Open Access Original Research Article

Effect of Nitrogen Rates and Flowering Dates on Fiber Quality of Cotton (Gossypium hirsutum L.)

Wenqing Zhao, Youhua Wang, Zhiguo Zhou, Yali Meng, Binglin Chen, Derrick M. Oosterhuis

Journal of Experimental Agriculture International, Page 133-159
DOI: 10.9734/AJEA/2012/954

 Nitrogen (N) supply during boll setting and maturation period of cotton can be critical in determining fiber quality. The study aims to investigate the relationship between N rates and formation of fiber length, strength, maturity and micronaire in bolls with different flowering dates. Field experiments were conducted using two cotton cultivars (Kemian 1 and NuCOTN 33B) and three N fertilization rates (0, 240, and 480 kg N ha-1) in Nanjing and Xuzhou in 2005 and in Anyang in 2007, China. The fiber length, strength, maturity, micronaire, and N concentration per unit area (NA) of the subtending leaf of cotton boll were analyzed. 
N fertilization rates, flowering dates, and N fertilization rates × flowering dates significantly (P ≤ 0.05) affected NA and the formation of fiber length, strength, maturity and micronaire. N fertilization rates affected fiber quality by influencing NA which was significantly related to rate and duration of the fiber quality formation process. The optimal NA for fiber quality formation was varied. For bolls flowering before August 25, when mean daily temperature during boll maturation period (MDTBMP) was higher than 21°C, NA in the 240 kg N ha-1 treatment was optimal for fiber length, fiber strength, maturity, and micronaire formation. For bolls flowering after September 10 when MDTBMP was lower than 21°C, NA in the 480 kg N ha-1 treatment was optimal for fiber quality development. Higher N application rate can sustain a higher NA level in its subtending leaf, leading to the less decrease magnitude of fiber length, strength, maturity, micronaire in late flowering dates. 240 kg N ha-1 is the recommended N application strategy for optimal quality, but we could diminish the negative influence of climate stress on fiber quality by supplemented N fertilizer in later flowering season.

Open Access Original Research Article

Growth and Body Conformation Responses of Genetically Divergent Australian Sheep to Spirulina (Arthrospira platensis) Supplementation

B. W. B. Holman, A. Kashani, A. E. O. Malau-Aduli

Journal of Experimental Agriculture International, Page 160-173
DOI: 10.9734/AJEA/2012/992

The hypothesis that supplementation with Spirulina will increase liveweight, growth and body conformation with significant interactions between sire breed and sex was tested using purebred Merino weaners and first-cross weaners from Merino dams sired by Dorset, Black Suffolk and White Suffolk rams under the same pasture-based management system. Our experimental objective was to evaluate the effects of varying levels of Spirulina supplementation, sire breed and gender on liveweight and body conformation traits. We utilized a complete randomized block experimental design balanced by 4 sire breeds, 3 supplementation levels and 2 sexes in which weaned prime lambs with an average liveweight of 37.6 ± 5.2 kg and body condition score of 3.1 ± 0.4 at 6 months of age were balanced by sire breed and gender and randomly allocated into 3 treatments (8 lambs per treatment) – the control group grazing without Spirulina (0%), low (10%wt/vol) and high (20%wt/vol) Spirulina. Lambs in the low and high Spirulina treatment groups were drenched daily with Spirulina prior to being released for grazing with the control group of lambs over a 6-week trial period, following a 3-week adjustment phase. Weekly measurements of chest girth, withers height, body length, body condition score and liveweight were taken. Mixed linear model procedures in SAS with sire breed, sex, Spirulina level and their second order interactions as fixed effects and sire as a random variable, were used for statistical analysis. Spirulina level significantly influenced lamb liveweight (P<0.018), body condition score (P<0.001) and body length (P<0.015). Lambs on Spirulina levels of 10% recorded the highest mean liveweight of 41.9 ± 0.7 kg. Spirulina levels of 20% did not significantly improve liveweight compared to the control group (0%). Highly significant sire breed interactions with Spirulina level (P<0.001) resulted in the heaviest (47.08 kg) and lightest (35.14 kg) average liveweights in Black Suffolk-sired crossbreds and purebred Merino lambs respectively, supplemented at the 20% Spirulina level. Body conformation (P<0.001) and liveweight (P<0.014) responses to Spirulina supplementation significantly varied between ewe and wether lambs. It was evident that a cost-effective supplementation strategy with Spirulina for optimal liveweight gains in weaner lambs was achieved at the 10% level. These findings will aid sheep farmers in making informed choices about appropriate sire breed and gender combinations in their enterprises when supplementing with Spirulina for growth improvement as a strategic pathway for the early attainment of market weights in prime lambs. We concluded that based on the empirical experimental evidence within the scope of this study, the tested hypothesis is acceptable.

