scholarly journals Application of Sulfentrazone in Stages of Germination of IAC 90 Cassava Cuttings in Clay Soils and Sandy

2015 ◽  
Vol 33 (2) ◽  
pp. 305-314
Author(s):  
J.S. Zimmer ◽  
S.D. Ferreira ◽  
J.R. Ramella ◽  
A.C.P. Rodrigues-Costa ◽  
N.V. Costa
Keyword(s):  
Experimental Design ◽  
Clayey Soil ◽  
Sandy Soils ◽  
Development Stage ◽  
Clay Soils ◽  
Initial Growth ◽  
Initial Development ◽  
The Third ◽  
Productive Potential

Weeds interfere dramatically in the productive potential of cassava; however, information regarding herbicides that are selective to crops is still scarce. Thus, the aim in this study was to assess the initial growth of IAC 90 cassava plants after the application of sulfentrazone at different stages of germination of cassava in clayey and sandy soils. Three experiments were simultaneously deployed: the first experiment consisted in the application of sulfentrazone in the non-germinated stage of cassava cuttings; the second one in the stage of germinated cassavas cuttings (0.9 cm shoots); and the third one in applications in the stage of cassava cuttings with buds emerging (6.5 cm shoots and emerging from the soil). For each experiment the experimental design in randomized blocks was used in the 2 x 5 factorial arrangement with four replications. The factors were composed of two soils (sandy and clayey) and five doses of sulfentrazone (0, 250, 500, 750 and 1,000 g ha-1). It was found that depending on the herbicide dose, development stage of the buds of cassava cuttings and the type of soil, damage can occur in the initial development of the IAC 90 cassava plants. The greatest potential of sulfentrazone selectivity has occurred in applications in the non-germinated cassava cuttings stage and in doses lower than 500 g ha-1 in the clayey soil.

scholarly journals SULFENTRAZONE SELECTIVITY AND EFFICIENCY IN CASSAVA CROPS IN SANDY AND CLAYEY SOILS

2015 ◽  
Vol 33 (4) ◽  
pp. 787-793 ◽  
Author(s):  
N.V. COSTA ◽  
S.D. FERREIRA ◽  
J.R. RAMELLA ◽  
G. MORATELLI ◽  
R.F. DOURADO
Keyword(s):  
Experimental Design ◽  
Sandy Soil ◽  
Active Ingredient ◽  
Clayey Soil ◽  
Soil Conditions ◽  
No Tillage ◽  
Clayey Soils ◽  
Conventional System ◽  
Productive Potential ◽  
Tillage System

ABSTRACT Weeds have the potential to dramatically interfere in cassava cultivation, reducing its productive potential; however, there are few studies on the selective herbicides in this crop. Therefore, the objective was to evaluate in this work the selectivity and efficiency of sulfentrazone in cassava crops grown in sandy and clayey soils. Two experiments were carried out: The first one was carried out in sandy soil conditions in the conventional system; and the second one was carried out in clayey soil conditions in the no-tillage system. The experimental design was a randomized block with four replications. The treatments consisted in doses of 250, 500, 750 and 1,000 g ha-1 of sulfentrazone, and weeded and non-weeded controls. Sulfentrazone application in cassava crops has linearly reduced the production of roots in a proportion of 0.0153 and 0.0107 t ha-1 at each increment in grams of the active ingredient, respectively. It was concluded that sulfentrazone was not selective for cassava crops grown both in sandy and in clayey soil; however, it was highly effective in weed control in both soils.

scholarly journals Germination and tolerance of cowpea (Vigna unguiculata) cultivars to water stress

2018 ◽  
Vol 22 (6) ◽  
pp. 407-411 ◽  
Author(s):  
Emanoela P. de Paiva ◽  
Francisco V. da S. Sá ◽  
Salvador B. Torres ◽  
Marcos E. B. Brito ◽  
Romulo C. L. Moreira ◽  
...  
Keyword(s):  
Water Stress ◽  
Experimental Design ◽  
Seed Germination ◽  
Dry Matter ◽  
Euclidean Distance ◽  
Development Stage ◽  
Dry Matter Accumulation ◽  
Initial Development ◽  
Cowpea Cultivars ◽  
Randomized Experimental Design

