Pesticide Use in Arizona Lettuce: Understanding and Reducing Risk

Lettuce

Management

Pests

Lettuce Publications

Jan 2025

Keys to Effective Aphid Management in Leafy Vegetables (2025)

Publication (PDF, 180kb)

Authors: John C. Palumbo

For vegetable growers to successfully compete in the fresh market, they must be able to produce high quality, insect-free crops. This is particularly challenging for growers of leafy vegetables where damage by aphids can seriously reduce yield and quality. In many areas that produce lettuce, aphids are considered the most economically important insect pest found on the crop
Jul 2024

Insecticide Usage on Conventional and Organic Lettuce in the Desert, 2005-2024

Publication

Authors: John C. Palumbo

The development of accurate data on insecticide usage is important to the assessment of IPM programs in Arizona. A reliable estimate of insecticide use patterns is one of our most objective tools for assessing changes in management practices. This information allows us to build relevant databases for measuring user behaviors and adoption of new IPM technologies. For PCAs, it can translate their efforts into economic terms for their clientele and confirms their value to the lettuce industry by showing the importance of their cost-effective management in desert lettuce production. This summary provides estimates of insecticide use during the 2023-24 growing season and trends on lettuce IPM over the past 20 years.
Jul 2023

Trends in Insect Losses and Management on Desert Lettuce: A 19-Year Summary

Publication

Authors: John C. Palumbo

The development of accurate data on lettuce yield losses is important to the assessment of IPM programs in Arizona. Reliable estimates of yield losses caused by key insect pests occurring in lettuce is our most objective tools for assessing change in management practices. This information allows us to build relevant databases for measuring the pest status of important insect species found on desert lettuce, as well as the economic impacts they are responsible for. This information also serves as a resource to assist applied scientists in prioritizing research projects in developing IPM programs for desert lettuce. For PCAs, this data can demonstrate their efforts into economic terms for their growers, and justifies their value to the lettuce industry by showing the importance of insect pests in desert lettuce production. This summary over the past nineteen growing seasons (2004-2023) provides real world data on the pest status of key insect species, economics of insect management, and estimates of yield losses in lettuce.
Jun 2023

Insecticide Usage on Conventional and Organic Lettuce in the Desert, 2022-2023

Publication

Authors: John C. Palumbo

The development of accurate data on insecticide usage is important to the assessment of IPM programs in Arizona. A reliable estimate of insecticide use patterns is one of our most objective tools for assessing changes in management practices. This information allows us to build relevant databases for measuring user behaviors and adoption of new IPM technologies. For PCAs, it can translate their efforts into economic terms for their clientele and confirms their value to the lettuce industry by showing the importance of their cost-effective management in desert lettuce production. This summary provides estimates of insecticide use during the 2022-23 growing season and trends on lettuce IPM over the past 19 years.
Jul 2022

Insect Losses and Management on Desert Lettuce: An 18 Year Summary

Publication

Authors: John C. Palumbo
Jun 2022

Insecticide Usage on Conventional and Organic Lettuce in the Desert, 2021-2022

Publication

Authors: John C. Palumbo

The development of accurate data on insecticide usage is important to the assessment of IPM programs in Arizona. A reliable estimate of insecticide use patterns is one of our most objective tools for assessing changes in management practices. This information allows us to build relevant databases for measuring user behaviors and adoption of new IPM technologies. For PCAs, it can translate their efforts into economic terms for their clientele and confirms their value to the lettuce industry by showing the importance of their cost-effective management in desert lettuce production. This summary provides estimates of insecticide use during the 2020-21 growing season and trends on lettuce IPM over the past 17 years.
Jun 2019

Insecticide Usage on Desert Lettuce, 2018-2019

Publication (PDF, 512KB)

Authors: John C. Palumbo

A total of 28 surveys were completed of insecticide usage on desert lettuce, representing an estimated total of 33,275 fall acres and 35,156 spring lettuce acres from Yuma and neighboring Imperial Counties (Holtville/Brawley/BardWinterhaven).
Jun 2019

Insect Losses and Management on Desert Lettuce: A 15-Year Summary

Publication (PDF, 799.9KB)

Authors: John C. Palumbo

This article details the results of a survey aimed at assessing what kind of yield losses are suffered on lettuce due to insect pests. It contains data spanning over fifteen years (2005-2019).
Apr 2019

Lettuce Aphid on Late Season Produce - 2019

Publication (PDF, 1.1MB)

Authors: John C. Palumbo

This article describes the Lettuce Aphid. It covers it's physical description, economic damage, insecticidal control, and methods for identifying this insect. Very little has been reported about Lettuce Aphids under desert conditions.
Oct 2018

