- Author: Ben Faber
SACRAMENTO — The California Department of Food and Agriculture (CDFA) and the United States Department of Agriculture (USDA) have established a 94-square mile quarantine in portions of Riverside and San Bernardino counties following the detection of the citrus disease huanglongbing (HLB), or citrus greening, in a single citrus tree in the city of Riverside. HLB is a deadly disease of citrus plants and closely related species, and can be transmitted from tree to tree by the Asian citrus psyllid.
The quarantine boundaries are on the north, Interstate 10; on the east, Box Springs Mountain Reserve; on the west, Riverside Municipal Airport; and on the south, East Alessandro Boulevard. HLB quarantine maps for Riverside and San Bernardino counties are available online at: www.cdfa.ca.gov/plant/pe/InteriorExclusion/hlb_quarantine.html. Please check this link for future quarantine expansions in these counties, should they occur. Quarantines are already in place for HLB in portions of Los Angeles and Orange counties.
The quarantine will prohibit the movement of all citrus nursery stock out of the area, while maintaining existing provisions allowing the movement of only commercially cleaned and packed citrus fruit. Any fruit that is not commercially cleaned and packed, including residential citrus, must not be removed from the property on which it is grown, although it may be processed and/or consumed on the premises.
Residents are urged to take several steps to help protect citrus trees:
- Do not move citrus plants, leaves or foliage into or out of the quarantine area, or across state or international borders. Keep it local.
- Cooperate with agricultural crews placing traps, inspecting trees and treating for the pest.
- If you no longer wish to care for your citrus tree, consider removing it so it does not become a host to the pest and disease.
CDFA crews have already removed the infected tree and are in the midst of a treatment program for citrus trees to knock down Asian citrus psyllid infestations within 800 meters of the find site. By taking these steps, a critical reservoir of the disease and its vectors will be removed, which is essential to protect the surrounding citrus from this deadly disease.
HLB is a bacterial disease that attacks the vascular system of plants. It does not pose a threat to humans or animals. The Asian citrus psyllid can spread the bacteria as the pest feeds on citrus trees and other plants. Once a tree is infected, there is no cure; it typically declines and dies within a few years.
CDFA, in partnership with the USDA, local county agricultural commissioners and the citrus industry, continues to pursue a strategy of controlling the spread of the Asian citrus psyllids while researchers work to find a cure for the disease.
—California Department of Food and Agriculture
Over 20 new trees in Southern California have been confirmed HLB-positive. The new finds raise the total number of trees with huanglongbing disease found in California to around 100. All of the trees found in the state have been located in residential areas.
The Citrus Pest and Disease Prevention Program (CPDPP) issued a press release that stated 21 trees in Anaheim, and four trees in Pico Rivera tested HLB-positive. The CPDPP, a program of the California Department of Food and Agriculture (CDFA), stated the current quarantine in Southern California would be slightly expanded in Orange and Los Angeles Counties.
The new detections were found due to intensive surveying that's part of the response program. Highly trained crews sample trees where HLB-positive Asian citrus psyllids have been found. CDFA says their Sacramento facility can process 10,000 samples a month.
All of the detections in California have been residential trees. The CPDPP is currently running an outreach program that involves public service announcements, coordination with officials, and large public events in the quarantine area. The goal is to educate residents on the disease and the insect that spreads it. Go to the CPDPP website to find out more about the disease, insect, and quarantines.
Photo: HLB symptoms
- Author: Ben Faber
SACRAMENTO — A portion of Los Angeles County has been placed under quarantine for the Oriental fruit fly following the detection of nine flies in the Hollywood area. The quarantine zone measures 75 square miles. A link to the quarantine map may be found here:https://www.cdfa.ca.gov/plant/off/regulation.html
“California's fruit fly season extends from late summer through the fall,” said California Agriculture Secretary Karen Ross. “These pests like Southern California for some of the same reasons other travelers do: the pleasant climate and the tremendous variety of food. Fortunately, with the help of local residents, we have a great track record of eradicating these infestations.”
To prevent the spread of fruit flies through homegrown fruits and vegetables, residents living in the fruit fly quarantine area are urged to not move any fruits or vegetables from their property. Produce may be consumed or processed (i.e. juiced, frozen, cooked, or ground in the garbage disposal) at the property where it was picked.
