scholarly journals PONTAS TIPO CONE COM VARIAÇÃO DA TAXA DE APLICAÇÃO E VELOCIDADE NA CULTURA DO ALGODOEIRO

Nativa ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 301
Author(s):  
Thiago Martins Machado ◽  
Monyse Fin Barbosa ◽  
Adelina Vitória Servelhere de Rezende ◽  
Ronan Sauer Bueno

A Ramulária é uma das principais doenças fungicas do algodoeiro, trazendo consequências graves para sua produtividade e qualidade de fibras. Com o intuito de abater os gastos e melhorar os parâmetros da aplicação, o trabalho tem por objetivo avaliar diferentes tipos de pontas de jato cônico e pingente, variando a taxa de aplicação e velocidade na pulverização do algodoeiro. Foram utilizadas pontas de jato cone vazio e cheio de diferentes fabricantes e também pingente associado a ponta cone vazio. As velocidades de deslocamento do pulverizador avaliadas foram 20 e 27 km h-1. As taxas de aplicações foram de 50 e 80 L ha-1. Os parâmetros avaliados foram: DMV, amplitude relativa (dispersão), volume, densidade e cobertura. O DMV foi satisfatório para todos os tratamentos. A ponta P2 obteve resultados inferiores nos parâmetros densidade de gotas, DMV e dispersão. Na velocidade de 27 km h-1 os parâmetros volume de aplicação, densidade e cobertura obtiveram melhores resultados em comparação com a velocidade de 20 km h-1. A taxa de aplicação mais elevada melhorou os parâmetros de qualidade de aplicação na densidade de gotas, cobertura e volume. O acessório pingente não obteve resultado significativo para densidade, dispersão, volume e cobertura na cultura do algodoeiro.Palavras-chave: algodão, qualidade de gotas, tecnologia de aplicação. CONE TYPE NOZZLES WITH VARIATION OF SPRAY RATE AND SPEED IN COTTON CULTURE ABSTRACT:Ramularia is one of the main fungal diseases of cotton, with serious consequences for its productivity and fiber quality. In order to reduce costs and improve the parameters of the application, the objective of this work is to test different types of conical and pendant jet tips, varying the rate of application and speed of cotton spraying. We used empty cone tips filled with different manufacturers and also pendant associated with empty cone tip The velocities evaluated were 20 and 27 km h-1. The application rates were 50 and 80 L ha-1. The parameters evaluated were: DMV, relative amplitude (dispersion), volume, density and coverage. DMV was satisfactory for all treatments. The full cone jet tip obtained lower results in the parameters of droplet density, DMV and dispersion. At the top speed the parameters application volume, density and coverage obtained better results compared to the lowest speed. The higher application rate improved the application quality parameters in droplet density, coverage and volume. The pendant accessory did not obtain significant results for density, dispersion, volume and coverage in the cotton crop.Keywords: cotton, drops quality, application technology.

2015 ◽  
Vol 29 (4) ◽  
pp. 665-674 ◽  
Author(s):  
Darrin M. Dodds ◽  
Christopher L. Main ◽  
L. Thomas Barber ◽  
Charles Burmester ◽  
Guy D. Collins ◽  
...  

Field studies were conducted in Alabama, Arkansas, Georgia, Louisiana, Mississippi, North Carolina, and Tennessee during 2010 and 2011 to determine the effect of glufosinate application rate on LibertyLink and WideStrike cotton. Glufosinate was applied in a single application (three-leaf cotton) or sequential application (three-leaf followed by eight-leaf cotton) at 0.6, 1.2, 1.8, and 2.4 kg ai ha−1. Glufosinate application rate did not affect visual injury or growth parameters measured in LibertyLink cotton. No differences in LibertyLink cotton yield were observed because of glufosinate application rate; however, LibertyLink cotton treated with glufosinate yielded slightly more cotton than the nontreated check. Visual estimates of injury to WideStrike cotton increased with each increase in glufosinate application rate. However, the injury was transient, and by 28 d after the eight-leaf application, no differences in injury were observed. WideStrike cotton growth was adversely affected during the growing season following glufosinate application at rates of 1.2 kg ha−1 and greater; however, cotton height and total nodes were unaffected by glufosinate application rate at the end of the season. WideStrike cotton maturity was delayed, and yields were reduced following glufosinate application at rates of 1.2 kg ha−1 and above. Fiber quality of LibertyLink and WideStrike cotton was unaffected by glufosinate application rate. These data indicate that glufosinate may be applied to WideStrike cotton at rates of 0.6 kg ha−1 without inhibiting cotton growth, development, or yield. Given the lack of injury or yield reduction following glufosinate application to LibertyLink cotton, these cultivars possess robust resistance to glufosinate. Growers are urged to be cautious when increasing glufosinate application rates to increase control of glyphosate-resistant Palmer amaranth in WideStrike cotton. However, glufosinate application rates may be increased to maximum labeled rates when making applications to LibertyLink cotton without fear of reducing cotton growth, development, or yield.


