Automated System Predicts Grape Yields
Suszkiw April 21, 2006
Estimating grape yields is a time-consuming, laborious affair. But
that could change, thanks to a high-tech helping hand from Agricultural
Research Service (ARS) scientists in
There, ARS horticulturist
Tarara and colleagues have developed an automated system for estimating
grape yields based on tension changes in the trellis wire used to support the
vine crop. Her team is still field-testing the system. The hope is that the
yield estimates it produces will allow growers and processors to better
synchronize their pruning, watering, picking and juice-making operations.
According to Tarara, who works in ARS'
Crops Research Unit at Prosser, the current method of estimating grape
yields involves counting berry clusters on sample vines, followed by counting
and weighing of individual berries. The averages are then compared to records
from past seasons to predict the current crop's likely yield.
Imprecise estimates can sometimes be costly. For example, an inflated
yield estimate might lead a winery to order more barrels than it actually
needs. The "pain" is in the price tag: New American oak barrels start at around
$300, while new French oak barrels cost from $600 to around $800 each.
The scientists' automated system employs a device called a load cell
to detect increases in the tension of trellis wire as grape clusters form and
berries enlarge. A data logger records signals generated by the tension changes
every 10 seconds, formulating an average every 15 minutes. Now, Tarara's team
must download, inspect and "clean" data logger information for processing and
eventual use in predicting grape yield. Once validated with field tests,
though, the process will be completely automated, providing users with
real-time information on their crop's progress, according to Tarara.
Her team's yield research complements a broader viticulture program at
Prosser aimed at helping Pacific Northwest growers claim a greater share of
domestic and world grape markets through improved farm practices and mechanized
more about the research in the April 2006 issue of Agricultural
ARS is the U.S. Department of
Agriculture's chief scientific research agency.