Buy a New Fig Instead of Propagating the Same One

Q. I have a large fig tree that gives me small green figs and that is all I get. I think not enough water as you said. I also saw the picture of cuttings to grow another tree?  Can I do that or should I buy a second tree? What about pruning? Is this a good time? 

A. I would buy another tree. They are not that expensive and you can get a different type of fig than the one you have now. Variety is the spice of life!

            But first you have to figure out what fig you have. Figs are all green when young and turn either yellow, off white, purple, purplish brown or nearly black. The white or yellow types have a more delicate flavor while the darker ones are usually more robust in their flavor. One dark one that has been given some nice reviews from homeowners in the valley is Blackjack and it is a smaller tree.

            Just make sure when you prune a fig tree, if you want two crops from it, that you leave some growth present that is last years. If you cut the tree back and take off all the growth from 2012 you will only have one crop, the main crop. If you leave some of this growth from last year you will have two crops of figs.

            You can prune as soon as the leaves drop. Figs can handle any amount of pruning you want to give them. I will be giving some pruning classes out at the orchard when I am back in Las Vegas on December 22 beginning at 9 am.

Should I Use a Systemic Insecticide on My Fruit Trees?

Q. Several weeks ago I noticed whiteflies on my dwarf orange tree. I went to Lowes where they recommended the following product: Bayer Advanced Tree & Shrub Protect and Feed. Upon reading the instructions it states: Do not use on plants grown for food but does not mention trees or shrubs. Can you please tell if this product is safe to use and if not what would you recommend?



Picture can be found at
Bayer link to this insecticide and the label
 

A. I cannot tell you if it is safe to use on edible crops or not. I went back and looked at the product label online. Some formulations of the product the manufacturer claims you can use on SOME edible crops including fruit trees.

            The manufacturer also claims 12 month control of some insect pests using this product. Some formulations say you can spread the granules under the tree. The tree in turn takes up this product through its roots where it spreads through the plant where this poison then gives 12 month control to pests listed on the label.

            This means that the product has spread through the entire plant systemically to provide enough of this product inside the tree to control these insects for 12 months. This also means the poison should ALSO be in other plant parts as well, such as fruit.

            These products undergo extensive testing for so-called “safety” issues that must be done before receiving a label approved by EPA. So our EPA is saying that this product has met its tolerances of “safety” (the feds do not like you to use the word “safe” in instances like this because they do not guarantee any pesticide is “safe”) and have approved this label. The product is supposed to be at such low levels in the plant that the government considers it safe to eat.

            Now, in my opinion, I would NEVER eat fruit from a fruit tree that has been treated with a systemic insecticide, period. Particularly when the manufacturer has claimed 12 month control of insects after its application! It does not make any sense to me to eat fruit from this tree in the same year it was treated with this type of pesticide. I hope this helps.

How to Prune Table Grapes

Q. I have a couple of vines of grapes. Should I cut them back so the stem is about 1 ft. high? I've been doing that and have not gotten many grapes from my Thompson plant and none from my seedless Flame. These plants are about 5 years old.

This picture was taken in the spring of 2012, about the second week of March.
You can see a grape spur in the upper right quadrant of the picture, reddish
brown, that has two leaves coming from buds . It was cut back from a much
longer stem, which grew in 2011, following the directions in this posting.
Since this grape can be spur pruned, I cut this longer stem back so that only
two buds remains on the spur. Those buds gave rise to the leaves you see.
Also coming from these buds will be growth that will form the grape clusters
or bunches. Follow this spur back to its base and you will see it connected to
a short stem, brown in color, older than the spur. This was the previous year's
spur. At the base is even older wood which has a characteristic greyish color.
 

A. If you continue to cut off all of last year’s (2011) vine growth, you will never have grapes. Bunches of grapes produced in 2012 come from buds on growth that was produced in 2011, the previous year. The only thing you have to do now is decide how much of the growth produced in 2012 you will leave remaining after you have finished pruning. By the way, I usually delay the final pruning of grapes until at least mid-February to avoid loss of fruit from late freezes.



Another spur which has been cut intentionally too long.
If there is damage from winter cold and the end of the
spur dies, there is enough of the spur left for it to recover.
The oldest growth at the bottom is grey. The spur on top
is reddish brown. In between is a former spur which is
brown. The spur has three buds. Bottom bud is pointy on
the bottom right of the spur. The next bud up is on the left
side where a side shoot has been cut back. The third bud is
on the top right where another side shoot was cut back.
After cold weather has passed at the mid to end of February
you would cut the spur 1/4 inch above the second bud. After
you get some experience, cut it back 1/4 inch above the
bottom bud leaving only one bud.

