David Doll0 commentsJune 28, 2020Insects, Technology

Technology Corner: Spear-Lep w/Vestaron

EDITOR’S NOTE: This entry is the first in a new and (hopefully) ongoing series to highlight new technology related to almond and tree nut production. The question/answer format is set to focus more on the technical aspects and application of the technology. Since we are approaching hull-split, I thought a reasonable place to start would be with Vestaron, a company which recently released a new class of insecticides.Thanks to Noel Cornejo for taking the time to answer my questions. Question (Q): Spear-Lep is a new group of insecticides that has been shown to be effective on lepidopteran pests, such as peach twig borer, codling moth, and navel orangeworm. What is the active ingredient and how does this product work? Answer (A): The active ingredient is an insecticidal peptide called GS-omega/kappa-Hxtx-Hv1a. It was carefully optimized to target the nicotinic acetylcholine receptor in the insect nervous system, but at a receptor site distinct from Spinosad and neonicotinoids. The end result is paralysis of the lepidopteran larvae that ingest it. Q. Is this product directly toxic to insect pests? Or does it have to be consumed? How is the activity on developing larvae (may have been answered above)? A. For lepidopteran pests Spear works through ingestion. Extensive studies confirm activity against neonates as well as later instars of all species tested to date. At high v/v concentrations, Spear works though topical contact against smaller, soft-bodied pests such as mites, thrips and whiteflies. Q. How is this product different from what is currently on the market and is there any efficacy data comparisons among the various products on the market?  A. This novel class of insecticidal peptide is the first of its kind. Identified in nature, and then optimized painstakingly in the lab, Vestaron’s peptide insecticides are designed to target neuromuscular receptors proven through

Read More
David Doll6 CommentsJanuary 19, 2018Horticulture, Insects

How late can almonds be shaken for winter sanitation?

Winter sanitation is critical in managing navel orangeworm (as well as some other diseases) within almonds. Removing this past year’s remaining almonds – also known as mummies – is a time intensive process. Sanitation occurs by winter poling crews or by re-shaking the trees. This “winter-shake” is a quick way of removing the majority of the mummy nuts and, in high mummy-count orchards, is often used in combination with poling crews. With a dry November and December, winter-shaking of almonds have been delayed. This has led to several questions regarding how late almonds trees can be shook. Work done over 35 years ago by Steve Sibbett and colleagues found no impact on nut set, yield or size when winter shaking as late as January 31st. This was approximately 8 days prior to pink bud. The author concluded that shaking should be concluded by January 25th within the southern San Joaquin Valley, while it could be a week later in later blooming areas. Cited article: http://calag.ucanr.edu/archive/?type=pdf&article=ca.v037n07p20 When winter-shaking, it is common to see buds on the ground. Even though there may be several hundred buds, a reduction of yield shouldn’t be expected. This is due to the large number of buds that are present on an individual tree. For example, in a 3000 lb/acre mature orchard with 140 trees/acre, approximately 40,000 buds are on each tree, based on a 25% fruit set. Even if substantially higher buds drop from the tree after shaking, observations from several researchers suggest that the tree would compensate with a higher set percentage. Being that this research is over 30 years old, there is a need to update the work. Modern shakers are more effective as well as adjustable. It may be possible to shake closer to bloom without effect (although 8 days prior to pink

