Subtropical Fruit Crops Research & Education
University of California
Subtropical Fruit Crops Research & Education

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Florida Orange Production UP!!!

The USDA has summarized the US citrus crop for 2018-19 and it is up for both California and Florida, with CA accounting for 51% of US production! But the Florida orange crop is  up from last year.  This is the state that is getting hammered by huanglongbing amongst all the other demands being made on that industry.  This is good news for citrus. 

The full report is Here

But the summary is:

Citrus utilized production for the 2018-19 season totaled 7.94 million tons, up 31 percent from the 2017-18 season. California accounted for 51 percent of total United States citrus production; Florida totaled 44 percent, and Texas and Arizona produced the remaining 5 percent.

Florida's orange production, at 71.8 million boxes, is up 59 percent from the previous season.Grapefruit utilization in Florida, at 4.51 million boxes, is up 16 percent from last season's utilization. Florida's total citrus utilization increased 56 percent from the previous season. Bearing citrus acreage, at 387,100 acres, is 13,800 acres below the 2017-18 season.

Utilized citrus production in California increased 15 percent from the 2017-18 season. California's all orange production, at 49.8 million boxes, is 13 percent higher than the previous season. Grapefruit production is down 16 percent from the 2017-18 season but tangerine and mandarin production is up 35 percent. Utilized production of citrus in Texas is up 29 percent from the 2017-18 season. Orange production is up 33 percent from the previous season and grapefruit production increased 27 percent. Total citrus production in Arizona's lemon production is up 35 percent from last season.

The value of the 2018-19 United States citrus crop increased 1 percent from last season, to $3.35 billion (packing house-door equivalent). Orange value of production decreased 7 percent from last season and grapefruit value is down 1 percent.

Tangerine and mandarin value of production is 31 percent higher than last season but lemon value of production is down 4 percent.

Overall comparisons discussed above are based on similar fruit types. The revised production and utilization estimates are based on all data available at the end of the marketing season, including information from marketing orders, shipments, and processor records. Allowances are made for recorded local utilization and home use. Estimates for the 2018-19 California Valencia oranges and grapefruit are preliminary.

BUT, the latest news from the Central Valley navel forecast is that it is down,

The 2019-20 California navel crop is down 7% from last season, according to the first U.S. Department of Agriculture estimate.

With harvest expected to begin in October, the California navel  forecast is 76 million (40-pound) cartons, down 7%  percent from the previous year, the USDA said Sept. 12.

Farming is a roller coaster.

citrus cornucopia
citrus cornucopia

Posted on Thursday, October 3, 2019 at 2:29 PM
Tags: California (13), citrus (338), Florida (3), HLB (71), production (10)

Alcohol Loving Ambrosia Beetles

Ambrosia beetles, which are a large group of several thousand species worldwide, belong to the bark beetles. All species are characterized by the ability to cultivate fungi. Invasive Shot Hole Borers that attack avocado and a range of native and landscape trees in California and the Laurel Wilt Disease that hammers avocado in Florida are ambrosia beetles. These beetles cultivate fungi in living trees and over time, the fungus is what kills the tree.

Beetles share the work of cultivating their fungal gardens: some clean the tunnel systems that are being eaten into the wood; others clear the dirt from the nest and clean their fellow workers -- always with the aim of optimizing the symbiosis of beetle and fungus.

It's been long known that alcohol is produced by weakened trees and that these trees are recognized and colonized by the beetles. Traps baited with alcohol are used to catch the catch the insects when they fly. Alcohol is very attractive to the beetles in large part because the fungi they feed on performs best in an alcohol-rich environment. Alcohol is normally used as a preservative to impede other fungi, such as molds from growing, and this is the case for the fungi associated with these beetles. They prefer to grow in an environment where other fungi don't grow.

Here's an interesting article showing how this preference by disease-causing fungi allows them to thrive in a normally harsh environment. Maybe it can be exploited.

Christopher M. Ranger el al., "Symbiont selection via alcohol benefits fungus farming by ambrosia beetles," PNAS (2018).

