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COTTON RESPONSE TO WATER DEFICITS AT DIFFERENT GROWTH STAGES
2017
JOÃO HENRIQUE ZONTA | ZIANY NEIVA BRANDÃO | JOSIANE ISABELA DA SILVA RODRIGUES | VALDINEI SOFIATTI
Water deficit at certain cotton growth stages can cause severe damage to crop development, affecting physiological processes and reducing reproductive structures, with consequent yield losses. The objective of this study was to evaluate the response of cotton cultivars under water deficit applied at different stages of the crop cycle. We compared the number of bolls per meter, cotton yield, and water use efficiency for eight different cotton cultivars under a water deficit of 15 days. We selected the following growth stages: Emergence (EM), First Square (FS), First Flower (FL), Peak Bloom (PB), and First Open Boll (FOB). The control treatment was irrigated with 100% ETc. The experiment was conducted in Apodi, RN State of Brazil, semiarid region, using a sprinkler irrigation system. The number of bolls per meter, cotton yield, and water use efficiency were influenced by the interaction of cultivars x deficit periods. Lowest values were observed for water suppression in the FL and PB stages. When the water deficit was imposed in the initial stages of growth (EM to FS) or after the FOB stage, the cotton yield reduction was not significant. At the same stage and water deficit, the behavior of the different cultivars was similar. Producers are urged to take this information into account when developing irrigation schemes for cotton crops, thereby avoiding water deficits during the most critical periods of the crop cycle.
Mostrar más [+] Menos [-]COMBINATIONS OF CORIANDER AND SALAD ROCKET CULTIVARS IN BICROPPING SYSTEMS INTERCROPPED WITH CARROT CULTIVARS
2017
JOSIMAR NOGUEORA DA SILVA | FRANCISCO BEZERRA NETO | JAILMA SUERDA SILVA DE LIMA | GARDÊNIA SILVANA DE OLIVEIRA RODRIGUES | AURÉLIO PAES BARROS JÚNIOR | ARIDÊNIA PEIXOTO CHAVES
The objective of this study was to evaluate combinations of coriander and salad rocket cultivars in bicropping systems intercropped with carrot cultivars in strips under the conditions of Mossoró-RN. The work was conducted at the Experimental Farm Rafael Fernandes from July to December 2014. The experimental design was a randomized complete block design with four replications and treatments arranged in a factorial design with additional treatments of type 2 x 2 x 2 + 2. The treatments consisted of the combinations of two coriander cultivars (Verdão and Português) and two rocket cultivars (Cultivada and Folha Larga), intercropped with two carrot cultivars (Brasília and Esplanada) plus two additional treatments, where the first are the cultivars in monocropping and the second the types of cropping (single and intercropped). We evaluated fresh and dry shoot mass in coriander and rocket and fresh and dry shoot mass as well as dry root mass, commercial and total root productivity, and classified root productivity in carrot. In the intercropping systems we evaluated land equivalent ratio, productive efficiency index, and score of the canonical variable, besides the indicators of economic efficiency (gross income, net income, rate of return and profit margin). Highest agroeconomic efficiency in intercropping systems was achieved with the combination of the coriander cultivar 'Verdão' and the rocket cultivars 'Folha Larga' or 'Cultivada' as well as the carrot cultivars 'Brasília' or 'Esplanada'. Regardless of the tested cultivar combinations, systems with coriander and salad rocket intercropped with carrot showed higher efficiency than monocropping systems.