            Let me walk you through the steps for pruning table grapes. You can prune wine grapes this way but wine grapes should be pruned slightly different.  With wine grapes we want to be more careful to “balance” the load of fruit with the growth of the vine to get better quality grapes.

            I like to prune grapes in either one step in mid-February or a two-step process with an initial pruning of the grapes at leaf fall and a final pruning on the February date. Some people are itching to cut those grapes early and this will give them something to do. Otherwise just delay the pruning.

            There are two things to know before you begin. First, the wood where the fruit is produced is on last year’s growth which is a different color from older, nonproductive wood. It is usually more reddish. I will post pictures on my blog next week so you and others can see what I am talking about.

            Secondly, most grapes are pruned so that the amount of last year’s wood, the reddish colored wood, is only an inch or two long. But there are two table grapes that are NOT pruned like this. These are Thompson seedless and Black Monukka. These are pruned so that the remaining reddish, last year’s wood is about 12 to 18 inches long.

            When you leave just a very short length of reddish wood remaining after pruning then this is called spur pruning and this short stub of red wood is called a spur. When you leave a long piece of this reddish wood, then this is called a cane and you are cane pruning.



This is the tangle of new growth you must either remove or cut back to spurs. The new growth in the right places and spaced the right distance apart will be cut back to spurs, one or two buds in length.

            Pruning your grapes early can possibly result in no fruit production this next year in our climate. If there are some very low temperatures and strong, cold dry winds blowing across your vines after you prune it is possible to freeze back the spurs or canes and lose your crop or severely reduce it. If you delay pruning until February, you reduce that risk.

            Here is how to prune. Find the end of a stem or branch of a grape vine. Follow it until you see a place where there is a definite change in color from red to grey and the wood looks older. There is a clear separation between these two colors. This is where the 2012 growth began (red) and growth in 2011 (grey and older) ended.

            On the outside of the reddish stem you will see buds on either side. The last years red growth (on buds close to the separation of colors) is where the fruit will be produced for most grapes.

            For those grapes that require spur pruning, you can cut the reddish stem back leaving only two buds remaining. Prune ¼ inch beyond the second bud from the grey wood with a straight cut.



Another picture of one year old wood that will be cut back to either a spur
or a cane. Canes are just long spurs. Grapes like Thompson Seedless have
buds at the base of the new growth that will not produce grapes, just leaves.
So in the case of Thompson Seedless we have to cut their "spurs" extra
long so we include buds that will have fruit. Spurs are cut long enough
so that the buds that produce fruit (usually after the bottom ten buds) are
included. These extra long spurs are called "canes".

            For those grapes which should be cane pruned, like Thompson seedless, you should cut the red growth or cane so that there are ten buds remaining. Essentially it is just a much longer spur. This will leave a reddish cane in length something less than 18 inches.

            Grape vines are notorious for bleeding after they have been cut. In other words you may see water coming from the cut ends. Don’t worry about that. It is normal and will heal.

            When the vine sets small, BB-sized fruit in bunches, it is time to go ahead and remove bunches that are poorly formed or have not set berries very well or are too small.

            The remaining bunches are then pinched at the bottom, removing about 1/3 of the bunch. This increases the size of the berries that are remaining in the bunch. If your berries are small, then you did not remove enough bunches or you did not pinch the bottom of the bunch enough. Both are important.

Science in Action: Part III. Frankenplants

They have been called Monster plants, Frankenseeds or Frankenplants. Scientists have inserted "antifreeze" protein genes from flounder into tomatoes to protect the fruit from frost damage, chicken genes have been inserted into potatoes to increase disease resistance, firefly genes have been injected into corn plants. These are plants created in laboratories that never could have been developed by the traditional means of plant breeding.

Bizarre examples of genetically modified organisms

Plants that have been genetically engineered to resist herbicides and insects, resist freezing temperatures, produce pharmaceutical drugs and to convert nitrogen directly from the soil and developed by large multinational companies at tremendous cost are now being grown in the hopes of much larger profits. Biotechnologies of this type have evolved so quickly that the scientific community has split in the controversy and the rapid advancement of this science has left the general public and many scientists behind in ignorance and Universities scrambling for position.

