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Make More Avocado Fruit

At a recent grower meeting at South Coast Research and Extension Center in Irvine, Carol Lovatt gave a talk on the use of gibberellic acid to increase avocado fruit set and yield.  The registration for the use only occurred this spring, barely in time for growers to use it, so not many applied it.  Then we had this heat wave in July and a lot of fruit, whether it had been treated or not, fell off.  A show of hands was asked of the growers present, who had applied it this spring.  Of the 100 people or so in attendance, only five raised their hands.  Of course, this is not a scientific survey, but most would try it again this coming spring, even though they might not have seen results this year.

The following are guidelines that were provided on how to use it, if you should so choose this coming spring:

Use of ProGibb LV PlusR Plant Growth Regulator on Avocado to Increase Fruit Size and Yield

Carol Lovatt

Professor of Plant Physiology, Emerita, and Professor in the Graduate Division, Department of Botany and Plant Sciences, University of California, Riverside

ProGibb LV PlusR. On March 27, 2018, gibberellic acid (GA3) was approved for use on avocado to increase fruit size and yield. The only material registered for this purpose is ProGibb LV PlusR, a low volatile organic compound (LVOC) formulation, manufactured by Valent BioSciences, Corporation (Libertyville, IL). Only this product may be used; the older formulation sold under the name ProGibbR and other generic GA3 products cannot be used. Note: (i)the restricted entry interval is only 4 hours; (ii) the preharvest interval is 0 days; and (iii) ProGibb LV PlusÒ can be used in certified organic orchards.  

 Application Time. ProGibb LV PlusR is applied as a foliar spray at the cauliflower stage of avocado inflorescence development. The applications should be made when 50% of the trees in the block have 50% of their bloom at the cauliflower stage. This means that 25% of the bloom will be at an earlier stage of inflorescence development and 25% will be approaching bloom (open flowers). If you are unable to make the application at this time, being slightly late in applying the treatment affords better efficacy than being too early. Note: applications made at full bloom are typically not effective.

ProGibb LV PlusR Dose and Dilution Rate. The sprays should be applied like a pesticide spray to give full canopy coverage, especially of the developing inflorescences, but not sprayed to run-off. For ground application, use 12.5 fluid ounces of ProGibb LV PlusR (25 grams active ingredient [g ai]) in 100 gallons of water/acre. For aerial (helicopter) application, use 12.5 fluid ounces (25 g ai) in 75 gallons of water /acre. The maximum allowable dose is 25 g GA3 (active ingredient)/acre. Note: the results of our research documented that lower and higher doses are less effective.

Spray Solution pH. The final pH of the spray solution in our research was between pH 5.5 to 6.0. ProGibb LV PlusR is stable at pH 4.0 to 8.5. The pH of the water used should be adjusted accordingly. Note: prolonged exposure of GA3 to a pH > 8.5 should be avoided to prevent breakdown of the material.

Additional Information on Spray Volume. In our research, for ground applications, we used the same amount of GA3 (25 g ai/acre) but a spray volume of 200 to 250 gallons of water/acre, depending on tree size, to achieve good coverage without causing the material to run-off the tree and with minimum spray volume left in the tank after application. Use of spray volumes greater than label rate of 100 gallons of water/acre for ground application is the decision of the Agricultural Commissioner for each county. Consult with your County Agricultural Commissioner, if you wish to apply ProGibb LV PlusR (25 g ai) in more than 100 gallons of water/acre as a ground spray. For the aerial (helicopter) application, the greatest efficacy was achieved with ProGibb LV PlusR (12.5 fluid ounces, 25 g ai) in 75 gallons of water/ acre.

Wetting Agent. In our research, we used the organosilicone surfactant Silwett L-77R or Widespread MaxR (Loveland Industries, Greely, CO) at a final concentration of 0.05%. Similar pure organosilicone type surfactants are acceptable.

Photo: Cauliflower stage inflorescence. Source: Salazar-García et al., 1998.

Posted on Wednesday, August 8, 2018 at 6:28 AM

Unlikely Critters Found in Avocado Orchards

Wildlife isn't always restricted to wild spaces.

Avocado orchards and other agricultural landscapes also buzz with species that forage and reproduce in these spaces. Birds and herbivores are able to find food and shelter in these cultivated areas, but what about carnivores?  In a study published in PLOS ONE, researchers at the University of Washington have discovered that mammalian carnivores also occupy avocado orchards in southern California.