ABSTRACT The objective of this study was to evaluate the tolerance of cowpea cultivars to water stress, during seed germination and seedling establishment. For this, a completely randomized experimental design was used in a factorial scheme consisting of nine cultivars of cowpea (BRS Guariba, BRS Potengi, BRS Itaim, BRS 17 Gurguéia, BRS Aracê, Paulistinha, Maratanã, Costela-de-Vaca and Canapu-Branco) and two levels of osmotic potential induced by PEG 6000 (0.0 MPa (control) and -0.4 MPa) in four replicates of 50 seeds. The variables analysed were germination, germination first count, root and shoot lengths, and dry matter accumulation of shoots and roots. The dissimilarity between the genotypes was also determined by Euclidean distance. Germination and initial development of cowpea cultivars are impaired by the reduction in the potential to -0.4 MPa. The cultivars BRS Guariba, BRS Aracê, Paulistinha and Canapu-Branco are the most tolerant to water stress, while BRS Potengi, BRS Itaim, BRS 17 Gurguéia, BRS Maratanã and Costela-de-Vaca are the most sensitive in the early development stage.

scholarly journals Selectivity of herbicides in initial growth of pre-budded seedlings of sugarcane

2018 ◽  
Vol 9 (3) ◽  
pp. 393-401
Author(s):  
Antonio Carlos Silva Junior ◽  
José Luiz Carvalho de Souza Dias ◽  
Dagoberto Martins
Keyword(s):  
Experimental Design ◽  
The Other ◽  
Average Height ◽  
Initial Growth ◽  
Initial Development ◽  
Sugarcane Crop ◽  
Herbicide Treatments

With the advent of new implantation technologies of sugarcane crop, the aim of this study was to evaluate the selectivity of herbicides in pre-budded cultivars of sugarcane seedlings. With the formation of seedlings from a gem of high sanity in tubes with substrates, seedlings, with an average height of 20 cm, were transplanted to 12 L pots filled with soil. The experimental design was a completely randomized factorial arranged in a (3x8), being the cultivars, CTC 7, CTC 14 and RB966928; and the herbicides (g ha-1): ametryn + trifloxysulfuron-sodium (1280 + 32.4); imazapic (150); halosulfuron (150); isoxaflutole (90); ametryn (5000); ametryn + clomazone (1500 + 1000) and amicarbazone (1500), applied 10 days after transplanting; and a control without application. The three cultivars of sugarcane visually studied responded differently to the application of herbicide treatments tested, being the herbicides ametryn + trifloxysulfuron, imazapic, halosulfuron and ametryn which caused less phytotoxicity. However, when confronting the other parameters analyzed, it was observed that ametryn + trifloxysulfuron, isoxaflutole, ametryn, ametryn + clomazone and amicarbazone for CTC7 cultivar, ametryn + clomazone and amicarbazone for CTC14 and amicarbazone for RB966928, caused loss to the initial development of the crop.

scholarly journals Ethylene and 1-methylcyclopropene action over senescence of nasturtium flowers

2015 ◽  
Vol 33 (4) ◽  
pp. 453-458 ◽  
Author(s):  
Tania P Silva ◽  
Fernando L Finger
Keyword(s):  
Floral Development ◽  
Development Stage ◽  
Flower Senescence ◽  
Premature Senescence ◽  
Flower Opening ◽  
Development Stages ◽  
Post Harvest ◽  
The Third ◽  
Exogenous Ethylene ◽  
Floral Bud

