The Tropical Fruit Forum

One of the best approaches to growing citruses in the face of the devastating Greening Disease is to grow it in screenhouses that will prevent the Asian Citrus Psyllids from entering. The other benefits would be of course is that it would be easier for these growers to switch to organic growing by getting rid of many insecticides that won't be needed as frequently as before. Agriculture have been growing vast amounts of crops inside greenhouses, and screenhouses are even cheaper than greenhouses. So this is one of the best ways to combat the greening disease and not losing the citrus crops.  These screenhouses are quicker to build too, and along with the availability of disease-free budwoods from CCPP or other repositories for producing disease-free seedlings, greening disease could become history. It would employ a lot more people.


https://www.baynews9.com/fl/tampa/news/2019/08/07/growers-association-spends-millions-on-new-method-of-growing-citrus

This is applicable not only to Tropical plants but to almost all plants in general but this is the most visited section, so I posted it here.

Foliar application is the best way to deliver nutrients into the plants. We know this already since ancient times.  What is new in this article is that nutrients can travel from the leaves, through the plant's cuticle, through the vascular bundle and then being exudated into the root system where it is needed in the  rhizosphere to interact with symbionts, or help control root problems, or change physical properties of soil to improve nutrient and water uptake. They have traced this pathway by using Gold nanoparticles. Not all nutrients are needed by the plants for growth alone, some nutrients they use it by putting it into the soil root zone to enhance their nutrient and water uptake. Something new that I learned is that those important nutrients for use in the root system can be applied to leaves instead of directly into the soil as the plants can deliver it at point of use, and therefore is almost 100% efficient without nutrient losses.



https://phys.org/news/2019-06-route-nutrient-delivery.html?fbclid=IwAR2qhRZ86NMdZFTvu3rzOfIw9oR8vumZpE-Jbp2cNmdL1eU4OhkciULhdw4

"Most almonds produced today are naturally tasty and safe to eat. Back then, though, many were bitter and poisonous."

A very interesting history of almonds. There's even a 14th century method to convert a wild poisonous almond into palatable and edible ones! There's no need to do that today.

"St. Basil's Hexaemeron, a Christian text from around the fourth century, contains a curious botanical instruction: Pierce an almond tree in the trunk near its roots, stick a "fat plug of pine" into its center, and its almond seeds will undergo a remarkable change.

"Thus the ... bitter almonds ... lose the acidity of their juice, and become delicious fruits," the text reads. "Let not the sinner then despair of himself. ... If agriculture can change the juices of plants, the efforts of the soul to arrive at virtue can certainly triumph over all infirmities." The cause of this change, scientists later theorized, was stress: Jamming pine wood into the almond tree's core may have halted production of the toxins.

We don't need pine wood to turn almonds sweet anymore. Most almonds produced today are naturally tasty and safe to eat. Back then, though, many were bitter and poisonous. Even today, consuming 50 — or fewer — wild, bitter almonds could potentially kill an adult, and just a handful contain enough cyanide to be lethal to a child.

Over time, farmers have bred domesticated almond trees to produce mostly sweet seeds. But wild almonds helped us out — and now, we know just how they went from deadly to delicious. A study published this week in the journal Science, which sequenced the almond genome, shows that a single genetic mutation "turned off" the ability to make the toxic compound thousands of years ago — a key step before humans could domesticate them."


https://www.npr.org/sections/thesalt/2019/06/13/732160949/how-almonds-went-from-deadly-to-delicious

We have alkaline soil, alkaline water, very hot summers, not an ideal place to grow blueberries, but I managed to have productive harvests.

We’ve been harvesting a bowlful of blueberries every day from our yard. My selection of cultivars is such that we have blueberries starting from February up to first week of August. But now is the peak time.

Southmoon, Revielle and Misty are my biggest bushes and they have wide gaps in terms of peak harvest and their fruits don't ripen at the same time.  The medium sized bushes are Jubilee and O'neal. Then I have small pots and grafted branches of Berkeley, Bluemoon, Patrick, Blueray, Sharpblue, Pink Lemonade and Reka. I also have yet unnamed seedling blueberries given to my by David Young, and I call them DY1, DY2 and DY3 and am excited to evaluate their fruits maybe within a couple more years. I love Southmoon the best so far.

I have three distinct microclimates where I placed my blueberries. I have almost tropical, subtropical and temperate microclimates to make sure they would produce fruits at different times. In the hot California summers, I keep them all away from the afternoon sun, only the morning sun, so they don't suffer any leaf burns.

One thing that the blueberries don't like even during the winter, never let the potting media dry out!  The potted blueberries love to sit in 1 to 2 inches of standing water, so I put a 3" deep drain catching pan at the bottom of the pot. This will make sure your blueberries won't dry out during the hottest days.

