- Author: Mark Bolda
We finally have a label for the insecticide Sequoia. It will be a good one to have in our roster of insecticides in strawberry, not only because it is pretty darn effective in controlling lygus, but also because it can be rotated in with the remaining usable materials we have and keep them effective that much longer.
It does come with the caveat of only being 12 months long, but there always is the possibility of renewal plus the regular Section 3 label is being worked on at the Federal level. Use directions for the Section 18 for Sequoia attached below as a pdf file.
The only way to get these labels in California is to have the efficacy from the field to prove that the insecticide actually does what it is supposed to do. This was a job led out of this office of UCCE, and it was a major commitment that stretched over something like 5 years. My colleagues and I get up well before daybreak to beat the wind and do the sprays, are out there week after week to collect the samples, and spend many hours at the microscope counting the lygus, beneficials and other bugs. This was a ton of work over many years and effort put in by some very committed people, in particular Shimat Joseph and Monise Sheehan of UC Cooperative Extension and Hillary Thomas at the time with the CSC, but at the end of the day the effort very much worth it because we got you your Sequioa label for lygus in strawberries.
I am very grateful to Dow Chemical, now Corteva Agrisciences, Jean-Mari Peltier who sheparded the application through the CDPR and all the growers who collaborated with us for the tremendous support they gave us over the years to get this label to you.
Growers, this is a Section 18, so as always you have to get it on your restricted use permit.
Questions about efficacy? Lots of studies on this site, type in lygus or sulfoxaflor in the search box and you'll see plenty of information on it.
You are welcome.
Sequoia Strawberry Sec 18 Final Label 10.30.18
- Author: Mark Bolda
- Author: Shimat Joseph
Former UCCE Entomology Advisor Shimat Joseph and I just had the linked paper below published in Crop Protection.
Excellent overview of the lygus problem in California strawberries and evaluation of a combination of bug-vac use and the insecticide sulfoxaflor (not registered yet, but useful for this study since it actually works) for management of this pest.
A few points out of the paper to take back to the farm:
1- The use of the bug-vac alone was not sufficient to reduce lygus populations to below that of the untreated check.
2- Treatments using the insecticide sulfoxaflor alone and in combination with the bug-vac reduced the numbers of lygus and the number of cat faced fruit.
3- Neither the bug-vac or sulfoxaflor had any effect on predaceous heteropterans and spiders compared to the untreated check.
The implication out of this work and paper is that the use of an effective insecticide will continue to be the best tactic for control of lygus and mitigation of its damage in strawberries.
Link is here, it will be active until the beginning of October:
https://authors.elsevier.com/a/1XWqVxPFYekQG
- Author: Christian Nansen, Elvira de Lange, Alison Stewart, Department of Entomology and Nematology, UC Davis
- Author: Mark Edsall, California Strawberry Commission
- Author: Surendra K. Dara
The western tarnished plant bug (or lygus bug) and different species of spider mites are major arthropod pests in California strawberries. While predatory mite releases are very popular for controlling spider mites in both organic and conventional fields, a significant amount of chemical pesticides are used for arthropod pest management in conventional fields. Nearly 280,000 pounds of active ingredient of at least 30 chemical and botanical pesticides were used in 2016 in California strawberries (USDA-NASS, 2016; CDPR, 2017) and malathion, bifenazate, naled, acequinocyl, and fenpropathrin were the most common of about 79,000 pounds of chemical pesticides. A uniform and thorough coverage of pesticide sprays is essential for effective pest management and also for reducing excessive pesticide use that could lead to resistance and environmental health issues (Shi et al., 2013). Evaluation of pesticide spray applications and their performance will help improve current pest management strategies in strawberry as they did in other crops (Nansen et al., 2011; Nansen et al., 2015).
Several factors such as the tractor speed, spray nozzles, spray volume, boom height, adjuvants, pressure, canopy characters, micro and macroclimatic conditions influence the spray coverage. A better understanding of these factors will help improve the pesticide use and efficacy, optimize the cost, and reduce pesticide drift and other associated risks (Nansen and Ridsdill-Smith, 2013).
A study was conducted during 2016 and 2017 to evaluate multiple spray configurations under varying weather conditions where more than 4000 data points were collected. Data for only two spray configurations, using Albuz ATR 80 Lilac and Albuz ATR 80 Green nozzles, are shown here.
Configuration 1: Albuz ATR 80 Lilac nozzles were used in 144 experimental applications delivering 32-80 gallons of spray volume per acre. Water-sensitive spray cards (TeeJet, Wheaton, IL) were clipped to the petioles of strawberry leaves in horizontal and vertical orientation (1 card per application for each orientation). They were placed in the strawberry canopy prior to spray applications and the coverage was determined based on the pattern on the cards using the SnapCard smartphone application. Data suggested that spray volume does not always translate into a good spray coverage (Fig. 1). There was a wide variation in the coverage that ranged from 0-55% at 33 gpa and 5-80% at 80 gpa suggesting the influence of other factors. Taking the operational and weather conditions into account, a multiple linear regression analysis was conducted to measure the relationship between predicted and observed spray coverage which appeared to have a linear correlation (Adjusted R2=0.27; F+52.6; P < 0.001) (Fig. 2). Wind speed, wind gust, ambient temperature, pressure, and tractor speed were used as explanatory variables in this analysis. Based on this regression model, four possible scenarios were developed with predicted spray coverage values (Table 1). A 2 mph increase in the wind speed from 6 mph to 8 mph could reduce the spray coverage from 61 to 45% when the tractor runs at 1 mph or from 30 to 13% when the tractor runs at 2 mph.
