/P, SI, PI and UHM length, respectively. Index 13 gave significant genetic gain 18.46, 20.55 and 5.76% for SCY/P, LY/P and PI, respectively. Single trait selection for LY/P showed significant genetic gain of 19.75, 20.30 and 14.01% for SCY/P, LY/P and NB/P, respectively. The results indicated that selection index was better than single trait selection in detecting the superior families in LY/P. Generally, it could be concluded that the present program for maintenance and renewing Egyptian cotton varieties is a precise and perfect program to preserve the fiber quality, but, not suitable for improving yielding ability. In consequence, this program should be modified to allow the isolation of superior high yielding off types from the breeding nursery characterized by improvement in one or more fiber quality.
World Journal of Agricultural Research. 2016, 4(6), 166-172. DOI: 10.12691/wjar-4-6-3
Pub. Date: September 27, 2016
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by K.L.N.W. Kumari, D.C. Abeysinghe and R.M. Dharmadasa
Original Research
Stevia rebaudiana (Bertoni) Bertoni (Asteraceae) is a small perennial herb which is widely cultivated for its sweet leaves and possesses 250-300 times the sweetness than sucrose due to the presence of steviol glycosides (mainly stevioside and rebaudioside). It is commonly known as candy leaf, sweet leaf and sugar leaf. Even though, this plant has been studied extensively for its sweetness, information on therapeutically important active components presence in stevia is scattered or lacking. Therefore, the present study was undertaken to determine the distribution of Total Phenolic Content (TPC), Total Flavonoid Content (TFC) and Total Antioxidant Capacity (TAC) of different parts and different leaf positions of S. rebaudiana. Leaf fresh weight, dry weight and leaf area at different leaf positions were recorded. The TAC, TPC and TFC were determined using Ferric Reducing Antioxidant Power Assay (FRAP), modified Folin-Ciocalteu colorimetric method and calorimetric method respectively. Leaf fresh weight and leaf dry weight were increased with the maturity. All tested plant parts demonstrated the presence of TPC, TFC and TAC. The significantly higher TPC, TFC and TAC were reported in leaves than other parts of plant. The order of increase of active components was leaf>flower>stem>branch>root. TPC, TFC and TAC of different leaf positions revealed that TAC, was decreased gradually from immature to mature leaf (1st leaf>2nd leaf>3rd leaf>4th leaf>5th leaf). Moreover, all tested phytochemicals (phenolics and flavonoids) and antioxidant capacity were significantly higher in extracts prepared from the first leaf. Interestingly, a strong significant correlations were observed between TAC and tested secondary metabolites (TFC, R2=0.85). The results of the present study are vital important in cultivation, harvesting and quality control aspects of S. rebaudiana.
World Journal of Agricultural Research. 2016, 4(6), 162-165. DOI: 10.12691/wjar-4-6-2
Pub. Date: September 06, 2016
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by E.J.S. De Soysa, D.C. Abeysinghe and R.M. Dharmadasa
Original Research
Pimenta dioica (L.) Merr. (Myrtaceae) (Eng.Allspice) is an industrially and therapeutically important, evergreen aromatic spice plant widely used in food, perfumery and cosmetic industries around the globe. Allspice, which tastes like a blend of Cinnamomum zeylanicum Blume, Elettaria cardamomum (L.) Maton, Syzygium aromaticum (L.) Merr. &L.M.Perry and Myristica fragrans Houtt. is a common flavoring compound in Asian, Middle Eastern and Jamaican cuisines. However, comparative essential oil content, total antioxidant capacity (TAC) and total phenolic content (TPC) of these similar taste spices is scattered. Therefore, the present study compares the qualitative phytochemical contents, essential oil contents, total antioxidant capacity (TAC) and total phenolic content (TPC) of C. zeylanicum, E. cardamomum, S. aromaticum and Myristica fragrans Houtt. with leaf extracts of Pimenta dioica using previously published protocols. Results revealed that all tested phytochemicals namely alkaloids, flavanoids, saponins, steroid glycosides and tannins are present in all selected spice species compared. The highest essential oil content was reported from clove buds followed by nutmeg mace, nutmeg seed, cardamom, allspice and cinnamon respectively. Leaf extracts of P. dioica exhibited significantly higher total antioxidant capacity (344.9 ± 4.2 mg TE/g DW) and total phenolic content (134.3 ± 7.6 mg GAE/g DW) compared to selected spices except clove. Presence of all tested phytochemicals, comparable amounts of essential oils, greater amount of total antioxidant capacity and total phenolic content undoubtedly demonstrate high potential of Pimenta dioica (allspice) as a spice crop for large scale cultivation in Sri Lanka.
World Journal of Agricultural Research. 2016, 4(6), 158-161. DOI: 10.12691/wjar-4-6-1
Pub. Date: August 27, 2016
13919 Views4604 Downloads