Mostrar más [+] Menos [-]GENETIC DIVERGENCE AMONG COTTON GENOTYPES GROWN IN THE MAIN SEASON AND OFF SEASON
2017
THIAGO ALEXANDRE SANTANA GILIO | DEJÂNIA VIEIRA DE ARAÚJO | WILLIAN KRAUSE | HUGO HENRIQUE RIBEIRO ROSA | JOÃO PAULO ASCARI
The objective of this work was to evaluate the agronomic performance and estimate the genetic divergence of 18 cotton genotypes grown in the main season (sowed in December, 2012) and off season (sowed in January, 2013), considering their agronomic characteristics and resistance to Ramularia leaf spot. A randomized block experimental design was used, with five replications. The characteristics evaluated were plant height, first branch height, position of first fruiting branch, height of first fruiting branch, length between nodes, number of nodes, average number of bolls per plant, average boll weight, area under the disease progress curve (AUDPC) related to the Ramularia leaf spot severity, weight of 100 - seed from the plant middle third, fiber percentage, average production per plant, yield and cotton fiber quality. The results were subjected to individual and joint analysis of variance and the genetic divergence was estimated according to multivariate procedures (Mahalanobis' generalized distance and Tocher's optimization method). The dissimilarity matrices were summed to estimate the genetic divergence, considering both growing periods. Genetic variability was found among the genotypes evaluated, in both the main season and off season. The characteristic that most contributed to the genetic divergence in the main season was the production per plant and, in the off season, was the fiber percentage. According to the results of the present work, the crosses between the genotypes BRS - 335 and FMT - 707; FM - 910 and FMT - 707; and IMA - 08 - 12427 and FMT - 707 are recommended.
Mostrar más [+] Menos [-]TESTS FOR THE SELECTION OF FORAGE TURNIP PROGENY TO ORDER THE VIGOR AND LONGEVITY OF SEEDS
2017
SILVIA SANIELLE COSTA DE OLIVEIRA | CIBELE CHALITA MARTINS | FRANCISCO ELDER CARLOS BEZERRA PEREIRA | MARIA TEREZA GOMES LOPES | SALVADOR BARROS TORRES
Forage turnip (Raphanus sativus L. var. oleiferus Metzg.) progeny with seeds of higher physiological quality are of importance for farmers and seed producing companies. The objective of this work was to identify tests to be used in laboratories for the selection of turnip progeny having seeds of higher germination, vigor, seedling emergence in the field, and storage potential. Seeds of 100 turnip progeny of paternal half-sibs were evaluated as to water content, 1,000-seed mass, first count of the standard germination test, accelerated aging, and seedling emergence in the field. The seeds were subjected to storage for 12 months in unifoliate paper bags kept under room conditions and then evaluated by means of the standard germination test, first count of the standard germination test, and water content. The data were examined as to variance and genetic and phenotypic correlations, heritability, coefficients of genetic variation, and selection gain. The standard germination test, first count of germination, and the accelerated aging test can be used to select forage turnip progeny for seed physiological quality and storage potential. None of the tests used were efficient at selecting progeny with high field emergence.
Mostrar más [+] Menos [-]PLANT DENSITY AND NITROGEN FERTILIZATION ON COMMON BEAN NUTRITION AND YIELD
2017
ROGÉRIO PERES SORATTO | TIAGO ARANDA CATUCHI | EMERSON DE FREITAS CORDOVA DE SOUZA | JADER LUIS NANTES GARCIA
The objective of this work was to evaluate the effect of plant densities and sidedressed nitrogen (N) rates on nutrition and productive performance of the common bean cultivars IPR 139 and Pérola. For each cultivar, a randomized complete block experimental design was used in a split-plot arrangement, with three replicates. Plots consisted of three plant densities (5, 7, and 9 plants ha-1) and subplots of five N rates (0, 30, 60, 120, and 180 kg ha-1). Aboveground dry matter, leaf macro- and micronutrient concentrations, yield components, grain yield, and protein concentration in grains were evaluated. Lower plant densities (5 and 7 plants m-1) increased aboveground dry matter production and the number of pods per plant and did not reduce grain yield. In the absence of N fertilization, reduction of plant density decreased N concentration in common bean leaves. Nitrogen fertilization linearly increased dry matter and leaf N concentration, mainly at lower plant densities. Regardless of plant density, the N supply linearly increased grain yield of cultivars IPR 139 and Pérola by 17.3 and 52.2%, respectively.
