The Western Chestnut

Leaf analysis has been widely used for many years as a means of diagnosing and correcting nutrient disorders and for estimating fertilizer needs prior to the occurrence of nutrient disorders. It has been shown that leaf element content may be regarded as an index to the plant’s nutritional status, which is related to growth and to crop production and quality. Leaf nutrient levels fall in the ranges of deficient, below normal, normal, above normal, and excess. These standard ranges have been established with fertilizer experiments in Oregon and elsewhere. Leaf nutrient levels, however, may vary throughout the season and from leaf to leaf on the plant, as well as from plant to plant in the field or orchard. The standards were developed to take these variables into consideration. Consequently, leaf sample values are valid only for leaves collected during the proper period, from the proper part of the plant, and handled in the standard fashion.

The results you receive from OSU are based on recommendations by Jeff Olsen, Extension Specialist for fruit trees and nuts in Yamhill County and are an attempt to give you an idea of your trees’ needs.

WCGA members have been participating in foliar analysis since 2000 and sending their results to Jeff so that we may get a baseline for what’s "normal" and desirable in chestnuts. Your participation will contribute to this study and benefit you in addition by providing information about your trees’ nutrients needs.

Depending on where you live, mid-July to mid-August is the time to do the sampling. Samples from healthy, productive trees are to be used. Take 10 leaves from each of 5 trees randomly selected from all sides of each tree, only one leaf from a shoot. Collect leaves that are free of disease, dirt and/or damage. Pick leaves so that the petiole remains on the leaf.

Your analysis can be done by any of the following:

Whichever lab you choose to use, call them to get the kit they may require for shipping your samples. Make sure to send your results to Jeff Olsen, 2050 Lafayette Ave., McMinnville, OR 97128. His phone is 503-434-7517 or 503-434-8915.

Central Analytical Laboratory
Plant Analysis
Dept. of Crop and Soil Science
Oregon State University
ALS 3079
Corvallis, OR 97331-7306
541-737-2187

Agri-Check, Inc.
Agricultural Testing Laboratory
PO Box 1350
Umatilla, OR 97882
800-537-1129 or 541-922-4894

Western Agricultural Laboratories
10220 SW Nimbus Ave.
Bldg. K9
Portland, OR 97223
503-968-9225