If you want to go organic, fertilize them with acidifying organic fertilizer such as cottonseed meal, and other blueberry fertilizers approved by OMRI. As for the potting media, use sphagnum moss, peat moss, mixed with sand and soil sulfur. Regularly apply soil sulfur in little amounts about monthly after you flush the potting media with rainwater or acidified water.  If you're okay with non-organically approved fertilizers, apply tiny amounts of Osmocote Plus slow release fertilizer once a year, but regular twice monthly application of ammonium sulfate or urea.

I am in Woodland California and our city water is alkaline, and the blueberries hate it, so I save a lot of rainwater. I flush the pots with rainwater once a month. If you didn't save rainwater and need to acidify the water, you can add little bit of sulfuric or phosphoric at a time until the water pH is between 4 to 5 and use it to flush the pot once a month.

Blueberries needed to be watered daily during the growing season. Twice a day when it is over 100 deg F during the summer. During winter, watch out for weeklong periods of no rain, you may need to water them once during that time.
 
I am still in the process of moving my blueberries from the pots to the ground, which is my ultimate goal. In order to do that, I am preparing sparkleberries for planting and am growing them from tiny seeds. Sparkleberry can thrive in our alkalaline soils and is graft compatible with blueberries. Some grafts are known to last more than 30 years, so I plan to make multi-grafted blueberries with sparkleberry as the rootstock. Then I don't have to deal with the acidifying the soil and water in order to get blueberries!

It took me ten years to discover on my own,  the secrets of growing blueberries in our area not suited for blueberries. I took it as a challenge and now am sharing how it can be successful.  Am still on a long term quest for another milestone, which is having a multi-grafted blueberry growing in the ground. But the research goes on and on in trying out various cultivars and the container growing.

0bb4 by Joe Real, on Flickr


0bb2 by Joe Real, on Flickr

0bb1 by Joe Real, on Flickr

One of my frustrations in creating a multi-grafted loquat tree is that most loquats are susceptible to fireblight. If we had a weird season that there would be rains when the loquats are in bloom, fireblight spreads so easily and it can kill the tree. I used to have an 8-n-1 loquat tree but it succumbed to fireblight during one of those unlucky years.  I don't want to apply antibiotics to control fireblight but am working on other alternatives.

So I am starting to build a multi-grafted loquat tree again from seedling. And it's pushing out. I usually start with a couple of seedlings and use one as a backup. Once they've reached appropriate size and survived, into the ground they'd go and I give the other one away to friends.

I would let the side shoots live so I can graft on them next year!



Side Veneer graft looking good!



This one hasn't pushed out yet. I removed the paraffin tape cover to hasten the take or its death. The sooner I know, the better, as I am ready to re-graft just in case.

One of my Lapins cherry grafts have been producing polka dot cherries for two years now. The cherry tasted good, but it is weird that it has polka dots instead of dark red color just like in my other grafts. Did this branch mutate? Was it infected? Was the label on the scionwood exchange correct? I don't know of any cherry that's polka dotted. This picture was from last year, the cherry was hit by hail, so I thought it turned polka dots. This year, the blotches of red are better looking and the cherries are tastier, too bad I forgot to take the pic before I gobbled them up!

Royal Rainier Cherries are loaded and almost ready that the birds are having a hard time eating it all! 😁. Actually they’re already very good eating. Hasn’t reached peak flavor yet.

This tree is actually 15-n-1 cherry tree. About 95% of the canopy is Rainier because I turn them into wine. The others I just maintain to be a couple of feet long branches, enough to give me samples for evaluating their fruits.

I do a lot of interspecific grafting (32 species of prunus grafted together), sometimes inter-genera grafting (Eriobotrya, Cydonia, Malus,Pyrus, Crataeugus, Aronia... or Microcitrus, Eremocitrus, Citrus, Fortunella...). I just encountered a scientific paper showing that the grafting combo can alter the grafted plants epigenetically and the result can be inheritable for self-pollinated plants or having true-to-type progenies. I'll have to review this paper again when I have the time. I just skimmed through it. My 160-n-1 tree may have inheritable changes that can be passed on already, either the subsequent scionwood or of course, the seeds from these are dramatically random hybrids.

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0061995

What's the cold hardiest cultivar of Cherimoya or Atemoya? Anyone willing to share their experience or a ranking of the cold hardiness of existing cultivars? Thanks!

They're old but still applicable!

Perhaps a very important observation that has been bugging me for a while now and so I have to share it. Shown below are potted Sparkleberry and grafted Boukhobza blood orange. These plants had normal blooms last year but this year they bloomed like crazy!!! The only difference is that my dear wife sneaked in and planted some succulents on these pots! I know from more than 40 years ago that most succulents have allelopathic effects on other plants, it was one of my Science Fair projects during my first year high school. Perhaps this year’s way above normal blooms that I have observed may have been triggered by the chemicals excreted by the clandestinely added succulents. Since I don’t have the luxury of time and space to verify my observations, perhaps you can replicate and validate my suspicions. It would make for a very interesting graduate research studies or undergraduate thesis. Perhaps you can just acknowledge my observations if you have observed it in your formal research studies.

