Most Brazilian soils have deficiencies of B and Zn, and demand the supply of these nutrients so that production is not hampered. The present study aimed to test the application methodology and doses of B and Zn in perennial soybean seeds. The physical, physiological and nutritional characteristics of the covered seeds and the initial growth of the plants were evaluated in laboratory and greenhouse. Two methodologies were used for the application of micronutrients. In Method 1, the B and Zn doses were added once in the 6th coating layer, followed by a jet of glue, after the first portion of lime + glue. In Method 2, the doses of micronutrient were divided into four equal and individual portions, to be applied to the 3rd, 6th, 9th and 12thlayers followed by a jet of glue. This was added after the first portion of lime + glue. For both the methods, 7 treatments were defined: TR1 - Seeds without coat; TR2 - Coated seeds without micronutrients; TR3 – 50 g of H3BO3 kg-¹ of seeds + 50 g of ZnSO4 kg-¹ of seeds; TR4 – 100 g of H3BO3 kg-¹ of seeds + 50 g of ZnSO4 kg-¹ of seeds; TR5 – 150 g of H3BO3 kg-¹ of seeds + 50 g of ZnSO4 kg-¹ of seeds; TR6 – 150 g of H3BO3 kg-¹ of seeds + 100 g of ZnSO4 kg-¹ of seeds; TR7 – 200 g of H3BO3 kg-¹ of seeds + 100 g of ZnSO4 kg-¹ of seeds. For laboratory tests, a completely randomised design was performed, and randomised blocks were used in greenhouse tests. Methods 1 and 2 increased the B + Zn contents in the seeds by approximately 97 times and 22 times respectively. The micronutrient application methodology in the 6th coat layer promoted greater increases in seed mass and higher levels of B and Zn. Consequently, the plants originated from these seeds had their vigour reduced. Both methods did not significantly influence the initial plant growth.
Albert Einstein Mathias de Medeiros Teod, Graciele da Silva Campelo Borges, George Gérson Araújo da Silva, Cristhian Alfredo Diaz Jopia, Marília Hortência Batista Silva Rodrigue, Ana Paula Nunes Ferreira, Kalinne Passos dos Santos, Jaína Geovana Figueiredo Lima Santos, Arthur Xavier Mesquita de Queiroga
The objective of this study was to evaluate the post-harvest shelf-life of 'Golden' papaya fruits submitted to biodegradable coatings based on potato starch, associated or not with lemon grass essential oil under different storage conditions. The experiment was conducted in a completely randomized design with two factorial schemes, where the first one was 3x6, corresponding to three coating techniques: control (T1: no coating), 2% potato starch (T2), potato starch at 2 (T3) and six evaluation periods (0, 4, 8, 12, 16 and 20 days), stored under refrigeration (10 ± 2°C for 12 days and then transferred to the condition 25 ± 2°C for an additional 8 days). In the second experiment, the 3x4 factorial scheme, represented by three coating techniques: (T1), (T2) and (T3) and four evaluation periods (0, 4, 8 and 12 days) stored in ambient condition 25 ± 2°C), with three replicates of two fruits per plot. The potato starch (T3) coating associated with lemon grass essential oil and refrigeration, controlled ripening and further enhanced its efficiency in the control of anthracnose.
Aims: The research aimed to evaluate the in vitro antifungal effect of the essential oil of peppermint (Mentha x piperita L.) in the control of Alternaria alternata.
Study Design: The experiment was conducted in a completely randomised experimental design with five treatments in four replicates each.
Place and Duration: The work was conducted at the Center of Science and Technology Agri-food of the Federal University of Campina Grande, Pombal-PB, Brazil, between February and March of 2018.
Methodology: The essential oil was added to the PDA culture medium (Potato-Dextrose-Agar) autoclaved and subsequently poured into Petri plates. The treatments comprised five concentrations of the oil (0.0, 0.4, 0.6, 0.8, and 1.0%). After the inoculation with fungi, the plates were incubated for 14 days in a B.O.D incubator at 27±2°C. With the data of mycelial diameters, the percentage of mycelial growth inhibition (PGI) and index of mycelial growth speed (IMGS) were calculated.