The authors used motion-activated cameras to observe animals in orchards and in adjacent wild lands in Santa Barbara and Ventura.  Avocado orchards were of particular interest due to their location near native vegetation.

Through their investigation, the researchers detected more carnivores in the avocado orchards than in neighboring wild land sites. At least 7 out of the 11 native carnivores in the area were spotted roaming the orchards, including bear, coyotes, gray foxes and bobcats.


Having delicious avocados handy may explain why some omnivores such as bears and raccoons are present in the area, however, little is known about why animals like bobcats and mountain lions might leave their wild habitat for cultivated land. One possibility is that the orchards provide water and fruits for herbivores, and an increased herbivore population could translate to more prey for the carnivores. The orchards may also serve as shelter, offering forest cover similar to oak woodlands in the area.

These native species cannot always persist in protected reserves, so it is important to learn how cultivated lands can serve their lifestyle and behaviors. The carnivores may not be searching for the perfect guacamole ingredient; however there is no doubt that the avocado orchards are serving as a habitat for a wide range of species.

Citation: Nogeire TM, Davis FW, Duggan JM, Crooks KR, Boydston EE (2013) Carnivore Use of Avocado Orchards across an Agricultural-Wildland Gradient. PLoS ONE 8(7): e68025. doi:10.1371/journal.pone.0068025


Posted on Monday, August 6, 2018 at 6:31 AM

Avocado Foliar Fertilization Doesn't Work Well

Simon Newett, Extension Horticulturist.Department of Primary Industries and Fisheries, Maroochy Research Station, Mayers Road, Nambour 4560, Queensland, Australia. Previously published in: Talking Avocados (published by Avocados Australia Ltd), 11(2), 24-27.


Foliar fertiliser application is sometimes promoted as an effective means of supplying nutrients to avocado.  On the market are various products being promoted as foliar nutrients for avocado, some proponents even suggest that their products do away with the need for soil applied nutrients.  This article briefly reviews the literature relating to foliar feeding of avocado and examines the anatomy of the avocado leaf and flower in relation to nutrient uptake.

The avocado leaf
The structure of plant leaves has evolved primarily to capture sunlight and exchange gases, roots have evolved to absorb nutrients and water and anchor the plant. Any absorption of nutrients by leaves is therefore likely to be more fortuitous than by design. In some crops passive nutrient absorption by leaves is occasionally sufficient to supplement the supply of nutrients taken up by the roots.  Most often this involves trace elements, which as their name suggests are required in very small amounts (eg. copper and zinc).  However if non-mobile elements or elements with limited mobility in the plant (eg. calcium, phosphorus, zinc, boron and iron) are absorbed when foliar sprayed they are not likely to make it down to the roots where they are also needed.  Most nutrients will move freely in the water stream but the movement of many is restricted in the phloem, hence leaf applications don't meet the requirements of deficient trees.  Occasionally major elements (such as nitrogen and potassium) are applied to make up for a temporary shortfall or provide a boost at a critical time.  Citrus is an example of a crop where some benefits from foliar applied nutrients have been reported.

The ability of the leaf to absorb nutrients from its surface must depend to some degree on the permeability of its epidermis (outer layer) and the presence and density of stomates (pores for the exchange of gases).  Scanning Electron Microscope studies of mature leaves and floral structures in avocado show the presence of a waxy layer on both the upper and lower surfaces of mature avocado leaves (Whiley et al, 1988).  On the upper surface the wax appears as a continuous layer and there are no stomates.  On the lower surface the wax layer is globular and stomates are present.  Blanke and Lovatt (1993) describe the avocado leaf as having a dense outer wax cover in the form of rodlets on young leaves and dendritic (branching) crystals on old leaves including the guard cells (guard cells surround stomates).  The flower petals and sepals in avocado have stomates on their lower surfaces and no wax layers on either surface, which might explain why floral sprays of boron might work.

Literature review
Based upon total leaf nitrogen concentration, Embleton and Jones (unpublished) in a replicated trial in California in the early 1950's found no response to leaf sprays of urea on mature 'Fuerte' avocado trees in the field.  Up to three sprays a year were applied.

Nevin et al (1990) reviewed urea foliar fertilisation of avocado and found only one study (Aziz et al., 1975) that reported positive results in terms of fruit yield.  This trial by Aziz et al (1975) involved drenching sprays of significant amounts of urea four times a year (250 to 500 g of nitrogen per tree annually).  It is unclear whether or not considerable amounts of the drenching spray reached the ground, nevertheless, the amounts applied were very high for foliar applications.  No leaf analysis data was reported.

