خيارات البحث
النتائج 151 - 160 من 240
GREEN BEAN YIELD AND PATH ANALYSIS IN COWPEA LANDRACES
2016
THAISY GARDÊNIA GURGEL DE FREITAS | PAULO SÉRGIO LIMA E SILVA | JÚLIO CÉSAR DOVALE | EDICLEIDE MACÊDO DA SILVA
Cowpea ( Vigna unguiculata (L.) Walp.) is widely cultivated in northeast Brazil for production of both green grains and dry grains. Green grains are cowpea grains with a 60 to 70% moisture content that are very appreciated by the local people. The cultivation of cowpea in northeast Brazil is performed mostly using landraces and the low yields achieved in some areas of that region are generally attributed to the cultivation of less productive landraces. The objectives of this research were to identify the best landraces in terms of green bean yield and the characters that hold the most positive direct effects on this yield via path analysis. Twelve landraces of undetermined growth were evaluated in two experiments conducted in Mossoró, Brazil. The first experiment (E1) was sprinkler - irrigated and the second (E2) was conducted under rainfed conditions, but was irrigated whenever necessary. Pod yield and dimensions and green grains were evaluated, in addition to the main grain yield components. A randomized block design with five replications was used. The data presented here identified eight landraces with the highest yields. In addition, cowpea yield was higher in the dry season (E1) than in the rainy season (E2). The number of pods per plant had the largest direct positive effect on green grain yield.
اظهر المزيد [+] اقل [-]RESIDUAL ACTIVITY OF HERBICIDES APPLIED TO COTTON ON CROPS CULTIVATED IN SUCCESSION
2016
ELIEZER ANTONIO GHENO | RUBEM SILVÉRIO DE OLIVEIRA JUNIOR | JAMIL CONSTANTIN | HUDSON KAGUEYAMA TAKANO | ALEXANDRE GEMELLI
Herbicides with high persistence in soil can cause problems for crops sown in succession to their application. Thus, the aim of this study was to estimate, in greenhouse conditions, the safe period of time after application of preemergent herbicides used on cotton crops (isolated or in mixtures) for the crops grown in succession (bean, corn, and soybean). The experimental design was completely randomized in a factorial scheme (5 x 11) + 1, with five repetitions. For each experiment, treatments combined different time periods between herbicide application and sowing of crops (280, 210, 140, 70, and 0 days before sowing of crops) with eleven herbicide treatments: fomesafen (625 g ha - 1 ) prometryne (1250 g ha - 1 ), diuron (1250 g ha - 1 ), S - metolachlor (768 g ha - 1 ), clomazone (1000 g ha - 1 ), fomesafen + prometryne (625 + 1250 g ha - 1 ), fomesafen + diuron (625 + 1250 g ha - 1 ), fomesafen + S - metolachlor (625 + 768 g ha - 1 ), fomesafen + clomazone (625 + 1000 g ha - 1 ), fomesafen + clomazone + diuron (625 + 1000 + 1250 g ha - 1 ), and fomesafen + clomazone + prometryne (625 + 1000 + 1250 g ha - 1 ), plus an untreated control. Applications of diuron showed the greatest persistence, causing the largest carryover effects for the three crops evaluated. The other treatments showed residual effects or affected crop development when sowings were performed up to 70 days after application. At later periods no significant damage was observed.