Read More
Jhalendra Rijal1 CommentMarch 22, 2017Insects

Seasonal Insect Pest Monitoring Updates in Almonds

This year has been a challenging year to conduct any winter cultural practices due to constant rainstorms and flood situations. By now, however, mummy nut removal from the trees and ground should have been completed. Orchard sanitation is a very effective cultural method to control navel orangeworm (NOW) in nut crops. Almond mummies not only harbor overwintering larvae (Fig. 1), but also serve as the resource for egg laying (Fig. 2) by NOW females in the spring, during which new nuts are not yet vulnerable to NOW infestation. For insect monitoring in almonds, we already passed the trap placement timing (February 15) for Oriental fruit moth (remember the biofix of OFM was February 16 last year). Put navel orangeworm egg traps out by March 15 (South San Joaquin Valley) or by April 1 (North San Joaquin and Sacramento Valleys). Use black egg traps filled with the almond meal + 10% crude almond oil. Hang the traps at head height on the north side of the Nonpareil tree, at least 5 trees in from the edge. Put one trap per 10 acres with at least 4 traps per orchard. Remember to change the bait frequently as wet and lumpy bait is not effective in attracting females for egg laying. The biofix of NOW egg laying was April 18 last year. Follow the link for the details. Pheromone traps and lures are available to monitor male NOW activity. Although the relationship between egg and pheromone traps has not been fully understood, pheromone trap capture data still helps in making NOW control decision. In the orchard with NOW mating disruption, use of the pheromone trap is strongly recommended to assess whether the mating disruption is working. Negligible to no moth capture is expected if the mating disruption is working properly. For San Jose scale,

Read More
Jhalendra Rijal0 commentsDecember 22, 2015Insects

Role of Winter Sanitation for Navel Orangeworm Management

Written by: Jhalendra Rijal, Area IPM Advisor, UC-Cooperative Extension (San Joaquin, Stanislaus, Merced) Navel Orangeworm (NOW) is a primary pest of almonds, pistachios, and walnuts, with other significant crops hosts such as fig, citrus, pomegranates. This pest was first introduced in southern California in 1942 potentially from Central and/or South America. Because of the wide host range, this pest was quickly spread to the entire Central Valley within 5-7 years of its first introduction, established and had become a major production threat in almond and other nut crop production. Adults are greyish-brown moths (about ½ inch long) with grey markings on wings. Eggs are laid in mummy nuts or in the nuts with initiation of hull-split. Tiny first instar larvae bore into the nutmeat and all stages of larva feed on nuts producing large amount of webbing and feces (i.e. frass). Larvae are white to pink with a reddish-brown head, and with a typical crescent-shaped markings on the second segment of the body just behind the head. The mature larvae (5th instar) can grow upto ¾ inch in size. Besides direct damage on nuts, NOW larval damage can lead to fungal infections, such as the mold that produces aflatoxin, known to cause carcinogenic and mutagenic effects on human. The larvae overwintered in mummy nuts that are in trees or on the ground. Among non-chemical ways of reducing NOW populations or damage include early harvest and winter mummy removal (i.e. sanitation).  Winter Sanitation of orchards during the winter is the most effective way to reduce the damage in upcoming season. Mummy nuts should be removed from the trees before bud swelling stage (late January/early Feb.) by shaking the trees or by hand polling. The nuts should then be destroyed on the orchard floor by discing or flail mowing by March 15. UC IPM

Read More
Franz Niederholzer0 commentsMay 29, 2015Insects

Navel orangeworm management at harvest: When, what, & how to get the best results

Franz Niederholzer, UCCE Farm Advisor, Colusa & Sutter/Yuba Counties; Emily Symmes, UC IPM Area Advisor, Sacramento Valley Almond nuts become vulnerable to navel orangeworm (NOW) damage at hull split.  In the south Sacramento Valley this year, Non-pareil hull split is expected in the last week of June, about the same time as last year, based on the prediction model developed by UC researchers (see it on-line at:  http://fruitsandnuts.ucdavis.edu/Weather_Services/almond_hullsplit_prediction/).  Protecting nuts from NOW (and peach twig borer) with hull split sprays and timely harvest are key to delivering a high quality crop to the huller and maximizing grower returns.  If you haven’t already, now is a good time to plan your hull-split spray(s). Non-pareil (NP) nuts split first – and have the most value.  Not surprising, the primary focus in NOW management is protecting NP nuts.  The worst NOW damage to NP nuts occurs if the nuts are still in the trees when 3rd generation NOW egg laying begins.  Harvest should occur when 100% of the nuts have split but the hulls are still green (see picture below). If this can be accomplished before 3rd generation egg laying, a significant portion of NOW damage to NP can be avoided.  Preconditioning of just-shaken nuts accelerates their drying and hastens pickup, reducing nut exposure to protein feeding ants and allowing irrigation ASAP before pollinizer harvest.  Careful orchard monitoring of NOW populations using egg traps and degree days indicate when egg laying should occur.  This can be supplemented with using pheromone traps to follow male flights.  In addition to timely harvest, properly timed and applied hull split sprays can help reduce the overall NOW population in the orchard and thus limit crop damage and income loss from current and future resident NOW generations. Once hull split occurs, growers can target different NOW generations depending