ABSTRACT: This work describes ethylene and 1-methylcyclopropene (1-MCP) action on post-harvest shelf life of four development stages of nasturtium flowers. To reach this goal, we carried out three experiments. In the first and second experiments, we studied five ethylene (0; 0.1; 1; 10; 100 and 1000 μL/L) and three 1-MCP concentrations (0.25; 0.5 and 0.75 μL/L), respectively. In the third experiment, 1-MCP was followed by combined with ethylene (only 1-MCP; only ethylene; and 24 hours of exposure to 0.75 μL/L 1-MCP followed by 24 hours of exposure to 100 μL/L ethylene). All experiments had two control treatments, one keeping non-exposed flowers inside and another outside exposure chambers. Experiments were set in factorial design, in complete blocks at random, with four 10-flower replications each. Flower senescence was determined by a pre-established visual scale and by observing floral bud development. Ethylene dose above 10 μL/L induced flower wilting and premature senescence from the second floral development stage. Furthermore, higher concentrations of exogenous ethylene promoted irregular flower opening and/or morphological abnormalities in opened flowers. 1-MCP effectively extended post-harvest longevity of nasturtium flowers, independent of the concentration and even in the presence of exogenous ethylene.

Prognostic criteria for Polar Lows

2021 ◽  
Author(s):  
Natalia Vazaeva ◽  
Otto Chkhetiani ◽  
Michael Kurgansky
Keyword(s):  
Numerical Simulation ◽  
Wind Velocity ◽  
Large Scale ◽  
Satellite Image ◽  
Development Stage ◽  
Mature Stage ◽  
Initial Development ◽  
Polar Lows ◽  
Prognostic Criteria ◽  
Main Challenge

<p>Polar lows (PLs) are important mesoscale (horizontal diameter up to 1000 km) maritime weather systems at high latitudes, forming pole ward from the polar front. We consider the possible prognostic criteria of PLs, in particular, the kinematic helicity as a quadratic characteristic related to the integral vortex formations and the kinematic vorticity number (KVN). To calculate such characteristics we use reanalysis data and the results of numerical simulation with the WRF-ARW model (Version 4.1.) for the PLs over the Nordic (Norwegian and Barents) seas. For comparison, experimental data are used.</p><p>Our estimate of helicity is based on the connection of an integral helicity (IH) in the Ekman layer with the geostrophic wind velocity, due to the good correlation between IH and half the sum of the wind velocity squared. We have chosen IH averaged over preselected area covering the locality of PLs genesis. This area was moving along with the centre of PL during the numerical simulation.</p><p>The genesis of PLs can be divided into three stages: (i) an initial development stage, in which a number of small vortices appear in a shear zone; (ii) a late development stage, characterized by the merger of vortices; (iii) a mature stage, in which only a single PL is present. Approximately one day before PL formation, a significant increase in helicity was observed. The average helicity bulk density of large-scale motions has values of 0.3 – 0.4 ms<sup>-2</sup>. The local changes in helicity are adjacent to the front side of the PLs. The IH criterion described facilitates the identification of the PLs genesis area. For a more detailed analysis of the PL genesis, it is recommended to apply KVN, which is the additional indicator of PL size and intensity. At the moment of maximum intensity of PLs KVN can reach values of 12 – 14 units. The advantage of using KVN is also in its clear change directly in the centre of the emerging PLs, which allows to precisely indicates the limits of the most intense part of PLs.</p><p>The main challenge is to make the operational forecast of PLs possible through the selection of the prognostic integral characteristics of PLs, sufficient for PLs identification and for analysis of their size and intensity in a convenient, usable and understandable way. The criteria associated with vorticity and helicity are reflected in the PLs genesis and development quite clearly. At this time, such a claim is only a hypothesis, which must be tested using a larger set of cases. Future work will need to extend these analyses to other active PL basins. Also, it would be interesting to compare the representation of PLs by using any other criteria. It is intended to use our combined criteria as a precursor to machine learning-based PLs identification procedure where satellite image analysis and capture of particular cloud patterns are currently applied in most of the cases. It would eliminate the time consuming first stage of collecting data sets.</p><p>This work was supported by the Russian Science Foundation (project No. 19-17-00248).</p>

scholarly journals Microbiota indigenous milk, mesophilic lipolytic and proteolytic colonial cheese matured, produced at different times of the year