Corn Earworm Management on Desert Produce - October 2018

Publication (PDF, 273KB)

Authors: John C. Palumbo

This article describes the Corn Earworm and where it can be found. It covers it's physical description, economic damage, insecticidal control, and methods for identifying this insect.
Sep 2018

Vegetable Planting Calendar for Maricopa County

Publication (PDF, 634KB)

Authors: Kai Umeda

In the low desert regions of the southwest, including Maricopa County, most any type of vegetables and fruits can be grown successfully when appropriate varieties are selected and planted at the right time. The climate, the season, and potential pests all impact the selection of what to plant when.
Jun 2018

Insecticide Usage on Desert Lettuce, 2017-18

Publication (PDF, 328KB)

Authors: John C. Palumbo

A total of 25 surveys were completed of insecticide usage on desert lettuce, representing an estimated total of 44,180 fall acres and 37,720 spring lettuce acres from Yuma and neighboring Imperial County. This article concludes that the reduced risk insecticides will continue to play an increasing role in management of pests in desert lettuce.
May 2017

Insecticide Usage on Desert Lettuce, 2016-17

Publication (PDF, 290KB)

Authors: John C. Palumbo

A total of 20 surveys were completed of insecticide usage on desert lettuce, representing an estimated total of 33,562 fall acres and 33,469 spring lettuce acres from Yuma and neighboring Imperial County. This article concludes that selective reduced risk insecticides will continue to play an increasing role in management of pests in desert lettuce.
Apr 2017

Insecticide Usage on Desert Lettuce, 2015-16

Publication (PDF, 225KB)

Authors: John C. Palumbo

A total of 22 surveys were completed in the 2016 workshop, representing an estimated total of 28,650 fall acres and 29,920 spring lettuce acres from Yuma and neighboring Imperial County. This article concludes that selective reduced risk insecticides will continue to play an increasing role in management of pests in desert lettuce, but some broad spectrum products such as pyrethroids still will be needed.
Mar 2017

Liriomyza Leafminer Management on Desert Melons

Publication (PDF, 371KB)

Vegetable Leafminer, and American Serpentine Leafminer pests are often mistaken for one another. They attack a wide range of over 50 host crops. This article describes their economic damage, their development, and ways to help manage their population. Pictures are also added to aid in identification.
Oct 2016

Insecticide Resistance Management Guidelines for Lepidopterous Larvae in Lettuce

Publication (PDF, 1.23MB)

Authors: John C. Palumbo

This article contains a figure illustrating some of the chemical management options for beet armyworm, cabbage looper, and corn earworm. With suggestions on how to apply the chemical control.
Jul 2016

Insect Losses and Management on Desert Lettuce: 2004‐2016

Publication (PDF, 321KB)

Authors: John C. Palumbo

This article details the results of a survey aimed at assessing what kind of yield losses are suffered on lettuce due to insect pests. It contains data spanning over twelve years (2004-2016).
Apr 2016

Insecticide Usage on Arizona Lettuce, 2015-16

Publication (PDF, 187KB)

Authors: John C. Palumbo

A total of 19 surveys were completed in the 2015 workshop, representing an estimated total of 25,905 fall acres and 26,255 spring lettuce acres from Yuma and neighboring Imperial County. This article concludes that the local produce industry has made great strides in minimizing environmental impacts in lettuce production. There have not been any major reports of field failures.
Mar 2016

Leafminer Management on Desert Vegetables

Publication (PDF, 380KB)

Authors: John C. Palumbo

This article describes the Leafminer in great depth and their relation to Desert Vegetables. It includes it's description and their development. Their Economic Damage, Monitoring/Sampling, and suggestions regarding management practices.
Feb 2016

Insect Management on Desert Produce Crops: Western Flower Thrips 2016

Publication (PDF, 357KB)

Authors: John C. Palumbo

Western flower thrips are major pests to lettuces, cabbage, and spinach because of the damage they cause to these plants. This article describes their development, Economic Damage, and suggestions for their management.
Nov 2015

Impact of Planting Date on Aphid Infestations and Contamination in Head Lettuce

Publication (PDF, 382KB)

Authors: John C. Palumbo

A five year study was conducted with the goal of identifying planting windows during the season when lettuce is at risk from aphid infestations. The studies indicate that planting date and temperature likely have a strong influence on seasonal abundance of aphids.
Sep 2015

Biology and Management of Downy Mildew of Lettuce

Publication (PDF, 695KB)

Authors: Michael E. Matheron

This document describes the characteristics of downy mildew found on lettuce. Giving an in depth explanation of how it survives. Later it gives suggestions on how to manage downy mildew of lettuce.
Aug 2015