Galindo-Tovar (1983) was able to increase leaf nitrogen concentrations in ‘Hass' avocado seedlings grown in a glasshouse with low concentrations of urea.  However similar treatments on 3-year-old ‘Hass' in the field for each month during spring failed to increase leaf nitrogen in mature leaves sampled a week after spraying.  The author cited evidence for crops other than avocado suggesting that urea can penetrate leaf surfaces when grown in a greenhouse, but when grown in the field under full sun, leaf surfaces are different and resist movement of nitrogen into the leaf.

Klein & Zilkah (1986) reported substantial uptake of foliar urea-N when detached leaves of 'Fuerte' avocado were dipped in urea solutions.  Zilkah et al (1987) reported the translocation of 15N from foliar-applied urea to vegetative and reproductive sinks of both 'Fuerte' and 'Hass' avocado.  Despite the apparent response achieved by Aziz et al in Egypt, Klein & Zilkah, and Zilkah et al in Israel, attempts at the University of California to demonstrate significant uptake of nitrogen from foliar sprays have not been successful (Nevin et al., 1990).

Research at the University of California, Riverside, provided evidence that the leaf nitrogen content of 'Hass' avocado was not increased by foliar application of urea at the same concentration that increased citrus leaf nitrogen content two-fold (Nevin et al., 1990).  Maximum uptake of 14C-urea by 'Hass' avocado leaves was physiologically insignificant after 2 days. Over 96% of the 14C-urea applied was recovered from the leaf surface even after 5 days.  Maximum uptake of 14C-urea by leaves of 'Gwen' and 'Fuerte' was less than 7%.  15N, 14C-urea and 65Zn are radioactive forms of nitrogen, urea and zinc respectively that are used to track their movement through the plant.

Sing and McNeil (1992) conducted a study on an orchard with a history of potassium deficiency where high magnesium levels in the soil competed with potassium for uptake.  Foliar applications of 3.6% potassium nitrate were applied at half leaf expansion, full leaf expansion and one month after full leaf expansion.  These foliar applications of potassium nitrate were effective in increasing the potassium level in the leaves of 'Hass' avocado trees, however two to three foliar applications per year were required to achieve the same result as one application of potassium sulphate (banded) to the soil once every 2 to 3 years.  Accounting for labour and material costs the foliar sprays of potassium nitrate were estimated to be more expensive than soil applied potassium sulphate applied every three years.  The foliar sprays also affected the levels of other nutrients in the leaf, some negatively.

Calcium is receiving attention as an element in avocado fruit associated with better quality and longer shelf life.  Several different calcium products were tested during the 1980's as foliar sprays in South Africa in an attempt to raise fruit calcium levels but none were found to be effective.

Veldman (1983) reported that the treatment of avocado trees with one, three and six calcium nitrate sprays did not successfully control pulp spot in avocado fruit and there was no increase in fruit calcium levels on sprayed treatments.

Whiley et al (1997) report that calcium foliar sprays during fruit growth have little effect on internal concentrations in most fruit due to poor absorption by fruit, and lack of translocation within the tree.

Some benefits have been reported from foliar application of boron if applied at flowering.  Timing is important because it appears that absorption takes place through flower structures and not leaves.

Jayanath and Lovatt (1995) reported on results of four bloom studies (two glasshouse and two field experiments) which demonstrated the efficacy of applying boron or urea sprays to 'Hass' avocado inflorescences during early expansion (cauliflower stage) but prior to full panicle expansion and anthesis.  Anatomical analysis of the flowers provided evidence that the boron prebloom spray increased the number of pollen tubes that reached the ovule and also increased ovule viability, but to a lesser degree than urea.  The urea prebloom spray increased ovule viability compared to boron-treated or untreated flowers.  Urea also increased the number of pollen tubes that reached the ovule, but to a lesser degree than boron.  However, combining boron and urea resulted in a negative effect even when the urea was applied 8 days after the boron.  Lovatt (unpublished) provided an update on this work at the World Avocado Congress in 1999, after 3 years of field trials the only treatment to have a positive effect on pollination was the boron in Year 2, the most likely reason why it didn't work in other years was thought to be low temperatures.  There were only hardened leaves present at the time of foliar applications suggesting that uptake was through flower parts.