The most common pathway for these pests to enter the state is by “hitchhiking” in fruits and vegetables brought back illegally by travelers as they return from infested regions around the world or from packages sent to California. To help prevent infestations statewide, officials asks residents to refrain from bringing or mailing fresh fruit, vegetables, plants, and soil into California unless agricultural inspectors have cleared the shipment beforehand.
While fruit flies and other invasive species threaten California's crops, the vast majority of them are detected in urban and suburban areas.
“That's why it's important for residents to cooperate with quarantine restrictions and allow authorized agricultural workers access to properties to inspect fruit and oriental fruit fly traps for signs of an infestation,” said Secretary Ross.
Following the principles of Integrated Pest Management (IPM), the California Department of Food and Agriculture (CDFA) uses a “male attractant” technique in its eradication effort for this pest. This approach, which has successfully eliminated dozens of fruit fly infestations in California, significantly reduces the amount of insecticide required to eradicate the population, and only targets the fruit flies – no other insects or animals are harmed. The treatment program is being carried out over several square miles surrounding the sites where the oriental fruit flies were trapped.
The oriental fruit fly is known to target more than 230 different fruits, vegetables, and plants. Damage occurs when the female fruit fly lays her eggs inside the fruit. The eggs hatch into maggots and tunnel through the flesh of the fruit, making it unfit for consumption.
The oriental fruit fly is widespread throughout much of the mainland of Southern Asia and neighboring islands including Sri Lanka and Taiwan, and has invaded other areas, most notably Africa and Hawaii.
Residents with questions about the quarantine may call the CDFA Pest Hotline at 1-800-491-1899.
—California Department of Food and Agriculture
Photos: OFF adults and Grapefruit infested with larvae of oriental fruit fly, Dacus dorsalis.
- Author: Ben Faber
This is a post from BBC:
http://www.bbc.com/news/business-40946159
From fashion to energy - the rind and seeds of Sicily's most famous citrus fruit, the humble orange, are being used in a range of greener, healthier business initiatives.
In 2011, Adriana Santonocito was a design student in Milan when she first had the idea of making sustainable textiles from what was naturally abundant, and widely wasted, in her native Sicilian city of Catania.
Her challenge was to find a way for the rinds of hundreds of thousands of tonnes of oranges to be put to good use.
Now, thanks to her creative thinking, it is possible to make whole items of clothing using fibre that originated from the fruit.
Chemical process
Ms Santonocito's concept was inspired by a question posed in her university dissertation. Could a luxurious silk foulard be made from citrus by-products, that would otherwise be thrown away or fed to cattle? Fiber uses chemical reagents to separate the cellulose from the orange remains
The question was particularly relevant in Sicily, where many thousands of tonnes of citrus fruit are juiced every year, leaving massive amounts of waste.
The 39-year-old found her answer in the university's labs, and it earned her a patent.
It was already known that cellulose could be extracted from orange rinds. But Ms Santonocito discovered that, using chemical reagents, it could then be turned into yarn, which could be dyed and blended with other textiles, such as cotton or polyester.
Together with her university colleague Enrica Arena, she founded Orange Fiber in 2014, and set about selling the silk-like material to clothes-makers. head up a 12-strong team
This year, the famous Italian fashion label Salvatore Ferragamo used it in its spring-summer collection. The aim was to make its high-end shirts, dresses and foulards more sustainable.
Orange Fiber, which now has a team of 12 people, operates from a local juice-processing plant, where it gets its waste material for free.
The business is partially seasonal, operating during the months of the year when the juice-maker works. But once the orange rind has been transformed into cellulose, it can be put in storage for use later.
Antonio Perdichizzi, an early investor in Orange Fiber, says the firm stood out to him because, unlike most innovative start-ups in Italy, it isn't digital.
Fiber uses the rinds of juiced oranges
"Italy doesn't invest much in innovation, but brilliant ideas and skills win despite a lack of resources," he adds.
Rosario Faraci, a professor of business, economics and management at the University of Catania, says the firm is an example of how "creativity and entrepreneurial spirit" is creating new jobs and businesses in the region.
Fibre - not fat
Oranges could also make baked goods healthier, and stay fresher, thanks to a new procedure which transforms them into an innovative fat-free flour.
The new technique is currently being tested at the University of Catania and results are encouraging.
At the moment, almost all bakers use fat, such as butter or margarine in their cooking.
