Getting into the Practice of Monitoring Your Field Before Treating for Pests

I spend a lot of time on the road, traveling around the Valley to scout out cotton and alfalfa fields to check on pests and development of the plants.

Recently, it struck me to see some growers treating their cotton fields (which are adjacent to alfalfa) for lygus. In contrast, growers participating in our San Joaquin Sustainable Farming Project haven’t made any new treatments. Instead, they are monitoring their fields and waiting for the pest counts to reach the Integrated Pest Management threshold for treatment. I’m encouraged by this trend.

Lygus can still cause problems for cotton plants.

For years, University of California IPM specialists have advocated these practices. I remember Walt Bentley, a veteran UC IPM entomologist,  stressing to almond growers to forget the old practice of using the calendar as a treatment guide. Monitor your crop, keep track of pest counts and use that information to help you make a treatment decision. That message never gets old.

In fact, I’m finding lygus almost a non-factor in some fields. But it’s still important to keep an eye out for the pests. Small cotton bolls are still soft and susceptible to nymphs picking at them, resulting in the fruit dropping to the ground. My crystal ball predicts cut-out around the first weekend of August.

Cotton plants are nearing cutout in the Valley.
- Texas AgriLife Extension Service photo

Meanwhile, I’m finding a slight increase in aphids around the cotton fields. But the numbers don’t warrant treatment at the moment.

The plants are looking good. I’m seeing 80 percent fruit retention on the top of the plant and about 90 percent retention at the bottom – or first five fruiting branches. We should see some nice yields at harvest.

Things are quiet with alfalfa, as well. While there has been an increase in worm counts, it doesn’t warrant treatment for now. Growers have finished their fourth cutting and preparing for the next one soon.

Read more about these issues on the blog by Dr. Pete Goodell of UC IPM.

It was great meeting with growers and pest control advisors during our Cotton and Alfalfa Field Day in Los Banos on Tuesday. I want to thank our speakers Dr. Goodell, UCCE farm advisor Dan Munk and UC Davis alfalfa specialist Dan Putnam.

About Almonds: I want to share a recent chat with Walt Bentley about this year’s almond season. “The season is going very well. The disease pressure we’ve seen in the past is not being seen in the orchards we are monitoring. I’m not seeing near the issue of rust that we had. Much like last year, we’re not seeing very much spider mite problems. The pressure from mites has been low. The crop yields for nonpareils and the hard shell varieties have been excellent. Although we did start a little cooler and wetter than in the past, the main difference from last year is we’re experiencing what I call a normal year with hull split occurring in the early part of July. Last year we had hull split till about July 25, which was extremely late. I think that helped us in managing our navel orangeworm problem. Managing the diseases has been excellent.”

“Another big is now for growers from Fresno north is the management of preharvest irrigation to reduce the incidence of hull rot and harden the trees for proper shaking. Contact your local farm advisor, PCA or look to the Almond Doctor blog by UCCE Merced County farm advisor David Doll on dealing with preharvest irrigation practices.”

Things Are Pretty Quiet in the Valley of the Cotton

 Picture lush green cotton fields with the mighty Sierra Nevada or Coast Range in the background. You’re almost hypnotized by the wavy lines coming from the air rising off the hot summertime ground. There is a sense of calmness across the Valley.

Weather conditions are ideal for cotton this summer.

Indeed, things are pretty calm for cotton and alfalfa growers so far. While everyone is quite busy tending to their fields, there isn’t a lot excitement taking place. No major bug infestations. No big worries about plant diseases. No surprises from Mother Nature. We hope it stays that way.

My crystal ball says we’re about two weeks away from cut-out. That will indicate how much cotton will be in the “basket” by the fall harvest.

At the moment, I’m spotting a little more lygus and worms (primarily loopers with a few beet armyworms) during my field scouting rounds. Recently, one grower treated his field for lygus while another treated for both lygus and worms. I estimate only about a quarter of the growers whose fields I check regularly have treated their fields for pests. That’s a good sign.

Lygus damage to a square. The pest is still worrisome.

As you know, lygus remain a threat through cutout and final boll set. Beet armyworms will destroy small bolls during early July. Check out UC IPM online for more information about lygus and armyworms in cotton.

Watch out for the cabbage looper.
                                - UC IPM photo

This time of year, cabbage loopers are the main worm threat – the alfalfa looper is found in May and early June. Loopers will chew off leaves on the cotton plant, causing the fruit to mature too fast. However, these pests aren’t too numerous to cause significant damage and can be kept under control by natural enemies such as pirate bugs. Here’s the UC IPM link about loopers.

Overall, it has been a light year for crop-damaging bugs all over the Valley – not just this area. More growers following sustainable farming practices has certainly helped. They are using biological controls such a natural habits or strip cutting alfalfa fields to keep pests from migrating to neighboring cotton fields. I call that smart farming.

A calm year for bugs along with good summer Valley heat translates into ideal growing conditions for cotton. I’m seeing plants with 14 fruiting branches. On average, plants are at 7 to 8 nodes above white flower. I can say “All’s Quiet on the Westside Front.”

