Ideas for applicators to use residue lab

Published online: Jun 09, 2013

There are many conditions applicators should note that can impact the effectiveness of a herbicide application including the environment before and after spraying, the pesticide mix of various herbicides or a mix with insecticides or fungicides, spray pattern with various nozzles and plant characteristics including the leaves.

Applicators can manage their risk through training, gathering information and documenting their application process. When an issue emerges, these actions can help answer questions, track down probable causes, and assist in a testing strategy to determine the problem or impact to the crop or environment.

Yearly refresher of pesticide applicator license training along with specific company procedures will help standardize each loading process of an applicator rig. A checklist is helpful for employees with heavy workloads during the busy seasons to ensure critical steps are completed in each application or process, suggests SGS laboratories.  

"A logbook should be used to record information such as the lot number of the herbicide, sprayer and settings used for the application, when and who mixed the chemical, when and who applied the chemical, the location of the application and field application notes or comments," the lab company suggests. "This information should be supplemented with weather and field information prior to and following the herbicide application. All of these details will assist in answering questions if an issue arises."

There are additional notes that can be wise to have even if the application unit has telemetry connection so that application information is stored in the applicator computer system or transferred to the headquarters main computer.  

What seems somewhat impractical, SGS suggests a commercial applicators might retain sample of the chemical mix (2 to 4 ounces) or each sprayer load (16 ounces) be saved for the season in case there are any issues with the application.

"Herbicide drift is the most common cause of crop damage, followed by soil carryover, misapplications and product contamination," SGS claims. "When an issue arises, details recorded in the applicator's logbook will help piece together a testing strategy. A sampling strategy may involve taking one sample from the affected area, two samples if there are non-affected and affected areas within a field, or three samples if a drift pattern gradient appears in the field. For suspected drift problems, plant tissue samples are used to diagnose the problem, whereas soil carryover issues utilize soil for the test substance."

SGS provides a herbicide residue sampling guide to assist the producer, crop consultant and/or claim specialist in attaining the best samples for a laboratory to test. Rose Neal, pesticide residue scientist at the company's Brookings, S.D., laboratory, has more than 20 years of experience in residue analysis and can assist clients in determining a testing plan for individual situations. SGS tests for pesticide residues in soil, plant material and water.

Additional herbicides have been added in 2013 to the screen packages, which include plant growth regulators, neutral herbicides, sulfonylureas, imidazoles, and clethodim. Individual analysis for glyphosate, glufosinate, flumioxazin, aminopyralid, pyroxsulam, florasulam, cloransulam, flumetsulam, and isoxaflutole is available. Other pesticide tests may be available or needed as diverse testing can be necessary to assist in soil and plant fertility, plant and seed diseases, as well as contaminants in soil, plant, grains or feeds.