ISHS Acta Horticulturae 686: VI International Congress on Hazelnut
THE METHODS AND RESULTS OF THE OREGON AGRICULTURAL STATISTICS SERVICE: ANNUAL OBJECTIVE YIELD SURVEY OF OREGON HAZELNUT PRODUCTION |
| Authors: | J. Olsen, J. Goodwin |
| Keywords: | Corylus avellana |
| Abstract:
According to an industry-wide tree survey conducted in 2000-2001, the hazelnut industry in Oregon currently has 29,140 acres (11,793 hectares) in production on 681 operations. The largest crop in the history of the industry was in 2001 at 49,500 tons (54,563 metric tons). Each year the Hazelnut Marketing Board (HMB) funds the Oregon field office of the United States Department of Agriculture (USDA) National Agricultural Statistics Service (NASS) to conduct an early season objective yield survey which is used to inform HMB marketing efforts. The results of the survey are released in the third week of August, and have a great influence on the Hazelnut Growers Bargaining Association’s negotiations of a minimum grower field price for the year. An objective yield survey consists of actual counts and measurements of tree characteristics in sample orchards by trained enumerators and laboratory analysis of the picked green nuts. A sample of 180 randomly selected orchards is used in the survey, with two randomly selected trees per orchard. Half of each year’s sample trees come from trees that were sampled the previous year. In April, before nut set, two primary scaffold branches per tree are marked for sampling. In the first week of August, all nuts from the sample scaffold branches are picked from the tree and sent to the laboratory for analysis. The husks are peeled and the nuts are cleaned and sorted into eight size groups. All of the sample nuts are cracked and weighed, with defective nuts identified. The principle formula used to produce a total yield for the industry in Oregon is: production per tree x the total number of trees in production. The production per tree is the product of nuts picked per tree, average nut size and dry weight per good nut. The two major types of data expansions used to set the forecast number are direct expansion and linear regression expansion. A ratio expansion of the current year’s direct expansion with those of the previous year for the same sample is also used. Over the last thirty-four years, the performance of the NASS objective yield survey has been remarkably accurate, with an average difference of only 8.1% between predicted and actual yields. NASS releases the official production forecast for the Oregon hazelnut crop in August, with revisions, if necessary, issued the following June. The Hazelnut Marketing Board’s final production totals are available in the spring following the harvest. | |
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