PEAQ is an aid for determining when to take the first cutting of alfalfa. PEAQ stands for Predictive Equations for Alfalfa Quality. The PEAQ method will work on any cutting of alfalfa to determine the maturity of the crop and when to start cutting. PEAQ sticks are available or you can use a yard stick and the chart.

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Forage yield, quality and stand persistence are considerations for deciding on when to cut. The Relative Feed Value (RFV) drops at a faster rate on the first and second cutting than on the third cutting. When to start the first cutting is determined by desired forage quality. Second cutting is normally taken on a time interval, 28-33 days after first cutting; the third cutting, where the RFV declines slower, can be taken at 10-25% bloom so the plant can store a high level of energy reserves in the roots.

PEAQ and How to Use It :

If the field is 30 acres or less, you need to take 5 two-foot square sample areas and do the following:

1. Determine the stage of the most mature stem.

   Vegetative - stem is more than 16” tall, no visible buds or flowers.

   Bud Stage - 1 or more nodes with visible buds, no flowers visible.

   Flower Stage - 1 or more nodes with at least one open flower.
    

2. Using a Yard stick measure the height of the tallest stem (not the highest leaf). The tallest stem isn’t always the most mature stem. Using a PEAQ stick requires no chart to obtain the RFV reading of the alfalfa.
3. Use the PEAQ chart to determine RFV at each sampling location and average readings across the field.
4. On average, 20 points of RFV are lost through the harvest process and additional points are lost as the plants mature during harvest. You need to factor in harvest loss and plant maturation loss when figuring a RFV target to decide when to start cutting the alfalfa crop.
5. You need to consider grasses and weeds in your fields. The PEAQ equations are accurate only on alfalfa. Grasses generally lower RFV, whereas weeds can reduce, increase, or have no effect on final RFV value.

Start Cutting Formula:

Desired RFV + RFV Harvest Loss + Maturity Loss/day x Estimated Number of days to Harvest = Starting RFV.

Example:

(150 RFV desired) + (20 RFV points for Harvest Loss) + (5 RFV Maturity Loss/day x 5 days to harvest) =
150 + 20+ 25 = 195

Therefore, 195 is the starting point using the PEAQ method to achieve 150 RFV alfalfa.