اظهر المزيد [+] اقل [-]SUNFLOWER MEAL AND EXOGENOUS ENZYMES IN INITIAL DIETS FOR BROILERS
2016
TACIANA MARIA MORAES DE OLIVEIRA | RICARDO VIANNA NUNES | CINTHIA EYNG | EVELINE BERWANGER | DOUGLAS FERNANDO BAYERLE
This research aimed to evaluate the effects of different levels of sunflower meal (SFM) and the supplementation of a multienzyme complex in the initial diets of broilers on their performance, intestinal morphometry and carcass characteristics. In all, 1100 1 - d - old male chicks were distributed in a completely randomized design with 2 x 5 factorial arrangement (with and without a multienzyme supplement and five levels of SFM inclusion - 0, 4, 8, 12 and 16%), and five replications per experimental unit. The experimental diets were provided until the chickens were 21 - d - old and thereafter all birds received the same diet up to 42 d, to evaluate the possible residual effects of treatments. The SFM inclusion impaired performance from 1 to 21 d of age and the animals that received SFM during the initial phase, failed to recover from the negative effects on performance parameters. The multienzyme supplement improved the intestinal morphometry and was more effective than non - supplemented diets on performance, independent of the SFM inclusion level. The carcass and cuts yield of the wings and leg were significantly affected by the multienzyme supplementation. In conclusion, the SFM inclusion impaired performance variables and intestinal morphometry without affecting carcass yield; however, the supplementation of an enzyme complex counteracted the negative performance and intestinal morphometry effects.
اظهر المزيد [+] اقل [-]SULFENTRAZONE PHYTOREMEDIATION UNDER FIELD CONDITIONS
2016
ALESSANDRA FERREIRA BELO | FÁBIO RIBEIRO PIRES | ROBSON BONOMO | ALBERTO CARGNELUTTI FILHO | LUIS HENRIQUE ORTELAN TENIS
Phytoremediation is a technique that has been used with increasing frequency to decontaminate soils treated with herbicides that have long - term residual effects, such as sulfentrazone. The goal was to assess phytoremediation of the herbicide sulfentrazone under field conditions by the species Canavalia ensiformis and Crotalaria juncea . The treatments consisted of combinations of the plant species C. ensiformis and C. juncea plus a control treatment (with manual weeding) and four doses of the herbicide sulfentrazone. The experimental design used herein was a split - plot randomized block design with four replicates per subplot. The treatments were kept in the field for 75 days. After this period, the experimental area was again furrowed and fertilized, considering the requirements for Pennisetum glaucum , a plant used as an indicator of the presence of sulfentrazone. Thirty - four days after sowing pearl millet, the fresh and dry shoot masses of the plants were assessed. At the end of the cycle, the plant height, stem diameter, internode length, number of leaves, number of panicles, and fresh and dry panicle masses were determined. Previous cultivation of phytoremediation species C. ensiformis and C. juncea promotes sulfentrazone remediation. C. ensiformis is the most efficient species for the decontamination of the herbicide sulfentrazone under field conditions.
اظهر المزيد [+] اقل [-]GROWTH OF Mimosa caesalpiniifolia Benth., UNDER SHADE IN THE NORTHEAST SEMI-ARID REGION OF BRAZIL
2016
JOSÉ RIVANILDO DE SOUZA PINTO | JEFERSON LUIZ DALLABONA DOMBROSKI | JOSÉ HERMOGENES DOS SANTOS JUNIOR | GABRIELA OLIVEIRA DE SOUZA | ROMULO MAGNO OLIVEIRA DE FREITAS
Seedling production for reforestation aims to achieve the best plant growth in a minimal amount of time, to provide good survival and growth levels after transplantation. During cultivation, it is necessary to know the shading levels that lead to the best growth. The objective of this study was to assess the growth of young Mimosa caesalpiniifolia Benth. plants provided with various amounts of shade in the northeast semi-arid region of Brazil. Four types of shade cloth were tested (0, 30, 50 and 70%). Shoot length, stem diameter, stem dry matter, leaf dry matter, total dry matter and leaf area were assessed. Leaf area ratio, specific leaf area, absolute growth rate, relative growth rate and net assimilation rate were also calculated. The different shading levels affected M. caesalpinifolia growth, with the best growth indicators observed in plants grown under 50% shade, with increases in plant height, leaf area and total dry matter observed compared to the full sun condition.
