Open Access Original Research Article

Photosynthetic and Production of Urochloa ruziziensis Inoculated with Azospirillum brasilense under Drought

Lucas Guilherme Bulegon, Vandeir Francisco Guimarães, Roberto Cecatto Júnior, Andre Gustavo Battistus, Adriano Mitio Inagaki, Anderson Daniel Suss

Journal of Experimental Agriculture International, Page 1-9
DOI: 10.9734/jeai/2019/v38i630315

Aims: The objective of this study was to evaluate the photosynthetic activity and production of Urochloa ruziziensis when inoculated with Azospirillum brasilense in the presence and absence of drought.

Study Design:  Randomized block design and factorial 2x2.

Methodology: The first factor was the presence or absence of seed inoculation with A. brasilense strains AbV5 + AbV6; the second factor was the presence or absence of drought. The variables evaluated were: relative water content (RWC), soil gravimetric moisture, net assimilation rate of CO2, response in function of active photon flux density, apparent quantum efficiency, light compensation point, absolute integrity of membrane, damage to membranes, dry mass aborted leaves, and total dry mass of aerial part.

Results: Results demonstrate that plants maintained in drought presented a reduction in all evaluated variables. Under conditions of drought the use of A. brasilense promoted smaller variations in RWC, net assimilation rate of CO2, apparent quantum efficiency, light compensation point, absolute integrity of membrane, and damage to membranes; no variations were observed for dry mass, aborted leaves or total dry mass of aerial part.

Conclusion: The inoculation of U. ruziziensis seeds with A. brasilense mitigates drought damage in plant physiology, but it does not mitigate leaf losses or plant productivity.

Open Access Original Research Article

Evaluation of Agronomic Performance of Amaranthus (Amaranthus cruentus cv. BRS Alegria) in Times and Seed Densities

Fábio Kempim Pittelkow, Aloisio Bianchini, Pedro Silvério Xavier Pereira, Luana Maria de Rossi Belufi, Maria das Graças de Assis Bianchini, Rodrigo Pengo Rosa

Journal of Experimental Agriculture International, Page 1-13
DOI: 10.9734/jeai/2019/v38i630317

The genus Amaranthus comprises several species of the Amaranthaceae family whose leaves and seeds are regularly consumed as food by populations in several countries, among which Brazil is not yet included. The objective of this work was to evaluate the productive potential of amaranth (Amaranthus cruentus cv. BRS Alegria) as a function of different seasons and sowing densities in succession to the soybean crop in the region of Lucas do Rio Verde, MT. The experimental design was a randomized complete block design, with four replications, in a 5x4 factorial scheme. The first factor refers to the five sowing seasons (16/02/2013; 26/02/2013; 05/03/2013; 20/03/2013 and 05/04/2013) and the second factor the four sowing densities (11.4, 20.0, 28.5 and 37.1 ppt m-2). The evaluated characteristics were: plant height (AP, in meters); stem diameter (DC, in millimeters); panicle length (CP, in millimeters); dry panicle mass (MSP, in g); dry mass of stalk (MSC, in g); sheet dry mass (MSF, in g); total dry mass (MST, in g); final population of plants (POP, in plants ha-1); productivity (PROD, in kg ha-1). The experimental data were submitted to analysis of variance and when means were significant the Tukey test to was utilized to compare the means. There was significant difference (p>0.05) in sowing density between the seasons, thus validating the variation of the desired sowing density between the seasons. The obtained real population and the different seasons of sowing were adopted as sources of variation of the other evaluated attributes. The later sows determined a longer time interval between sowing and panicle emission, as well as harvesting. The cumulative precipitation until the panicle and harvesting emission showed a great reduction as a function of the planting times. It is concluded that the productivity of the Amaranth crop is influenced directly by the number of plants per square meter and by the sowing season in succession the soybean crop.

Open Access Original Research Article

Population Fluctuation of Fruit Flies (Diptera: Tephritidae) in Domestic Orchards in the Paraíba Swamp Region, Brazil

Joálisson G. da Silva, Carlos Henrique de Brito, Robério de Oliveira, Clarice D. A. Corsato, Kennedy S. Gonzaga, José Ricardo L. Pinto, Jocélia G. da Silva

Journal of Experimental Agriculture International, Page 1-9
DOI: 10.9734/jeai/2019/v38i630318

