ABSTRACT The germination process of the Annona sylvatica A.St.-Hil becomes difficult because the seeds have physical and physiological numbness. Although, the objective was to evaluate the effect the gibberellic acid can have in overcoming this physiological process. So that, aimed to evaluate the effect of the gibberellic acid in the overcoming dormancy of araticum seeds. Two different projects were developed simultaneously (plants germination in the laboratory and emergence of seedlings in seed). At the laboratory, the experimental design used was completely casualized in factorial scheme 4 x 4. Evaluating the physiological aspect of the germination and vigor. The germination of the seeds presented superior performance when they were immersed in 1200 mg.L-1 of GA3, in 24 h of imbibition, reaching 67% of germination. In the emergence of seedlings in seed, the experimental design used was to randomize blocks in factorial scheme 4 x 5 (four accesses x five periods of immersion). After 110 days, evaluating physiological aspects of emergence and vigor. The emergence varied between 32 to 45% (accesses A1 and A3) in a period of 15 to 24 h (accesses A1 and A3 or A4). High concentration and longer period of soaking in gibberellic acid promote a bigger germination of the araticum seeds. There is a difference between the accesses of the species, necessary to evaluate before being collected, and in the present study the accesses A3 is promising for harvest.

ABSTRACT The sesame crop has great economic potential due to the various possibilities of exploitation, however, there is a lack of information about the chemical control of weeds in the crop, mainly about the application of herbicides in pre-emergence. Therefore, the objective of this study was to evaluate the economic viability and efficacy of herbicides applied in pre-emergence for the control of weeds in the sesame crop. The experimental design was in randomized blocks, with four replications. The treatments consisted of seven herbicides (diuron, flumioxazin, oxadiazon, oxyfluorfen, metribuzin, linuron, and S-metolachlor) and a mixture (metribuzin + oxyfluorfen) applied in pre-emergence. The two control treatments were weeded and nonweeded plots. The variables evaluated were percentage of control of the weed community, grain yield, gross and net income, rate of return, and profitability index. The highest productivity value was for weeding, followed by the herbicides diuron and flumioxazin, with 2,000.44 kg ha-1, 1,957.35 kg ha-1;, and 1,933.13 kg ha-1, respectively. The herbicides diuron and flumioxazin obtained the highest net income, in the amounts of R$ 7,831.26 and R$ 7,762.85, respectively. The diuron and flumioxazin applied in pre-emergence showed more than 80% in the control of weeds in the sesame crop, showing efficiency in the control. The use of herbicides applied in pre-emergence to control weeds, mainly diuron and flumioxazin, is as efficient as mechanical control, demonstrating the potential for use and economic viability in relation to mechanical control, which presents a high cost/benefit ratio.

ABSTRACT The work evaluated the potential for discrimination of land use and occupation around reservoirs, using spectral information obtained by multispectral, hyperspectral satellites and images obtained with an ARP (remotely piloted aircraft). The research analyzed the performance of different images classification techniques applied to multispectral and hyperspectral sensors for the detection and differentiation of soil classes around the Paus Brancos and Marengo reservoirs, located in Settlement 25 of Maio. The classes identified based on surveys in campaigns carried out in 2014 and 2015 around the reservoirs were: water, macrophytes, exposed soil, native vegetation, agriculture, thin and ebbing vegetation, in addition to the cloud and cloud shadow targets. The performance of the classifiers applied to the image of the Hyperion sensor was, in general, superior to those obtained in Landsat 8 image, which can be explained by the high spectral resolution of the first, which facilitates the differentiation of targets with similar spectral response. For validation of the supervised classification method of Maximum Likelihood, Landsat 8 (08/24/2015) and Hyperion (08/28/2015) images were used. The results of the application indicated a good performance of the classifier associated with the RGB composition of the chosen Hyperion image (bands R - 51, G - 161, B - 19) in the detection of the classes around this reservoir, producing a Kappa coefficient of 0.83. The availability of data from the Hyperion sensor is very restricted, which hinders the development of continued research, thus the use of images surpassed by RPA is extremely viable.