Photo: Party Beetles

Credit: Gernot Kunz

ambrosia beetles
ambrosia beetles

Posted on Wednesday, October 2, 2019 at 6:32 AM
Tags: ambrosia beetles (3), ISHB (7), KSHB (21), Laurel Wilt (7), PSHB (33)

Giant Tumbleweeds Eat Victorville

A new species of gigantic tumbleweed once predicted to go extinct is not only here to stay -- it's likely to expand its territory.

The species, Salsola ryanii, is significantly larger than either of its parent plants, which can grow up to 6 feet tall. A new study from UC Riverside supports the theory that the new tumbleweed grows more vigorously because it is a hybrid with doubled pairs of its parents' chromosomes.

Findings from the study are detailed in a new paper published in the Oxford University-produced journal AoB Plants.

"Salsola ryanii is a nasty species replacing other nasty species of tumbleweed in the U.S.," said study co-author Norman Ellstrand, UCR Distinguished Professor of Genetics. "It's healthier than earlier versions, and now we know why."

Humans are diploid organisms, with one set of chromosomes donated by the mother and one set from the father. Sometimes a mother's egg contains two sets of chromosomes rather than just the one she is meant to pass on. If this egg is fertilized, the offspring would be triploid, with three sets of chromosomes. Most humans do not survive this.

Plants with parents closely related enough to mate can produce triploid offspring that survive but are unable to reproduce themselves. However, a hybrid plant that manages to get two copies from the mother and two from the father will be fertile. Some species can have more than four sets of chromosomes. They can even have "hexaploidy," with six sets of chromosomes.

Scientists have long assumed there must be some kind of evolutionary advantage to polyploidy, the term for hybrids that have multiple sets of chromosomes, since it poses some immediate difficulties for the new hybrids.

"Typically, when something is new, and it's the only one of its kind, that's a disadvantage. There's nobody exactly like you to mate with," said study co-author Shana Welles, the graduate student in Ellstrand's laboratory that conducted the study as part of her Ph.D. research. She is now a postdoctoral fellow at Chapman University.

The advantage to having multiple sets of chromosomes, according to the study, is that the hybrid plant grows more vigorously than either of its parents. This has been suggested as the reason polyploidy is so common in plants. However, it has not, until now, been demonstrated experimentally.

Polyploidy is associated with our favorite crops; domesticated peanuts have four sets of chromosomes, and the wheat we eat has six.

Though tumbleweeds are often seen as symbols of America's old West, they are also invasive plants that cause traffic accidents, damage agricultural operations, and cause millions in property damage every year. Last year, the desert town of Victorville, California, was buried in them, piling up to the second story of some homes.

Currently, Salsola ryanii has a relatively small but expanding geographic range. Since the new study determined it is even more vigorous than its progenitors, which are invasive in 48 states, Welles said it is likely to continue to expand its range. Additionally, Welles said climate change could increase its territory takeover.

Though this tumbleweed is an annual, it tends to grow on the later side of winter.

"It's one of the only things that's still green in late summer," Welles said. "They may be well positioned to take advantage of summer rains if climate changes make those more prevalent."

Given its potential for damage, the knowledge now available about Salsola ryanii could be important for helping to suppress it, and Ellstrand believes that is what should happen before it takes over.

"An ounce of prevention is a pound of cure," he said.

Commandos from Cannon Air Force Base, N.M., clear tumbleweeds from a residential area in Clovis, N.M., 2014. U.S. Air Force/Senior Airman Ericka Engblom

giant tumbleweed
giant tumbleweed

Posted on Monday, September 30, 2019 at 6:23 AM
Tags: salsola (1), tumbleweed (1)

Black Hearted Pomegranate

Pomegranate (Punica granatum) is a specialty crop now grown on more than 10,000 acres in California.  Pomegranate production has increased for both fresh market and juice in the last several years, and with this increase, random internally rotted fruit has become more noticed. The outside of the fruit looks perfectly fine, but internally the fruit is rotted and the arils (the flesh covered seeds that are eaten and juiced) are black. Pretty disgusting. Some fruit recently has shown up at harvest and the grower was unaware of the problem until the fruit was opened by a customer. The only difference between good fruit and affected fruit is that the blackhearted fruit is a bit lighter in weight. The absence of external symptoms makes the diagnosis of the disease very difficult, and consumers encountering the disease may change their perception of the pomegranate's many health benefits.