Author(s):  
Tânia Bayer ◽  
Milton F. Cabezas-Guerrero ◽  
Casimiro D. Gadanha Junior ◽  
Alci E. Loeck

ABSTRACT The present research studied the performance of flat-fan and hollow-cone nozzles, with application rates of 20 and 30 L ha-1, and rotary disc atomizer with application rates of 10 and 15 L ha-1. The test was conducted with a fungicide spray tank composed of Azoxystrobin + Difenoconazole, in which the density and penetration of droplets into the canopy were evaluated using a water-sensitive paper and the distribution of the active ingredients in the plant was evaluated through the chromatographic analysis. Higher application rates resulted in higher droplet density in the upper stratum of plants. In all treatments, the penetration of the droplets was 26% into the middle stratum and 23% into the lower stratum, in relation to the top of the crop, resulting in an average 25% penetration of droplets into the leaf canopy. The active ingredients were distributed in greater quantity in the upper stratum of the plant. For the same weight, the upper part of the ‘Puitá Inta CL’ rice cultivar has a leaf area 6.4 times larger than the lower part. It was concluded that higher application rate leads to higher droplet density in the upper stratum of the leaf canopy and that all systems and application rates promoted similar penetration of droplets into the canopy.


2011 ◽  
Vol 57 (No. 8) ◽  
pp. 372-380 ◽  
Author(s):  
L. Trakal ◽  
M. Komárek ◽  
J. Száková ◽  
V. Zemanová ◽  
P. Tlustoš

The aim of this study was to evaluate metals (Cd, Cu, Pb and Zn) sorption behavior after biochar application into a metal-contaminated soil. Additionally, two different types of biochar originated from the same organic material (contaminated and uncontaminated) at different application rates (1% and 2% w/w) were evaluated as a novelty of the experiment. Batch sorption/desorption experiments were established to compare the sorption behavior of metals originating from single- and multi-element solutions. Zinc as one of the main contaminants in the studied soil was easily desorbed in the presence of Cu, Pb and to a lesser extent by Cd. This desorption was reduced after biochar application. The obtained results proved the different sorption behavior of metals in the single-metal solution compared to the multi-metal ones due to competition effect. Moreover, during multi-element sorption, Zn was significantly desorbed. The applied biochar enhanced Cu and Pb sorption and no changes were observed when contaminated and uncontaminated biochar was used. Furthermore, the application rate (1% and 2% w/w) had no effect as well. In summary, it is needed to point out that the applied rates of biochars were insufficient for metal immobilization in such contaminated soils.


2016 ◽  
Vol 16 ◽  
pp. 191-195
Author(s):  
S.E. Chok ◽  
M.C.E. Grafton ◽  
I.J. Yule ◽  
M.J. Manning

Aerial topdressing using differential rate application technology improves fertiliser spreading on hill country farms. However, the system's ability to place fertiliser accurately and precisely within an area needs to be determined. Accuracy was determined by comparing measured and intended application rates. Precision was indicated by the coefficient of variation (CV), which is the standard deviation of the measured application rate over the mean of this rate. Two trials were carried out, where aircraft deposited fertiliser at two application rates and fertiliser was captured using cone-shaped collectors. The average measured application rate for both trials was less than the intended rate. The CV ranged from 35 to 57%, and was lower than CV's from pilot-operated hopper systems (78%). A one-way analysis of variance test found the difference between measured application rate in the high and low application zone was statistically significant. The results indicate work is required to improve the accuracy and precision of the differential rate system, however, the system shows promise. Keywords: differential rate application technology, aerial spreading, fertiliser placement


2011 ◽  
Vol 21 (3) ◽  
pp. 367-375 ◽  
Author(s):  
Heping Zhu ◽  
James Altland ◽  
Richard C. Derksen ◽  
Charles R. Krause