Biology and Management of Fusarium Wilt of Lettuce

Publication (PDF, 486KB)

Authors: Michael E. Matheron

Fusarium wilt of lettuce is caused by the soil-borne fungus Fusarium oxysporum f. sp. lactucae. This article decribes the nature of the disease and it's development. It also gives suggestions for how to manage it.
Jun 2015

2015 Insecticide Usage on Arizona Lettuce

Publication (PDF, 203KB)

Authors: John C. Palumbo

A total of 19 surveys were completed in the 2015 workshop, representing an estimated total of 25,905 fall acres and 26,255 spring lettuce acres from Yuma and neighboring Imperial County. This article concludes that the local produce industry has made great strides in minimizing environmental impacts in lettuce production. There have not been any major reports of field failures.
Feb 2015

Insect Management on Desert Produce: Corn earworm / Tobacco budworm

Publication (PDF, 271KB)

Authors: John C. Palumbo

A serious pests to heads of lettuce, the Corn Earworm can cause serious damage. This article describes their development, Economic Damage, and suggestions for their management.
Feb 2015

Insect Management on Desert Produce: Corn earworm / Tobacco budworm 2015

Publication (PDF, 271KB)

Authors: John C. Palumbo

This article describes the Corn Earworm and where it can be found. It covers it's physical description, economic damage, insecticidal control, and methods for identifying this insect.
Feb 2015

Trends in Insecticide Usage on Arizona Lettuce 2014

Publication (PDF, 133KB)

A total of 22 surveys were completed in the 2014 workshop, representing an estimated total of 27345 fall acres and 24955 spring acres from Yuma and neighboring Imperial County. This article concludes that the industry has made great strides to incorporate the newer insecticides
Dec 2014

Genetic Diversity and Fungicide Sensitivity of Phymatotrichopsis omnivora

Publication (PDF, 383KB)

Authors: Chitrampalam, P. and Olsen, Mary W.

Cotton root rot, caused by Phymatotrichopsis omnivora, is the most destructive disease of dicotyledonous plants in Arizona. There are no known reliable control methods for this disease, and the difficulty in its management is most often directed at its survival deep in soils and its wide host range. Genetic diversity in P. omnivora and its potential role in disease are unknown. Isolating the fungus and reproducing the disease in the greenhouse or laboratory are problematic, making it difficult to assess the efficacy of potential treatments.
Oct 2014

Insect Management on Desert Produce Crops: Leafminers

Publication (PDF, 375KB)

Authors: John C. Palumbo

This article describes the Leafminer in great depth and their relation to Desert Vegetables. It includes it's description and their development. Their Economic Damage, Monitoring/Sampling, and suggestions regarding management practices.
Aug 2014

Methods of Measuring for Irrigation Scheduling - When

Publication (PDF, 1.3MB)

Authors: Martin, Edward C.

Proper irrigation management requires that growers assess their irrigation needs by taking measurements of various physical parameters. Some use sophisticated equipment while others use tried and true common sense approaches. Whichever method used, each has merits and limitations. In developing any irrigation management strategy, two questions are common: “When do I irrigate?” and “How much do I apply?” This bulletin deals with the WHEN.
Feb 2014

Insect Management on Desert Produce Crops: Western Flower Thrips 2015

Publication (PDF, 161KB)

Authors: John C. Palumbo

Western flower thrips are major pests to lettuces, cabbage, and spinach because of the damage they cause to these plants. This article describes their development, Economic Damage, and suggestions for their management.
Feb 2014

Foxglove Aphid on Desert Lettuce Crops

Publication (PDF, 218KB)

Authors: John C. Palumbo

The foxglove aphid has been infesting desert commercial crops since 2002. This article discusses the description, damages, and methods of control for the foxglove aphid in lettuce crops.
Feb 2014

Diagnosing Nutrient Deficiencies Quick-Reference

Publication (PDF, 429KB)

Authors: Shawna Loper

Nutrient deficiencies can be identified in field through visual observations. However, additional analysis, either plant or soil testing is often necessary to confirm nutrient stress. The following is a quick-reference flow chart that can be used in field to identify potential nutrient deficiencies. Each nutrient has unique deficiency symptoms. Deficiencies will appear in many ways. It can be confused with other plant problems like pathogens or spray damage. But nutrient deficiencies can often be recognized because they tend to form symmetrical patterns, where both sides of leaf or plant parts show the same pattern.
Jul 2013

Measuring Water Applications

Publication (PDF, 144KB)