Open Access Original Research Article

Evaluation of Heavy Metal Toxicity on Radish: Comparison between Soil and Floating Hydroponics Systems

M. Di Salvatore, A. M. Carafa, A. Mingo, G. Carratù

Journal of Experimental Agriculture International, Page 174-185
DOI: 10.9734/AJEA/2012/862

Two plant growing methods, namely use of soil and a floating hydroponic system, were compared in order to determine whether the response of radish to Cd, Cu, Ni and Zn was affected by the cultural system. Seed germination, plant biomass (root, shoot, hypocotyl), and heavy metal accumulation in different parts of the radish plants were monitored. The presence of heavy metals in the germination medium had no effect on seed germination, while the biomass of plants grown in hydroponics was negatively affected by the presence of metals in the nutrient solution. In both cultural systems, the amount of metals in roots, hypocotyls and shoots increased significantly with the increasing metal concentration in the growth media; the highest concentrations of heavy metals were found in the roots. The bioconcentration factor (BCF) and translocation factor (TF) values for the four metals were found to be considerably different between both growing systems. The different responses of plants suggest that in contaminated soils the plants are in the presence of lower quantities of available metals than those found in the corresponding substrates of the hydroponic system.

Open Access Original Research Article

Long Term Assessment of the Agronomic and Economic Benefits of Cocoa Food Crop Intercropping in the Absence of Fertilizer Application

K. Opoku-Ameyaw, F. K.Oppong ., K. Acheampong, F. M. Amoah

Journal of Experimental Agriculture International, Page 186-197
DOI: 10.9734/AJEA/2012/1015

Aim: To investigate the long term benefit of intercropping cocoa with some food crops with no fertilizer input.
Study Design: Randomized complete block design with four replicates.
Place and Duration of Study: Cocoa Research Institute of Ghana Substation at Bunso, between June 1998 and March 2011.
Methodology: Plantain, cassava and maize were planted alone or as mixtures to give the following intercrop combinations: sole crop cocoa, cocoa/plantain, cocoa/cassava, cocoa/maize, cocoa/cassava/plantain, cocoa/cassava/maize, cocoa/plantain/maize and cocoa/plantain/cassava/maize. The girth and height of cocoa seedling, the yield of the food crops and cocoa, some physic-chemical properties of the soil and the profitability of the various combinations were assessed using analysis of variance. Percentage canopy development of cocoa under the various treatments was analyzed after square root transformation of the data.
Results: Intercropping significantly (P<0.05) reduced the girth of cocoa seedlings in the cocoa/plantain combination only in the second year. The height of cocoa plant was not significantly influenced by the treatments. The cocoa/plantain/cassava/maize combination had the lowest but non-significant levels of N, P and K in the soil at the end of three years of food crop intercropping. Between 2001 and 2011, although the amount of harvested cocoa was not significantly affected by the treatments, cocoa beans from the intercrops was 28-60% more than the sole crop cocoa except in the case of the cocoa/cassava combination where there was a slight decrease in yield. Economic analysis of the treatments showed that intercropping was profitable. Higher net benefits were achieved where the combinations contained plantain and maize.
Conclusion: Intercropping cocoa with food crops is beneficial since it generally increased cocoa bean yield and income even in the absence of fertilizer application. It is suggested that intercropping should be carried out during establishment to ensure increased productivity of the land.