The last two articles discussed how the disease crown gall was used, in the very early days of genetic engineering, to insert genetic information into plants. This ultimately led to technologies like the “gene gun” and how genes, like the one that produces the toxin from Bacillus thuriengensis (Bt), could be inserted so that crops could be protected from insects.

These two articles made it sound like biotechnology may lead to a scientifically founded Garden of Eden. To be fair, in Part III, a few of the arguments against this technology follows.

Genetic engineering is an imperfect science and not enough is known about what will happen in the long run. Many times researchers who insert genes, creating new organisms, operate with a scatter-gun approach, not knowing where the gene will end up over time or what effects it will have in the long run. Science knows very little about what a gene might trigger or interrupt depending on where it is inserted into the new host plant or animal.

Though often thought of as being precise by laypeople, inserting genes is a rather crude technology, lacking precision and predictability. The "new" gene can end up somewhere or doing something unexpected. For example, when genes for the color red were placed into petunias, this gene not only changed the color of the flower petals but also, unexpectedly, decreased the plant’s fertility and changed the growth of its roots and leaves. Salmon, which were genetically engineered to produce a growth hormone, not only grew bigger than expected and too fast but also turned green. These were unpredictable, scientifically termed pleiotropic, effects.

How do we know that a genetically engineered food plant will not produce new toxins and allergenic substances? How will the nutritional value of genetically modified foods change or will it? What will be the effects on the environment that comes in contact with these plants and on the wildlife in the food chain? Remember DDT? Examples of unexpected results from biotechnology:

·       An attempt to make potato plants resistant to sap-sucking insects has made them more vulnerable to other kinds of insect pests.

·       Crops such as maize and cotton have already been made resistant to chewing insects by adding a gene for Bt. But adding the Bt gene has led to speculation that there will be an increased attack by insects such as leafhoppers and aphids due to an unexpected drop in chemicals that deter their feeding.

·       The stems of a genetically altered, herbicide-resistant soybean were found uncharacteristically to crack open in hot climates.

All these questions are important questions yet they remain unanswered until the biologically altered plant leaves the test tube and enters the real world. The argument is that biotechnology fostered by corporations tends to ignore caution in favor of profits.

Genetically engineered organisms will disrupt our environment. Traditional plant breeding was limited to plants or animals that were compatible biologically which in turn limited the diversity of possible offspring. Breeding through gene-splicing techniques will create life forms that have never before existed, theoretically in billions of different possible combinations which can result in billions of different possible outcomes, some predictable and others not. As these new life forms escape or are introduced into the environment and enter different habitats they may do so with no environmental checks and balances.

We can look at past scenarios where biological organisms were released into new habitats with no checks and balances to see what will happen. While many have adapted without severe problems, a small percentage of them have not. These include the Kudzu vine, gypsy moth, saltcedar, Dutch Elm disease, Chestnut blight, starlings and the Mediterranean fruit fly to name a few. Whenever a genetically engineered organism is released it must be remembered that it may cause a disruption to a complex environment with pre-existing relationships that have developed over long periods of evolutionary history.

This has been characterized sometimes as a type of environmental “pollution”. But because this pollution is a “living pollution” these organisms will be more unpredictable than nonbiological pollutants. Genetically engineered products reproduce. When genetically engineered crops are grown for a specific purpose, they cannot be easily isolated both from spreading into the wild and from cross-pollinating with wild relatives.

It has already been shown that cross-pollination with “normal plants” can take place almost a mile away from the genetically engineered plantings. Three mile buffers are now being recommended in some countries. If we accept the concept that the environments and habitats have their own corrective mechanisms that allow them to “heal”, then radical changes to these environments from genetically modified organisms will require stronger corrective measures if it can be healed at all.

Ordinary pests could become "Super-pests". Much of the current effort in profit-centered, agricultural biotechnology is centered on the creation of herbicide-tolerant, pest-resistant and virus-resistant plants. The idea is to sell farmers patented seeds in the hope of increasing a company's share of both the seed and pesticide markets. The chemical companies hope to convince farmers that the new pest-tolerant crops will allow for a more efficient eradication of pests. In the case of herbicides, farmers will be able to spray at any time during the growing season, killing weeds without killing their crops.