ABSTRACT The aim of this study was to evaluate mango hybrids obtained by open pollination based on the physical and chemical traits of the fruit, and to analyze the genetic diversity among these hybrids to find plants that produce quality fruit both for direct consumption and for industrial processing. The hybrids under study were generated from seeds produced from crosses with unknown genotypes as a result of open pollination. The unknown genotypes were randomly scattered in areas dedicated to growing a Tommy Atkins variety, and plants were obtained from mango seeds generated through sexual propagation. To assess genetic diversity, cluster analysis was carried out, as well as principal component analysis. Two hybrids were most prominent in terms of fruit weight, fruit length, fruit diameter, pulp weight, and pulp yield, with mean values greater than 245 g for pulp weight and 70% for pulp yield. Regarding fiber content in the pulp, six hybrids had a score of "2", that is, moderately fibrous fruit. For acidity and soluble solids content, the hybrids exhibited variations from 0.19 to 1.06% of citric acid and from 13.1 to 20.6 ºBrix, respectively. For peel color, tones ranging from reddish orange to yellow and green were observed. As for pulp color, there was variation from orange to light yellow tones. There was variability among the mango hybrids regarding the fruit traits analyzed, and hybrids that produce fruit that combine traits of economic interest were identified.

ABSTRACT Maize is widely cultivated in Brazil, and nitrogen is a major nutrient for its yield. Azospirillum brasiliense bacteria help in plant nutrient supply; however, maize-Azospirillum symbiosis is not very efficient and requires selection of genotypes with a more efficient association. Multivariate indexes facilitate selection using a single value, and GGE-biplot analysis enables the visualization of the genotype-environment interaction from this value. The present study aimed to select progenies that effectively associate with the bacteria and study the efficiency of progeny selection using a multivariate index observed in the GGE-biplot method. The experiments were conducted in two cities in the state of Mato Grosso do Sul. In a simple 16 × 16 lattice, 256 genotypes were evaluated in the presence and absence of diazotrophic bacteria. PH, SL, SD, FI, HGM, SS, and GY were measured for the construction of a selection index. Genotypes exhibited significant genotype–environment interactions for all evaluated traits, allowing their use in the selection index. High-yield genotypes were not those with the highest selection index values. The traits GY, SD, HGM, SS, SL, and PH contributed the most to the construction of the index. The no-till system may have contributed to the weaker response of maize inoculated with Azospirillum brasiliense. Genotype 96 had the highest values of the characteristics used to calculate the GISI, along with the stability between environments.

ABSTRACT The objective of this work was to estimate and compare phenotypic and genetic parameters after three cycles of intrapopulation recurrent selection for fresh corn grown under three nutrient availability conditions. Three experiments derived from the same population (MV-003) were conducted to assess the ability of progenies to absorb nutrients, one under adequate fertilization (control; MV-006), one under low nitrogen availability (N; MV-006N), and one under low phosphorus availability (P; MV-006P). The experiments were carried out in randomized blocks, with 64 half-sib progenies and three replications for each nutritional condition. Chlorophyll index, plant height, ear insertion, ear diameter, ear length, unhusked ear yield, and marketable husked ear were evaluated. The populations showed variability for the three nutrient availability conditions. The variability reduced after only three selection cycles; thus, evaluating a higher number of half-sib progenies, above 64, under low N and P availability is indicated. The rates used to identify the most efficient progenies in breeding programs should be close to the appropriate one, with a slow reduction after the selection cycles. The variability will be thus maintained, with a greater possibility of identifying more promising progenies. In addition, the frequency of favorable alleles increases more gradually and effectively. The N and P rate of 60 kg ha-1 is not indicated as a critical level for the initial phase of the program.

ABSTRACT Bromeliads are the target of predatory extractivism and consequently many species are included in the red list of threatened species, such as those belonging to the genus Neoregelia. Although Neoregelia mucugensis has not been evaluated for the degree of threat, its exploitation is exclusively extractive and its occurrence in Chapada Diamantina-BA is subject to the action of fires that affect the region annually. In this context, applying techniques aimed at protecting this genetic resource is fundamental for both the maintenance of its natural populations and the ex situ conservation of this genetic material. Plant tissue culture techniques have been successfully applied for the conservation of several bromeliad species. One of the methods used is slow growth, which consists in reducing plant metabolism and consequently decelerating its growth, which allows the maintenance of in vitro plant collections without the need for subculture. In this context, the objective of this study was to test the reduction of salts in the culture medium and the addition of osmoregulators on the induction of slow growth of N. mucugensis. Plants were subjected to treatments composed of different concentrations of MS medium and mannitol for a period of 12 months, when then analyses were conducted to evaluate growth, chlorophyll content and regeneration capacity of shoots in vitro. It was found that the treatment containing MS ½ and 7.8 g.L-1 of mannitol is indicated for in vitro conservation of N. mucugensis with maintenance of the regenerative capacity of its tissues.

