Posts Tagged: valley
New pest infesting almonds and pistachios in the San Joaquin Valley
Crop sanitation will be key to controlling the invasive carpophilus beetle
Growers and pest control advisers (PCAs) should be on the lookout for a new pest called carpophilus beetle (Carpophilus truncatus). This pest was recently found infesting almonds and pistachios in the San Joaquin Valley, and is recognized as one of the top two pests of almond production in Australia. Damage occurs when adults and larvae feed directly on the kernel, causing reductions in both yield and quality.
Populations of carpophilus beetle were first detected in September in almond and pistachio orchards by University of California Cooperative Extension Specialist Houston Wilson of UC Riverside's Department of Entomology. Pest identification was subsequently confirmed by the California Department of Food and Agriculture.
Wilson is now working with Jhalendra Rijal, UC integrated pest management advisor, North San Joaquin Valley; David Haviland, UCCE farm advisor, Kern County; and other UCCE farm advisors to conduct a broader survey of orchards throughout the San Joaquin Valley to determine the extent of the outbreak.
To date, almond or pistachio orchards infested by carpophilus beetle have been confirmed in Stanislaus, Merced, Madera and Kings counties, suggesting that the establishment of this new pest is already widespread. In fact, some specimens from Merced County were from collections that were made in 2022, suggesting that the pest has been present in the San Joaquin Valley for at least a year already.
“It has likely been here for a few years based on the damage we've seen," Rijal said.
This invasive beetle overwinters in remnant nuts (i.e. mummy nuts) that are left in the tree or on the ground following the previous year's harvest. Adults move onto new crop nuts around hull-split, where they deposit their eggs directly onto the nut. The larvae that emerge feed on the developing kernels, leaving the almond kernel packed with a fine powdery mix of nutmeat and frass that is sometimes accompanied by an oval-shaped tunnel.
Carpophilus beetle has been well-established in Australia for over 10 years, where it is considered a key pest of almonds. More recently, the beetle was reported from walnuts in Argentina and Italy as well. Carpophilus truncatus is a close relative to other beetles in the genus Carpophilus, such as the driedfruit beetle (C. hemipterus) that is known primarily as a postharvest pest of figs and raisins in California.
Monitoring for carpophilus beetle is currently limited to direct inspection of hull split nuts for the presence of feeding holes and/or larvae or adult beetles. A new pheromone lure that is being developed in Australia may soon provide a better monitoring tool for growers, PCAs and researchers.
“We're lucky to have colleagues abroad that have already been hammering away at this pest for almost a decade,” said Haviland. “Hopefully we can learn from their experiences and quickly get this new beetle under control.”
The ability to use insecticides to control carpophilus beetle remains unclear. The majority of the beetle's life cycle is spent protected inside the nut, with relatively short windows of opportunity available to attack the adults while they are exposed. The location of the beetles within the nut throughout most of their life cycle also allows them to avoid meaningful levels of biological control.
In the absence of clear chemical or biological control strategies, the most important tool for managing this beetle is crop sanitation.
“Given that this pest overwinters on remnant nuts, similar to navel orangeworm, crop sanitation will be fundamental to controlling it,” Wilson said. “If you needed another reason to clean up and destroy mummy nuts – this is it.”
In Australia, sanitation is currently the primary method for managing this pest. And here in California, new research and extension activities focused on carpophilus beetle are currently in the works.
“It's important that we get on top of this immediately,” said Wilson. “We're already starting to put together a game plan for research and extension in 2024 and beyond.”
If you suspect that you have this beetle in your orchard, please contact your local UC Cooperative Extension farm advisor (https://ucanr.edu/About/Locations/), County Agricultural Commissioner (https://cacasa.org/county/) and/or the CDFA Pest Hotline (https://www.cdfa.ca.gov/plant/reportapest/) at 1-800-491-1899.
/h3>Living With Oaks in the Home Landscape
No doubt you have seen many species of oaks living in wild areas of Northern California. But...
