Nematodes and Tree Fruits Howard Ferris Department of Nematology University of California, Davis November 4, 1999

male female

male female

male female

Plant-feeding nematodes…….. Cause mechanical injury to cells and tissues Cause cell death Modify cell development Modify cell function Disrupt uptake of water and nutrients Alter photosynthate partitioning Create avenues of ingress Predispose plants to other stresses

Signs and symptoms….. Stunting, slow growth, dieback Chlorosis and nutrient deficiencies Wilting Reduced yield Lack of response to other treatments Root symptoms –Root tip stunting –Galls at root tip or along roots –Lesions on roots

Migratory endoparasite of almond apricot peach nectarine plum prune walnut grape rose Lesion nematodes

Migratory ectoparasite of almond apricot peach nectarine plum prune walnut cherry grape grasses Predisposes Prunus sp. to bacterial canker Ring nematodes

Root-knot nematodes Meloidogyne spp Sedentary endoparasites of Lovell peach root English walnut Many grape cultivars Many weed species Many cover crops

Migratory ectoparasite of almond apricot peach nectarine plum prune walnut cherry grape Virus vector in Prunus sp. Dagger nematodes

Migratory ectoparasite of almond apricot peach nectarine plum prune walnut cherry grape Pin nematodes

Management strategies…. Planting site selection, non-host rotation Preplant soil disinfestation Clean equipment, water Certified planting stock Rootstock selection Biological antagonists, the soil food web Postplant management — amendments — nematicides — cover crops

Preplant disinfestation - nematicides Methyl bromide 1,3-dichloropropene (Telone) metam sodium (Vapam)

Cover / Rotation Crops

Rootstock selection - Juglans

Rootstock selection - Prunus

Biological antagonists, the soil food web Bacteria Fungi Nematodes Microarthropods Consider: Food web maturity Susceptibility to disturbance Indicators of food web condition

Postplant management - amendments onion garlic pumpkin rapeseed herbal remedies cover crops and green manures

A) Ac = Allium cepa, As = Allium sativum, Cc = Coptis chinensis, Ec = Eugenia caryophyllata, Nt = Nicotiana tabacum, Sa = Sinapis alba. B) Ac = Asparagus cochinchinensis, Me = Manihot esculenta, Ss = Stemona sessifolia, Zo = Zingiber officinale. C) Ap = Andrographis paniculata, Gb = Ginkgo biloba, Hh = Hedera helix, Sa = Senna alexandrina. D) Cl = Coix lacryma-jobi, No = Nerium oleander, Rc = Ricinus communis, Tg = Torreya grandis.

Postplant management - nematicides

Management strategies - Summary Planting site selection, rotation Clean equipment Certified planting stock Rootstock selection Preplant disinfestation Biological antagonists, the soil food web Postplant management — amendments — nematicides — cover crops