Plants engineered to be pest resistant could become so invasive they are a weed problem themselves, or they could spread their resistance to wild weeds making them more invasive. A growing number of ecologists are concerned with "gene flow" which is the transfer of genes to weeds by way of cross-pollination. Researchers are concerned that manufactured genes for herbicide tolerance, and pest and viral resistance, might escape and create weeds that are resistant to herbicides, pests and viruses.

A Danish research team documented the transfer of a gene from a genetically modified crop to a weed surrounding the crop. This was unexpected among biotechnologists since they had dismissed this possibility even though critics had warned for years prior that it could happen.

Another fear is that insecticide-producing plants might create "super bugs" resistant to the effects of the new pesticide-producing genetic crops and that virus-resistant transgenic crops pose the equally dangerous possibility of creating new viruses that have never before existed in nature.

Putting the crowning touches on ecologists’ fears was the refusal by the insurance companies to insure against catastrophic environmental damage caused by genetically engineered organisms released into the environment.

Regardless of the criticism, bioengineered plants are here to stay. The question will remain how this new technology will be handled responsibly.

This article was previously published by the author in Southwest Trees and Turf

Jeeesh. So You Want to Grow Magnolia in Las Vegas. Here's How.

Q. I'm probably going to be at the mercy of the stock at the local nursery this weekend. I really liked the 24 gallon Magnolia tree they had but do you think my space of 18' x 14' will be too small for a Magnolia?



Southern magnolia growing near Decatur
and Red Rock in Las Vegas

A. As long as you understand I am not endorsing the planting of a magnolia but if that is what you want, then read the following. Magnolias can get huge and so if you want to enjoy it for a few years and yank it out when it no longer does well, then go for it. You might get ten or more years before this happens.

            Do not put it close to a hot (south or west facing) wall. BUT you must plant in a hole that is three or four feet wider than the container. Mix good compost (bagged and good stuff will be expensive) half and half with the soil you take from the hole and remove large rocks (baseball sized or larger).

            Mix a fertilizer like 16-16-16 with this backfill; about one handful for each ten gallon bucket. Mix it all together and put this modified soil back into the hole surrounding the rootball of the plant.

            As you are putting this soil back into the hole, add water from a hose so it makes it the consistency of quicksand to get rid of air pockets and the slurry flows all around the root ball.

Another Southern magnolia growing near Eastern and
Harmon. Notice the dieback beginning in the top.
Roots cannot provide enough water to the tops during
mid summer and the low tolerance of this plant to
temperature and humidity extremes.

            Plant at the same level as it was in the container. Water it deeply, three times, immediately after planting and when the soil has drained each time. It will be watered after planting best with something that can deliver a lot of water because this tree will require lots of water each time it is watered.

            The amount of water should be equivalent to filling a basin around the tree with three inches of water; if it is a 15 gallon plant then apply 15 gallons of water. You don’t have to use a basin but this basin idea should give you an idea of the amount needed.

            If you use drip emitters, then you should have initially at least three emitters for a 15 gallon tree. If it is a 24 inch boxed tree, then you should put at least at four emitters. As the tree gets larger, you will need to add more emitters and more water, perhaps one or two gallons more at each application per year of growth. Big trees use more water than little trees.

            Lastly, dig out an area around the tree that will allow you to put about four inches of wood mulch in an area covering a circle, at least eight feet in diameter, around the tree. The key with this tree is the right location, soil modification at the time of planting, adequate irrigations and wood mulch under the tree.

The Truth About Deep Root Fertilization of Trees and Shrubs

Q. Is deep root fertilization a good way to fertilize our African sumac tree, purple sage bushes and the purple plum tree?  I’ve seen advertisements from some landscapers for this process.  

Where are the roots of trees and shrubs growing
in a lawn?

A. There is nothing special or magical about deep root fertilization from landscapers or done by yourself. If done properly, and many do not, the fertilizer is injected into the soil at the depth of the roots. This is usually only a few inches beneath the surface of the soil.

            Deep root fertilizer applications have made a name for themselves mostly where trees and large shrubs are growing in a lawn. By applying it beneath the surface of the lawn, high rates of fertilizer are applied without damaging or killing the lawn or causing the lawn to have dark green spots of tall grass where the fertilizer is injected. The rates of fertilizer applied is quite high so the “saltiness” of the fertilizer (all fertilizers are salts of some sort) would normally kill the grass if that fertilizer is applied directly to the lawn.

