Cucurbits

 

Nematodes (Cucumber, Melon, Pumpkin, Squash, and Zucchini)

 

Howard F. Schwartz and David H. Gent

 

 

Identification and Life Cycle

Several species of nematodes can cause economic damage to cucurbit crops in the High Plains production region, including root-knot nematodes (Meloidogyne spp.), root lesion nematodes (Pratylenchus spp.), and perhaps others.  Nematode damage to cucurbit crops in the High Plains is poorly studied, and other nematode species may be economically important .  The life cycle of different nematode species vary, and may include feeding on the outside of roots or penetration and development within roots.   Nematodes survive between susceptible crops by feeding on other crops and weeds, and are spread in contaminated soil on machinery, windblown soil, and infested seed pieces.

 

Plant Response and Damage

Root-knot nematodes cause round to spindle-shaped galls on roots.  Aboveground symptoms of nematode injury often appear as patches of stunted, yellow, and dying plants.  Infected plants may wilt when stressed by high temperature or moisture extremes. 

Management Approaches

 

Biological Control

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

 

Cultural Control

Prevent the introduction of nematodes in clean fields by thoroughly cleaning equipment between fields.  Plant transplants free from nematodes.  Avoid the reuse of irrigation water.  Provide adequate fertilizer and irrigation for crop development to reduce the impact of nematode feeding.  Sprinkler irrigation tends to be more effective than furrow irrigation for supplying even water to nematode-damaged plants.  Practice a three-year or longer crop rotation to non-hosts such as small grains.  Control weeds that may serve as alternate hosts of nematodes.  Promptly incorporate crop residues after harvest to limit nematode reproduction. 

 

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-treatments with nematicides.

 

Product List for Nematodes:

Pesticide

Product per acre

Remarks

Nematicide/Insecticide

Mocap 15% Granular

13 lbs

Registered for cucumber; Restricted use; preplant incorporate 2 to 4” deep. 

Mocap EC

2.4 fl oz/1000 ft banded

3.33 qts broadcast

Registered for cucumber; Restricted use; preplant incorporate 2 to 4” deep.

Fumigant


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.

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.

 

 

Categories: Cucurbits, Disease, Nematodes, Cucumber, Melon, Pumpkin, Squash, Zucchini

Date: 04/01/2007