The same is true for alfalfa. I’ve seen just a couple fields treated for loopers and armyworms. Growers are now into their fourth cutting and ready to irrigate their fields for the next harvest. Looking good here, too.

Summer Field Day: Don’t miss your chance to get the latest information and tips about this year’s cotton and alfalfa season on Tuesday when we’ll have our summer Cotton and Alfalfa Field Day. It’s from 10 a.m. to noon at Bowles Farming, located at the intersection of Hereford and Bisignani roads in Los Banos. The speakers are: UC IPM Advisor Dr. Pete Goodell on insects and pests in alfalfa and cotton-managing the crop through mid-season; UCCE Fresno farm advisor Dan Munk on cotton crop development and its impact on pest management; and UCCE and UC Davis alfalfa specialist Dan Putnam on current issues affecting IPM in alfalfa. Directions are available in the events section of the Sustainable Cotton Project’s website – www.sustainablecotton.org.

I want to thank Walt Bentley of UC IPM and UCCE Merced’s David Doll for their informative presentations at our Almond Field Day last week. The turnout was very good. More than three dozen growers and pest control advisors received great advice about pest and diseases issues as they preparing for the harvest. I’ll have more about almonds next time.

Cotton Growers Working Hard to Bear the Fruits of Their Labor

 For cotton growers, the hard work this season is starting to show the signs of the fruits of their labor.

Across the Valley, I’m seeing nice, healthy plants with 10 to 12 fruiting branches. The presence of lygus is here and there with no significant numbers in the fields. I’ve heard of some treatment applications, but nothing major.

The hot weather has been good for the plants. Right now, growers are irrigating their fields for a second time – with some on their third irrigation. The frequency depends on the soil type. The sandy soil requires more watering. As a rule, most growers will irrigate their cotton four to five times during the season. Sandy soils are usually irrigated five to six times. By my count, we’re about half way through with irrigation. If you check the calendar, we around the mid-point to the fall harvest.

Looking at nodes above white flower.

Still, we’re far from over the hump. After completing our plant mapping, we can anticipate cut-out about two to three weeks away. Cut-out is the final stage of cotton plant growth before the bolls open up. The plant mostly has more mature fruit with squares and blooms noticeably absent. Terminal growth also ceases.

Simply put, this is the maximum amount of fiber growers can expect by harvest. It’s like your tomato plants. You reach a certain point in the season when those green tomatoes won’t ripen and turn that juicy red color.

                                                    - Texas AgriLife Extension Service graphic

Right now, we’re at seven to nine nodes above white flower – a good sign with benchmark being five nodes above white flower. We’re right on schedule. It could be an above average year for yields this fall. UC IPM offers tips and nodes above white flower and lygus monitoring.

Things are pretty quiet around the alfalfa fields. Every grower is finished with the third cutting with most getting ready for the fourth harvest soon. I haven’t seen any issues with worms.

Field Days Alert: Don’t forget our Almond Field Day is this Thursday, July 19 from 10 a.m. to noon at the Rushing Ranch, 11599 W. Shaw Ave., Fresno. Walt Bentley of UC IPM will discuss late-season consideration for insect and mite management in almonds. UCCE Merced’s David Doll will focus on post-harvest practices to reduce disease and pest issues. He also will offer tips about increasing tree productivity and managing water at harvest. Bring your questions.

 Also, I hope you marked your calendar for our Cotton and Alfalfa Field Day set for Tuesday, July 24 from 10 a.m. to noon at Bowles Farming, the intersection of Hereford and Bisignani roads, in Los Banos. The speakers are: UC IPM Advisor Dr. Pete Goodell on insects and pests in alfalfa and cotton-managing the crop through mid-season; UCCE Fresno farm advisor Dan Munk on cotton crop development and its impact on pest management; and UCCE and UC Davis alfalfa specialist Dan Putnam on current issues affecting IPM in alfalfa. Directions are available in the events section of the Sustainable Cotton Project’s website – www.sustainablecotton.org.  Two hours of continuing education credits have been applied for at each of the meetings. Both field days will offer lots of good information.

Cotton Fruit Staying Put: Could There be a Bumper Crop?

Fireworks weren’t the only things popping last week. With warm summer temperatures, cotton flowers came out in full bloom across the San Joaquin Valley.

Everywhere you look, the lush green cotton fields were ablaze with colorful flowers. The color is even more spectacular this year because of the abundance of bolls still on the plants.  During my travels, I’m seeing cotton plants with a minimum of 80 percent fruit retention. Some even are at an eye-popping 100 percent retention.

I’m starting to think growers could be in store for a very good yield, or bumper crop, this fall. This time of year you usually see plants retaining 60 to 69 percent of their fruit.

National Weather Service June temps for the Fresno-area.

Mother Nature has been very good for cotton growers, providing ideal growing conditions for their plants. We haven’t had a lot of severe, hot weather days over a sustained period of time. In the past month, the average high temperature was 92.8 degrees in the area, according to the National Weather Service. The normal high for June is 92.1.

