Resumo em Inglês:

ABSTRACT Agriculture has caused numerous concerns regarding the preservation of natural resources. In this context, agroforestry systems are emerging as a more sustainable alternative. The present study aimed to evaluate growth characteristics, radiation use efficiency, biomass partition, and yield of soybean grown in two agroforestry systems and full sun. A field experiment was conducted in Southern Brazil during the 2014/2015 crop year, in which transmissivity of solar radiation, leaf area index, radiation use efficiency, and yield of soybean were evaluated. The solar radiation dynamics varied among the study factors, mainly due to the agroforestry arrangements. Shading influenced the leaf area index, radiation use efficiency, biomass partition, and soybean yield. Based on the soybean yield values generated in this study, the use of more spaced agroforestry arrangements and Peltophorum dubium forest species is recommended. However, because the yield values were below the expected levels, it is not yet possible to confirm the full potential of soybean crop in agroforestry systems. Thus, new studies should be conducted in order to generate alternatives that make soybean cultivation feasible in agroforestry systems, such as assessing the use of more spaced agroforestry arrangements, the insertion of the soybean crop in the initial years of cultivation of agroforestry, as well as reduce intraspecific competition by decreasing the plant population of the crop.

Resumo em Inglês:

ABSTRACT Cerrado biome is responsible for part of Brazilian food production. However, due to inadequate soil management practices, large areas of crop and forage are degraded, leading to environmental and economic losses. A crop-livestock-forest system (CLFS) is a sustainable production strategy that integrates different cultivations. This objective of this study was to evaluate agronomic characteristics and maize (Zea mayz L.) yield when consorciated with Panicum maximum cv. Tamani, cultivated between rows of eucalypts clones. The statistical design used was randomized blocks, constituted by the following treatments: Maize + AEC 043; Maize + AEC 007; Maize + AEC 2111; and Maize + AEC 2034. The analyzed variables included: spikes length, number of rows, number of grains per row, number of grains per spike, and grain yield. Based on the obtained data, it is possible to conclude that trees did not affect maize yield in a CLFS. Considering that only 66% of the area was used for agriculture, maize yield was higher than when it is planted in total area.

Resumo em Inglês:

ABSTRACT Extraction of olive oil gives rise to large quantities of pomace and liquid effluents, since on average only 21% of the weight of the olive corresponds to oil, the remaining 79% consists of water, bark, pulp and stone. With the intention to make available new forms of use of this residue, this research was proposed, with aimed to optimize the extraction of phenolic compounds from olive pomace resulting from oil extraction using methanolic extracts. The analysis of phenolic compounds (TPC) and the evaluation of the antioxidant activity (AA) were performed by spectrophotometry, and the individual phenols were carried out by LC-ESI-qTOF-MS. The data were evaluated by the application of the response surface methodology (RSM). The condition that promoted the highest TPC in an extract was using 40% methanol, 70 °C and 180 minutes (extract 7). The highest AA was in the extract obtained with 40% methanol, 45 °C and 180 minutes (extract 5). The highest individual phenol sum (IPS) was in the extract with 80% methanol, 45 ºC and 180 minutes (extract 6). Therefore, it is possible to conclude that the RSM was an interesting tool to measure the best conditions for extraction of phenolic compounds from olive pomace.

Resumo em Inglês:

ABSTRACT Anthurium solitarium Schott is a species that might be used both as potted plant and cut foliage, but it is indispensable to have an adequate substrate to achieve desirable growth and commercial standard. Thus, the present research aimed at evaluating the ornamental potential and commercial quality of Anthurium solitarium grown in bamboo compost. The experimental design was in randomized blocks, with six substrates and three replicates with five plants in each experimental plot. Seedlings were grown for 270 days in substrates containing different percentages (v:v) of bamboo compost (BC) and coconut fiber (CF): T1 (100% CF), T2 (75% CF + 25% BC), T3 (50% CF + 50% BC), T4 (25% CF + 75% BC), T5 (100% BC); and a control treatment, T6 - commercial substrate Basaplant® (100% CS). The number of leaves, the leaf area, leaf (LDW) and root dry weight (RDW), root length and volume, LDW/RDW ratio and total dry weight. Leaf nutrient contents were determined. The ornamental potential, commercial acceptance and quality of the plants were also evaluated. Plants grown in substrates with BC showed higher growth, ornamental potential, market quality and acceptance than those grown in CF and CS.

Resumo em Inglês:

ABSTRACT In this study, 55 tomato genotypes from different geographical regions were evaluated with ISSR markers (Inter Simple Sequence Repeats). The seven ISSR primers originated 63 amplified bands, of which 90.48% were polymorphic. The cluster analysis based on the Nei-Li similarity coefficient using the average genetic clustering method (UPGMA) revealed the conformation of five clusters at a level of similarity of 72%. The ISSR technique did not discriminate tomato genotypes according to the species or region of provenance. The STRUCTURE analysis and the dendrogram did not reveal a genetic structure in the population evaluated. The genotypes of the species of S. pimpinellifolium, S. l. cerasiforme, S. lycopersicum and S. peruvianum were found consistently grouped, showing a close genetic relationship among them. A high genetic variation among the individuals within each of the groups formed was suggested by the AMOVA. The ISSR markers were effective in assessing the genetic diversity and structure of populations of tomato genotypes. The high genetic variability found in this study indicates the valuable genetic potential present in tomato germplasm, especially of wild species, which could be used for future breeding programs of the species.

