Last updated: September 15, 2023
Article
Historic Orchard and Fruit Tree Condition Assessments
This text comes from the Historic Orchard and Fruit Tree Stabilization Handbook, published by the National Park Service with California Department of Parks and Recreation (2012).
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The condition assessment process is an essential first step in the stabilization of old fruit trees and orchards.
The condition assessment provides managers with baseline information about the total number of living and dead trees, tree identity, location, general condition class, and the various threats and risk of losses to potential resources. The condition assessment process is not designed to answer questions about historic significance and integrity, but rather to provide managers with the information needed to establish priorities for stabilization and to begin to perform and track stabilization actions.
The goal of a condition assessment is to assign a condition class of "good", "fair", "poor", or "dead" to each fruit tree, as a result of observing and documenting the field conditions and creating a unique identity for each tree. The recommended protocol for assessing condition guides the assessor to consider the full tree by examining the orchard floor in the vicinity of the tree, the roots, trunk, canopy, and area above the canopy, in order to identify deficiencies and summarize the general status of each tree with a condition class.
Fruit Tree Condition Classes
Like other cultural resouces, the condition classes of old fruit trees and orchards are based on a measure of relative stability or instability, rather than industry standards for the acceptable condition of new trees or nursery stock.
| Condition | Description |
|---|---|
| Good | The tree has new growth at the terminal ends of shoots and only minor physical damage, defects, disease or insect damage, and/or only minor dieback or deadwood present. |
| Fair | The tree has decreased new growth with moderate physical damage, defects, disease or insect damage, or moderate dieback or deadwood present. |
| Poor | The tree is in a general state of decline with little or no new growth, major physical damage, defects, disease or insect damage, or major dieback or deadwood present. |
| Dead | The tree is dead. |
Using the Fruit Tree Condition Assessment Field Form
The Fruit Tree Condition Assessment Field Form is recommended for recording each tree, and it guides the examination based on various zones to assess condition.
Identification Data
The most critical information in the field form dataset is the Field Identification Number, the Location, and the Date of assessment. These data initiate the means for future tracking of the tree.
The Field Identification Number is a unique identifier assigned to each tree. The identifier may be composed of letters and numbers, potentially incorporating the site location, row or column location (within an orchard grid) as well as tree number. The Field Identification Number may be attached to each tree with an easily visible metal plant tag, however, the tag should not be relied upon as the only means of later reconnaissance. For example, a digital site map with field identification numbers is a more reliable source.
The Location data should be captured with at least the minimum level of accuracy to allow for future reconnaissance. Ideally, location data has sufficient accuracy to allow for projection on a map, by capturing geographic coordinates such as UTMs or latitude/longitude data.
The Date data is the date on which the tree is examined. This data field is updated upon future condition assessments.
The Park data is the name of the park or unit in which the tree is located.
The Inspected By data is the name(s) of the assessor(s). While different assessors may capture the data, consistency in approach between assessors is very important, to avoid disparities in the assignment of condition classes.
The Species data is the basic taxonomic rank of the tree, such as almond, apple, apricot, fig, lemon, olive, orange, pear, peach, persimmon, pomegranate, and walnut, etc. While fruits and leaves are the most immediate indicators of species, tree size, form and bark are also diagnostic for trained horticulturists. The Species data field should be left blank until a positive identification can be made by a trained individual.
The Variety data is the taxonomic rank below species, such as "Red Delicious," "Bartlett," "Eureka," or "Navel." Variety is usually determined through examination of fruits, and is generally not identifiable in the absence of fruit. In addition, old fruit trees with low vigor may produce poorly developed fruits that are uncharacteristic of the variety. The Variety data field should be left blank until a positive identification can be made by a trained individual.
The Diameter data is the diameter of the trunk at the location just below the point of attachment of the lowest scaffold limbs, rather than at breast height, which is the more common arborist's standard for tree diameter. Fruit trees often have short trunks, with the scaffold limbs borne within three feet from the ground, and therefore the concept of trunk diameter at breast height is probably irrelevant. The diameter can be measured approximately using a tape measure sighted perpendicularly to the trunk, or by measuring the circumference and converting into the diameter by dividing the circumference by 3.14.
The Tree Significance data is a check mark indicating whether the tree is known to be historically significant as an individual, or as a contributing feature to a larger significant property. Old fruit trees that have lost integrity or newer fruit trees that have been planted or naturalized on a site may also be documented in the condition assessment process, and so "non-contributing feature" for known non-historic trees, may be checked.
The condition assessment process informs but does not directly determine historic significance and integrity. A determination of significance and integrity is made as a result of historical research and the analysis and evaluation of existing conditions with respect to historic conditions. Significance may be "unknown," and this data field should be checked until the full process of determination is performed.
Condition Assessment Data
The condition class of the Condition Assessment dataset is assigned as a result of completing the inspection. It is the last dataset to be completed.
The class is assigned based on the aggregate of the presence or absence of new growth and the combined deficiencies of all tree growth zones. The classes represent a spectrum of stability, and are relative assessments. The condition class is used in setting priorities for stabilization actions of individual trees, and therefore it is important to be consistent in applying the definitions of class from tree to tree.
A photo that illustrates the condition of the tree is useful for tracking changes in condition in the future.
