Efficacy of Herbicides When Spray Solution Application Is Delayed

Peter M Eure,Loren R Fisher,David L Jordan,Alan C York

doi:10.1155/2013/782486

Peter M Eure, Loren R Fisher + Show 2 more

Open Access

https://doi.org/10.1155/2013/782486

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Abstract

Information is limited concerning the impact of delaying applications of pesticides after solution preparation on efficacy. Experiments were conducted to determine weed control when diclosulam, dimethenamid-P, flumioxazin, fomesafen, imazethapyr, pendimethalin, andS-metolachlor were applied preemergence the day of solution preparation or 3, 6, and 9 days after solution preparation. Herbicide solutions were applied on the same day regardless of when prepared. Control of broadleaf signalgrass, common lambsquarters, entireleaf morningglory, and Palmer amaranth by these herbicides was not reduced regardless of when herbicide solutions were prepared. Surprisingly entireleaf morningglory control by all herbicides increased when herbicide application was delayed by 9 days. In separate experiments, control of broadleaf signalgrass by clethodim, common ragweed by glyphosate and lactofen, entireleaf morningglory by lactofen, Italian rye grass by glyphosate and paraquat, and Palmer amaranth by atrazine, dicamba, glufosinate, glyphosate, imazethapyr, lactofen, and 2,4-D was affected more by increase in weed size due to delayed application than the time between solution preparation and application.

Highlights

Unforeseen circumstances such as high wind speed, excessive rain, and equipment failure may prevent timely application of spray solutions
In cotton (Gossypium hirsutum L.), performance of ethephon, indoxacarb, methomyl, spinosad, and thidiazuron was influenced when spray solution application was delayed 1 or more days, whereas efficacy of acephate, carfentrazone, diuron plus thidiazuron, ethephon plus cyclanilide, indoxacarb, lambda-cyhalothrin, lambdacyhalothrin plus thiamethoxam, methomyl, thidiazuron, and thiodicarb was not affected when left in spray solution for up to 9 days [15]
Rainfall of at least 0.65 cm occurred within 11 days after herbicide application in all experiments

Summary

Introduction

Unforeseen circumstances such as high wind speed, excessive rain, and equipment failure may prevent timely application of spray solutions. Experiments were conducted to determine the influence of delayed applications on efficacy of seven residual soil-applied herbicide spray solutions prepared up to 9 days prior to application. In addition to visible estimates of control, above-ground fresh weight of three broadleaf signalgrass, common ragweed, and Palmer amaranth plants representative of plants in each plot was determined 4 weeks after optimum timing of herbicide application.

Results

Conclusion