Valley Oak. UC Regents
Italian Ryegrass Research Updates (2022 Trials)
Summary note: This is a belated research update from herbicide trials (targeting...
Analysis of Sediments Deposited by 2023 Floods in the Salinas Valley
Richard Smith, Joji Muramoto, Tim Hartz and Michael Cahn
UCCE Emeritus Farm Advisor, Extension Specialist, Emeritus, Extension Specialist and Irrigation and Water Resources Farm Advisor.
The winter of 2023 had the highest rainfall years in the last 25 years. The high rainfall resulted in flooding onto farmland along the main branch of the Salinas River in both January and March. The flood waters disrupted planting schedules as well as inundated established plantings resulting in a disruption to the beginning of the vegetable production season.
The river also deposited a layer of sediments in flooded fields (Photo 1). The sediments came from several sources: river sediments from as far away as San Luis Obispo County; sediments from side channels; and soil sediments scoured from upstream farms. Several growers and industry personnel have asked what is the composition of these sediments? In April after the flooding had subsided, we collected samples at river crossings from San Lucas to Salinas. The layer of sediment left by the flood waters tended to curled up as it dried out and were easy to collect. Any field soil was brushed from the bottom of the sediments and they were sent to the UC Davis Analytical Laboratory for analysis.
Tables 1 and 2 have analysis of the sediments collected. The data in the table is arranged with sites from south to north; the two side channels, Arroyo Seco and Monroe Canyon are listed separately. Monroe Canyon is the drainage that comes from the west side of Hwy 101 just south of the intersection of Hwy 101 and Central Avenue north of King City; it cuts through a large section of the Monterey shale formation that contains elevated levels of cadmium.
The San Lucas, Arroyo Seco and Monroe Canyon samples are coarser indicating that they were transported by rapid water movement, while the rest of the samples are dominated by silts and clays, indicating that they were transported by slower moving water. In general, there is a good correlation between the clay content of the sediments and nutrient and organic matter content. Higher nutrients in the silt and clay sediments include total nitrogen, calcium, magnesium, sulfate, zinc and iron. The sediments are generally fertile which may indicate that they are at least partially composed of soil eroded from farmed fields farther upstream. Sediments that are low in phosphorus likely originated from non-farmed or vineyard areas.
The elevated cadmium levels measured in sediments from the Arroyo Seco and Monroe Canyon indicate that these side channels carried sediments from the Monterey shale formation which has naturally high levels of cadmium into the Salinas River. Presumably these sediments originating in the Monterey shale formation are transported to areas further downstream by flood waters.
Photo 1. Sediments deposited in a field along the Salinas River
Table 1. Analysis of river sediment samples from locations from San Lucas to Salinas and two side channel locations.
Table 2. Analysis of river sediment samples from locations from San Lucas to Salinas and two side channel locations.
Soil health monitoring conducted at SJV reduced disturbance and cover cropped fields!
Soil health monitoring conducted at SJV reduced disturbance and cover cropped fields!
As part of the USDA NRCS Conservation Innovation Grant, Creating a no-till network in California, extensive baseline soil sampling has now been done at several San Joaquin Valley farms that are employing the soil health management practices of no-tillage, strip-tillage and/or cover crops. These farms include sites at the diversified permanent and annual crop farm of Eddie Sajian in Hanford, CA, the dairy silage fields of Rick Adams near Laton, CA, the grazing pasture lands of Paul Strojan in Farmington, CA, cotton fields at Bowles Farming in Los Banos, CA, and tomato acreage of Woolf Farming in Huron. Determinations of soil carbon, aggregation, infiltration, and % residue cover have been done at each site and findings have been discussed with partner farmers for each location. In addition, participating farmers have been encouraged to begin conducting their own ongoing monitoring by using the assay techniques shown here. They were also provided with a PVC meter square quadrat to use in sampling surface biomass and a set of sieves as shown below that are used for determinations of soil aggregate stability.
Slide of soil health test kit materials given to network farmer participants CIG NRCS State No-till 2022
Capture aggregate stability scoring Woolf 2021