Whiley et al (1996) report that despite an increase in fruit set with foliar sprays of boron during flowering there has been no convincing evidence that showed increased final yield.  Root growth has a requirement for boron and in deficient trees it is unlikely that sufficient nutrient from foliar applications would be translocated to the roots.  Foliar applications have the advantage that specific organs can be targeted to enhance their boron concentrations, but with the disadvantage that insufficient boron can be absorbed through leaves to mediate chronic deficiency in trees.  Soil applications have been shown to dramatically improve the health of boron deficient trees. 

Mans (1996) experimented with ‘Hass' trees that had leaf levels of nitrogen and boron below the accepted norms (N was 1.71% and B was 23ppm).  The aim of this trial was to see if supplying nutrients directly on the flowers could increase the yield of ‘Hass' trees growing in a cool environment.  Mans (1996) found that if a multi-nutrient spray that included nitrogen and boron was applied as the first flowers started to open then he could increase yield and distribution of fruit size.  The stage of flowering when spraying takes place was very important.  Sprays that were applied pre-bloom, at fruitset or when fruitlets were present were not effective.

Kadman and Lahav (1971-1972) reported that the only means to control iron chlorosis in already established avocado orchards is soil application of iron chelates since applications of various iron compounds by foliar sprays have not been successful on a commercial scale.  Gregoriou et al (1983) found that the quickest and most successful treatment of trees suffering from iron chlorosis on calcareous soils  was obtained by incorporating Sequestrene 138 Fe-EDDHA in the soil.

Kadman and Cohen (1977) found that avocado trees have difficulties in absorbing mineral elements through their foliage.  In spite of this, spraying of apparently zinc-deficient orchards was rather common in California and some other countries.  In Israel, some growers spray their orchards, but as experiments have shown, no apparent improvement occurs in leaves or fruits following such treatment.  The results presented in this paper indicate that the penetration of zinc through the leaves is so slight that there is practically no benefit through supplying it by foliar sprays.

Zinc deficiency is common in avocado and is particularly difficult to address on high pH (alkaline) soils.  Crowley et al (1996) evaluated methods for zinc fertilisation of ‘Hass' avocado trees in a 2-year field experiment on a commercial orchard located on a calcareous soil (pH 7.8) in California. The fertilisation methods were:
• soil or irrigation-applied zinc sulphate
• irrigation-applied zinc chelate (Zn-EDTA)
• trunk injection of zinc nitrate
• foliar applications of zinc sulphate, zinc oxide, or zinc metalosate.
Among the three soil and irrigation treatments, zinc sulphate applied at 3.2 kg per tree either as a quarterly irrigation or annually as a soil application was the most effective and increased leaf tissue zinc concentrations to 75 and 90 mg/kg respectively. Experiments with 65Zn applied to leaves of greenhouse seedlings, showed that less than 1% of zinc applied as zinc sulphate or zinc metalosate was actually taken up by the leaf tissue. There was also little translocation of zinc into leaf tissue adjacent to the application spots or into the leaves above or below the treated leaves.  Given these problems with foliar zinc, Crowley et al (1996) suggest that fertilisation using soil or irrigation applied zinc sulphate may provide the most reliable method for correction of zinc deficiency in avocado on calcareous soils.

Whiley and Pegg (1990) report that foliar applications of zinc have been found to be highly ineffective in Queensland orchards.

Price (1990) reports that zinc can be absorbed through the leaves (from foliar sprays, e.g. zinc sulfate, zinc chelate) but that insufficient zinc can be absorbed in this manner to meet the plants requirements, especially in avocados.  Since zinc is required at the growing points of new roots and shoots, it is essential that most zinc be taken up by the roots.

Foliar fungicide sprays
If leaf applied nutrient sprays in avocado give inconsistent or nil effects why do foliar sprays of phosphorous acid work for the control of root rot?  The amount of phosphorous acid uptake required for root rot control is small but even so, several applications per year are required to be effective and the canopy must be dense and healthy. The phosphonate concentration required in the roots for effective root rot control is in the order of 30 mg/kg.  To achieve this level either three to four sprays of 0.5% phosphorous acid per year are required at strategic times (Leonardi et al., 2000) or alternatively six or more sprays of 0.16% phosphorous acid per year must be applied.  Another factor contributing to the effectiveness of leaf applied phosphorous acid is that, unlike many nutrients, it is extremely mobile in the plant.