Open Access Original Research Article

Effects of Neem (Azadirachta indica A. Juss) Products on Aphis craccivora and its Predator Harmonia axyridis on Cowpea

P. K. Baidoo, D. Baidoe-Ansah, I. Agbonu

Journal of Experimental Agriculture International, Page 198-206
DOI: 10.9734/AJEA/2012/928

Aims: To assess the effectiveness of two neem formulations in the control of cowpea aphid, Aphis craccivora and how these affect its predator Harmonia axyridis.
Study Design: The experiment was conducted in a Randomized Complete Block Design in which cowpea was planted on raised beds.
Place and Duration of Study: The experiment was conducted on an experimental farm of the Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana during the minor rainy season of 2009.
Methodology: Two neem-based products were prepared from dried neem seeds: aqueous neem kernel extract (ANKE) and neem kernel powder (NKP). A standard chemical insecticide, lambda cyahalothrin was used as a reference insecticide and a control. There were four treatments and four replications. The neem formulations and chemical insecticide were sprayed onto cowpea plants to control A. craccivora. Data were collected on numbers of A. craccivoraH. axyridis and number of damaged leaves as well as the yield of cowpea.
Results: Significantly more A. craccivora were collected on the control plots than on the treated plots (P= 0.020). The numbers of A. craccivora on ANKE and NKP-treated plots did not differ significantly (P=0.320). Harmonia axyridis numbers on the various treatments did not differ significantly (P=0.301). Significantly more leaves were damaged on the control plots than the treated plots (P=0.012) but damaged leaves on the 2 neem-treated plots did not differ significantly. 
Conclusion: The two neem products were effective in reducing the population of A. craccivora. Thus application of neem products can be used as an alternative to chemical insecticide to control A. craccivora.

Open Access Original Research Article

Combining Natural Reaction Analogues and First Derivative Spectrophotometric Method to Enhance the Visible Spectra of a Non-Polar Crude Leaf Extract

Kwabena. J. Sarfo

Journal of Experimental Agriculture International, Page 207-218
DOI: 10.9734/AJEA/2012/990

Aim: This study was aimed at using natural reaction analogues and first derivative spectrophotometry to enhance the visible range of the non polar leaf extract.
Study Design: The leaf of Alchornea cordiflora was extracted so as to enrich the extract with chlorophyll holochromes and carotenoids. The ethanolic extract was designated as MX and used as the non polar leaf extract in the experiment.
Place and Duration of Study: Department of Biochemistry, University of Cape Coast, Ghana, between March 2011 and August 2011.
Methodology: A non-polar crude leaf extract was treated with naturally occurring reaction analogues of acidification, alkalinisation, oxidation and reduction. The spectra of the resulting solutions were analyzed by difference and first derivative spectrophotometric methods. 
Results: The treatment led to the enhancement of the chromophoric content and the general quality of the individual spectrum. The wavelength regions: 420-500, 440-500, 460-500, 500-600 nm of spectral improvement were selective to their respective analogue test substance and conditions used in a reaction
Conclusion: The 500-600 nm range was better than the Soret and the red regions to monitor the copper complexation with acidic non-polar leaf extracts of Alchornea cordiflora. Alkalinization, oxidation and reduction conditions also resolved the multiple peaks of the Soret region into distinct peaks that can be useful for monitoring and quantification of bioinorganic preparations from the leaf extract of Alchornea cordiflora.