ABSTRACT No isolated factor influences soybean development and production more than the sowing date, but the responses of cultivars sown on different sowing dates depends on their sensitivity to environmental conditions. Thus, this study evaluated the adaptability and stability of 17 soybean genotypes in relation to yield, as well as to the grain oil and protein contents as a function of different sowing times. The experiment was designed in randomized blocks with three replications and a 17 × 5 factorial scheme. The genotypes were: Conquista, CD 223 AP, Elite, Garantia, Bioagro lineage, M-Soy 8400, M-soy 8001, Nambu, Sambaíba, Esplendor, UFVS 2006, UFVS 2005, UFVTN 102, UVF 18, UFV 16, Valiosa, Vencedora, and the five sowing dates were: SD1 = 11/3, SD2 = 11/20, SD3 = 12/07, SD4 = 12/23, and SD5 = 01/09. The M-Soy 8001, UFV 18 and Garantia genotypes showed high oil contents, with adaptation to all sowing dates and stability when sown on the most favorable dates. The Bioagro lineage, CD 223 AP, and Garantia genotypes were adapted and stable when sown on all sowing dates and had higher protein contents than the other genotypes, regardless of the sowing date. The Elite, Nambu, and Garantia genotypes were adapted and stable when sown on the most favorable sowing dates and presented high grain yields when sown in early December. The findings indicate that the Garantia genotype is the most suitable for the growing conditions of the central-north region of the state of São Paulo.

ABSTRACT Splitting nitrogen (N) fertilizer application can be an efficient nutrient management technique to improve productivity and plant quality, as well as to reduce the negative environmental impact caused by N losses. In this context, the present study investigated how the management of N affects the agronomic characteristics of field-grown arugula plants. Nine treatments were assessed in a randomized complete block design, in a 4 x 2 + 1 factorial scheme, with three replicates. The evaluated factors were doses of N (60, 120, 180 and 240 kg N ha-1), split N fertilizer applications at side-dress (two and three times) and an additional treatment without a N supply. Maximum height was obtained with the application of 198 kg N ha-1. Nitrate content, fresh mass and productivity increased with increasing N doses. There was no effect of split N fertilizer applications on the characteristics evaluated. Therefore, the supply of 240 kg N ha-1 divided into two portions was considered as the best management strategy.

ABSTRACT Castor bean (Ricinus communis L.) is a plant native to Africa that presents important socioeconomic value for many countries, and has been the subject of breeding programs. In this context, the objective of this work was to identify genotypes with potential for improvement, focused on lowering plant height, using 19 hybrids and eight parents of R. communis. The study was developed at the experimental area of the Federal University of Recôncavo da Bahia in Cruz das Almas, BA, Brazil. The experiment was conducted in 2017 using a randomized block design with three replications, consisting of eight parents and 19 hybrids resulting from hybridization of these parents, grown with spacing of 3 meters between rows and 1 meter between plants. The characters stem diameter (SD), primary raceme insertion height (PRI), number of stem internodes (NSI), mean stem internode length (SIL), plant height (PH), number of harvested racemes (NHR), primary raceme length (PRL), and effective raceme length (ERL) were evaluated by analyzing the genetic parameters of variances and correlation between them. Five (H17, H2, H11, H13, and H6) of the 19 hybrids evaluated have potential to decrease PH of castor bean plants, presenting heights below 1.07 m. Direct selection for plant height is the most indicated for this purpose due to the high heritability of the character. However, the characters SD, PRI, and SIL stood out by assisting in indirect selection to decrease plant height because they can be early measured and present high heritability and strong correlation with PH.