Spray deposition and coverage at different application rates for nursery liners of different sizes were investigated to determine the optimal spray application rates. Experiments were conducted on 2- and 3-year-old ‘Autumn Spire’ red maple (Acer rubrum) liners. A traditional hydraulic sprayer with vertical booms between tree rows was used to apply the spray applications. Application rates were 10, 20, 30, and 40 gal/acre for the 2-year-old liners and were 20, 40, 60, and 80 gal/acre for the 3-year-old liners. Nylon screens were used to collect spray deposition of a fluorescent tracer dissolved in water, and water-sensitive papers were used to quantify spray coverage inside canopies. Spray deposition, coverage, and droplet density inside both 2- and 3-year-old liner canopies increased as the application rate increased. The minimum rates to spray 6.6-ft-tall, 2-year-old ‘Autumn Spire’ red maple liners and 8.7-ft-tall, 3-year-old liners were 20 and 40 gal/acre, respectively. An exponential equation was derived from these results to estimate the spray application rate required for different tree liner heights and to minimize excessive chemical use in rapidly growing tree liners.


2020 ◽  
Vol 66 (No. 9) ◽  
pp. 468-476
Author(s):  
Miroslav Jursík ◽  
Martin Kočárek ◽  
Michaela Kolářová ◽  
Lukáš Tichý

Six sunflower herbicides were tested at two application rates (1N and 2N) on three locations (with different soil types) within three years (2015–2017). Efficacy of the tested herbicides on Chenopodium album increased with an increasing cation exchange capacity (CEC) of the soil. Efficacy of pendimethalin was 95%, flurochloridone and aclonifen 94%, dimethenamid-P 72%, pethoxamid 49% and S-metolachlor 47%. All tested herbicides injured sunflower on sandy soil (Regosol) which had the lowest CEC, especially in wet conditions (phytotoxicity 27% after 1N application rate). The highest phytotoxicity was recorded after the application of dimethenamid-P (19% at 1N and 45% at 2N application rate). Main symptoms of phytotoxicity were leaf deformations and necroses and the damage of growing tips, which led to destruction of some plants. Aclonifen, pethoxamid and S-metolachlor at 1N did not injure sunflower on the soil with the highest CEC (Chernozem) in any of the experimental years. Persistence of tested herbicides was significantly longer in Fluvisol (medium CEC) compared to Regosol and Chernozem. Dimethenamid-P showed the shortest persistence in Regosol and Chernozem. The majority of herbicides was detected in the soil layer 0–5 cm in all tested soils. Vertical transport of herbicides in soil was affected by the herbicide used, soil type and weather conditions. The highest vertical transport was recorded for dimethenamid-P and pethoxamid (4, resp. 6% of applied rate) in Regosol in the growing season with high precipitation.  


Author(s):  
Subin Kalu ◽  
Gboyega Nathaniel Oyekoya ◽  
Per Ambus ◽  
Priit Tammeorg ◽  
Asko Simojoki ◽  
...  

AbstractA 15N tracing pot experiment was conducted using two types of wood-based biochars: a regular biochar and a Kon-Tiki-produced nutrient-enriched biochar, at two application rates (1% and 5% (w/w)), in addition to a fertilizer only and a control treatment. Ryegrass was sown in pots, all of which except controls received 15N-labelled fertilizer as either 15NH4NO3 or NH415NO3. We quantified the effect of biochar application on soil N2O emissions, as well as the fate of fertilizer-derived ammonium (NH4+) and nitrate (NO3−) in terms of their leaching from the soil, uptake into plant biomass, and recovery in the soil. We found that application of biochars reduced soil mineral N leaching and N2O emissions. Similarly, the higher biochar application rate of 5% significantly increased aboveground ryegrass biomass yield. However, no differences in N2O emissions and ryegrass biomass yields were observed between regular and nutrient-enriched biochar treatments, although mineral N leaching tended to be lower in the nutrient-enriched biochar treatment than in the regular biochar treatment. The 15N analysis revealed that biochar application increased the plant uptake of added nitrate, but reduced the plant uptake of added ammonium compared to the fertilizer only treatment. Thus, the uptake of total N derived from added NH4NO3 fertilizer was not affected by the biochar addition, and cannot explain the increase in plant biomass in biochar treatments. Instead, the increased plant biomass at the higher biochar application rate was attributed to the enhanced uptake of N derived from soil. This suggests that the interactions between biochar and native soil organic N may be important determinants of the availability of soil N to plant growth.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1368
Author(s):  
Wenzheng Tang ◽  
Wene Wang ◽  
Dianyu Chen ◽  
Ningbo Cui ◽  
Haosheng Yang ◽  
...  

