Effect of Pressure on the Quality of Pesticide Application in Orchards

Abstract

Only part of the active ingredient used in agrochemical applications in orchards is retained on the trees. The product that is not retained is lost as sedimentation in the soil and as drift, the latter being a major source of environmental pollution. Unfavorable atmospheric conditions affect the uniformity of distribution and increase product loss. This can be mitigated by the utilization of larger drops. The objective of the present work was to evaluate the effect of service pressure on distribution in the trees and product loss by using a conventional hydro pneumatic sprayer. A fluorescent tracer was applied on fruit trees by an airblast sprayer, with two treatments: high pressure (1800 kPa) and low pressure (500 kPa). Samples were collected from the trees, in columns and from the soil. The results indicated that there were no differences between the two treatments in the total quantity of deposits recovered from leaves. There was one third less drift with the low-pressure than with the high-pressure treatment, whereas deposits on the soil were similar with the two treatments, with the low-pressure treatment presenting a higher concentration of deposits in the proximity of the treated row. In conclusion, the use of sprayer systems that operate with low pressure is a valid alternative to reduce environmental pollution because it tends to loss to the area where the treatment is being applied, without affecting deposits on the trees.

Deposição da calda na cultura da soja em função de diferentes pressões de trabalho e pontas de pulverização

“…Por outro lado, pode ter ocorrido também perda para o solo, nas maiores pressões, contribuindo para o resultado apresentado. Di Prinzio et al (2010), analisando o efeito da pressão na deposição de calda no dossel de culturas arbóreas, também verificaram diminuição da deposição com o aumento da pressão. Viana et al (2008), estudando a cobertura de gotas no dossel de soja por diferentes pontas e pressões, verificaram comportamento diferenciado da pressão, em função da ponta empregada; em alguns casos ocorreu aumento Tabela 6: Depósito de traçador (µg cm -2 ) nas folhas inferiores da cultura da soja, após as aplicações com diferentes pontas de pulverização e pressões de trabalho Médias seguidas por letras distintas diferem entre si pelo teste de Tukey a 0,05 de significância; 2 Não foi aplicado teste de Dunnett, tendo em vista a não significância da interação fatorial e testemunha; 3 F ponta , F pressão , F int e F fatxtest : valores da estatística F para os fatores ponta, pressão, interação ponta e pressão e interação fatorial e testemunha, respectivamente.…”

“…A influência da pressão no tamanho das gotas é bastante conhecida (Di Prinzio et al, 2010); contudo, seu efeito na deposição, não o é, visto que também existem a influência do ângulo do jato e a da energia potencial das gotas. Nuyttens et al (2006Nuyttens et al ( e 2007 mostram que a combinação ideal da ponta de pulverização com a pressão pode maximizar a eficiência de deposição do produto no alvo; não estudam, entretanto, a relação entre pressão e deposição.…”

Application Pressure and Carrier Volume Affects the Concentration of Azoxystrobin on Peanut Foliage and in Soil

“…Application pressure of 207 to 620 kPa did not result in improved disease control for Alternaria blight of muskmelon, though in one situation, application of chlorothalonil at 827 kPa did result in better disease control than with 207 and 414 kPa (Egel and Harmon, 2001). Applications at two pressures (500 kPa and 1400 kPa) in a pear orchard resulted in a similar amount of deposits overall on the soil, but there was a higher concentration of deposits in close proximity to the tree with the lower pressure, and a higher concentration on the ground a farther distance from the tree with higher pressure (Di Prinzio et al, 2010).…”

Impact of the Parameters of Spraying with a Small Unmanned Aerial Vehicle on the Distribution of Liquid on Young Cherry Trees

“…The remainder of the spray settles on the ground beneath the trees, or it is carried away from the application site by the wind [28,29]. The quality of the spray application on trees is influenced by many factors such as the characteristics of the tree crown, the properly selected spray dose, the nozzle type, the distance between the spray nozzle and the tree surface being sprayed, the operating speed, the flow rate of fluid from the nozzle, the droplet size, the speed and direction of the air flow and the air capacity of the fan [30][31][32][33][34]. In addition, there are many characteristics of the tree crown that strongly influence the total spray deposition on the tree.…”