2017 ◽  
Vol 18 (4) ◽  
pp. 549-559
Author(s):  
Elisângela Borsoi Pereira ◽  
Magali Soares dos Santos Pozza ◽  
Paula Martins Olivo ◽  
Osmar Dalla Santa ◽  
Suzana da Cruz Pires ◽  
...  
Keyword(s):  
Weight Loss ◽  
Lactic Acid ◽  
Experimental Design ◽  
Relative Humidity ◽  
Water Activity ◽  
Cultural Importance ◽  
The Third ◽  
Randomized Experimental Design ◽  
Double Factorial ◽  
Production Period

SUMMARY Cheese is the oldest form of preserving milk nutrients having nutritional, economic and cultural importance. The objective of this study was to identify the best time of the year for production, and period, in months, for maturation of traditional colonial cheese, through analysis of water activity, weight loss and counts of lactic acid, mesophilic microorganisms—proteolytic and lipolytic. Records of temperature and relative humidity (RH) were maintained. A completely randomized experimental design was used in a double factorial scheme, considering production periods and maturation times. For all production periods evaluated, there was a significant reduction in the periods for water activity values. The counts of lactic acid bacteria ranged from 104 to 109 CFU/g. There was also stability in the number of colonies for lipolytic mesophilic microorganisms, until the third month of maturation. Low counts of proteolytic mesophiles were observed for the samples produced in May and June (5.70 and 5.53 log), respectively. The production period for the months of May and June corresponding to RH of 80% and average temperatures of 15°C were the most effective for production. Due to the presence of Listeria, it is recommended to respect the minimum time of 60 days of maturation for commercialization.

SOIL CONDITIONERS—THEIR EFFECT ON COARSE-TEXTURED SOILS, CROP YIELDS AND COMPOSITION

1957 ◽  
Vol 37 (2) ◽  
pp. 102-112
Author(s):  
R. M. Holmes ◽  
S. J. Toth
Keyword(s):  
Structural Changes ◽  
Crop Yields ◽  
Cultural Practices ◽  
Sandy Soils ◽  
Growing Season ◽  
Soil Aggregate ◽  
Crop Response ◽  
The Third ◽  
Soil Conditioners ◽  
The Stability

Crop response to soil structural changes caused by soil conditioner amendments was studied in several different sandy soils of New Jersey. The response varied with the crop and treatment. Those chemicals that were slightly hydrophobic were most effective and generally crop response was greatest on these treatments. Cations such as Na may be added in large amounts as part of some conditioners, and this may result in reduced uptake of other nutrients such as Mg. and K. Except for this effect, conditioners did not reduce nutrient uptake by plants. When elements such as Na and N are added in large amounts as part of some conditioners, there may be an increased uptake of these nutrients.Catalin and VAMA conditioners produced a dry surface mulch which appeared to reduce evaporation. Moisture reserves were, therefore, preserved through a drought and this resulted in increased growth of crops over those grown on other treatments. Cultural practices destroyed the stability of the conditioned aggregates, since in most cases the effect had largely disappeared by the third growing season. Chemicals which were effective in soil aggregate stabilization were also effective as anti-crustants when crusting was a problem.

scholarly journals AGRO-CLIMATIC SUITABILITY AND WATER REQUIREMENT FOR TANZANIA GUINEAGRASS CULTIVATION IN THE STATE OF CEARÁ

2017 ◽  
Vol 30 (4) ◽  
pp. 1028-1038 ◽  
Author(s):  
NAILSON LIMA SANTOS LEMOS ◽  
ANA CLARA RODRIGUES CAVALCANTE ◽  
THIERES GEORGE FREIRE DA SILVA ◽  
JOSÉ RICARDO MACEDO PEZZOPANE ◽  
PATRÍCIA MENEZES SANTOS ◽  
...  
Keyword(s):  
Sandy Soils ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Water Requirement ◽  
The State ◽  
Climatic Suitability ◽  
Irrigation Water Requirement ◽  
Productive Potential ◽  
Shallow Soils ◽  
Water Holding