Results: All concentrations of peppermint oil reduced the mycelial growth of A. alternata. The minimum and maximum inhibitions occurred in the concentrations of 0.4 and 0.8%, which reached -13.27 and 72.45%, respectively. Although the maximum inhibition was 72.45%, the average percentages were 41.67 and 37.18% at the highest concentrations, showing an intermediate power of inhibition. A dose-dependent behaviour, was observed which suggests that further increases in concentration may enhance the inhibition effect of the oil.
Conclusion: The peppermint oil can be used as a viable and sustainable antifungal product in the control of this pathogen. Due to the possible dose-dependent effect, the development of studies is recommended with concentrations around 2.25% to test if the oil reaches the total inhibition. The in vivo experiments are required to verify the oil feasibility on the control of A. alternata on plants and fruits.
The bean plant has a very high demand for nutrients, and as it has a short cycle, requires that the nutrients be readily available when needed, so as not to limit productivity. The use of organic fertiliser in beans is efficient, since due to the short cycle, the crop displays a satisfactory response to this type of fertilisation. The aim of this study was to evaluate the effects of organic fertiliser on the biometric parameters of the cowpea that reflect the productivity of bean plants. The experiment was carried out in the vegetable garden of the Federal University of Ceará, Pici Campus, and consisted of five treatments: control, mineral fertiliser, and organic fertiliser at doses of 100, 200 and 300% of the nitrogen recommendation for mineral fertilisation. At the time of harvest, 10 plants were collected from the working area of each plot to evaluate the number of pods per plant, grains per pod, 100-grain weight and mean pod length. The variables evaluated in the field experiment were submitted to statistical analysis using the SISVAR 5.3 software (System for the variance analysis of balanced data). The mean pod length, number of pods per plant, and 100-grain weight responded to the organic fertiliser relative to the mineral. Organic fertilisation is essential to achieve production components that indicate good crop yield. The absence of any nutrient can cause metabolic and nutritional disorders that prevent this aim from being reached. Organic fertiliser is associated with an improvement in the commercial quality of the beans.
Aims: This study aimed at testing the possibility of differentiating the geographical origin of I. violacea wild specimens by its carbon, nitrogen and oxygen stable isotopic compositions.
Study Design: Completely randomized design with 3 replications.
Place and Duration of Study: Sample: the laboratorial analyzes were carried out at the Institute of Biosciences in Botucatu, Brazil between January 2016 and December 2016.
Methodology: We collected the shoots of ten I. violacea wild specimens at each of the two selected regions in Brazil (Botucatu – SP and Três Lagoas – MS). Samples were dried in a forced-ventilation oven at 60ºC for 48 hours, and they were placed individually in plastic capped recipients containing lead spheres for the milling process. After that, the samples were weighed within individual capsules in a high precision balance and stored until analysis. For carbon and nitrogen analyses, tin capsules were used, and the average weight was 60 μg and 1100 μg, respectively. For oxygen analysis, the amount weighted was 170 μg within silver capsules. Isotopic analyses were performed by isotopic ratio mass spectrometry (IRMS) in triplicate. The isotope values were expressed in the standard delta notation (δ[‰]) with analytical errors of 0.2‰, 0.3‰ and 1.0‰ for carbon, nitrogen and oxygen, respectively. Results are presented as mean ± standard deviation. Principal component analysis was performed to define which isotope presents the greater variability.
Results: Results allowed to clearly differentiate I. violacea specimens collected from different regions. They provide the possibility of discriminating the geographical origin of I. violacea specimens by multiple element stable isotope analysis. Results also certified that multiple element isotope analysis can contribute to the building of a database containing the isotopic signature of I. violacea specimens with known origin.
Conclusion: The isotopic composition varied between plants of different regions. Thus, the technique is effective in I. violacea’s geographical origin discrimination.