Mostrar más [+] Menos [-]USE OF LIQUID FERTILIZER TO REDUCE THE PHYTOTOXIC EFFECTS OF GLYPHOSATE ON EUCALYPTUS
2017
MILER SOARES MACHADO | LINO ROBERTO FERREIRA | JOSÉ LUCAS DE PAULA | GUSTAVO ANTÔNIO MENDES PEREIRA | VALDINEI ARAÚJO GONÇALVES
Glyphosate is a non-selective herbicide used for weed control in eucalyptus forests. Glyphosate drifts are common and may cause serious damage to crops. An alternative to reduce such effects is to use antidotes capable of protecting eucalyptus. An experiment was conducted to evaluate the effects of the application of liquid fertilizer on eucalyptus plants subjected to a glyphosate drift simulation. The treatments were arranged in a 5 x 5 factorial design. The first corresponding factor was liquid fertilizer (0, 1, 2, 4, and 8 L c.p. ha -1 of Fertiactyl Pós®) and the second factor dose of glyphosate drift (0, 360, 720, 1,440, and 2,160 g e.a. ha -1). The products were applied together so that the spray did not reach the upper third of the plants. At 7, 28, and 49 days after application (DAA), the percentage of intoxication of eucalyptus was evaluated. At 56 days DAA, height, leaf area, leaf nutrient contents, and shoot and root dry matter were determined. Higher doses of glyphosate (1,440 and 2,160 g ha -1) caused intoxication levels above 90% at 28 and 49 DAA without using liquid fertilizer. The combination of 2,160 g ha -1 of glyphosate with 8.0 L ha -1 of liquid fertilizer resulted in an estimated eucalyptus dry matter 7% higher than in the control and 97% higher than using 2,160 g ha -1 of glyphosate without the liquid fertilizer. We conclude that the liquid fertilizer was effective in suppressing the harmful effects caused by glyphosate on eucalyptus plants.
Mostrar más [+] Menos [-]AGRONOMIC PERFORMANCE OF ERECT AND SEMI-ERECT COWPEA GENOTYPES IN THE NORTH OF MINAS GERAIS, BRAZIL
2017
JOÃO VÍCTOR SANTOS GUERRA | ABNER JOSÉ DE CARVALHO | JHONATA CANTUÁRIA MEDEIROS | ANDREY ANTUNES DE SOUZA | ORLANDO GONÇALVES BRITO
The objective of this work was to evaluate the agronomic performance of elite-strains of cowpea cultivars under the conditions of the north of Minas Gerais (MG), Brazil. Fifteen elite-strains and five erect and semi-erect cultivars of cowpea were evaluated in the 2014 and 2015 summer-fall crop seasons in Janaúba MG. A randomized block experimental design was used with four replications. Plant size, lodging and value of cultivation, pod length and grain yield were evaluated. The data of the two crops were subjected to individual and joint analysis of variance. The genotype-crop interactions significantly affected all studied variables. The strains MNC04-792F-146 and MNC04-792F-144 stood out as the most productive genotypes in both crops. The cultivars BRS Itaim and BRS Novaera presented adequate size and lodging characteristics for cultivation, and values of cultivation that meet commercial standards, thus representing good alternatives for the genotypes cultivated in the north of Minas Gerais.
Mostrar más [+] Menos [-]PHYSICAL, CHEMICAL AND MORPHOLOGICAL CHARACTERISTICS OF BANANA CULTIVARS DEPENDING ON MATURATION STAGES
2017
CÉSAR FERNANDES AQUINO | LUIZ CARLOS CHAMHUM SALOMÃO | PAULO ROBERTO CECON | DALMO LOPES DE SIQUEIRA | SÔNIA MACHADO ROCHA RIBEIRO
The objective of this work was to morphologically characterize 15 banana cultivars and assess the physical and chemical characteristics of their fruits at two maturation stages, unripe (pre-climacteric) and ripening. The plants were evaluated regarding their pseudostem height and diameter, petiole length, leaf blade length, width and length-to-width ratio. The cultivar Ouro had fruits with lower diameter, total length, market weight and fresh weight at both stages, and also firmer pulp when they were unripe. The cultivar Caru-Roxa had higher fresh fruit and pulp weights, and the cultivar Terrinha had the highest percentage of pulp dry weight percentage in unripe and ripe fruits. The cultivars Maçã and Ouro had higher pulp-to-peel ratio in unripe fruits. The ripe peels had lower fresh weight and thickness and higher dry weight percentage compared to unripe peels. The fruit peel of the cultivar Marmelo had the highest fresh weight at both stages. The cultivars Marmelo and Maçã had higher percentage of peel dry weight percentage at both stages. The unripe pulp had lower soluble solids. The titratable acidity in the pulp increased with ripening. The average plant height ranged from 2.25 to 6.15 m. The cultivars that had the largest pseudostem diameters had also the highest heights, except the Prata-Anã and Prata-Graúda. The cultivar and maturity stage influenced all the characteristics evaluated in fruits, except the total and market lengths, which did not vary with the ripening of fruits.
