Alfalfa producers can use an effective tool to predict alfalfa harvest timing. Predictive Equations for Alfalfa Quality (PEAQ) estimates forage quality by plant maturity and height. A PEAQ stick provides producers a way to sample fields as often as they wish.
These four simple steps from the Midwest Forage Association (MFA) explain how to use a PEAQ stick to estimate preharvest alfalfa quality.
Step 1: Choose a representative 2-square-foot area in the field.
Step 2: Determine the stage of the most mature stem in the area using the following criteria:
Step 3: Select the tallest stem in the 2-square-foot area. Measure it on the correct maturity scale (from step 2) by placing the stick at the soil surface and determining RFQ at the tip of the stem (not the tip of the highest leaf). Note that the tallest stem may not be the most mature stem. Measure carefully, making sure the stick is next to stem.
Step 4: Repeat these three steps in five representative areas across the field. Sample more areas if fields are larger than 30 acres.
Notes: This procedure estimates the Relative Forage Quality (RFQ) of the standing alfalfa crop but does not account for changes in quality due to drying, harvesting and storage. These factors may further lower RFQ by 15 to 25 points, assuming good wilting and harvesting conditions. Experts recommend testing forage quality after baling or ensiling.
This procedure assumes normal growth. If growth is affected by nutrient deficiency, insects or diseases, results may not be accurate.
For more information, visit midwestforage.org and click on "PEAQ Sticks."