California Ag Network

Tag: Pomegranates

  • Roof Rats Unnerve Farm Workers, Damage Orchard Crops

    Davis, Calif., (March 22, 2018) – Monitor for rodent activity and use bait stations before the growing season to prevent problems, UC ANR scientists recommend.

    Roof rats are running rampant in California orchards this year, according to UC Agriculture and Natural Resources scientists.

    “In pistachio and other nut orchards, roof rats are burrowing and nesting in the ground where they’re chewing on irrigation lines, causing extensive damage,” said Rachael Long, UC Cooperative Extension advisor. “They are also nesting in citrus trees, feeding on the fruit and terrifying field workers when they jump out as people are picking fruit. The chewing pests are also girdling citrus limbs, causing branch dieback.”

    The wet winter of 2017 led to lots of weed seeds for rats to eat. “Last season, rats were also nibbling on pomegranates, avocados, and other fruit and nut crops, rendering them unmarketable,” Long said.

    Holes in the ground around the base of pistachio trees throughout a Yolo County orchard puzzled the grower.

    “We looked for ground squirrels, but never saw any,” Long said. “We set up game cameras, but only got birds and rabbits. We put rodent bait in the holes, but the digging didn’t stop.”

    Long, the pest detective, cracked the case by consulting Niamh Quinn, UC Cooperative Extension human-wildlife interactions advisor based in Irvine. “She informed us that the damage we were seeing was from roof rats.”

    Burrowing roof rats sounds like an oxymoron. While roof rats generally don’t burrow in urban environments, their country cousins have been known to burrow.

    “It’s not true that they don’t burrow,” Quinn said. “When I worked as staff research associate for Roger Baldwin, UC Cooperative Extension wildlife specialist, that is mostly what we studied, burrowing roof rats in orchards.”

    Roof rats are nocturnal animals that climb trees and burrow underground.

    Control measures – Baldwin said, “It seems to be a good year for rats in a number of different areas and crops throughout the state. I’ve received more questions and comments about rats this year than perhaps the last 10 years combined. As for bait application, putting bait down burrow systems for rats doesn’t usually work too well, so I’m not surprised that approach didn’t work. Growers will likely have better luck with bait stations in the trees.”

    Because the rats climb, Baldwin suggests attaching bait stations to tree branches.

    “In addition, elevating the bait stations will eliminate access to bait for many protected mammal species, such as kangaroo rats,” Long said. “The bait diphacinone grain can be purchased from some ag commissioners’ offices. This is what Roger Baldwin said they tested and it worked.”

    As for the bait stations, they should be designed so that there isn’t any spillage for nontarget animals to eat, Long said.

    When roof rat outbreaks occur, rodenticides are often needed to prevent crop damage. However, timing is critical as diphacinone use is highly restrictive and not allowed during the growing season, which is beginning as the weather warms.

    “Check the product label for application instructions,” Long reminds growers. “It’s the law.”

    Because roof rats climb, UC Cooperative Extension wildlife specialist Rager Baldwin recommends attaching bait stations to tree branches.

    Identifying the pest – One way for growers to identify whether they have roof rats is by the size of the burrows. The nocturnal pests are active above ground in trees and below ground.

    “Roof rats can forage away from their nest, so you won’t likely find signs of their activity, such as rat droppings outside their burrow, to help identify them,” Long said.

    Ground squirrels are active during the day, so they are more likely to be seen, dig holes about 4 inches in diameter and forage above ground near their burrows. Vole and mouse holes are 1- to 2-inches in diameter. Roof rat holes are typically 3 to 4 inches in diameter and might have nut shells in front of them, for example pistachio or almond shells. Rabbits will feed on seedling crops, but do not dig burrows.

    Roof rats are prolific breeders that reproduce year-round, according to Baldwin. Females typically have three to five litters per year with five to eight young, enabling their populations to rapidly increase. The omnivores feed on a wide variety of plant and animal materials, allowing them to adapt to any environment, including urban and agricultural lands.

     

    “Rats are sneaky and hard to spot,” Long said. “If you see damage, including digging in the soil but no wildlife, suspect rats.”

    For more information on controlling roof rats, download Quinn and Baldwin’s free UC ANR publication 8513, Managing Roof Rats and Deer Mice in Nut and Fruit Orchards at http://anrcatalog.ucanr.edu/Details.aspx?itemNo=8513.

    For more information about ground squirrels, download the free UC IPM Best Management Guidelines http://www.groundsquirrelbmp.com or UC IPM Pest Note http://ipm.ucanr.edu/PMG/PESTNOTES/pn7438.html.

    Roof Rats are causing damage in nut and tree fruit orchards.
    Roof rat holes are typically 3 to 4 inches in diameter.
    Ground squirrels are active during the day and their burrows are 4 inches or more in diameter.

  • Tulare County Reports on Current Crop Status

    Visalia, Calif., (January 27, 2017) – Tulare County Agricultural Commissioner released the current status today of Major crops in the most valued county in the California Ag portfolio. They report that Growers continue to wait for fields to dry out in order to resume winter grain and field crop planting. The planted grains and field crops continue to mature at an excellent rate, reaping the benefit from all the recent rain. Sorghum seed continues to be received for future planting. Black-eyed beans were exported to Malaysia.