ABSTRACT This study aimed to define areas suitable, and the irrigation water requirement for, cultivation of Tanzania guineagrass in the state of Ceará, Brazil. Tanzania guineagrass yield was estimated by a mathematical model, which considers the crop actual evapotranspiration, resulting from the crop climatological water balance. The water requirement throughout the year was estimated for soils with a water holding capacity of 20 (shallow soils), 40 (sandy soils), 60 (soils with medium texture) and 100 mm (clay soils). The relative frequency of occurrence of monthly productions greater than 2,750 kg DM ha-1 month-1 was obtained for different areas in Ceará, representative of most of the state's economic mesoregions. Tanzania guineagrass annual yields in the state of Ceará were between 20,000-30,000 kg DM ha-1 year-1. During the rainy season, the productive potential varies with the economic mesoregion, which presents different climatic conditions. The state of Ceará is only suitable for the rainfed production of Tanzania guineagrass for 4 months each year, predominantly from February to May, while weather conditions do not favor the development of this grass in the remaining months.

scholarly journals Initial development and gas exchange of Talisia subalbens (Mart.) Radlk. under different shading conditions

2011 ◽  
Vol 35 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Fernanda Carlota Nery ◽  
Hilton Morbeck de Oliveira ◽  
Amauri Alves de Alvarenga ◽  
Sara Dousseau ◽  
Evaristo Mauro de Castro ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Native Species ◽  
Cultivated Plants ◽  
Initial Growth ◽  
Initial Development ◽  
Basal Diameter ◽  
Shoot Ratio ◽  
Root Shoot Ratio ◽  
Significant Difference ◽  
Different Levels

Ecophysiological studies under semi-controlled conditions in nurseries and greenhouses are essential to enable the use of native species to recover degraded areas and for commercial planting. Talisia subalbens (Mart) Radlk, 'cascudo', is a native fruiting species of the Cerrado on the verge of extinction. The ecophysiological performance of this species was evaluated in nursery conditions under different levels of shading (full sunshine, 30%, 50% and 70%). Initial growth, biomass allocation, gas exchange and chlorophyll content of the plants were analyzed. Full sunshine cultivated plants showed a higher accumulation of total, shoot, and root dry biomass. There was no significant difference in the root/shoot ratio among the treatments. Seedlings cultivated under full sunshine and 30% shading showed higher values for height, basal diameter, and leaf area. Differences in stomata conductance and photosynthesis rate were not observed among the different shading levels. Plants cultivated under 70% of shading had higher contents of chlorophyll a, b, and total. During the initial phase with higher levels of radiation were fundamental for the development of T. subalbens seedlings.

scholarly journals Nutritional Requirement of Sugarcane Cultivars

2018 ◽  
Vol 10 (4) ◽  
pp. 361 ◽  
Author(s):  
Vinicius S. G. da Silva ◽  
Mauro W. de Oliveira ◽  
Vilma M. Ferreira ◽  
Terezinha B. A. Oliveira ◽  
Elaine R. Galvão ◽  
...  
Keyword(s):  
Experimental Design ◽  
Block Design ◽  
Nutritional Requirements ◽  
Nutritional Requirement ◽  
Sugarcane Varieties ◽  
The Past ◽  
Randomized Block Design ◽  
Productive Potential ◽  
New Varieties

Sugarcane produces a large amount of biomass, extracts and accumulates high amounts of nutrients. In the literature the nutritional requirements for most cultivated varieties in the past are found, however there is little information on the new varieties currently planted. The objective of this study was to evaluate the nutritional requirement of four sugarcane varieties, currently very planted, in the cycles of plant-cane, first and second ratoon. The study was installed in a Yellow Oxisol. The experimental design was a randomized block design, with five replications, and four treatments: RB867515, RB92579, SP813250 and VAT90212. During maturation of the cane, in the three evaluation cycles, the productivity of natural biomass and the nutritional requirement of macronutrients of the varieties were determined. It was evidenced that the cultivars of sugarcane are of high productive potential and resemble the accumulation of biomass, observing a yield of 158, 128 and 107 t ha-1 in the cycles of plant-cane, first and second ratoon. Regarding the nutritional requirement, the varieties did not differ among them and expressed the following order of need in the plant-cane K > N > Ca > Mg > S > P, in the first and second ratoon, the sequence observed was K > N > Ca > S > Mg > P.

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