Open Access Short Research Article

Metamitron and Different Plant Growth Regulators Combinations in the Chemical Thinning of ‘Eva’ Apple Trees

Carolina Goulart, Suélen Braga de Andrade, Angelica Bender, Andressa Vighi Schiavon, Gabriel Almeida Aguiar, Marcelo Barbosa Malgarim

Journal of Experimental Agriculture International, Page 1-6
DOI: 10.9734/JEAI/2017/36809

Aims: The objective of this study was to evaluate the effect of the application of Metamitron and the combinations of NAA + BA and Promalin + BA on the fruit thinning of the Eva cultivar apple tree in southern Brazil.

Study Design: The experimental design used was a randomized complete block design, with four replications, with two plants per treatment in each block, following a one-step scheme with 10 treatments for the thinning factor.

Place and Duration of Study: The experiment was carried out in the agricultural year of 2013/2014 in a commercial orchard located in the municipality of Morro Redondo, RS, Brazil (Lat. 31º 40’ 60” S and Long. 52º 34” 50” W).

Methodology: Spraying of Metamitron was carried out at doses of 300, 350 and 400 mg L-1 and combinations of 5 mg L-1 of NAA + BA at doses 50, 75 and 100 mg L-1 and 0.5 ml L-1 of Promalin® + BA at doses of 50, 75 and 100 mg L-1. Only the doses of Promalin® were applied in full bloom, the other sprayings were carried out in fruiting with 5-8 mm in diameter. The variables analyzed were: number of fruits per trunk section area, number of fruits per plant, yield per plant, mean fruit mass, pulp firmness, fruit shape and diameter, fruit length, length/diameter ratio and soluble solids.

Results: A reduction in harvest load by Metamitron was only observed with the 300 mg L-1 dose. The combination of NAA 5 mg L-1 + BA 75 mg L-1 showed the highest fruit reduction, with a low fruit density per cm-2 and the highest average fruit mass. For the combinations of Promalin® + BA, as the increment of the dose of BA increased, there was a reduction of the number of fruits and consequently an increase in their size.

Conclusion: It was concluded that the Metamitron at the dose of 300 mg L-1 was able to cause thinning when applied in the fruit formation phase (5-8 mm). And the combinations of NAA 5 mg L-1 + BA 75 mg L-1and Promalin® 0.5 ml L-1 + BA 100 mg L-1 were able to reduce harvest load and increase the fruit size.

Open Access Short Research Article

Influence of Different Population Densities in the Production Performance of Azuki Bean Lines

J. dos S. Teixeira, J. da Silva, M. T. da Silva, F. S. de Oliveira, A. P. V. de Carvalho, L. A. R. de Lima, J. G. da Costa

Journal of Experimental Agriculture International, Page 1-6
DOI: 10.9734/JEAI/2017/36985

The demand for azuki beans has increased because of its indication to combat diabetes, composition with high levels of phytochemicals, bioactive and phenolic compounds. However, Brazil still cannot supply its demand for azuki beans. Being more studies on management are needed, to maximize the productivity of this culture. The objective of this study was to evaluate the influence of different population densities in the production performance of azuki beans lines. The experimental design utilized was randomized blocks arranged in 2 x 3 factorial scheme with four replications. The six evaluated treatments were constituted by the combination between two Azuki bean lines, the L1 line (obtained commercially) and line L2 (obtained from a farmer) and three population densities, 500,000 plants.ha-1 (with spacing of 0.3 m x 0.2 m), 375,000 plants.ha-1 (with spacing of 0.4 m x 0.2 m) and 300,000 plants.ha-1 (with spacing of 0.5 m x 0.2 m) (control treatment). The population density of 500,000 plants.ha-1 provided a higher grain yield when compared to the other population densities, reaching grain yield of 2,223 kg.ha-1. However, we observed the trend that population densities above 500,000 plants.ha-1 could have even greater yields.

Open Access Original Research Article

Growth Performance and Nitrogen Value of Broiler Finisher Birds (29-57 days) in Low-Protein Diets Supplemented with the Most Limiting Essential Amino Acids

S. O. Olawumi, P. A. Aye, J. T. Ogunlade, O. F. Alamuoye, F. T. Ojo

Journal of Experimental Agriculture International, Page 1-9
DOI: 10.9734/JEAI/2017/36365