But according to the research, half of this fat could be replaced by using flour obtained from orange rinds, seeds, and part of the pulp not used in juice-making. near Catania, liked the new flour
Like Orange Fiber, the researchers obtain the raw materials they need from local juice makers. They wash the rinds to remove the bitter flavour, then dry, process and whiten what remains.
Salvatore Barbagallo, a professor of agriculture at the University of Catania, says the flour is "perfectly sustainable" and costs almost nothing to produce. It also has "no impact" on the taste and fragrance of food that contains it.
His researchers made 300kg of the flour and got local bakers in Acireale, near Catania, to try it out.
The cooks, known for being conservative about new ingredients, were all happy with the results and could taste no difference in their pastries. The new flour is soluble
The researchers say they have found other uses for the flour, too.
It is soluble and can be added to drinks to provide health benefits. It could also be used by nutritionists and in medicine.
Natural fuel
Sicilian farmers have always used orange rinds as animal feed or fertiliser. But oranges can be a precious source of energy as well.
In Mussomeli, an ancient town near Caltanissetta in the middle of Sicily, orange waste products are used to make biogas which is turned into electricity.
The farm Nuova Scala used about 16,430 tonnes of rinds last year to produce 24,000 kWh of electricity.
Output varies depending on the amount of oranges produced, and the firm expects to get through 22,000 tonnes of orange waste in 2017.Disposing of oranges after they have been juiced can be expensive
Of course, all of these projects depend on local fruit companies, which produce many thousands of tonnes of citrus by-products annually.
Salvatore Imbesi, who owns the producer AgrumiGel, says the rinds, seeds and other non-edible parts of the fruit are called "pastazzo", and he produces about 40,000 tonnes of it a year.
He says Sicily as a whole produces about 200,000 tonnes, although unofficial estimates suggest the real figure could be higher.
Producers have an incentive to re-use pastazzo, because disposal can be expensive. Mr Imbesi says that in Sicily the total cost of disposal can reach 16m euros every year, "six for the cost of the transport, and 10 for the disposal itself".
Some of Sicily's fruit is sold fresh, including its famous blood oranges, with the rest turned into juices.
In 2016, the amount juiced included some 140,000 tonnes of lemons, 100,000 tonnes of blonde oranges, 100,000 tonnes of blood oranges, 20,000 tonnes of green mandarins and 20,000 tonnes of matured mandarins.
Finally, thanks to the new crop of innovative solutions, the squeezed fruit are being turned from expensive waste into exciting products.
- Author: Ben Faber
Soil and agriculture courses are being taught again at Ventura College. This was a commitment of outgoing President, Greg Gillespie. There are only a handful California community (junior) colleges that still teach soils. Luckily Santa Barbara City, Allan Hancock, Pierce, Mira Costa and a few other community colleges in the Central Valley have at least introductory courses in soils. Many of the leading growers in Ventura County got their start in college taking soils courses at Ventura College, then went on to four-year colleges to round out their educations. The community college classes have always been a taste, a dusting of understanding of soils and if someone wanted to dig deeper, they would go on to somewhere like Davis, Fresno, Riverside, Pomona or San Luis. The community colleges are part of the continuum, start there and then go anywhere.
Only a handful of community colleges continue to teach soils.
Dr. Jennifer Charles-Tollerup, the incoming Agriculture Instructor at Ventura College, brings a diverse set of experiences including 5 years in agricultural production systems, 4 years in agricultural research and education, 6 years in community college instruction as well as appointments in program development. She holds a PhD from the University of California, Riverside in Entomology with a concentration in Integrated Pest Management (IPM) and Statistics along with a Bachelor's from the University of California, Santa Cruz in Biology and Environmental Studies with emphasis in Botany and Agroecology. Jennifer trained as an Apprentice in Ecological Horticulture at UC Santa Cruz's Center for Agroecology and Sustainable Food Systems. She has worked on market gardens, family farms, and large-scale operations in citrus, grapes, nurseries, strawberries, herbs, lettuces, and edible flowers. Jennifer has used her academic and professional experience to coordinate elementary school garden programs.Jennifer readily supports the mission of the community college, to transform lives through education. Her approach involves building relationships with students and with agriculture partners, connecting the two together, and launching students into their life's work in agriculture. (this from CA Women in Ag newsletter, http://www.cwaventura.com/).More information about the Ventura College Agriculture Program can be found at http://www.venturacollege.edu/departments/academic/agriculture
Soil and agriculture courses are being taught again at Ventura College. There are only a handful California community (junior) colleges that still teach soils. Luckily Santa Barbara City, Allan Hancock, Pierce, Mira Costa and a few other community colleges have at least introductory courses in soils. Many of the leading growers in Ventura County got their start in college taking soils courses at Ventura College, then went on to four-year colleges to round out their educations. The community college classes have always been a taste, a dusting of understanding of soils and if someone wanted to dig deeper, they would go on to somewhere like Davis, Fresno, Riverside, Pomona or San Luis. The community colleges are part of the continuum, start there and then go anywhere.