    Table grapes from cold storage continue to be exported primarily to Canada and Mexico. Field work in vineyards and orchards: pruning, tying, berm sanitation, and brush shredding, are all on hold until workers can get back in wet fields. Kiwifruit are being exported to Colombia. Pistachios are being exported Belgium, China, Egypt, France, Hong Kong, India, Israel, Italy, the Netherlands, Spain, Sweden, and Vietnam. Almonds are being exported to Chile, China, Colombia, Germany, Hong Kong, India, Indonesia, Israel, Jamaica, Japan, Korea, the Netherlands, Norway, Pakistan, the Philippines, South Africa, Taiwan, the United Kingdom, the United Arab Emirates, and Vietnam. Pecans are being shipped to Australia, Lebanon, and Saudi Arabia. Walnuts are being shipped to Hong Kong. Pomegranates are primarily being exported to Mexico. In drier locations the removal of older orchards and vineyards continues in preparation for replanting with new varieties, but even this has been delayed by the extended wet weather.

    The citrus harvest was essentially stopped during the recent rains. With the clearer weather it should resume at a rapid pace. Navel oranges are being shipped to Australia, China, the Dominican Republic, Ecuador, Japan, Korea, Malaysia, Mexico, New Zealand, the Philippines, Singapore, and Thailand. The second application of copper fungicide has or will be made to meet the February 4th deadline for continued export to Korea. Mandarin oranges continue being shipped to Australia, Ecuador, El Salvador, Guatemala, Japan, and Mexico. Satsuma tangerines continue to be harvested and sent to domestic markets only. Melogold grapefruit are being exported to Japan and Korea. Lemons are being exported to Australia, China, Korea, and New Zealand. Removal of older orchards continues in preparation for replanting to new varieties in drier locations. The domestic market for citrus fruit remains steady at a good price.

    Winter vegetables continue to mature ideally. The wet weather stopped the harvest of cole crops, but the harvest should continue as fields dry in the coming days. Strawberries fields continue to thrive. Blueberries continue to be planted, weather permitting.

    Rangeland and dryland pasture continues to improve with the recent rainfall. Rangeland quality is benefiting from this week’s rain at the lower elevations. The fed cattle market price up at $120 per hundredweight.

    Bare root rose nursery stock continues to be received, processed and shipped out. Potted roses are currently being shipped. Shipments of wholesale nursery stock have remained slow due to winter weather and a lack of demand. Mature olive trees are being dug up and sold for landscaping as soil conditions permit.

  • USDA California Crop/Weather Report

    Sacramento, Calif., (January 17, 2017) – A continued abundance of moisture across the State for the entire week tapered off over the weekend as the upper-level trough pulled away to the east with surface high pressure building over the western United States.

    Temperatures were fairly consistent, but cooled slightly late last week as a drier airmass settled over the State.

    Nearly all locations in the State saw precipitation last week, with the heaviest rainfall impacting the northern and central Sierras from Tahoe northward to the Lassen Volcanoes area, where precipitation totals reached near 12 inches. Specifically, the area around Blue Canyon received a total of 9.99 inches of rain. The coastal mountains received heavy rainfall with 4 to 8 inches falling, while most of the valley received rainfall totals between 3 to 4 inches. Even the deserts, received up to 1 inch of rainfall over the weekend. The mountains once again received very heavy snow this week, with some areas receiving 2 feet of snowfall in a single day. Lodgepole reported a total of 23 inches of new snow on Thursday. The heaviest snow fell in the Tahoe region and in the mountains just to the north, where up to 5 feet of snow fell. Elsewhere in the mountains, 2 to 4 feet was the norm in the Southern Sierras, with coastal ranges seeing up to a foot of new snow.

    Temperature highs were in the 20s to 40s in the mountains, 40s to 60s valley, 50s to 60s along the coast and, 50s to 70s in the desert. The temperature lows were in the 20s to 30s in the mountains, 30s to 50s in the desert and the valley, and 40s to 50s along the coast.

    Recent rains benefited the growth of already planted grains and field crops, but the rain hindered ground preparations for continued planting. The forecast for optimal returns continued to look positive. Sorghum seed continued to be received for future planting. Hay alfalfa remained dormant.

    Some pomegranates were harvested. Deciduous fruit orchard continued to be pruned and brush shredded as weather conditions permitted. Most post-harvest field activities were halted due to the heavy rains and standing water. In drier locations the removal of orchard and vineyards continued in preparation for replanting with new varieties. Blueberry planting continued, as weather permitting. Rains continued to slow navel orange and mandarin harvest. Fungicide applications to citrus were made as conditions allowed.

    Nut orchards continued to be pruned and brush shredded as weather conditions permitted.  Most post-harvest filed activities were halted due to the heavy rains and standing water.

    In San Joaquin County, winter Farmer’s Market vegetables were harvested.  Commercial basil fields were cut and packaged when weather permitted.  In Madera County, tomato fields were being prepped for planting.  In San Luis Obispo County, winter vegetables such as Chinese Napa cabbage, bock choy, parsley, cilantro and spinach were harvested.  Spring vegetables were planted.  In Fresno County, there were heavy rains, but winter vegetables remained in good condition.  In Tulare County, the growth of the winter vegetables benefitted from favorable weather conditions.

    Non-irrigated pasture and rangeland greened up considerably due to recent rains. Range was reported to be primarily in fair to good condition. Snow and ice covered some grazing land in Modoc and Siskiyou Counties. Some dairies were impacted by standing water and sloppy conditions from the week’s precipitation. Sheep grazed idle fields and dormant alfalfa fields. Bees continued to be brought into the state in preparation for the bloom season. Bee keepers continued to feed their hives to compensate for the lack of blooming vegetation.