اظهر المزيد [+] اقل [-]EFFECTIVE PRECIPTATION, SOIL LOSS AND PLANT COVER SYSTEMS IN THE CAATINGA BIOME, BRAZIL
2016
HELBA ARAÚJO DE QUEIROZ PALÁCIO | JACQUES CARVALHO RIBEIRO FILHO | JÚLIO CÉSAR NEVES DOS SANTOS | EUNICE MAIA DE ANDRADE | JOSÉ BANDEIRA BRASIL
The objective of this work was to evaluate the influence of anthropic activities on the effective precipitation (eP) and soil loss in watersheds under different land uses in a tropical dry forest region. The experimental area was located in the central part of the State of Ceará, Brazil. The land uses evaluated were: fallow Caatinga (FC), thinned Caatinga (TC) and deforested Caatinga followed by a burning procedure and pasture cultivation (DBP). The areas were monitored in the rainy season (January to May, 2010), when 57 natural rainfalls occurred, totaling 941 mm of precipitation. The eP and sediment productions were quantified by the sum of all occurrences during the study period, and the soil loss was represented by suspended and dragged sediments. The eP was 15.13 mm and sediment produced was 167.81 kg ha - 1 in FC conditions. The eP values was smaller (11.28 mm) in the watershed with TC, which had soil loss sum of 42.04 kg ha - 1 . The largest annual eP was found in the DBP area, with 112.88 mm yr - 1 of accumulated water depth, which also showed the greater annual soil loss (3114.97 kg ha - 1 ). The greatest interference of plant cover in the two variables evaluated occurred in the first precipitation events, when the plants were not yet fully developed.
اظهر المزيد [+] اقل [-]EVALUATION OF CORN HYBRIDS UNDER CONTRASTING WATER AVAILABILITY CONDITIONS
2016
WILIAN HENRIQUE DINIZ BUSO | EMMANUEL ARNHOLD
The current study aimed to assess adaptability and stability of corn hybrids regarding grain yields when sown in three different seasons in the Brazilian cerrado. The research was carried out at the Experimental Farm of the IF Goiano, campus in Ceres - GO. Pre - sowing fertilization was made with 20 kg ha - 1 of nitrogen, 150 kg ha - 1 of phosphorus and 80 kg ha - 1 of potassium (04 - 30 - 16 formulation). Data were analyzed in a random block experimental design. We assessed tem corn hybrids (Truck, Fórmula, P30F53, P3646H, P30F35H, AGN 30A77H, AGN 30A37H, AG 8088PRO, DKB 390 and DKB Bi9440) in three sowing seasons (Nov. 18, 2011; Jan. 31, 2012 and Feb. 20, 2012) with three replications. Harvests were held on Apr. 4, 2012; Jun. 10, 2012 and Jul. 1, 2012. Each hybrid were assessed on yielding; and a graphical analysis was made to contrast hybrids and sowing seasons regarding stability and adaptability. Results showed a significant effect of the interaction between hybrids and sowing times. Therefore, we may state that the best hybrid in an environment would not be necessarily good in another. Thereby, we can infer that drought and corn genetic variability have diverse behaviors in each season. Over the two - dimensional graphics generated by GGE Biplot method, we observed an increased adaptability of AGN 30A77H when sown on Nov. 18, 2011 and on Jan. 31, 2012, followed by Fórmula; however, for P30F35H, it was on Feb. 20, 2012.
