- UC Pest Management Guidelines for Cotton
- Whitefly Management Guide
- Whitefly Webinars, Plant Management Network
August is the typical time for change in managing cotton pests in the San Joaquin Valley. As the plant is shifting from setting fruit to maturing fruit and our attention is shifting from protecting yield to protecting quality. Lygus becomes much less of a concern as bolls mature beyond 10 days after flowering and our attention focuses on preventing excessive honeydew from drifting down onto open bolls and exposed lint.
Minimizing the occurrence of sticky cotton remains a critical goal for San Joaquin Valley cotton. Close attention to fields
In the past several years, a resurgence in sweetpotato whitefly biotype B (formerly silverleaf) has been experience in the San Joaquin Valley. I am noting a very preventative approach in managing whitefly with treatments being applied at very low population densities. The concern for sticky cotton is real and the response to prevent it is understandable.
PCAs and growers should consult regularly to review their individual situations, determine a course with the remainder of the season in mind, and select insecticides based on the threat, the population composition and insecticide resistance principles.
There is a good collection of information available and the interested pest manager is directed to these list above for more details.
- Plant Management Network - Focus on Cotton Webinars
- CA Cotton Growers and Ginners Association - Slides for viewing from Whitefly-Aphid Workshops
- UC IPM - Pest Management Guidelines for Cotton
Producing the highest quality cotton lint is paramount for cotton growers, PCAs, ginners and merchants. Honeydew produced by sweetpotato whitefly, Biotype B (Bemisia tabaci) and cotton aphid (Aphis gossypii) can settle on open bolls and create sticky cotton. The contamination of cotton lint with sugary honeydew creates major problems with the spinning mills
UC IPM and California Cotton and Ginners Associations (CCGGA) recently hosted three workshops to remind the cotton community of the importance of managing these pests to prevent the development of sticky cotton.
The slides presented by IPM Advisor Pete Goodell and UC Davis Extension Entomologist Larry Godfrey are available through CCGGA link by clicking here.
In addition, a series of webinars on the subject has been produced by Cotton Incorporated and Plant Management Network. It is available through my website.
Detailed information on aphid and whitefly management can always be found at UC IPM Pest Management Guides.
There have been numerous reports of pale striped flea beetle in cotton around the Five Points area of Fresno County. Population densities of 20-30/50 sweeps have been found, causing some concern among PCAs. The most common species is the pale striped flea beetle, Systena blanda.
In most cases, flea beetle is usually a problem on seedling cotton, not on blooming cotton according to IPM Manual for Cotton in the Western US.
The manual states: "Flea beetles, small beetles with enlarge hind legs that enable them to jump, chew small round holes or pits in cotyledons and young leaves. They
However, given enough beetles moving into a cotton field at one time, damage can occur. One field I observed in late July had over 500 beetles for 50 sweeps and caused considerable leaf damage in the lower canopy. The source of beetles were neighboring alfalfa fields which were recently cut and water stressed.
Damage to the leaves was mainly superficial feeding. Leaves were not tattered nor did they display
While not normally a damaging pest to mature cotton, high population densities of pale striped beetle can potentially cause damage at any stage of growth.
Keeping current with research activities in cotton is essential for the IPM Professional.
On Wednesday, September 26th, 2013 there will be a meeting to review research efforts supported by the cotton industry. PCAs and growers are invited to attend to learn about recent breakthroughs in research on a number of cotton production issues including insects, Fusarium, weeds, harvest aids, irrigation and varieties.
- When: September 26, 2013, 8AM - 4 PM
- Where: University of California West Side Research and Extension Center
- 17353 W. Oakland Avenue, Five Points, CA
- (Corner of Oakland Ave. & Lassen Avenue, 6 mi. South of Five Points)
- What: 15 Projects will be presented. For full agenda, click here
Lunch will be provided by the California Cotton Growers Association.
Hope to see you there.
Useful Resources: Cotton Pest Management Guidelines - 2013 Revision
Lygus hesperus is a key pest in cotton IPM system. Feeding on the youngest floral buds,
In water short years, trying to compensate for lost early production is impossible. There just is not time to compensate for early loss within the limited time frame we have to make the high yield levels demanded by today’s market and production costs.
Fortunately, we have Lygus management options which can minimize the need for or the results caused by early insecticide intervention.
First: The monitor the Lygus population twice weekly during this critical period. UC IPM has just released revised thresholds for Lygus treatments in the Pest Management Guidelines (PMG) for Cotton which include:
- Early Squaring:
- < 5 fruiting branches, 1 -2 Lygus bug/50 sweeps
- 5-10 fruiting branches, 2-5 Lygus bugs/50 sweeps
- Mid-Squaring (1st flower - 1st mature boll, beginning of July): 7-10 Lygus bugs (at least 1 nymph) per 50 sweeps and expected or better fruit retention. If retention is higher than expected you may be able to wait and monitor again that week before making a treatment decision. If retention is lower than expected and Lygus bugs are present, consider treating.
- Late Squaring (after 1st mature boll): 10 Lygus bugs/50 sweeps, including the presence of nymphs
Second: Monitor the cotton plant’s growth and development, paying attention to fruit patterns and set. The first position is likely the only fruit to be observed during this period so look carefully and document the plant’s progress.
Third: If treatment is required, use the least disruptive product available. Refer to UC IPM information on selectivity and persistence of key cotton insecticides & miticides to help guide your decision.
Keeping the cotton plant in a vigorous reproductive state early in its fruiting cycle is a key IPM practice that will help manage the crop and other pests throughout the season.