Open Access Original Research Article

Effect of Plant Leaf Positions on Some Micronutrients, Anti-nutrients and Toxic Substances in Telfairia occidentalis at the Vegetative Phase

Amanabo Musa, Emmanuel O. Ogbadoyi

Journal of Experimental Agriculture International, Page 219-232
DOI: 10.9734/AJEA/2012/963

Pot experiment was conducted to determine the effect of leaf positions on the concentrations of some phytotoxins (cyanide, nitrate, soluble and total oxalates), micronutrients namely; vitamin C, β-carotene (provitamin A) and mineral elements (Fe, Mg, Cu, Zn, Ca Na and K) at vegetative phase of Telfairia occidentalis grown in nitrogen and non – nitrogen treated soil. The leaves of Telfairia occidentalis were harvested and analysed at three different leaf locations, namely; basal, middle and upper positions. The result obtained showed that no significant differences was observed in the cyanide concentration between basal and middle leaves and between middle and upper leaves, however, basal leaves had significant (p< 0.05) higher concentration of cyanide than upper leaves irrespective of soil nitrogen levels. The concentrations of nitrate and β-carotene in control and nitrogen fertilized Telfairia occidentalis were significantly (p<0.05) highest in upper, followed by middle and lowest in the basal leaf position. The soluble and total oxalates content in Telfairia occidentalis were significantly (p<0.05) higher in the basal and middle leaves than the upper leaves irrespective of soil nitrogen levels. While the vitamin C concentration in the vegetable was significantly elevated in basal leaves than the leaves obtain from middle and upper leaf locations. Analysis of mineral elements showed that Fe, Mg, Zn and Ca were concentrated more in the basal and middle leaves than the upper leaves while the K concentration was signififcantly (p<0.05) higher in the middle and upper leaves than the basal leaves in control and nitrogen treated Telfairia occidentalis. The results conclude that concentrations of most of the plant toxins are higher in the older leaves than younger ones. Thus inclusion of the younger leaves of Telfairia occindentalis in our meal will reduce the negative health effect associated with high ingestion of the phytotoxins.

Open Access Original Research Article

Genetic Variability and Inter Relationship between Yield and Yield Components in Some Rice Genotypes

A. E. Idris, F. J. Justin, Y. M. I. Dagash, A. I. Abuali

Journal of Experimental Agriculture International, Page 233-239
DOI: 10.9734/AJEA/2012/961

The study was conducted at the Sudan University of Science and Technology; College of Agricultural Studies, Shambat farm during the season 2009/10 to study genetic variability and correlation between yields, yield components in some rice genotypes. The experiment was laid out in a randomized complete block design (RCBD) with three replications. Seven characters were measured including yield, yield components. Phenotypic () and genotypic () variances, phenotypic (PCV) % and genotypic (GCV) %, coefficients of variation were estimated. Phenotypic and genotypic correlation between characters was determined. The results showed that there were highly significant differences (p≤0.01) between the most of the characters under study except for percentage of unfilled grains per panicle (%). The highest values of phenotypic and genotypic variance were recorded by yield kgha-1 Also grain yield was attained the highest values of phenotypic and genotypic coefficients of variation. Positive phenotypic and genotypic correlation coefficient was detected between grain yield and number of filled grains per panicle, harvest index, panicle length and number of grains per panicle. The present study revealed that there was highly genetic variability among the tested genotypes, indicating that it could be used for further improvement in rice breeding.