اظهر المزيد [+] اقل [-]TRINEXAPAC-ETHYL AFFECTS GROWTH AND GAS EXCHANGE OF UPLAND RICE
2016
RITA DE CASSIA FÉLIX ALVAREZ | CARLOS ALEXANDRE COSTA CRUSCIOL | ADRIANO STEPHAN NASCENTE | JOÃO DOMINGOS RODRIGUES | GUSTAVO HABERMANN | VESPASIANO BORGES DE PAIVA NETO
A major problem affecting some upland rice cultivars is the increase in plant size when subjected to high doses of nitrogen fertilizer, leading to high levels of lodging. A method to reduce the height of upland rice, and therefore lodging, would be to use plant growth regulators. However, little information exists on the effect of these regulators on plant physiological processes. Therefore, the objective of this study was to evaluate the influence of trinexapac-ethyl application in upland rice via analysis of growth and gas exchange. The experiment was carried out under greenhouse conditions using the BRS Primavera cultivar. A completely randomized design with eight replications was used. Treatments were carried out with and without the application of the plant growth regulator, and plants were subject to two-stage assessments in which physiological and gas-exchange indices were measured. The use of trinexapac-ethyl improved the growth of rice plants from the flowering to the physiological maturity stage, resulting in higher values of leaf area ratio, specific leaf area, and leaf matter ratio in treated plants. At the same time, it provided smaller reduction in net CO2 assimilation at the physiological maturity stage. Thus, net/apparent assimilation rate did not change after the application of growth regulator, but relative growth rate decreased in these treated plants. These results indicate the occurrence of self-shading in rice plants induced by what might be a supra-optimum trinexapac-ethyl concentration.
اظهر المزيد [+] اقل [-]BIOMASS YIELD OF CROTALARIA JUNCEA AFTER THINNING AND AT VARIED SOWING DENSITIES IN THE COASTAL PLATEAU OF PIAUÍ STATE, BRAZIL
2016
MAURO SERGIO TEODORO | FRANCISCO JOSÉ DE SEIXAS SANTOS | MAIRLA NASCIMENTO DE LACERDA | LUMA MELISA DA SILVA ARAÚJO
The northern region of Piauí state is an important center of irrigated organic fruit farming, wherein sandy soils with low organic matter content are predominant, besides climate with high temperatures, long periods of water deficit and constant wind. Given this situation, it becomes necessary to investigate alternative management options able to meet the challenges of agricultural productivity. In this context, green manuring becomes an important practice, mainly when using fast - growing species and with great potential for biomass production. Thus, a study was carried out at Embrapa Meio - Norte to measure Crotalaria juncea biomass yield after thinning and at various sowing densities. The evaluated parameters were plant height, stem diameter, number of branches per plant, fresh and dry weight of shoots and roots. The results showed that sowing density had no influence on plant height; however, unthinned plants reached greater heights, which might have been due to reduced competition for light. Thinning had no effect on diameters of plant stem base; on the other hand, lower planting densities promoted larger diameters also due to less competition. Likewise, the number of branches per plant was not affected by thinning, being greater at lower planting densities on account of less competition. Thinned plants achieved higher averages of fresh shoot weight. Nevertheless, shoot dry biomass was greater at higher planting densities. Furthermore, both fresh and dry weight of roots were not influenced by any of the adopted treatments.
اظهر المزيد [+] اقل [-]SQUAMOUS CELL CARCINOMA IN OVINES IN THE STATE OF ACRE
2016
EDUARDO MITKE BRANDÃO REIS | RENAN DE MELLO SPADETTO | SARA LUCENA DE AMORIM | GRAZIELA BARIONI | FELIPE BERBARI NETO
The squamous cells carcinoma (SCC), also known as epidermoid carcinoma, is a malign neoplasia of the squamous layer of the skin’s epidermis, very common in bovines of tropical countries such as Brazil, due to the chronic exposure of animals to ultraviolet radiation. The objective of this work was to describe SCC cases in sheep ( Ovis aries ), because it is known that this disease is rare in this species. A standard animal of approximately six years old was assisted in the municipality of Rio Branco, State of Acre, in Brazil, presenting cachectic state and multifocal tumors. Despite the rarity of this neoplasia in sheep, it is important to use preventive measures, such as: avoiding acquisition of depigmented animals, with absent or sparse fur coverage and, mainly avoiding prolonged exposure to ultraviolet lights, which could cause the appearance of this morbid disease.
اظهر المزيد [+] اقل [-]