Borys (1986) reports the dry matter distribution of roots to shoots in avocado seedlings average 26% and 74% respectively.  Using these figures and some critical nutrient and fungicide levels in avocado we can get some perspective on the relative quantities required.  In a tree consisting of say 100 kg of dry matter, about 26 kg would be in the roots and 74 kg in the shoots.  This tree with a phosphonate root level of 30 mg/kg would contain a total of about 0.8 g phosphonate in the roots.  With the optimal leaf levels of 50 mg/kg of boron and 2.5% of nitrogen, the tree would contain about 4 g and 1850 g of boron and nitrogen respectively in the canopy alone.  It can be seen from these relative amounts that the fungicide required is substantially less than the nutrients.
Apart from well-timed boron applications at flowering in situations where leaf boron levels are deficient, there is no clear evidence to support the use of foliar nutrient sprays in avocado to correct nutrient deficiencies or to supply nutrients for growth.  Occasionally a foliar nutrient spray may succeed in alleviating leaf deficiency symptoms, however this type of application will not provide the tree's longer-term requirements for this nutrient which should be addressed through soil applications.

I would like to thank Drs Chris Searle and Tony Whiley and Mr Garry Fullelove of the Queensland Horticulture Institute for their assistance in compiling this article.  The literature search was conducted using the AVOINFO avocado reference database.

Aziz, A.B.A., Desouki, I., El-Tanahy, M.M., Abou-Aziz, A.B. and Tanahy, M.M., El 1975. Effect of nitrogen fertilization on yield and fruit oil content of avocado trees. Scientia Horticulturae, 3 (1): 89-94.
Blanke, M.M. and Lovatt, C.J. 1993. Anatomy and transpiration of the avocado inflorescence.  Annals of Botany, 71 (6): 543-547.
Borys, M.W. 1986. Root/shoot relation and some root characteristics in seedlings of avocado and Chinini. California Avocado Society Yearbook 70: 175-198.
Crowley, D.E., Smith, W., Faber, B. and Manthey, J.A. 1996. Zinc fertilization of avocado trees. HortScience 31 (2): 224-229.
Galindo-Tovar, G.E. 1983.  Effects of urea spray concentration and surfactants on avocados.  M.S. Thesis, University of California, Riverside, USA. September.
Gregoriou, C., Papademetriou, M. and Christofides, L. 1983. Use of chelates for correcting iron chlorosis in avocados growing in calcareous soil in Cyprus. California Avocado Society Yearbook 67: 115-122.
Jayanath, I. and Lovatt, C.J. 1995.  Efficacy studies on prebloom canopy applications of boron and/or urea to 'Hass' avocados in California. World Avocado Congress III, Proceedings: 181-184.
Kadman, A., and Lahav, E. 1971-1972. Experiments with various treatments to cure chlorotic avocado trees. California Avocado Society Yearbook. 55:176-178.
Kadman, A. and Cohen, A. 1977. Experiments with zinc applications to avocado trees. California Avocado Society Yearbook, 61: 81-85.
Klein, I. & Zilkah, S. 1986.  Urea retention and uptake by avocado and apple trees. Plant Nutr. 9:1415-1525.
Leonardi, J., Whiley, A.W., Langdon, P.W., Pegg, K.G. and Cheyne, J. 2000. Progress on the use of foliar applications of phosphonate for the control of phytophthora root rot in avocados. 
Mans, C.C. 1996. Effect of foliar feeding of ‘Hass' at various stages of flowering.  South African Avocado Growers' Association Yearbook, 19: 31-32.
Nevin, J.M., Lovatt, C.J. and Embleton, T.W. 1990. Problems with urea-N foliar fertilization of avocado.  Acta Horticulturae 275: 535-541.  International Symposium on the Culture of Subtropical and Tropical Fruits and Crops. Vol. II. (J.C. Robinson, ed.), International Society for Horticultural Science. Wageningen, Netherlands.
Price, G. 1990. Thinking about zincing your trees? Talking Avocados, Third Edition, Aug/Sept, p.5.
Sing, J.L. and McNeil, R.J., 1992. The effectiveness of foliar potassium nitrate sprays on the 'Hass' avocado (Persea americana Mill.), World Avocado Congress II, Proceedings: "The Shape of Things to Come" (Lovatt, C.J. ed.) 1: 337-342.
Veldman, G. 1983. Calcium nitrate sprays on avocados at Westfalia Estate with the objective to reduce pulpspot. South African Avocado Growers' Association Yearbook, 6: 64-65.
Whiley, A.W., Chapman, K.R. and Saranah, J.B. 1988. Water loss by floral structures of avocado (Persea americana cv. Fuerte) during flowering.  Australian Journal of Agricultural Research, 39 (3): 457-467.
Whiley, A.W., and Pegg, K.G.1990. Correction of micro-nutrient deficiencies and control of Phytophthora root rot in avocado. Talking Avocados, Second Edition,  May/June, p. 11.
Whiley, A.W., Smith, T.E., Saranah, J.B. and Wolstenholme, B.N. 1996.  Boron nutrition of avocados, Talking Avocados, 7 (2): 12-15.
Whiley, A.W., Hofman, P.J and Coates, L.M. 1997.  From seed to tray - some field practices to improve avocado fruit quality.  Proceedings of the Australian Avocado Growers' Federation and the New Zealand Avocado Growers' Association Conference '97, 'Searching for Quality'.  Rotorua,  New Zealand, pp. 83-97.
Zilkah, S., Klein, I., Feigenbaum, S. and Weinbaum, S.A. 1987.  Translocation of foliar-applied urea 15N to reproductive and vegetative sinks of avocado and its effect on initial fruit set. J. Amer. Soc. Hort. Sci.  112:1061-1065.

