Mineral Nutrition of Leafy Lettuce and the Impact on Verticillium Severity

Verticillium wilt on lettuce is influenced by mineral nutrition


The Salinas Valley of California has had a serious problem with Verticillium wilt on lettuce since 1995. Areas of the Salinas and Pajaro Valleys cannot grow lettuce because Verticillium levels within the soil are too high and attempts to grow lettuce result in complete crop failure. Read more

Year of initiation:2011
Year of completion:2014

Interpretive Summary

Lettuce production in the US is worth more than US$1 billion annually. Until the mid-1990s lettuce was thought to be resistant to Verticillium wilt, but in 1995 it was first identified in the central coast of California. Some field infections have been so severe the entire field was lost. Adjustments in mineral nutrition can reduce Verticillium wilt severity.

The Salinas Valley of California has had a serious problem with Verticillium wilt on lettuce since 1995. There is evidence that the supply of mineral nutrients can influence the severity of Verticillium outbreaks. A greenhouse study is examining the effect of N, P and K nutrition on disease severity using a hydroponic growth system.

A series of greenhouse hydroponic studies have been initiated to determine the optimal concentrations of N, P and K for lettuce growth. This project is being conducted with the assistance of undergraduate interns in an effort to encourage students to pursue further study in agricultural sciences. Once the proper parameters for lettuce nutrition are established, Verticillium inoculum will be added to the nutrient solution and the degree of infection will be determined.

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Updates & Reports


2015 Annual Report


Project Description


The Interaction Between Plant Nutrition and Disease: Focus on Verticillium Brad Geary and Doug Jacobson
Better Crops With Plant Food
2016-4, page #25

Project Leader

Brad Geary, Brigham Young University

Project Cooperators


IPNI Staff

R. Mikkelsen


Americas \ Northern America \ USA \ Utah


plant disease, plant pests


Nitrogen (N), Phosphorus (P), Potassium (K)