Mostrar más [+] Menos [-]FIRST RECORD OF Xanthopastis timais IN AMARYLLIS AND EFFECT OF SOURSOP EXTRACT ON LARVAL MORTALITY
2017
LÍGIA BROGLIO MICHELETTI | SÔNIA MARIA FORTI BROGLIO | EURICO EDUARDO PINTO DE LEMOS | ROSEANE CRISTINA PREDES TRINDADE | ELLEN CARINE NEVES VALENTE
The aim of this study was to report the occurrence of Xanthopastis timais (Cramer, 1780) (Lepidoptera: Noctuidae) in amaryllis ( Hippeastrum hybridum Hort ., Amaryllidaceae), as well as estimating lethal concentrations (LC 50 and LC 99 ) of soursop seed extract, Annona muricata L. (Annonaceae), against its larvae. The experiment was carried out at the Laboratory of Entomology of the Research Center for Agricultural Sciences, Federal University of Alagoas, in Rio Largo - AL, Brazil . First, we collected caterpillars from amaryllis plants that were reared until pupal and adult stages (parental generation). Next, part of the adults was used for species identification, and the rest were bred to produce next generation (F1), being after that applied in a laboratory bioassay. The lab trial was performed in a completely randomized design, with six treatments and five replications containing three second - instar caterpillars. These larvae were fed pieces of amaryllis leaf (4 x 4 cm), which were previously soaked in treatments for 30 seconds and, air - dried on absorbent papers for one hour. Each treatment consisted of one concentration of ethanol extract of soursop seeds (0.0, 1.0, 0.5, 0.25, 0.125 and 0.0625% w/ v) with distilled water and DMSO at 1% (v/ v), for solutions. We noted that the lethal concentrations LC 50 and LC 99 were 0.29% (w/ v) and 2.27% (w/ v), respectively. In view of our results, we can state that larval stage of X . timais were influenced by extract application in terms of survival, mortality, larvae weight and larval stage length. Besides of that, it was the first time this species was recorded in Alagoas state.
Mostrar más [+] Menos [-]BUFFEL GRASS MORPHOAGRONOMIC CHARACTERIZATION FROM Cenchrus GERMPLASM ACTIVE BANK
2017
LEILA REGINA GOMES PASSOS BRUNO | RAFAELA PRISCILA ANTONIO | JOSÉ GERALDO DE AQUINO ASSIS | JOSÉ NILTON MOREIRA | IRLANE CRISTINE DE SOUZA ANDRADE LIRA
This study aimed to characterize buffel grass accessions of the Cenchrus Germplasm Active Bank (CGAB) from Embrapa Semi - Arid in a morphoagronomic way, checking the descriptors variability and efficiency in accessions on two consecutive cuts. Twenty - five accessions and five buffel grass cultivars were used in randomized complete block design with three replications. Evaluations were conducted after two consecutive cuts, each evaluation performed 90 days after each cut. Characterization was based on 15 quantitative and qualitative morphoagronomic descriptors. Quantitative descriptors were subjected to individual and joint univariate analysis of variance, followed by the Scott - Knott’s test at 5% significance. Yet qualitative descriptors were submitted to descriptive analysis. Both quantitative and qualitative descriptors were grouped based on the Gower algorithm for divergence analysis. A dendrogram and calculations of the characters relative importance for divergence were established. Genotype and cutting effects were significant for almost all descriptors in the joint analysis. This result indicates a genetic variability between genotypes and, regarding the cut, it indicates mainly differences in growth rate of each genotype in each cutting season. Genotypes were separated into three groups, which showed good genotype variation. The number of tillers per clump, followed by number of inflorescence and color of seeds, were the most relevant characters in genotype separation.
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