2018 Cotton Crop Proceeding Well

Late Season Pests Can Be a Challenge

By Patrick Cavanaugh, Editor

The 2018 cotton harvest will be starting in the southern part of the Central Valley later this month, and some growers will be facing pressure from pests.

California Ag Today recently spoke about the topic with Dan Munk, a UC Cooperative Extension Farm Advisor in Fresno County specializing in irrigation crop nutrient management and cotton production systems.

“The crop looks very good and loaded with cotton bolls. We don’t have a lot of boll losses, and that’s a real positive thing, so very excited about the potential for fairly high yields in the 2018 season. The biggest concern right now is pest management, press pressures as we approach the latter part of the season,” Munk explained.

The main issue this time of year is the honeydew that pest leave on the cotton. Honeydew is the exudate extracted by the insect as it feeds on the leaves.

“Because we have the bolls on the plant that have opened, we now have exposed lint and need to protect that lint from stickiness that’s created from whitefly and the aphid honeydew, which is basically the added sugars that those insects that feed on the leaves of the plant, and they excrete them and deposit them on the lint,” Munk said.

Munk explained that the big concern right now is dealing with pest pressures in terms of whitefly and aphid—both sucking insects. “The problem right now [is] where we’re seeing pest pressures—particularly from whitefly as we get later in the season—will build in many fields.

There are several approaches to controlling whitefly and aphids. One is to deal with the eggs that they produced. And then there’s a certain class of materials to deal with the eggs.

“There’s another class of materials that deal with the juveniles—that early form of the insect—and then there are ways to control the adults,” Munk said.

“A number of insecticides have been applied to deal with those various levels of insect populations based on the individual field situation,” he explained.

New IPM Work on Brown Stink Bug

New IPM Approach to Brown Stink Bug In Desert Cotton

By Patrick Cavanaugh, Farm News Director

This year, the UC Division of Agriculture and Natural Resources, Cooperative Extension, Riverside County began an Integrated Pest Management (IPM) program to control Euschistus servus, or brown stink bug, a problem in Southern California’s cotton production areas.

Vonny Barlow
Vonny Barlow, a UC Cooperative Extension farm advisor in Riverside County

Vonny Barlow, a UC Cooperative Extension farm advisor in Riverside County began evaluating brown stink bug in cotton last year, and he received additional funding this year from a National Institute of Food and Agriculture (NIFA) grant administered through North Carolina State University, to continue his research this year. Barlow just hired two interns to work with brown stink bug in the Palo Verde Valley in Southern California.

The pest was known to exist in Arizona for about eleven years, but was not a critical issue until about three years ago, when it moved into California. California cotton growers had to spend a lot of money to spray to manage the insect, and it just wasn’t economically feasible.

“In many areas in the south, the brown stink bug pierces into the cotton boll with its proboscis-like mouthpart—a stiff, short straw,” said Barlow. “Once the cotton boll is pierced, the brown stink bug tries to feed on the cotton seed. The problem is the puncture allows bacteria to enter and boll rot to set in. Boll rot is the issue because it lowers yield quality; without boll rot, the brown stink bug is much more of a manageable pest.”

Spraying is not the answer to control the bug, according to Barlow. “We are going to look at an area-wide pest management approach by just essentially surveying the pest control advisers (PCAs) and growers about cropping that is near or even some miles away from cotton,” he said. “Where is the brown stink bug showing up? When did it show up? Is it moving? When are you going to harvest? Is it moving into the cotton? That way, we can give the cotton growers a better idea of when they should start management practices for brown stink bug, instead of just routinely calendar-spraying every two weeks.”

“We hope to predict when brown stink bug will move into cotton. Farmers who just harvested wheat should expect it will come into your field within the week. Start scouting; it is another very good IPM tactic to reduce sprays and to better manage pests,” said Barlow.

Featured image: Brown Stink Bug (Source: Brown Stink Bug (Source: “Chemical Efficacy Trial using Select Insecticides against Brown stink bug, Euschistus servus on Commercially Planted Cotton” by Vonny Barlow, University of California, Agricultural and Natural Resources, Riverside County, April 2016 issue of “Postings from the Palo Verde” newsletter)

Whitefly and Aphid Pressure on Cotton

Cotton Growers: Beware of Whitefly and Aphid Pressure Early this Season 

By Laurie Greene, Editor

Pete Goodell
Peter B Goodell Ph.D., Cooperative Extension Advisor-IPM, Kearney Agricultural Research & Extension Center in Parlier, CA. (Source: UC ANR)

Pete Goodell, an IPM Advisor with UC Cooperative Extension based at the Kearney Agricultural Research & Extension Center in Parlier, Calif., noted that cotton growers should be treating for whitefly and aphid pressure earlier—instead of later—this season.

“On cotton, we are continually working with the whitefly and the green peach aphid. They have been a problem for the last 3-4 years, so we are continuously working with educational outreach to catch these pests early and manage their populations,” Goodell said.

Goodell explained, “I think with cotton acreage down significantly this year, we can really focus and ensure that everybody is aware of the pressure and how to handle the problem beginning in July. In some incidences, folks have misunderstood and treated whiteflys like aphids; folks started looking for the pests around the open cotton boll stage of growth. But that’s too late to treat for whitefly; growers must treat earlier to maintain a quality cotton crop.”

“That’s why we’re going to get ‘on the stick’ this year,” Goodell said. “We are going to hold a series of gin meetings and get the word out that growers need to start earlier to prevent damage from these insects.”

 

Feature photo source: Sweetpotato Whitefly, JackKellyClark, UC ANR