Knowledge about the population fluctuation of fruit flies (Diptera: Tephritidae) is an important tool for control methods adoption as recommended by Integrated Pest Management (IPM). The objective of the research was to evaluate the fruit flies population fluctuation in eight domestic orchards from Paraíba swamp region and to correlate this information with the plant phenology as well as the meteorological elements. This research was developed in two rural properties of each municipality, georeferenced, identified according to fruit species diversity criterion. Adult fruit flies capture were realized by plastic traps containing 300 ml of 5.0% hydrolyzed protein aqueous solution (Bio Anastrepha®) as food attractant. Climatic data were obtained daily by thermo hygrometers and through the Executive Agency of Water Management of the State of Paraíba - AESA. During the study period, a total of 3.159 fruit flies were collected, with 10 species belonging to the genus Anastrepha and one of the genus Ceratitis. Fruit flies infestation was observed monthly for both genera, Anastrepha and Ceratitis, however, this first stood out in the whole year. The MAD (captured flies number/traps installed number/collection days number) index in a few municipalities was superior to 0.5 being recommended to do fruit flies control in these areas. The seasonal occurrences, as well as the Tephritidae infestation rates in the domestic orchards are related to the availability of fruits.

Open Access Original Research Article

Plants Mineral Nutrition on the Preference of Glycaspis brimblecombei (Hemiptera: Aphalaridae) in Eucalyptus sp.

Lilian Guimarães de Favare, Otávio Peres Filho, Marcelo Dias de Souza, Diego Arcanjo do Nascimento, Sheila Espindola de Matos, Josamar Gomes da Silva Júnior, Alberto Dorval

Journal of Experimental Agriculture International, Page 1-9
DOI: 10.9734/jeai/2019/v38i630319

The plants nutritional maintenance is a support to their natural defense in relation to the insects attack of economic importance. The mineral nutrition arises as an alternative, since it provides the plants silvicultural conditions necessary to express all their productive potential, with the power of resistance to biotic constraints. Thus this study had as objective to evaluate the effect of different formulations of mineral fertilization in the eucalyptus plantations in relation to occurrence of Glycaspis brimblecombei (Moore), in the field. The experiment was carried out in the field from December 2015 to December 2016. The experimental arrangement was planned provided in the factorial design, with three origins of Eucalyptus sp. (Eucalyptus camaldulensis Dehn; hybrids (Eucalyptus urophylla S.T. Blake) x Eucalyptus grandis (Hill ex Maiden) and E. urophylla x E. camaldulensis); and seven nutritional formulations. The research data were subjected to analysis of variance (ANOVA), under a randomized block design in a factorial scheme (3 x 7), and the means compared by the Tukey test at 5% probability of error. The response variable used in the analysis was the occurrence of eggs and lerps, being transformed, in order to become suitable for parametric tests. The population fluctuation was carried out in the planting annual cycle. For the correlation analysis between the dependent and the independent variables, the data were analyzed by Pearson correlation (r) and their values were analyzed by using the Student's T-Test. The omissions influenced on the preference of the red gum lerp psyllid to Eucalyptus sp. In E. camaldulensis the omission of nitrogen and potassium influence on the preference and the absence of silicon causes the favoring of the pest oviposition. In the hybrid E. urophylla x E. grandis the absence of fertilization and the absence of nitrogen, phosphorus, potassium, individually, are less preferred.

Open Access Original Research Article

Potential of Entomopathogenic Fungi as Biological Control Agents of Whitefly (Bemisia tabaci biotype B) (Genn.) (Hemiptera: Aleyrodidae)

David Jossue López Espinosa, Igor Henrique Sena da Silva, Rogério Teixeira Duarte, Kelly Cristina Gonçalves, Ricardo Antonio Polanczyk

Journal of Experimental Agriculture International, Page 1-8
DOI: 10.9734/jeai/2019/v38i630320

The efficiency of isolates from entomopathogenic fungus Beauveria bassiana, Lecanicillium muscarium and Metarhizium rileyi in the control of eggs and third-instar nymphs of whitefly, Bemisia tabaci biotype B, was evaluated by pathogenicity and virulence tests, under laboratory conditions. For the pathogenicity tests, five leaflets of bean (Phaseolus vulgaris) plants containing 20 nymphs or 20 eggs of B. tabaci biotype B were used. The leaflets were immersed in suspension containing a concentration of 108 conidia/ml of each fungus isolate. Nymph mortality and egg viability were evaluated after seven days. The isolates that caused nymph mortality and egg viability above 80% were submitted to virulence tests, in order to estimate the lethal concentration (LC50) of each isolate. All isolates were pathogenic to eggs and third-instar nymphs of B. tabaci Biotype B. JAB07 of B. bassiana and LCMAP3790 of L. muscarium isolates presented the best results, with nymphs mortality of 96.68 ± 2.25% and 97.74 ± 1.56%, respectively. Additionally, JAB07 was the most virulent isolate, both for eggs and third-instar nymphs, with LC50 estimated of 0.012 and 0.006 × 103 conidia/ml, respectively. We suggest, future field trials are required in order to analyze the real efficiency of this isolate in the control of eggs and nymphs of B. tabaci biotype B in field conditions.