Dr. Jennifer Charles-Tollerup, the incoming Agriculture Instructor at Ventura College, brings a diverse set of experiences including 5 years in agricultural production systems, 4 years in agricultural research and education, 6 years in community college instruction as well as appointments in program development. She holds a PhD from the University of California, Riverside in Entomology with a concentration in Integrated Pest Management (IPM) and Statistics along with a Bachelor's from the University of California, Santa Cruz in Biology and Environmental Studies with emphasis in Botany and Agroecology. Jennifer trained as an Apprentice in Ecological Horticulture at UC Santa Cruz's Center for Agroecology and Sustainable Food Systems. She has worked on market gardens, family farms, and large-scale operations in citrus, grapes, nurseries, strawberries, herbs, lettuces, and edible flowers. Jennifer has used her academic and professional experience to coordinate elementary school garden programs.
Jennifer readily supports the mission of the community college, to transform lives through education. Her approach involves building relationships with students and with agriculture partners, connecting the two together, and launching students into their life's work in agriculture. (this from CA Women in Ag newsletter, http://www.cwaventura.com/).
More information about the Ventura College Agriculture Program can be found at http://www.venturacollege.edu/departments/academic/agriculture
Come learn the dirt on the differences - ground, alluvium, subsoil, topsoil, mud, muck, marl, mire, smut - there are, but some terms are more subtle than others. Check out your local college for their soils course work.
- Author: Craig Kallsen
University of California (UC) researchers and private industry consultants have invested much effort in correlating optimal citrus tree growth, fruit quality and yield to concentrations of necessary plant nutrients in citrus (especially orange) leaf tissue. The grower can remove much of the guesswork of fertilization by adhering to UC recommendations of critical levels of nutrients in the tissues of appropriately sampled leaves. Optimal values for elements important in plant nutrition are presented on a dry-weight basis in Table 1. Adding them in appropriate rates by broadcasting to the soil, fertigating through the irrigation system or spraying them foliarly may correct concentrations of nutrients in the deficient or low range. Compared to the cost of fertilizers, and the loss of fruit yield and quality that can occur as a result of nutrient deficiencies or excesses, leaf tissue analysis is a bargain. At a minimum, the grower should monitor the nitrogen status of the grove through tissue sampling on an annual basis.
Leaves of the spring flush are sampled during the time period from about August 15 through October 15. Pick healthy, undamaged leaves that are 4-6 months old on non-fruiting branches. Select leaves that reflect the average size leaf for the spring flush and do not pick the terminal leaf of a branch. Typically 75 to 100 leaves from a uniform 20- acre block of citrus are sufficient for testing. Generally, the sampler will walk diagonally across the area to be sampled, and randomly pick leaves, one per tree. Leaves should be taken so that the final sample includes roughly the same number of leaves from each of the four quadrants of the tree canopy. Values in Table 1 will not reflect the nutritional status of the orchard if these sampling guidelines are not followed. Typically, citrus is able to store considerable quantities of nutrients in the tree. Sampling leaves from trees more frequently than once a year in the fall is usually unnecessary. A single annual sample in the fall provides ample time for detecting and correcting developing deficiencies.
Table 1. Mineral nutrition standards for leaves from mature orange trees based on dry-weight concentration of elements in 4 to 7 month old spring flush leaves from non-fruiting branch terminals.
