How to Manage Pests

UC Pest Management Guidelines

Cucurbits

Yellows (Molybdenum Deficiency)

(Reviewed 11/05, updated 11/05)

In this Guideline:


SYMPTOMS

Crown leaves become bright yellow and margins become necrotic. Leaves are stunted and misshapened. Symptoms move out the runners until the entire plant is affected. Fruit set is eliminated and plants may be killed.

COMMENTS ON THE DISEASE

Yellows is the result of a molybdenum deficiency in cucurbit plants. Molybdenum is generally available in high enough quantity for all plant growth. However, under acid soil conditions molybdenum is difficult for melons of some cultivars to absorb. Yellows occurs commonly in the Stanislaus County production areas and has been associated with cut and fill areas along the California aquaduct and the Delta-Mendota Canal.

MANAGEMENT

A single application of sodium molybdate at 200 ppm will result in a complete recovery of affected plants in 2 to 3 days.

[Precautions]

PUBLICATION

[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Cucurbits
UC ANR Publication 3445

Diseases

  • R. M. Davis, Plant Pathology, UC Davis
  • T. A. Turini, UC Cooperative Extension, Imperial County
  • B. J. Aegerter, UC Cooperative Extension, San Joaquin County
  • J. J. Stapleton, UC IPM Program, Kearney Agricultural Center, Parlier
Acknowledgment for contributions to Diseases:
  • W. D. Gubler, Plant Pathology, UC Davis

Top of page


Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2014 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See our Home page, or in the U.S., contact your local Cooperative Extension office for assistance.

Agriculture and Natural Resources, University of California

Accessibility   /PMG/r116100611.html revised: January 8, 2014. Contact webmaster.