Story about the **Aravaipa**:
Here's what I found out about the Aravaipa Avocado.

There's a special story about it in the Fruit Gardener which I recommend you'd subscribe if you're into fruit growing. It isn't publicly available as it is copyrighted but accessible via paid subscription.

There were many avocado trees planted in Arizona and elsewhere near the Mexico Border when parts of the US were still under Mexico, sometime in the 1700's and earlier. So it must be a long time of selection pressure for the various trial avocado plantings, by people freely coming in and out of Mexico and from Central and South America long before the US was formed.

In 1906, a rancher's family purchased the deed to his land in 1906 in the Aravaipa Canyon, now a Conservation Preserve in Arizona, and there was already a good size avocado tree growing in it. The avocado tree must have first sprouted or planted in the mid to late 1800's. The ranch is located at the bottom of a Valley, on a small mesa, just about 10 to 15 feet above the stream bed, and about 180 feet from the Aravaipa River. This means that during winter, very cold air from the mountains, being denser, would drain into this valley creating very cold freezing conditions, but the cold air would continue to drain down further into the river, away from the avocado tree, away from the ranch. According to the rancher, there are a couple of times or more that the entire mesa was flooded with 6-8 ft of water up to the trunk of the tree. Over the more than 100 years since their family acquired the land, the ranch had experienced many wintry snow storms, with regular winters of mid-20's and plummeting as low as 10 deg F. During the summer, the temperature regularly get several days of 120 deg F and sometimes weeks of temperatures above the century mark.

The tree must be at least 125 years old and survived it all to be the great and unique specimen that it is to this very day. What sets apart this tree from other cold hardy specimen is that it is both very cold hardy and heat tolerant. The tree is also salt tolerant, able to thrive in saline sodic soils of Arizona, and tolerant of root rot from the flooding and prolonged wet soils during winter. The tree just laughs off freezing events and continues to be very productive.

The tree is now regarded by Arizona residents as a Native Arizona avocado, and is related to Hass, a Guatemalan race, and avocado aficionados know very well that Guatamelan varieties typically have rough tough skins and are the most cold sensitive. So indeed this variety is truly unique in that it is very cold hardy and heat tolerant at the same time. Hass will simply burn in very hot summer temperatures or die out or severely damaged after a few frosty nights during winter.

The cultivar is just starting to become popular. In my quest for having a fruit bearing avocado tree in North California, I seek out and added this to my collection. Thanks to my friend Harvey Correia who first told me about the story of the Aravaipa and let me take a cutting of it from his tree.

One of the drawbacks to its adoption is that some say it only tasted mediocre. Most people don't want anything that isn't at least as good tasting as Hass. Julie Frink, a revered avocado guru, wasn't impressed with its flavor and at best considered it mediocre. But for our area, being mediocre is preferable to having no avocados at all. The current ranch owners of the original Aravaipa tree told that the taste is really delectable when harvested and properly ripened, and they had more sampling of the fruits than anyone else. As for me, one sample isn't enough especially if you're tasting many other avocados. A sampling through time of various harvest dates and ripening period is the best gauge for evaluating the quality of the fruits. Also the age of the tree has tremendous effect on the fruit quality, just like old vines making better wines than newer vines. I learned that as a winemaker long time ago, that you'll have to bring wine across its journey through time, and one bottle isn't enough. Flavor quality changes through time. Sometimes a slight modification in the "curing" or storage of avocados can dramatically change their flavor profile, and we don't have a clue on how to handle Aravaipa Avocado, such as optimum harvest and storage time.

I hope to get a lot of fruits this year. So I hope to evaluate it properly for my personal recommendations. Regardless of taste, it is a must have variety, at least for me as I believe that it would surely be a good source of excellent rootstock just like the Duke, that are able to tolerate salt, heat, root rot, and very cold hardy.

Unlike the Duke avocado, the Aravaipa can be be ordered online and is often available. It costs more than the typical avocado tree from big box stores as the propagators don't have the economies of scale. But also be aware that there are two types of Aravaipa being sold, one is also sold as Arizona Avocado, and is the original Aravaipa, and the other one is sold as Don Juan which many said is not the original Aravaipa, but dual labeled as such. The Don Juan is said to produce better tasting fruits than Arizona, and so must be another cultivar and I have no idea about its cold, salt, heat and rot tolerance.

Here's a video link showing that the legendary tree exists. The family who owns the ranch and the original tree has invited one of the promoters, propagators and sellers of the Aravaipa avocado. The exact location of the ranch and the tree can't be disclosed to respect the owner's privacy.

https://www.youtube.com/watch?v=SC7VtIDRaNg