element |
unit |
deficiency |
low |
optimum |
high |
excess |
|
|
|
|
|
|
|
N |
% |
2.2 |
2.2-2.4 |
2.5-2.7 |
2.7-2.8 |
3.0 |
P |
% |
0.9 |
0.9-0.11 |
0.12-0.16 |
0.17-0.29 |
0.3 |
K (Calif.*) |
% |
0.40 |
0.40-0.69 |
0.70-1.09 |
1.1-2.0 |
2.3 |
K (Florida*) |
% |
0.7 |
0.7-1.1 |
1.2-1.7 |
1.8-2.3 |
2.4 |
Ca |
% |
1.5 |
1.6-2.9 |
3.0-5.5 |
5.6-6.9 |
7.0 |
Mg |
% |
0.16 |
0.16-0.25 |
0.26-0.6 |
0.7-1.1 |
1.2 |
S |
% |
0.14 |
0.14-0.19 |
0.2-0.3 |
0.4-0.5 |
0.6 |
Cl |
% |
? |
? |
<0.03 |
0.4-0.6 |
0.7 |
Na |
% |
? |
? |
<0.16 |
0.17-0.24 |
0.25 |
B |
ppm |
21 |
21-30 |
31-100 |
101.260 |
260 |
Fe |
ppm |
36 |
36-59 |
60-120 |
130-200 |
250? |
Mn |
ppm |
16 |
16-24 |
25-200 |
300-500? |
1000 |
Zn |
ppm |
16 |
16-24 |
25-100 |
110-200 |
300 |
Cu |
ppm |
3.6 |
3.6-4.9 |
5 - 16 |
17-22? |
22 |
*California and Florida recommendations for K are sufficiently different that they are presented separately. The California standards are based on production of table navels and Valencias, and those for Florida were developed primarily for juice oranges like Valencia.
The sampled leaves should be placed in a paper bag, and protected from excessive heat (like in a hot trunk or cab) during the day. If possible, find a laboratory that will wash the leaves as part of their procedure instead of requiring the sampler to do this. Leaf samples can be held in the refrigerator (not the freezer) overnight. Leaves should be taken to the lab for washing and analysis as quickly as is feasible.
Often separate samples are taken within a block if areas exist that appear to have special nutrient problems. The temptation encountered in sampling areas with weak trees is to take the worst looking, most severely chlorotic or necrotic leaves on the tree. Selecting this type of leaf may be counter-productive in that the tree may have already reabsorbed most of the nutrients from these leaves before they were sampled. A leaf-tissue analysis based on leaves like this often results in a report of general starvation, and the true cause of the tree decline if the result of a single nutritional deficiency may not be obvious. Often in weak areas, it is beneficial to sample normal appearing or slightly affected leaves. If the problem is a deficiency, the nutrient will, generally, be deficient in the healthy-looking tissue as well.
Groves of early navels that are not normally treated with copper and lime as a fungicide should include an analysis for copper. Copper deficiency is a real possibility on trees growing in sandy, organic, or calcareous soils. For later harvested varieties, leaves should be sampled before fall fungicidal or nutritional sprays are applied because nutrients adhering to the exterior of leaves will give an inaccurate picture of the actual nutritional status of the tree.
Usually leaf samples taken from trees deficient in nitrogen will overestimate the true quantity of nitrogen storage in the trees. Trees deficient in nitrogen typically rob nitrogen from older leaves to use in the production of new leaves. Frequently, by the time fall leaf samples are collected in nitrogen deficient groves, these spent spring flush leaves have already fallen. Nitrogen deficient trees typically have thin-looking canopies as a result of this physiological response. Since the spring flush leaves are no longer present on the tree in the fall when leaves are sampled, younger leaves are often taken by mistake for analysis. These leaves are higher in nitrogen than the now missing spring flush leaves would have been and provide an inaccurately higher nitrogen status in the grove than actually exists.
Critical levels for leaf-nitrogen for some varieties of citrus, like the grapefruits, pummelos, pummelo x grapefruit hybrids and the mandarins, have not been investigated as well as those for oranges. However, the mineral nutrient requirements of most citrus varieties are probably similar to those for sweet oranges presented in Table 1, except for lemons, where the recommended nitrogen dry-weight percentage is in the range of 2.2- 2.4%.
A complete soil sample in conjunction with the leaf sample can provide valuable information on the native fertility of the soil with respect to some mineral nutrients and information on how best to amend the soil if necessary to improve uptake of fertilizers and improve water infiltration.
P.S. from Ben Faber
What has been said here about citrus is also generally true for avocado, although the nitrogen sufficiency levels are lower than for citrus. For a more detailed discussion see: http://www.californiaavocadogrowers.com/sites/default/files/documents/11-Final-Report-Issued-Giving-Tools-for-Fertilization-and-Salinity-Management-Winter-2016.pdf
Photo: Nitrogen deficient avocado leaf