By Jennifer Russo
Collecting a little bit of information from the vineyard during the growing season can greatly improve your prediction of final yields with better accuracy than the eyeball method. Know your Bloom Date, Space between Vines, & Space between Rows. Calculate how many vines equate to 1/100th of an acre, and know how many Days After Bloom (DAB) samples were collected.
Row & Vine Spacing. If 9’ between rows the table provides the 1/100th acre calculation for you which equals 48.4 feet.
How many vines are in 48.4 feet if vines are spaced 8 feet apart? 48.4/8 = 6.05 vines (round down to 6)
Use Spatial Map to direct Sample locations to capture vineyard variation.
Clean Pick Fruit from Calculated 1/100th Acre (In this example it equals 6 vines from 48.4/8). Clean pick fruit from 2 vines from high vigor zone, 2 vines from medium vigor, and 2 vines from low vigor.
Total Weight of lbs of Fruit Collected. Weigh each sample taken above, be sure to subtract the weight of the bucket or bin used from total weight sum weights from all 6 samples to get total weight.
Consult Table on Back to Find Corresponding Crop Estimation.
Mechanical Crop Estimation
Cut a length of rope to guide your sampling lengths, lay it down along the row, clean pick with the harvester the length of the rope, weigh lbs of fruit collected. Walk behind afterwards to assess how many grapes are still on the vine/or that are on the ground.
Using the Chart:
Once you have the sample, the chart does the rest of the work for you. Follow the corresponding DAB down and the respective weight over and you have the estimated tons/acre at harvest. For example, let’s say it’s July 25th or 40 DAB (bloom on June 15th) and the fruit weighs 100 pounds. Crop estimated 8.3 ton/acre potential crop.