Authors: Ayman Mostafa

One of the challenges in using surface irrigation systems is determining the effective amount of water applied to a field. To get a good estimate, you must first calculate the gross amount of water applied and then, taking into system efficiencies, determine the amount of effective water applied (what the plants actually receive).
Feb 2013

Insect Management on Desert Produce Crops: Western Flower Thrips 2013

Publication (PDF, 306KB)

Authors: John C. Palumbo

Western flower thrips are major pests to lettuces, cabbage, and spinach because of the damage they cause to these plants. This article describes their development, Economic Damage, and suggestions for their management.
Aug 2012

Insecticide Resistance Management Guidelines for Beet Armyworm in Lettuce

Publication (PDF, 505KB)

Authors: John C. Palumbo

This article contains a figure illustrating some of the chemical management options for beet armyworm. With suggestions on how to apply the chemical control.
May 2012

Insecticide Use on Arizona Head Lettuce

Publication (PDF, 149KB)

Authors: John C. Palumbo

Management practices change and insecticide usage patterns are one of the most objective tools for assessing such change. This report contains two years (2011, 2012) of such information.
Mar 2012

Lettuce Aphid on Late Season Produce 2012

Publication (PDF, 336KB )

Authors: John C. Palumbo

This article describes the Lettuce Aphid. It covers it's physical description, economic damage, insecticidal control, and methods for identifying this insect. Very little has been reported about Lettuce Aphids under desert conditions.
Feb 2012

Insect Management on Desert Produce Crops: Western Flower Thrips 2012

Publication (PDF,161KB)

Authors: John C. Palumbo

Western flower thrips are major pests to lettuces, cabbage, and spinach because of the damage they cause to these plants. This article describes their development, Economic Damage, and suggestions for their management.
Jan 2012

Insect Management on Desert Produce Crops: Aphids 2012

Publication (PDF, 582KB)

Authors: John C. Palumbo

Aphids are major pests to desert produce due to the damage they cause. This article describes their development, Economic Damage, and suggestions for their management. The Green Peach Aphid, Potato Aphid, Foxglove Aphid, Lettuce Aphid, Cabbage Aphid, and Turnip Aphid are discussed.
Dec 2011

Measuring Water Flow in Surface Irrigation Ditches and Gated Pipe

Publication (PDF, 1.28MB)

Authors: Edward C. Martin

Measuring water in surface irrigation systems is critical for peak efficiency management. Irrigation management decisions should be made based on the amount of water applied and how this relates to the consumptive use demands of the plants and the soil water holding capacity.
Dec 2011

Determining the Amount of Irrigation Water Applied to a Field

Publication (PDF, 535KB)

Authors: Edward C. Martin

Critical to any irrigation management approach is an accurate estimate of the amount of water applied to a field. Estimating the amount of water applied to a field or to a set is fairly easy for surface systems.
Aug 2010

Quantitative Guidelines For Evaluating Herbicide Injury In Lettuce

Publication (PDF, 49KB)

Authors: Barry Tickes

There are three major herbicides that have been used in the production of lettuce in Arizona for the past 40 years. Kerb, Balan and Pefar. There are some risks such as stunting chlorosis or death of the crop. The goal of this project was to establish a correlation between detected herbicide levels in soil and lettuce tissue and potential crop injury.
May 2010

Estimated Insecticide Usage on head lettuce in Arizona 2005-2010

Publication (PDF, 119KB)

Authors: John C. Palumbo

Management practices change and insecticide usage patterns are one of the most objective tools for assessing such change. This report contains five years (2005-2010) of such information.
Jan 2010

Mean of Western Flower Thrips per Plant

Publication (PDF, 104KB)

Authors: John C. Palumbo

Chart detailing: Western flower thrips population levels in untreated romaine Lettuce at the Yuma Ag Center 4 days following heavy rainfall that occurred on 21, Jan 2010. Rainfall reduced Thrips.
May 1991

Nitrogen Management Guide for Lettuce

Publication (PDF, 472KB)

Authors: Thomas A. Doerge, Robert L. Roth, Bryant R. Gardner

The level of nitrogen fertility probably has more influence on the growth and yield of Lettuce than any other single plant nutrient because it is the nutrient most often deficient in Arizona soils.

Lettuce Presentations

Dec 2013

Pesticide Use in Arizona Lettuce: Understanding and Reducing Risk

Presentation (PDF, 4.97MB)

Authors: Paul Jepson, Michael Guzy, Peter Ellsworth, Al Fournier, Wayne Dixon, John Palumbo

Location Presented: European Food Safety Authority Scientific Colloquium XIX

ARIZONA PEST MANAGEMENT CENTER