Effect of sprayer parameters and wind speed on spray retention and soil deposits of pesticides: Case of artichoke cultivar

Irrational use of chemical method for crop protection, presents increasingly serious risks for human health and the environment. Droplet size and meteorological parameters are key factors to both environmental contamination and pest control efficacy. The objective of this study is to assess the impact of the nozzle use parameters, the operating pressure and the wind speed on droplet foliage deposition (retention) and soil deposition (losses), when treating artichoke. Several combinations were tested in a wind tunnel and in the field, under Mediterranean microclimatic conditions, using a fluorescent dye as a substitute for pesticide. Multiple regression models were built from tunnel data to predict foliage deposition and soil deposits, with determination coefficients of 0.96. Thus, models are able to simulate pesticide deposition on artichoke leaves and soil deposition, depending on sprayer parameters and wind speed. Foliage deposition and soil deposits rates ranged from 30 to 52% and 26 to 57% respectively for anti-drift nozzle. For conventional nozzle, rates varied from 20 to 38% and 31 to 62%. To improve retention and reduce spray losses, it is recommended to choose a medium droplet size when using an anti-drift nozzle, in conjunction with medium nozzle size, medium pressure and reduced wind speed.

EMERGÊNCIA E SOBREVIVÊNCIA DE PLANTAS DE SOJA A CAMPO EM RELAÇÃO ÀS PROFUNDIDADES E ÉPOCAS DE SEMEADURA

A PROFUNDIDADE DE SEMEADURA DA SOJA NA PLANTABILIDADE PATRÍCIA PEREIRA DIAS1*, SAULO FERNANDO GOMES DE SOUSA2, PAULO ROBERTO ARBEX SILVA3, TIAGO PEREIRA DA SILVA CORREIA4 e ANDERSON RAVANNY DE ANDRADE GOMES5 * Parte do texto foi extraído da tese da autora 1 Departamento de Produção Vegetal, Universidade Estadual Paulista ‘Júlio de Mesquita Filho’ - Av. Universitária, 3780 - Altos do Paraíso, 18610-034, Botucatu - SP, Brasil. [email protected] 2 Agroefetiva, Rua Lourival Ferreira, 11 - Distrito Industrial III, 18608-853, Botucatu - SP, Brasil. [email protected] 3 Departamento de Engenharia Rural e Socioeconomia, Universidade Estadual Paulista ‘Júlio de Mesquita Filho’ - Av. Universitária, 3780 - Altos do Paraíso, 18610-034, Botucatu - SP, Brasil. [email protected] 4 Faculdade de Agronomia e Medicina Veterinária, Universidade de Brasília, Caixa - Campos Universitário Darci Ribeiro ICC – Asa Norte, 04508, Brasília - DF, Brasil. [email protected] 5 Faculdade Regional da Bahia, Rodovia AL 220, 3630 - Senador Arnon De Melo - Planalto, Arapiraca – AL, Brasil. [email protected] RESUMO: O objetivo deste trabalho foi avaliar a cultura da soja semeada a campo em diferentes profundidades das sementes e épocas de semeadura e, dessa maneira, saber o quanto esses fatores influenciam a emergência e sobrevivência das plantas. O experimento foi conduzido em dois anos agrícolas, 2015/16 e 2016/17, com sementes de soja cultivar 5D634, na Fazenda Lageado, da Faculdade de Ciências Agronômicas – UNESP, Botucatu (SP), Brasil. O delineamento foi de blocos ao acaso em esquema fatorial 6 × 2, com seis tratamentos referentes às profundidades das sementes na mesma linha de semeadura: 0,02, 0,05 e 0,08 m do nível do solo, e combinação e alternância entre eles: 0,02 e 0,05, 0,02 e 0,08, 0,05 e 0,08 m e duas épocas de semeadura: outubro e novembro, com quatro repetições, totalizando 48 parcelas. Para a análise estatística, os dados foram submetidos à análise de variância (ANOVA), utilizando o teste de Tukey a 5% de probabilidade. A perda foi acima de 10% no estande de plantas na semeadura mais profunda (0,08 m), aliada à menor precipitação (outubro/2016), que contribuiu significativamente para esse resultado. Desta forma, a plantabilidade é prejudicada com o erro da profundidade de semeadura, aqui representada pela emergência e sobrevivência de plantas. Palavras-chave: Glycine max L., Plantabilidade, Estande de plantas. THE SOYBEAN SOWING DEPTH IN PLANTABILITY ABSTRACT: The aim of this work was evaluate the sowing of soybean seed with error in soil deposition and different month of sowing. The field experiment was carried out during two years (2015 and 2016) at Fazenda Lageado, Faculty of Agronomic Sciences - UNESP / Botucatu - SP, Brazil. The plots were randomized blocks in 6 × 2 factorial, six treatments referring to the depth of the seeds in soil: 0.02 (T1); 0.05 (T2 - control) and 0.08 (T3); 0.02 and 0.05 (T4); 0.02 and 0.08 (T5); 0.05 and 0.08 m (T6) and two sowing times: October and November. For statistical analysis the data were submitted to analysis of variance (ANOVA) using Tukey test at 5% probability. The number of plants in early stage decreased by over 10% in the deep seeding (0.08 m), added to the less rainfall (October / 2016) which contributed significantly to this result. Therefore, plantability is damaged by the error of sowing depth, represented here by the emergence and survival of plants. Keywords: Glycine max L., Plantability, Early stage.

A New Sensor for Robotic Mars Rovers in Sandy Terrains Predicting Critical Soil Flow Using the Spiral Soil Flow Model

SUMMARY The current contribution presents a new sinkage sensor specified for an unmanned ground vehicle to find the exact sinkage zone of a wheel interacting with the soil particles. This sensor will be wrapped around the wheel, and consequently, contact analog outputs will be used in soil deposition and bulldozing effect prediction. Furthermore, the new sensor will be used for a novel soil flow calculation estimating the total mass variation of the control volume of soil particles beneath the wheel. Accordingly, the spiral model simulating the displacement of the particle is implemented to calculate the soil deposition.