Configuration 2: Albuz ATR 80 Green nozzles were used in 276 experimental applications delivering 180-440 gallons of volume per acre. Since the droplet size from the Green nozzle is much larger than that from the Lilac nozzle, a better coverage is expected with the presumption of lesser sensitivity to environmental and operating conditions. However, data from the spray cards indicated a poor relationship between the spray volume and coverage under this configuration as well (Fig. 3). For example, both 200 and 350 gpa had a similar spray coverage. Multiple linear regression analysis, using strawberry canopy characteristics (plant height and width, dry weight, and canopy coverage), operating and weather conditions as explanatory variables, showed a significant linear correlation (Adjusted R2=0.45; F=199.5; P < 0.001) between observed and predicted spray coverages (Fig. 4). A prediction model under this configuration showed nearly 20% decline in spray coverage when the tractor speed increased from 1 to 2 mph (Table 2). Wind speed appeared to have a minimal impact, probably due to the droplet size.
This study demonstrates the importance of weather and operating conditions on spray coverage. Additional data will be collected in 2018 to expand our understanding of the factors that influence spray coverage. These studies will be useful to determine appropriate operating conditions such as the spray volume, tractor speed, and types of nozzles and identify weather conditions that are ideal to achieve good coverage. A free smartphone application is under development for the growers and PCAs to input weather and operating conditions to predict the spray coverage. This information will ultimately improve the pest control efficacy and contribute to sustainable pest management practices.
Acknowledgments: We thank the financial support of the California Strawberry Commission and the collaboration of several growers. We also thank the technical assistance of Daniel Olivier, Marianna Castiaux, and Ariel Zajdband, California Strawberry Commission and Robert Starnes, Jessie Liu, Laurie Casebier, Haleh Khodaverdi, and Isaac Corral, UC Davis.
References
CDPR. 2017. Summary of pesticide use report data 2016: California Department of Pesticide Regulation, p. 909.
Nansen C, Ferguson JC, Moore J, Groves L, Emery R, Garel N and Hewitt A. 2015. Optimizing pesticide spray coverage using a novel web and smartphone tool, SnapCard. Agronomy for Sustainable Development: 1-11. DOI: 10.1007/s13593-015-0309-y.
Nansen C & Ridsdill-Smith TJ (2013) The performance of insecticides – a critical review: Insecticides (ed. by S Trdan) InTech Europe, Croatia, pp. 195-232.
Nansen C, Vaughn K, Xue Y, Rush C, Workneh F, Goolsby J, Troxclair N, Anciso J, Gregory A, Holman D, Hammond A, Mirkov E, Tantravahi P and Martini X (2011) A decision-support tool to predict spray deposition of insecticides in commercial potato fields and its implications for their performance. Journal of Economic Entomology 104: 1138-1145. DOI: 10.1603/EC10452.
Shi M, Collins PJ, Ridsdill-Smith TJ, Emery RN and Renton M. 2013. Dosage consistency is the key factor in avoiding evolution of resistance to phosphine and population increase in stored-grain pests. Pest Management Science 69: 1049–1060. DOI: 10.1002/ps.3457.
USDA_NASS. 2016. Quick stats.
- Author: Ben Faber
Last May/June during a hot period and soon after fruit set, avocado growers and PCAs in the Oxnard/Camarillo area were calling in about young fruit about he size of a quarter showing up with white spots. Cutting into the fruit there might only be a small black spot just below the injury. Because that's what it is, a wound response on the part of the fruit to a physical damage. This occurred on several orchards also in the San Luis Obispo area and it seemed to happen in orchards that had recently been sprayed for avocado thrips. No piercing-sucking insects were found at any of these sites. Insects that would feed by feeding on the fruit and causing damage and malformed fruit. Insects that could typically make probing inspections of fruit prior to laying eggs. No eggs or larvae were found in the fruit. Nothing like lygus bug, BMSB, Bagrada bug or other stink bugs was found.
http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=15198
Did it have anything to do with the spray? With the hot weather? With the hot weather and the spray? With the hot weather and the insects that came with it? Did it have anything to do with the hot weather? Did it have anything to do with insects?
And then late June, the calls stopped. No more damaged fruit was being found. And then a lone call from Cayucos. Damage was found on young and older fruit. New damage seemed to be occurring on the fruit that normally sets later in that northern area. The grower walked the orchard and didn't find any bugs. The PCA swept the grove for insects. A yellow sticky card was put out.
So far, no insect has been found on the fruit. So what caused and "is" causing the damage to the fruit? It's not clear. Fruit that was damaged in Oxnard back in late May was tagged to see if it recovered. Ten fruit were flagged and two months later, those tagged fruit were still on the trees. So either the fruit that was attacked fell off with the initial damage or the fruit observed later had healed itself. Fruit have this capacity when they are actively growing to cover over damage. Often it is malformed. In most of cases with this fruit, the damage was very superficial. Occasionally, there deeper pits, but we didn't see any burrowing or tunneling.
If anyone else saw similar damage and has more to offer about this happening, I would be glad to hear about it.
Photos: Damaged fruit that was flagged and observed 2 months later.
- Author: Mark Bolda
Shimat, Pete and I are holding a grower breakfast this coming April 14. Place is the UCCE auditorium at 1430 Freedom Blvd, Suite E in Watsonville. Format will be an open discussion - it's a great opportunity to speak with some of the best in the business on lygus.
And of course enjoy a fine breakfast, courtesy of UC Cooperative Extension!