This study evaluated the growth performance and nitrogen utilization of broiler birds of Arbor Acre heavy strain (29-57 days) in which ideal protein concept was tested using the most limiting essential amino acids (EAAs), L-Lysine, DL-Methionine, L-Tryptophan and L-Threonine. Six dietary treatments in which crude protein varied from 20.0% to 8.0% were used to feed broiler birds at the finishing phase (29-57 days) of production. Growth parameters and nitrogen retention were investigated and data obtained were analysed statistically using Minitab (Ver. 16). The results obtained indicated the broilers raised on the 17.0% crude protein diet had the highest significant (P<0.05) average feed intake (FI) of 108.13± 0.74 g/bird/day but had feed conversion ratio (FCR) of 2.82± 0.01 similar to diet in which CP was conventionally fixed at 20.0% with minimum EAAs supplementation. The best protein efficiency ratio (PER) of 3.80±0.03 obtained for broilers on the least CP level of 8.0%. The average nitrogen retention (NR) values were similar (P>0.05) and higher than other values at 3.06±0.01 g N and 3.01±0.01 g N for birds on the control diet and birds on 20.0% CP with minimum EAAs supplementation, respectively. The average apparent nitrogen digestibility (AND) value of 76.37±0.18% was the highest and significant (P<0.05) for birds on 20.0% CP with EAAs supplementation. Growth parameters for birds on conventional control diet had the best FCR. However, birds reared on 17.0% CP diet with EAAs supplementation had similar growth parameters with birds reared on another 20.0% CP diet with EAAs supplementation. Crude protein can therefore be reduced by 3 percentage points without any detrimental effects on the growth performance indices of broiler finisher birds (29-57 days). However, the poor nitrogen retention (NR) and apparent nitrogen digestibility (AND) for birds on the low protein diets is noteworthy.

Open Access Original Research Article

Influence of Harvesting Stage on Seed Quality Aspects of Pumpkin (Cucurbita pepo L.)

W. J. Tarus, J. O. Ochuodho, N. K. Rop

Journal of Experimental Agriculture International, Page 1-9
DOI: 10.9734/JEAI/2017/36296

Statement of the Problem: The availability of certified seeds to rural farmers is very important for sustainable agriculture in developing countries. Farmers usually harvest the fruits of pumpkin for food then use the extracted seed at the time of planting. Yet the fruit at harvest may not coincide with the seed quality. This causes the mixture of mature and immature seeds at harvest hence causing poor seed quality.

Aim: This study was done to examine the influence of harvesting stage-Days After Anthesis-(DAA) and different sites of the North-rift of Kenya, on seed quality aspects of pumpkin.

Methodology: Two types of pumpkin seeds, from round fruit and oval fruit, were planted in the rainfall season of 2015. Four harvesting stages (30 DAA, 40 DAA, 50 DAA and 60 DAA) were done on the two pumpkin types at three sites (AIC Cheptebo, Kaiboi Technical Training Institute-KTTI and University of Eldoret-UOE). The seeds were then extracted and seed testing was done on germination and seed vigor.

Results: The seeds from fruits harvested at 60 DAA showed higher seed weight, germination and vigor compared to those from fruits harvested at an earlier stage of 30 DAA. Seed weight, germination and vigor for the two pumpkin types were not significantly different at P≤0.05. In spite of the different harvesting stages and pumpkin types, the best seed qualities were observed for seeds harvested from AIC Cheptebo compared to seeds from KTTI and UOE.

Conclusion: This showed that seed physiological maturity occurs at 60 DAA and that higher temperature (30⁰C) which was at AIC Cheptebo favored better physiological maturity evaluation in the pumpkin. Therefore, pumpkin is a warm-season crop.

Open Access Original Research Article

Pesticidal Activity of Plant Extracts and a Mycoinsecticide (Metarhrizium anisopliae) on Cowpea flower Thrips and Leaves Damages in the Field

Raoul Borkeum Barry, Albert Ngakou, Elias Nchiwan Nukenine

Journal of Experimental Agriculture International, Page 1-15
DOI: 10.9734/JEAI/2017/37002

The potentials of Azadirachta indica, Boswellia dalzielii aqueous extract and Metarhizium anisopliae, alone and/or in combination, as well as a reference insecticide Decis in controlling the cowpea flower thrips (Megolurothips sjostedti) were compared on two Vigna unguiculata varieties in the field. The field trials were arranged in a completely randomized block design with nine treatments, each of which was replicated four times. The nine treatments included a control, and the eight tested insecticide products. Vigna unguiculata plants were sprayed at flowering thrice with insecticide products at 5 days interval. Data assessment consisted of counting adults and thrips larvae population after three sprays, following up their dynamics, then estimating damages caused on leaves. All the tested insecticides significantly (p < 0.0001) reduced the populations and stabilized the dynamics of both adults and larvae thrips on the studied cowpea varieties. These bio-insecticides also contributed to the substantial reduction (p = 0.0002) of damages on cowpea leaves caused by thrips compared to the control treatment. The combination M. anisopliae + A. indica B. dalzielii was the best of all treatments with nearly 90% reduction of these pests. The cowpea variety B125 was more sensitive to the pest control than the local Bafia variety. As the outcome of the study, Azadirachta indicaBoswellia dalzieliiM. anisopliae and their combinations could be considered as potential natural insecticide in the management of thrips population on V. Unguiculata in the fields. This would increase V. unguiculata yield and free environmental pollution from synthetic insecticides.