Weather conditions favorable for agricultural spraying in Rio Grande do Sul State

Abstract

Knowledge of the periods when the meteorological conditions are favorable for agricultural spraying is important in agricultural planning, particularly in fleet dimensioning. This study aimed to determine, on a temporal scale, favorable weather conditions for agricultural spraying in Rio Grande do Sul State, Brazil. In addition, the times and months of the year that have the most and least suitable conditions for agricultural spraying were investigated, as well as the meteorological conditions that are frequently limiting and their relationships with the geographic coordinates and altitude of the location. Hourly data from automatic weather stations in 12 locations were collected, totaling 56,500 days and 1,356,009 hourly observations. Wind speeds greater than 3 km h-1 and less than 10 km h-1, air temperatures up to 30 °C, and relative air humidity above 55% were considered favorable. The data were released after descriptive analysis considering the registered frequency and mean. Altitude showed a moderate negative correlation with wind speed favorability. Air temperature was the meteorological element with the greatest favorability for agricultural spraying in the Rio Grande do Sul State, whereas wind speed was the most limiting meteorological element. There were no differences in favorability between the months of the year. The most favorable times were from 6:00 p.m. to 11:00 a.m. and the most unfavorable from 12:00 p.m. to 5:00 p.m. Considering the condition in which air temperature, wind speed, and relative air humidity were adequate for agricultural spraying simultaneously in the Rio Grande do Sul State, 43.2% of the periods were favorable.

Developing an algorithm to geographically estimate the available time for agricultural field spraying in the state of Mato Grosso do Sul

“…Agricultural spraying activity is often paused on the field due to inadequate weather or soil in high humidity conditions, which is unsuitable for the transit of agricultural machinery over the soil. Overall, the ideal weather conditions for pesticide applications are established as temperatures below 30°C, relative humidity above 55%, and wind speed between 3 and 12 km h -1 (Radons et al, 2022). Agricultural spraying in unfavorable environmental conditions promotes an increase in spray drift.…”

“…Londrina, v. 44, n. 2, p. 469-484, mar./abr. 2023 spraying, which is represented by minimal wind speed and a higher relative humidity index, has generally been found to range between 6:00 p.m. to 11:00 a.m. (Radons et al, 2022). Recently, night spraying has been adopted to minimize losses caused by adverse weather conditions (low air humidity, high temperature, or high wind speed), reducing the risk of drift and losses through evaporation (Tian et al, 2020).…”