The Peach Replant Problem in Ontario: I. Symptomatology and Distribution

Abstract

In Ontario, serious difficulties are frequently encountered in the establishment of young peach trees as replacements in old orchard sites. Symptoms vary from slight stunting to complete absence of growth. Causal factors described in conflicting reports in literature on the subject and information gained from examination of affected trees attest to the complexity of the problem. The failure of the replanted trees has been ascribed to the activity of insects and nematodes as well as to the effect of nutritional disturbances, toxic agents, and spray residues. The problem is being studied as a co-ordinated investigation by plant pathologists, entomologists, microbiologists, horticulturists, nematologists, and chemists. The account given here is introductory to a series of papers dealing with the various phases of the investigation and includes mainly a review of the literature and a description of the symptoms and effects of the disorder.

The Short Life and Replant Problems of Deciduous Fruit Trees

“…Another report from California by De Vay et al (1967) stated that the decline of peach trees is a chronic root problem affecting 2-to 16-year-old trees, particularly in light soils. In Ontario, serious difficulties are frequent in the establishment of replants on old orchard sites (Koch 1955; Boyce 1957, 1958a,b;Mountain and Patrick 1959;Patrick 1955;Ward and Durkee 1956;Wensley 1956). Agrios (1971) reported from Greece that peach and apricot trees die within three to four years of first tree decline symptoms.…”

“…Gilmore (1959) noticed slower growth of peach on replant sites than on new peach sites. The difficulties frequently encountered in the establishment of peach replants on old sites in Ontario are characterized by Koch (1955) as variable from slight stunting to a complete absence of growth; in addition to stunting, reported chlorosis of peach trees on replanted land. Hung and Jenkins (1969) described the death of peach trees as either a slow decline over a period of several years or a quick decline within a year or two of planting on an old orchard site.…”

“…In the early spring of 1962, no pathogenic organism was consistently associated with the diseased tissue, although yeasts and bacteria seemed a t least partially responsible for killing thousands of peach trees in Georgia (Chandler et al 1962). However, in addition to cold injury and nutritional disturbances, peach replant failures have been reported to be caused by the activity of insects, bacteria, certain fungi, and nematodes (Clayton 1975a;Koch 1955). …”

The toxicity of peach tree roots

“…Among the symptoms are retarded growth, interveinal chlorosis of the top portion of the tree, and the 'witches broom' type of root growth 9 The failure of peach replants in old orchard soils has been attributed to toxic agents, insects, nutritional disturbances, spray residues, fungi, and nematodes 3. There are conflicting reports in the literature concerning the role of toxins derived from peach root residue decomposition in the peach replant problem.…”

Etiology and control of orchard replant problems: a review

“…Difficulties in establishing tree fruits in nurseries or old orchard sites are generally termed "replant problems" or "replant diseases" (Koch 1955, Patrick et al I964, Mai & Abawi 1981. These problems of pome and stone fruits are widespread in all of the major fruit-growing regions of the world and have been recognized for more than 200 years (Mai & Abawi 1981).…”