In order to meet the growing food demand of the global population and maintain sustainable soil fertility, there is an urgent need to optimize fertilizer application amount in agricultural production practices. Most of the existing studies on the optimal K rates for apple orchards were based on case studies and lack information on optimizing K-fertilizer management on a regional scale. Here, we used the method of combining meta-analysis with the K application rate-yield relationship model to quantify and summarize the optimal K rates of the Loess Plateau and Bohai Bay regions in China. We built a dataset based on 159 observations obtained from 18 peer-reviewed literature studies distributed in 15 different research sites and evaluated the regional-scale optimal K rates for apple production. The results showed that the linear plus platform model was more suitable for estimating the regional-scale optimal K rates, which were 208.33 and 176.61 kg K ha−1 for the Loess Plateau and Bohai Bay regions of China, respectively. Compared with high K application rates, the optimal K rates increased K use efficiency by 45.88–68.57%, with almost no yield losses. The optimal K rates also enhanced the yield by 6.30% compared with the low K application rates.


2018 ◽  
Vol 40 (3) ◽  
pp. 304-312 ◽  
Author(s):  
Lais Tessari Perboni ◽  
Dirceu Agostinetto ◽  
Leandro Vargas ◽  
Joanei Cechin ◽  
Renan Ricardo Zandoná ◽  
...  

Abstract: The goals of this study were to evaluate herbicide application rates at different timings for preharvest desiccation of wheat (Trial 1), as well as to evaluate the effect of the timing of herbicide desiccation at preharvest and harvest timing (Trial 2) on yield, germination, and herbicide residue in wheat seed. In Trial 1, treatments consisted of two application rates of glufosinate, glyphosate, paraquat, or paraquat+diuron and a control without application; application time periods were in the milk grain to early dough stage, soft dough to hard dough stage, and hard dough stage. In Trial 2, treatments consisted of different application time periods (milk grain to early dough stage, and soft dough to hard dough stage), different herbicides (glufosinate, 2,4-D+glyphosate, and untreated control), and different harvest times (5, 10 and 15 days after herbicide application). One thousand seeds weight, yield, first and final germination count, and herbicide residue on seeds were evaluated. Preharvest desiccation with paraquat, glufosinate, and 2,4-D+glyphosate at the milk grain to early dough stage reduces wheat yield. Regardless of the herbicide and application rate, application in the milk grain to early dough stage and soft dough to hard dough stage provides greater germination of wheat seeds, except at the lower dose of paraquat. Systemic herbicides accumulate more in wheat seeds.


Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1136
Author(s):  
Se-Won Kang ◽  
Jin-Ju Yun ◽  
Jae-Hyuk Park ◽  
Ju-Sik Cho

A field experiment was carried out to investigate crop productivity, emissions of carbon dioxide (CO2) and nitrous oxide (N2O), and soil quality of an upland field treated with compost and varying rates of biochar (BC) derived from soybean stalks during crop growing periods in a corn and Chinese cabbage rotation system. Compost was supplemented with BC derived from soybean stalks at varying rates of 5, 10, 15, and 20 t ha−1 (BC5, BC10, BC15, and BC20, respectively); the control (BC0) area was untreated. Our results reveal that crop productivity and emissions of CO2 and N2O varied significantly with the biochar application rate. Moreover, irrespective of the biochar application rate, crop productivity was improved after BC application as compared to the control treatment area, by 11.2–29.3% (average 17.0 ± 8.3%) for corn cultivation and 10.3–39.7% (average 27.8 ± 12.7%) for Chinese cabbage cultivation. Peak emissions of CO2 and N2O were mainly observed in the early period of crop cultivation, whereas low CO2 and N2O emissions were determined during the fallow period. Compared to the control area, significant differences were obtained for CO2 emissions produced by the different biochar application rates for both crops. During the two cropping periods, the overall N2O emission was significantly decreased with BC5, BC10, BC15, and BC20 applications as compared to the control, ranging from 11.1 to 13.6%, 8.7 to 15.4%, 23.1 to 26.0%, and 15.0 to 19.6%, respectively (average 16.9% decrease in the corn crop period and 16.3% in the Chinese cabbage crop period). Soil quality results after the final crop harvest show that bulk density, soil organic carbon (SOC), pH, and cation exchange capacity (CEC) were significantly improved by biochar application, as compared to the control. Taken together, our results indicate that compost application supplemented with biochar is potentially an appropriate strategy for achieving high crop productivity and improving soil quality in upland field conditions. In conclusion, appropriate application of biochar with compost has the concomitant advantages of enriching soil quality for long-term sustainable agriculture and reducing the use of inorganic fertilizers.


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