Inspection Data
The Inspection dataset guides the assessor to examine the fruit tree within different growth zones, and to record the presence of specific deficiencies in these zones.
Zone 0 corresponds to the orchard floor within the vicinity of the tree but outside the root zone or dripline of the tree canopy. In this zone, the assessor is looking for deficiencies outside the healthy growing conditions of an open, low ground cover, (or possibly no ground cover in some orchards) with a continuous, stable substrate.
Deficiencies found in this zone include overgrown ground cover (taller than six inches) or encroaching vegetation that is competitive with the fruit trees, or evidence of deficient substrate conditions, such as wildlife colonization (burrows, nests) or drainage problems (puddles, gullies).
Zone 1 corresponds to the root system of the individual fruit tree, found within or just beyond the edge of the drip line. In this zone, the assessor is looking for deficiencies outside the healthy growing conditions of an open, low ground cover (or possibly no ground cover) with a continuous, stable substrate covering the
tree roots.
Deficiencies found in this zone include exposed, damaged roots, accumulated debris (either vegetative or non-vegetative), root suckers or unseasonably early fruit drop, indicating the presence of health stressors.
Zone 2 corresponds to the base of the tree trunk, where the trunk meets the roots. In this zone, the assessor is looking for deficiencies outside the healthy condition of a sound trunk flare meeting the substrate.
Deficiencies in this zone include the absence of a trunk flare when the base of the trunk is buried by accumulated substrate; damage to the trunk due to wildlife browsing, with girdling or loss of bark; signs of pests and diseases such as cankers or fruiting bodies; signs of structural instability such as cracks, splits or cavities; and/or signs of encroaching vegetation such as root suckers or competitive undergrowth.
Zone 3 corresponds to the trunk of the tree between the base and the point of attachment of the scaffold limbs. In this zone, the assessor is looking for deficiencies outside the healthy condition of a sound, upright trunk with continuous bark cover.
Deficiencies found in this zone include signs of structural instability due to a leaning or hollow trunk or with cracks and splits; signs of pests and diseases such as cankers, fruiting bodies or wildlife nests; signs of unmanaged vigor such as epicormic growth (shoots arising directly from the trunk, rather than the terminal branches); or signs of dieback such as loss of scaffold limbs, or hanging or attached deadwood.
Zone 4 is a large zone, corresponding to the major scaffold limbs, branches, shoots and foliage of the tree. This is the zone that usually captures our attention. In this zone, the assessor is looking for deficiencies outside the healthy condition of sound, structurally balanced scaffold limbs, with a well-branched (also known as a "well-feathered") canopy, with a majority of live branches and shoots, well-covered with live foliage.
Deficiencies in this zone include signs of dieback such as deadwood, loss of limbs, sparse foliage, or no new or diminished new growth (look for the length of new wood at the shoot tips and compare to the previous year's growth; six inches is a measure of "good" growth for an old fruit tree); signs of pests and diseases such as cankers, fruiting bodies or wildlife nests; signs of competitive vegetation such as encroaching plants or water sprouts (vertical, unbranched vegetative shoots that compete with the desired canopy of the tree); or signs of poor fertility or drought such as discolored, curled or sparse foliage, premature leaf drop or dieback of terminal shoots.
Zone 5 is the area above or around the tree canopy which provides light and air and a physical space for new growth. In this zone, the assessor is looking for deficiencies outside the healthy condition of a complete absence of other vegetation, objects or features that may block light and air or impinge upon the
space for the tree to grow.
Deficiencies in this zone include encroaching competitive vegetation, both direct (adjacent) and indirect (not adjacent but with the ability to cast more than six hours of shade per day), or encroaching objects or features such as temporary structures, stored or stockpiled materials and
equipment.
Field Condition Assessment Recommendations
The Recommendations dataset prompts the assessor to record any immediate or particular needs of the individual tree for stabilization or the potential for future removal, in the case of a condition class of "dead."
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Upon completion of the Inspection part of the dataset, the condition class is assigned, based on an aggregation of the deficiencies observed in all tree growth zones. After compiling the data for all trees, the first round of condition assessments is complete.
A Note on Format
The preferred format for dataset capture is electronic rather than hard-copy, due to the flexibility of data transfer to other management tools such as electronic databases and GIS. The field form dataset can be captured with the data-logger of a GPS unit, or directly input into the spreadsheet of an electronic tablet or other portable electronic device. If data are recorded in hard copy on the field form, later transfer into an electronic medium is recommended.
Re-Assessing Condition
The condition of biotic cultural resources such as old fruit trees and orchards is dynamic, and the condition assessment should be periodically repeated to maintain accurate management records.
An annual condition assessment is recommended to note any changes in condition. A comprehensive condition assessment is recommended every five years, to include a review of the complete dataset in the field form. The complete dataset should be updated with each assessment to reflect current conditions and priorities for stabilization.
Setting Priorities
The condition assessment data are used to set priorities for stabilization actions. The data provide the manager with the number, location and general condition classes of fruit trees on a site or within an orchard. Ideally, the condition assessment data for all fruit trees on a site or within an orchard are compiled electronically into one database, searchable by tree identification number, species, variety or condition, and tree locations are projected on a site map.
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