Photo: Waxy avocado leaves

Posted on Friday, August 3, 2018 at 6:00 AM

And Human Heat Stress


When employees work in hot conditions, employers must take special precautions in order to prevent heat illness. Heat illness can progress to heat stroke and be fatal, especially when emergency treatment is delayed. An effective approach to heat illness is vital to protecting the lives of California workers.

California law requires employers to identify and evaluate workplace hazards and take the steps necessary to address them. The risk of heat illness can be significantly reduced by consistently following just a few simple steps. Employers of outdoor workers at temporary work locations must be particularly alert and also plan for providing first aid and emergency medical services should they become necessary. All workers should be accounted for during and at the end of the work shift. Heat illness results from a combination of factors including environmental temperature and humidity, direct radiant heat from the sun or other sources, air speed, and workload. Personal factors, such as age, weight, level of fitness, medical condition, use of medications and alcohol, and acclimatization effect how well the body deals with excess heat. 

Heat Illness Risk Reduction

1. Recognize the Hazard. There is no absolute cut-off below which work in heat is not a risk. With heavy work at high relative humidity or if workers are wearing protective clothing, even work at 70oF can present a risk. In the relative humidity levels often found in hot areas of California (20 to 40 percent) employers need to take some actions to effectively reduce heat illness risk when temperatures approach 80 F. At temperatures above 90 F, especially with heavy work, heat risk reduction needs to be a major concern.

    2. Water. There must be an adequate supply of clean, cool, potable water. Employees who are working in the heat need to drink 3-4 glasses of water per hour, including at the start of the shift, in order to replace the water lost to sweat. For an eight-hour day this means employers must provide two or more gallons per person.  Thirst is an unreliable indicator of dehydration. Employees often need ongoing encouragement to consume adequate fluids, especially when the workload or process does not encourage breaks.

3. Shade. The direct heat of the sun can add as much as 15 degrees to the heat index. If possible, work should


be performed in the shade. If not, employers where possible, should provide a shaded area for breaks and when employees need relief from the sun. Wide brimmed hats can also decrease the impact of direct heat.

  1.  Acclimatization. People need time for their bodies to adjust to working in heat. This “acclimatization” is particularly important for employees returning to work after (1) a prolonged absence, (2) recent illness, or (3) recently moving from a cool to a hot climate. For heavy work under very hot conditions, a period of 4 to 10 days of progressively increasing work time starting with about 2 hours work per day under the working conditions is recommended. For less severe conditions at least the first 2 or 3 days of work in the heat should be limited to 2 to 4 hours. Monitor employees closely for signs and symptoms of heat illness, particularly when they have not been working in heat for the last few days, and when a heat wave occurs. 
  2.  Rest Breaks. Rest breaks are important to reduce internal heat load and provide time for cooling. Heat illness occurs due to a combination of environmental and internal heat that cannot be adequately dissipated. Breaks should be taken in cooler, shaded areas. Rest breaks also provide an opportunity to drink water.
  3.  Prompt Medical Attention. Recognizing the symptoms of heat illness and providing an effective response requires promptly acting on early warning signs. Common early symptoms and signs of heat illness include headache, muscle cramps, and unusual fatigue. However, progression to more serious illness can be rapid and can include unusual behavior, nausea/vomiting, weakness, rapid pulse excessive sweating or hot dry skin, seizures, and fainting or loss of consciousness. Any of these symptoms require immediate attention.

