HPIPM:Eggplant, Pepper and Tomato Nematodes

Author: Howard F. Schwartz and David H. Gent

Taxonomy

Domain	Eukarya
Kingdom	Animalia

Scientific Name

Nematoda

Scientific Name Synonyms

Nematodae

Common Name

nematodes, roundworms, threadworms

Identification and Life Cycle

Several species of nematodes can cause economic damage to tomato, eggplant, and pepper in the High Plains production region, including root-knot, sting, and stubby-root nematodes. The life cycles of different nematode species vary, and may include feeding on the outside of roots or penetration and development within roots. Some nematodes vector viruses (i.e., tomato black ring virus, tomato ringspot virus, and tobacco ringspot virus) or predispose plants to other diseases (i.e., Verticillium wilt). Nematodes survive between solanaceous crops by feeding on other crops and weeds, and are spread in contaminated soil on machinery, wind blown soil, and irrigation water.

Plant Response and Damage

Nematode injury varies among species, but can include galls on roots (root-knot), necrosis of roots (root-lesion), a “rat-tail” appearance (sting nematode), or a subtle stubby-appearance (stubby-root). Aboveground plant symptoms may range from no apparent injury to less vigorous growth to stunting, yellowing, wilting, and death. Nematodes reduce tomato yield by an estimated 15% in the southeastern US, but accurate estimates of crop loss are not available in the High Plains.

Biological Control

Incorporation of green manure crops such as sudangrass, sesame, rapeseed, white mustard, or perennial ryegrass the season before solanaceous crops are planted can reduce some nematode populations.

Cultural Control

Crop rotation may provide suppression or control of some nematode species, but most nematodes that attack solanaceous crops have host ranges that include many crops and weeds. Therefore, effective weed control is essential for reducing nematode populations. Adequate but not excessive irrigation and fertilization will help plants tolerate some nematode feeding. Flooding fields can reduce nematode populations.

Chemical Control

Nematicides and soil fumigation effectively suppress many nematode species, but are most effective when combined with cultural practices that reduce nematode populations. Nematode injury often only occurs in localized areas in fields, and these areas can be effectively managed by spot-treatment with nematicides.

Product List for Nematodes:

Pesticide	Product per acre	Remarks
Nematicide/Insecticide
Vydate L	2-8 pints depending on crop	Restricted use; Maximum of 3-4 gallons per season depending on crop; May be applied by drip irrigation; 3 day PHI for tomato; 7 day PHI for eggplant and pepper
Fumigants
Telone II	9-15 gal	Restricted use; Preplant application, aerate 7-14 days.
Telone C-17	10-17 gal	Restricted use; Preplant application, aerate 7-14 days.
Vapam	40-100 gal	Restricted use; Preplant application, aerate 7 days.
Paecilomyces lilacinus strain 251
MeloCon WG	2 - 4 lbs	up to 14 days prior to transplanting; apply as banded or broadcast spray in 20 to 40 gal of water/A

The information herein is supplied with the understanding that no discrimination is intended and that listing of commercial products, necessary to this guide, implies no endorsement by the authors or the Extension Services of Nebraska, Colorado, Wyoming or Montana. Criticism of products or equipment not listed is neither implied nor intended. Due to constantly changing labels, laws and regulations, the Extension Services can assume no liability for the suggested use of chemicals contained herein. Pesticides must be applied legally complying with all label directions and precautions on the pesticide container and any supplemental labeling and rules of state and federal pesticide regulatory agencies. State rules and regulations and special pesticide use allowances may vary from state to state: contact your State Department of Agriculture for the rules, regulations and allowances applicable in your state and locality.