Software Helps Farmers and Ranchers
Spot Critical Changes in Crop Growth Stages

Greg McMaster has built a computer program, PhenologyMMS (Modular Modeling System), that predicts the timing of plant growth stages so that Central Great Plains farmers and ranchers can know how their crop is progressing and when to apply pesticides, fertilizers, and water. PhenologyMMS also helps them time other management tasks. McMaster developed this decision-support tool after answering numerous calls from farmers and ranchers who wondered when their crop would be at the right stage to spray as required by the pesticide label.

McMaster is an agronomist at the Agricultural Research Service’s Agricultural Systems Research Unit in Fort Collins, Colorado.

The pesticide label gives the scientific name of the growth stage, but no other hints. McMaster’s program gives common names to go with the scientific names and tells growers how to identify the stages and when to expect them, based on weather reports and soil moisture.

To find the right timing, farmers answer questions such as, “What is your planting date?” and “How wet was your soil at planting time?” To answer this question, farmers choose one of these descriptions of soil moisture: “optimum,” “medium,” “dry,” or “planted in dust.” The last step is identifying the nearest weather station to access weather data to run a simplified model of growth for each crop chosen. The driving force of the program is cumulative temperature.

The program then simulates crop growth stages for the entire growing season, giving farmers a good idea of when each stage should occur.

McMaster says the program is unique because it covers many crops. Most such programs cover only one crop. “This program includes corn, wheat, barley, sorghum, dry beans, sunflowers, and several millet varieties and is continually being expanded,” McMaster says.

The program can be used independently or inserted into existing crop-growth models. It can be downloaded at tinyurl.com/PhenologyMMS.—By Don Comis, Agricultural Research Service Information Staff.

Gregory S. McMaster is in the USDA-ARS Agricultural Systems Research Unit, 2150 Centre Ave., Fort Collins, CO 80526; (970) 492-7340.

"Software Helps Farmers and Ranchers Spot Critical Changes in Crop Growth Stages" was published in the May/June 2011 issue of Agricultural Research magazine.