Resumo em Inglês:

ABSTRACT Analyzes of plant growth throughout the crop vegetative cycle are important to know the dynamics of the plant development. Thus the objective of this work was to study the development of potato genotypes throughout the crop cycle, in three environments. Experiments were conducted in Canoinhas-SC, Pelotas-RS, and Brasília-DF, Brazil, in the 2018 crop season. A randomized complete block experimental design with three replicates was used. Traits related to different plant parts of clones F183-08-01 and F50-08-01 and the cv. Asterix were evaluated as a function of time and, at the end of the cycle, for tuber yield. The two clones were found to have high tuber yields, but later development than 'Asterix'; consequently, its management must be adapted to this trait. Leaf mass, leaf number, leaf area index and root mass plus stems were correlated with each other, and leaf area index, leaf number and leaf mass can be quantified through only one of these traits, due to the high correlation between them. There were also positive and significant correlations between the height of the tallest stem and the root plus stem mass and the tuber mass, indicating that more vigorous plants have higher tuber yield.

Resumo em Inglês:

ABSTRACT In plant breeding programs, the selection of potential progenies in early generations of inbreeding is an essential step. Considering that, the adoption of topcrosses helps the breeder in the selection, this study aimed to verify the potential of S2 strains for synthesis of synthetic varieties and to obtain experimental information on yield and agronomic potential of topcross hybrids. As such, 75 topcross hybrids were generated from crossing 75 S2 lines with F2 generation of the commercial hybrid. The 75 hybrids were grown in a field, along with two commercial hybrids in a randomized complete block design with 4 replicates and in 4-meter plots. Flowering, plant height, height, diameter, length and weight in the ear, and grain yield traits were examined. Analysis of variance was performed, the combining ability was estimated, and, from the means, the Scott & Knott test was conducted. So, the topcross hybrids that distinguished themselves for grain yield were those composed by lines 67, 14, 44, and 69, presenting high CGA, therefore indicating good potential for producing synthetic or base population. For the other traits of agronomic interest that were assessed in maize, a potential for selection with different focuses was found: reduction of cycle and height and increase in length and diameter of the ear.

Resumo em Inglês:

ABSTRACT Weed management consists of a fundamental practice in cassava, with mechanical and chemical control widely used. The objective of this work was to evaluate the efficacy of pre-emergence herbicides, as well as to determine the interaction of these with weeding complementation in the weed management in cassava. Two experiments were conducted in Junqueiro (Alagoas). In 2015/16, the experimental design was based on randomized blocks, with treatments distributed in a split-split-plot scheme, with four replications. In the main plot, four pre-emergence associations of clomazone + flumioxazin in different doses were evaluated, in addition to a control without herbicide. In the subplots, the Caravela and Pretinha cassava cultivars were evaluated, while in the sub-subplots the control complementation was evaluated using or not the manual weeding. In the 2016/17, the plot design and layout remained the same as for 2015/16, except for the composition of the herbicide treatments, since the standardization of clomazone dose has been chosen, varying only the doses of flumioxazin. The association of clomazone and flumioxazin has shown efficacy in weed control, with a greater residual as higher doses are used. This association provided higher shoot and root yield. Weeding complementation along the cassava cycle can increase its yield.

Resumo em Inglês:

ABSTRACT This study evaluated the relationship between the resistance of Lipaphis pseudobrassicae to the parasitoid Diaeretialla rapae and the effects of the insecticide acetamiprid on the aphid. Four groups of L. pseudobrassicae collected in Uberlândia, MG, were used. The first two were formed by individuals of the same clone (C1), which were resistant (C1R) or susceptible (C1S) to the parasitoid. The third group was formed by resistant individuals to the parasitoid descended from a clone collected in canola (C2R) and the fourth group, from a population collected in a commercial plantation of collard greens (P1). Determination of LD50 was done with three replications of 10 aphids, subjected to dose-response assays, with the application of five concentrations of the insecticide acetamiprid (0.01, 0.1, 1, 10 or 100 ng a.i./aphid) and a control treatment consisting of acetone alone. There was no significant difference in the LD50 of individuals of the same clone, C1R and C1S (0.06 ng a.i./aphid for both clones). C2R had the highest LD50 (0.14 ng a.i./aphid), while P1 had the lowest (0.01 ng a.i./aphid). These results suggest that resistance against the parasitoid is not, therefore, associated with the effects of insecticide on L. pseudobrassicae.

Resumo em Inglês:

ABSTRACT The use of strategies such as sequential applications and mixtures may increase the control spectrum and the residual effect of chemical control of weed in the cassava crop. Thus, the objective was to evaluate the selectivity and efficacy of sequential applications and tank mixture of herbicides in the control of weed in the cassava crop cultivar ‘Baianinha’. The experimental design was of randomized blocks, with eleven treatments and four replicates. The treatments consisted in: harrowed control, control without harrow, clomazone, mesotrione, S-metolachlor, clomazone+S-metolachlor, mesotrione+S-metolachlor, clomazone+mesotrione, sulfentrazone/clomazone, clomazone/[mesotrione+S-metolachlor], S-metolachlor/[mesotrione+clomazone]. The doses used for clomazone, mesotrione, sulfentrazone and S-metolachlor in the single applications, in sequence and in tank mixture were of 1,25, 0,24; 0,6 anf 1,92 kg ha-1, respectively. The first application of the sequential treatments occurred 50 days after planting (DAP) and the second at 92 DAP. The applications of mesotrione, mesotrione+clomazone and mesotrione+S-metolachlor, were carried late, at 92 DAP. Based on the data obtained, it is concluded that the mixture mesotrione+S-metolachlor and the sequential application of clomazone/[mesotrione+S-metolachlor] were selective to cassava ‘Baianinha’ and efficient in the weed control (over 80% up to 148 days after planting).