Initially, it was thought that the disease was caused by various fungi that can decay only the arils. However work by Themis Michailides from UC Kearney REC has shown that after inoculation of pomegranate flowers and developing fruit that the main cause of black heart is Alternaria spp. These fungi are very abundant in nature and cause diseases in a multitude of crops. Another fungus that is also isolated from pomegranate with black heart is Aspergillus niger. However, the decay caused by A. niger is softer than that caused by Alternaria and results in exuded juice. In addition, another major difference between black heart caused by Alternaria spp. and that caused by Aspergillus is that the latter decays both arils and rind of fruit and frequently symptoms reach the outer surface of fruit, which helps in the diagnosis of the disease. Inoculations with Alternaria spp. reproduce the typical symptoms of black heart (internal decay of the arils without any external symptoms).

Inoculations periodically with Alternaria spp. showed that most of the infections occur at bloom time and that spores of the fungus that are introduced into the fruit (puncturing from thorns, hemipteran feeding like aphids and stink bugs, or cracking) can result in black heart. The current research focuses on the identification of the various species of Alternaria that cause black heart, the understanding of the infection process, and the development of procedures to manage the disease.

Alternaria alternata and related species commonly occur on plant surfaces and in dying or dead tissues of plants. The pathogens overwinter on plant debris in or on the soil and in mummified fruit. The spores are airborne and can be carried to the flowers with soil dust. Infections may also start from insect and bird punctures on fruit. Research in the San Joaquin Valley showed that the petal fall stage seems to be the most susceptible stage when most of the infection occurs. However, infection can occur throughout the long bloom and fruit development periods.

Estimated losses are usually less than 1% but can be up to 6%.

So how does a grower reduce black heart? Fungicide coverage has been a problem for bloom fungicides, but Michailides has shown some promising new materials. Good orchard management practices, such as dust control and sanitation (removal of old fruit and dead branches), may reduce the incidence of the disease. Infected, healthy-appearing fruit may be dropped to the ground by gently shaking the tree at the time of harvest. Avoid water stress and overwatering that may result in fruit cracking.

Thorough sorting and grading of pomegranates for discoloration and cracking can help avoid packing diseased fruit.

See the Themis' slide show:

And see the star of the show:

pomegranate half
pomegranate half

Posted on Friday, September 27, 2019 at 6:04 AM
Tags: black heart (3), pomegranate (6)

Avocado Tours Next Week

Join us for our Annual Meeting
PO Box 4205
Ventura, CA 93007


California Avocado Society's
2019 Annual Meeting
The 104th Annual Meeting will be in Ventura
Please Mark your calendar
October 4, 2019 (Friday)
Friday, October 4 is the Field Tour, President's BBQ then Short General Meeting.
Topics on the Tour

Mature high-density plantings and pruning - what happens over time!
A test planting of three scions on nine different rootstocks.
How to recover from fire damage.
Commercial avocado propagation with grafting demonstration.
Hansen Agricultural Research & Extension Center, 287 South Briggs Rd., Santa Paula.
Registration starts at
8:00-8:45 AM
Field Tour Locations and Maps distributed on-site
Plenty of parking at Hanson Ag Center - Carpooling is encouraged.
BBQ Lunch at Hanson Ag Center
1:00 PM
Following Lunch
Short meeting, a guest speaker, and CAS Annual Awards
Guest Speaker
Ed Williams - Ventura County Agricultural Commissioner
Talk about the future of glyphosate, conflicts between hemp production and avocado farms, and other vital issues for avocado growers.
Make it an Avocado week and plan on attending the famous Carpinteria Avocado Festival

Avocado Festival October 4-6, 2019

avocado berms
avocado berms

Posted on Wednesday, September 25, 2019 at 2:28 PM
Tags: avocado (289)

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