Read More
David Doll0 commentsApril 6, 2015General

Mid-Spring Considerations/Update

The 2015 almond season is in full swing. Many orchards have went through their drop, fertilizer applications and irrigation have began, and pest management concerns are beginning to form. Below are some thoughts and considerations from recent field visits. 1. Crop development is ahead of schedule – by as much as a month. Kernel fill is beginning in many ‘Nonpareil’ orchards, meaning that ‘Butte’/’Padre’ orchards won’t be far behind. This timing is important as about 80% of the season’s nitrogen budget should be applied prior to kernel fill – which may occur as early as early May! Secondly, it indicates that at this point – “What you see is what you’ll maximally get” in regards to kernel size, and farming practices – more particularly irrigation practices – can only reduce crop size. 2. Peach Twig Borer’s (PTB) “May Spray” timing looks to be an April timing. In the Merced area, our traps picked up a biofix around March 15th, which means we will be approaching 300 DD in about 7-10 days. Keep in mind that the spring spray timing for PTB is 300-400 degree days after the biofix. It may also be possible for the May Spray to have some effect on NOW.  Frank Zalom (UC Davis Entomologist) has found through research trials that timing the spray to 100 DD post NOW biofix (egg traps) and around 400 DD post PTB biofix can provide good control of NOW and PTB at harvest. 3. Rain is predicted for Tuesday (the 7th). Hopefully some rain will fall in the valley to help with the multitude of water issues. This rain may also bring some potential for fungal disease – especially rust and scab. Consider an application if there has been a history of disease. This application can be made 1-2 days after the rain event and

Read More
David Doll4 CommentsJune 26, 2014Insects

Speed Doesn’t Kill Part 3: Economics

There has been a lot of research focusing on spray rig speed and spray coverage. Work by Jack Dibble back in the 70s-90s indicated that the best coverage is achieved at 1.5 MPH, and was the basis of the compromised recommendation of 2.0 MPH. This work has since been repeated by Dr. Joel Siegel (along with several collaborators) and Dr. Ken Giles and colleagues at Arbuckle, CA, and has indicated that at higher speeds, control of navel orangeworm (NOW) is lost in the upper canopy of the tree (>15′ high). This, interestingly enough, is where the majority of the crop is located. A few articles have been posted on this in the past (Speed Doesn’t Kill, Speed Doesn’t Kill, part 2).

Read More
David Doll2 CommentsApril 17, 2014Horticulture

Pros and Cons of Earlier, Warmer Spring

A few discussions this week around an “earlier” than normal year for insects and nut development. We are somewhere around 10-12 weeks post bloom in the Northern San Joaquin Valley. Nut developing is progressing as expected. We have experienced higher than normal temperatures during stage one of growth which may lead to sizing issues – especially in later blooming varieties (i.e. ‘Fritz’) – similar to what we saw in 2013. Endosperm development should begin or has begun in most ‘Nonpareil’ and pollinator orchards. I suspect that kernel fill will be earlier, leading to an earlier ripening/hull-split/harvest timing.

Read More
David Doll2 CommentsOctober 22, 2013Insects

2013 Navel Orangeworm Insecticide Efficacy Trial (Merced Co.)

We have completed our data analysis of our 2013 navel orangeworm trial from an orchard near Le Grand, CA. Below is the report: Objective:  To evaluate the efficacy Brigade (bifenthrin pyrethroid), Proclaim (Emamectin benzoate), Brigade+Proclaim, Altacor (rynaxypyr), Entrust (spinosad), Intrepid (methoxyfenocide), and two different rates of Intrepid Edge™ (spinetoram and methoxyfenozide, GF 3028) for control of navel orangeworm (NOW) timed at Monterrey hull-split in California almonds.

Read More
  • 1
  • 2