Useful resources:

        On-line training for Year Round IPM Programs    

        UC IPM  website

        Cotton Pest Management Guidelines

The UC Statewide IPM Program has announced the availability of an on-line tutorial to aid in the use of Year Round IPM Programs.

Year Round IPM Programs were developed as another means to retrieve information from the comprehensive Pest Management Guidelines. While the Guidelines are organized by pest, the Year Round Program condenses a year's worth of management activities for key pests into one checklist arranged by season or crop stage. Over half the crop groups in the Guidelines have a Year Round program associated with it, cotton being one.

The on-line training series provides seven video chapters as a "guided tour" of the benefits and uses of the Year-Round IPM Program in field, orchard, and vineyard crops. All the videos except the introduction contain short interactive quizzes.

The seven chapters include:

1. Introduction
2. Prevention
3. Pest identification
4. Monitoring
5. Management decisions
6. Management methods
7. Environmental concerns and summary

The on-line training can be reached by clicking here

Useful cotton monitoring and treatment guidelines:

• Lygus
• Aphid, Whitefly, Spider mite

The season thus far has been good, even with a delayed planting. Almost every cotton field is nearly at a similar same stage of development, has good fruit development and retention and is facing low Lygus bug threats. Flowering continues to move up the plant as it turns its attention from vegetative to reproduction by filling bolls and developing lint.

What are the pest management issues that could come into play?

• 
  Lygus: our experience and the literature indicate that Lygus is less of a threat during July and August than in June. While field should continue to be monitored weekly, cotton plants with excellent fruit load will be shedding fruit due to physiological rather than due to Lygus feeding. Population levels which can be tolerated are 7-10 bugs/50 sweeps with the presence of immature Lygus.

 

 

•  Aphids and whiteflies: Always a potential threat during August which is why a weekly field inspection is so important. Sample 5^th leaf from top looking for
  

  Aphid mummies and parasites. Photo: JK Clark
    incipient  colonies. See earlier Post for details. A key natural enemy are wasp parasites, which are commonly being seen attacking cotton aphids. Look for dried, empty shells of aphids with circular emergence holes.

 

• Spider mites: these were a problem last year so continue monitor the fields, especially near dusty roads or sources of mites, such as corn or almonds. For management details, see Cotton Pest Management Guidelines

 

Useful links:

• Common Natural Enemies: Your Allies in IPM of Cotton
• Common Whiteflies in SJV Cotton
• Aphids Common to Alfalfa and Cotton
• Sampling Whiteflies in 7 Minutes or Less
• UC IPM Pest Management Guidelines for Aphid in Cotton
• UC IPM Pest Management Guidelines for Whitefly in Cotton

Sticky cotton is a condition the San Joaquin Valley cotton growers have been able to avoid in most years, due to no small contribution of natural enemies which prey and parasitize these pests.

However, whiteflies and aphids are always present and can cause major problems if not watched carefully.

There are a number of aphids and whiteflies that could be found in cotton and our IPM focus has been on proper identification of sweetpotato whitefly (or silverleaf)and cotton (or melon) aphid.

Dr. Peter Ellsworth, IPM Specialist with University of Arizona Cooperative Extension and his colleagues have produce a great one page factsheet reminding us of the sampling procedure for whiteflies in cotton.  This procedure is a binomial process which removes the requirement to count every insect on the sample leaf. It requires the 5^th leaf from the top to be selected and the entire sampling activity can be conducted in 7 Steps in 7 Minutes. Click here to read the leaflet.

The AZ approach has been adopted by UC Pest Management Guidelines for Cotton and the 5^th leaf is the same sample unit for cotton aphids. While aphid honeydew has a different

constituency than whitefly, both can damage lint quality and cause major harvest, ginning and spinning problems. Details of aphid and whitefly sampling can be found in the Cotton Pest Management Guidelines.

Useful resources:

• Year round IPM Program for Cotton: Early Squaring Activities:
• Monitor Cotton Growth – Early Squaring
• Monitoring to Make Lygus Decisions
• Calculate Expected Square Retention
• Cotton Field Check (June 2011) - Why the Cotton plant is the Great Indicator for Lygus Management

 

For San Joaquin Valley cotton growers, one of the most important production decisions is to get the plant into a vigorous fruiting cycle and to hold the early fruit so the plant is manageable for the remainder of the season.

During the earliest fruiting period, retention of fruit on the first 10 fruiting branches is top priority and the most difficult to interpret. We understand the Acala Upland retention very well but are stretching the data for Pima. However, using the Acala data developed over 20 years ago provides valuable guidelines in evaluating fruit loss and retention.

There are many factors which can cause squares to drop including weather, management factors, and insects. In the 2012 season, the early development has promoted rapid growth and fruit set, favoring the plant over thrips. Lygus will be the primary insect pest to monitor by frequent field inspections (twice weekly is recommended) and monitoring retention. Low populations densities of Lygus need to be monitored closely to ensure that loss of early fruit set meets the expected retention for the age and fruit load of that field.

June is a critical month to manage Lygus but once the initial fruit is set and bloom occurs, greater densities of Lygus can be tolerated. If June treatments are required remember to:

• Make sure the fruit loss can be related to Lygus;
• Lygus are present
• Selective products are utilize to preserve the natural enemies already in the field
• Practice good insecticide resistance management practices and take care to not over use any particular active ingredient