Open Access Original Research Article

Weight-Length Relationship for Clupeonella cultriventris caspia (Svetovidov, 1941) in Iranian Waters of the Southwest Caspian Sea

G. Moradinasab, H. Raeisi, R. Ghorbani, S. Y. Paighambari, R. Davoodi

Journal of Experimental Agriculture International, Page 240-246
DOI: 10.9734/AJEA/2012/1064

The aim of this study was to record the weigh-length relationship (WLR) parameters for Clupeonella cultriventris caspia of Iranian coastal waters of Caspian Sea. Samples were taken during fishing surveys using conical lift nets during the summer and autumn of 2010. Total length (TL in cm) and body weight (BW in g) were measured. The lowest and highest b value was obtained for males, 2.372, and during summer time, 2.699. Linear regressions of length–weight relationships were significant for C. cultriventris caspia. The b value of the length-weight relationships showed negatively allometric growth both in males (b = 2.37) and females (b = 2.57).Similar growth pattern (negative allometric) was also observed in summer and autumn. The Analysis of co-variance (ANCOVA) revealed was significant difference in WLRs between sexes and seasons for C. cultriventris caspia in the Guilan coastal waters (Southwest Caspian Sea, Iran).

Open Access Original Research Article

Effect of Gamma Rays on Seed Germination, Seedling Height, Survival Percentage and Tiller Production in Some Rice Varieties Cultivated in Sierra Leone

S. S. Harding, S. D. Johnson, D. R. Taylor, C. A. Dixon, M. Y. Turay

Journal of Experimental Agriculture International, Page 247-255
DOI: 10.9734/AJEA/2012/820

Thirteen rice varieties cultivated in Sierra Leone were used to examine varietal differences in radiosensitivity to gamma radiation during the wet season of 2006 in the lowland ecology. Dry seeds of rice varieties were exposed to gamma radiation ranging from 50 to 800 Gy to determine their responses to radiation and the effective radiation dose for mutation breeding. Percentage germination, percentage survival (field condition), seedling height and tiller production were the traits measured on the M1 generation. The results indicated that increasing doses of gamma irradiation had no effect on germination for the first seven days under laboratory conditions. Percentage survival of germinated seedlings from the 8th to 14th day under laboratory conditions decreased significantly with increase in radiation dose up to 600 Gy. With increase in radiation above 300 Gy a reduction in seedling height and percentage survival under field conditions was observed in irradiated plants of M1 generation. Increase in gamma ray doses from 50 to 300 Gy had little or no effect on tiller production as there were no significant differences in tiller number of irradiated seeds and non-irradiated (control) for all the varieties evaluated. The LD50 values determined from regression analysis based on percentage field survival ranged from 345 Gy for ROK18 to 423 Gy for ROK22. These ranges of LD50 values determined for the different rice varieties could be useful in rice varietal improvement programmes in Sierra Leone.

Open Access Original Research Article

Loan Size and Its Determinants as Critical Growth Factors for Rural Farmers in Imo State, Southeast Nigeria

S. U. O. Onyeagocha

Journal of Experimental Agriculture International, Page 256-268
DOI: 10.9734/AJEA/2012/975

This study analyzed the loan demand requirements of rural staple and poultry farmers in Owerri Agricultural Zone of Imo State, Nigeria. Also, the factors affecting loan size were analyzed. In carrying out this cross-sectional study, data were collected with stratified sampling technique, using structured and pre-tested questionnaires from 100 loan beneficiaries and five financial institutions in the zone. The study lasted for a period of six months, effective April, 2010. Expect value method was used to determine their optimum loan requirement while OLS multiple regression analysis technique was employed in determining factors affecting loan size of beneficiaries. Results showed that the potent factors affecting loan size were farm size, level of education, enterprise type, farmers experience and dependency ratio. The result further indicated that the respondents were highly limited by capital as the financial institutions met only 60% of their capital needs. The optimum loan requirement determined for the farmers were N292, 315, and N435, 753 for Cassava and Yam farmers respectively, for farm size of 0.80 hectare. For poultry farmers of about 120 birds, the optimum loan requirement estimated was N492, 500. These figures would serve as reference points for financial institutions in loan administration of farmers of similar status and area. The financial institutions were admonished to consider providing start-up capital for the youths and fresh graduates, who apparently are yet to make in-road into farming as a business. On the other hand, government was urged to provide fiscal and monetary incentives to financial institutions supporting agriculture in view of the delicate nature of farm business.