Green lacewing is a beneficial bug.

Indeed, we recorded only four consecutive days of triple-digit temperatures – although the record-breaking 109 degrees on June 7 was a bit much for late spring. In fact, there were just five days of 100-degree weather last month. Of course, there are still 2½ months of summer left with hot July days on tap (the average high for the month is 98.4 degrees).  Very high heat can be a problem for setting bolls (seed and lint quality) because of pollen sterility. Also, night temperatures of 75 degrees or higher that can affect rest for the plant and hamper energy into developing fruit. But so far, so good.

While lygus numbers are going up, they generally haven’t reached the threshold for treatment. I’ve heard of only two fields being treated locally. Now is the time to keep track of the pest counts and continue to monitor your fields regularly.

A ladybug feeds on aphids.

Right now, cotton is getting its second irrigation. With the plants nice and green, the fields are becoming attractive homes for aphids, especially as nearby tomato, cantaloupe and watermelon fields dry out for the harvest.  The highest count I’ve seen in one field is a 10 percent infestation. It’s no time to be alarmed since the bolls aren’t open and there’s no threat of getting sticky cotton at this time. Beneficial insects such as lady bugs and green lacewings can take care of the numbers at the moment. In a few weeks, I will be releasing beneficial insects to control aphids in fields enrolled in our San Joaquin Sustainable Farming Project. My advice is to keep a close eye on the aphid situation.

Meanwhile, the alfalfa crop is between the third and fourth cutting. I’m spotting some aphids and worms in the fields. My hats off to growers who leaving uncut strips of alfalfa to keep pests from migrating to nearby cotton fields. They earn my “Good Neighbor Award.” Keep up the good work.

Field Days  Ahead: Don’t miss our two upcoming field days in Fresno and Los Banos. Our Almond Field Day is Thursday, July 19 from 10 a.m. to noon at the Rushing Ranch, 11599 W. Shaw Ave., Fresno. Walt Bentley of UC IPM will discuss late-season consideration for insect and mite management in almonds. UCCE Merced’s David Doll will focus on post-harvest practices to reduce disease and pest issues. He also will offer tips about increasing tree productivity and managing water at harvest.

Our Cotton and Alfalfa Field Day is Tuesday, July 24 from 10 a.m. to noon at Bowles Farming, the intersection of Hereford and Bisignani roads, in Los Banos. The speakers are: UC IPM Advisor Dr. Pete Goodell on insects and pests in alfalfa and cotton-managing the crop through mid-season; UCCE Fresno farm advisor Dan Munk on cotton crop development and its impact on pest management; and UCCE and UC Davis alfalfa specialist Dan Putnam on current issues affecting IPM in alfalfa. Directions are available in the events section of the Sustainable Cotton Project’s website – www.sustainablecotton.org.  Two hours of continuing education credits have been applied for at each of the meetings. Both events will be very information. Spread the word.

Patience Can Pay Off When Making Treatment Decisions

It’s a familiar scene: You’re stopped at a busy intersection and another driver pulls next to you and starts revving up his engine like a wannabe drag racer. Trying to time the signal, he punches the gas pedal and speeds through the intersection – before the light turns green.

Lately, I’ve seen a few cotton growers resemble over-eager drivers.  They seemed to be jumping the gun on treating their fields for lygus. I believe they could have waited.

This is where using a sweep net to take pest samples and plant mapping to measure fruit retention becomes an important tool in the treatment decision-making process. I wholeheartedly agree with this advice from UC IPM: “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.” To read more about this topic, here’s a link to the lygus pest management guidelines.

- UC IPM graphics

As I tell growers, cotton plants can’t hold all their fruit and it’s normal to lose a certain amount. My rule of thumb is to hold off on treatment for a fruit retention rate above 80 percent. The treatment threshold comes into play when the rate falls below 80 percent retention, especially for Pima varieties which have small bolls.

A cotton boll in pre-bloom.

I saw one field being treated even though fruit retention was at 85 to 90 percent. When you’re above the 80 percent threshold, you should continue monitoring your field and taking pest samples. You may see lygus counts drop because the bugs are heading off to more preferred conditions in nearby alfalfa fields.

By jumping the gun, growers could impact the ecological balance by harming natural predators which play a big part in using biological controls to managing crop-threatening pests. Besides, beneficial insects are good for the pocketbook as well as the environment. Using softer materials can help preserve the beneficial insect population.

Alfalfa is drying around an uncut strip.

In the alfalfa fields, growers are cutting their crop for the third time this season. Some already are preparing for the fourth cutting, irrigating the fields and adding a bit of fertilizer to spur growth. Remember to keep leaving strips of uncut alfalfa to keep lygus from migrating to nearby cotton fields. Be a good neighbor.

I’m seeing an increase in worm activity. So far, there no signs of growers treating their alfalfa for worms. Remember to keep monitoring the fields.

Looking ahead, July will be another busy month with little time to rest – even on the Fourth of July holiday this Wednesday. Like farmers around here, Independence Day is another work day for Valley agriculture. Wishing everyone an enjoyable Fourth of July holiday.