Even the initial symptoms may indicate serious heat exposure. If medical personnel are not immediately available on-site, and you suspect severe heat illness, you must call 911.

Regardless of the worker's protests, no employee with any of the symptoms of possible serious heat illness noted above should be sent home or left unattended without medical assessment and authorization.

7. Training. Supervisors and employees must be trained in the risks of heat illness, and the measures to protect themselves and their co-workers. Training should include:

  • Why it is important to prevent heat illness
  • Procedures for acclimatization
  • The need to drink approximately one quart per hour of water to replace fluids.
  • The need to take breaks out of the heat
  • How to recognize the symptoms of heat illness
  • How to contact emergency services, and how to effectively report the work location to 911.
Posted on Wednesday, August 1, 2018 at 6:30 AM

Learn to Dragon Fruit

2018 Pitahaya/Dragon Fruit Production Seminar

San Diego County Farm Bureau

420 South Broadway, Suite 200 | Escondido, CA 92025

Friday - August 24, 2018

7:00am – 4:30pm


  • San Diego County Agriculture – Water, Policies and Regulatory Update
  • Pitahaya Research Update – Variety Evaluation and Performance, Genetic Characterization
  • Irrigation Water Management Strategies and Pitahaya Irrigation
  • Pitahaya Post Harvest Management & Sensory Evaluation
  • Pitahaya or Dragon Fruit Markets and Marketing - An Overview and Global Perspective
  • Pitahaya Orchard Establishment & Economics Considerations
  • Pitahaya Fertility Management & Soil Analytical Reports (Tentative)
  • Nematode Issues and their Impact for Pitahaya Production
  • Insect Pest Management & Pesticide Use Safety for Pitahayas and Other Specialty Crops
  • Weeds and Weed Management Strategies for Specialty Crops, including Pitahaya
  • Diseases – Diagnosis and Management Strategies for Pitahaya Production
  • Hydroponics – An Evaluation of Soilless Substrates for Pitahaya Production (Tentative) 


2018 Pitahaya/Dragon Fruit Festival/Field Day

UC South Coast Research and Extension Center

7601 Irvine Boulevard | Irvine, CA 92618

Saturday - August 25, 2016

6:30am – 3:30pm


  • Review of Pitahaya Varieties and Hand Pollination Demonstration
  • Integrated Pest Management Strategies for Specialty Crops Production
  • Pitahaya Irrigation Research and System Design Consideration
  • Pitahaya Trellis Systems Demonstration
  • Pitahaya Production for Home or Backyard Growers
  • Pitahaya or Dragon Fruit and Ice Cream Tasting 




REGISTER EARLY. This event has sold out in the past!! Attendance is limited to 60 participants for the seminar on August 24th and 100 for the festival/field day on August 25th. This would also help us plan for handouts and cuttings. No refunds will be issued, but substitutions are allowed.


PRICINGincludes continental breakfast, refreshments, lunch, (Catered by Phil's BBQ on 8/24), pitahaya/dragon fruit ice cream, smoothie tasting, and an information packet:

  • Package Registration for Seminar & Festival/Field Day: $80.00, 

If paid online with a credit card or post-marked by Friday - August 17, 2018.

No package registrations after this date.


  • Seminar Registration ONLY: $60.00, 

If paid online with a credit card or post-marked by Friday - August 17, 2018

$70.00 after this date or at the door, if space allows*


  • Festival/Field Day Registration ONLY: $ 40.00,

If paid online with a credit card or post-marked by Friday - August 17, 2018

$50.00 after this date or at the door, if space allows*


*Walk-ins will be allowed if space is available, but you MUST have exact change or checks. Credit cards will NOT be accepted day of.


Please be aware that you WILL be turned away if space is not available! NO EXCEPTIONS.


TO REGISTER,please complete the online registration form at:


For registration questions, please contact

Erin Spaniel

Administrative Assistant II


Posted on Monday, July 30, 2018 at 7:02 AM

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