These are the brown spots in your lawn that will occur
if you drop fertilizer on one spot or place it too shallow
under the lawn. It should be 6 to 8 inches under the surface.

            Also, lawn grasses are fertilizer “hogs”. Because of their fibrous root system they take fertilizer, nitrogen in particular, easily and quickly from the soil thus robbing it from deeper rooted trees and shrubs. By placing a complete fertilizer (one containing all three elements, nitrogen, phosphorus and potassium) several inches beneath the soil surface, it places the slower moving phosphorus and potassium right at where the roots are feeding.

            Commercial companies will usually use a liquid fertilizer and inject it with what is called a “soil needle” or deep root feeder. This is a probe that is connected to a tank on the back of a truck containing a fertilizer solution. A hose comes from the tank through a pump and, under high pressure, the liquid fertilizer is injected into the soil.

Granular fertilizer placed next to a bubbler in wood mulch so
the fertilizer will be moved to the roots by the water
coming from the bubbler.

            Real fancy units will allow the operator to squeeze the handle on the injector (a probe with holes in it to allow the fertilizer solution to injected into the ground) and inject a precise amount of fertilizer solution with each injection. The operator can inject the soil in dozens of places under the tree very quickly an be on his or her way.

            You will know if they are doing it correctly by how deeply they push the injector. If they push it too deeply, the fertilizer will be placed beyond the plant roots and a large amount will be wasted. If they don’t push it deep enough and it is in a lawn, then you may have burn spots in the lawn. Burn spots are usually less of a problem in the winter months.

            You can do deep root fertilize your own trees and shrubs by using tree and shrub fertilizer stakes and pounding them into the soil beneath the soil surface a few inches. You can also do it by irrigating the lawn and, while the soil is still moist, pushing a shovel into the soil in spacings about two feet apart under the canopy.

Fertilizer stake. The plastic cap is placed over the fertilizer
stake so that it does not shatter when pounded into the
wet soil under a tree near the source of water.

            The shovel is pushed into the soil all the way, pushed forward so that the slit cut by the shovel is open, and dropping some fertilizer into the open slit. You then pull the shovel out and push the slit closed with your foot. Irrigate immediately after you are finished.

            If your trees are in a desert landscape with drip irrigation then the whole idea of deep root fertilizer comes into question. When trees and shrubs are watered by drip irrigation then I would question whether deep root fertilizer applications are necessary. All the fertilizer will be “pushed” by watering from the drip emitters.

            Roots of trees and shrubs in a rock or desert landscape will not grow like they would in a lawn. Instead, with drip irrigation, roots grow profusely near the emitters and do not go “searching” for water or grow toward water. They are not psychics.

            With drip emitters is best to drop your fertilizer in slits next to the emitters or use tree fertilizer stakes at the emitters.

The Birdsnest Mushrooms in Your Mulch - Kids Will Love Them!

Reader's "pods found in the garden. All of these might nearly
fit on a quarter to give you a rough idea of their size.

Q. I figured I can't let more than three months go by without pestering you with a question! Attached are two photos of some mystery pods I found in the garden when doing some clean up. One is with the pods closed, and the second is with them open and with what appears to be small black seeds. Any idea what this is?

 

A. These are not pods at all but what is called birds nest mushrooms. These do look like tiny little pods with black seed like things inside them. Like other mushrooms or saprophytic (feed off of dead things) fungi they “feed” of off decaying organic matter in the soil. We can see these fairly commonly in compost heaps, decaying mulches or other places where organic waste is decomposing. They are interesting and kids love these little things.

Unopened or just opening "pods" of the reader

            Nothing to worry about. They feed off of DEAD plants so no harm to living plants or you. They are decomposers so they help to break down litter on or in the soil after or during a warm wet period. I attached a fact sheet from Texas A and M on this interesting form of plant life. I will post your pictures on my blog for others to see them.

 

Birdsnest and other inhabitants of wood chips and compost

Science in Action: Part II. Designer Plants

Designer Plants
Robert Ll. Morris

Genetic engineering has changed commercial plant breeding forever. In years past we always thought of obtaining new plants by simple breeding and hybridizing. But to get for instance elms resistant to elm leaf beetle or turfgrass resistant to Roundup these plants had to be permanently changed in ways that simple breeding and hybridizing had not been able to accomplish. The major limitation was that the plants had to be relatively close in their evolutionary history so that a transfer of new information from one plant to another by traditional breeding techniques could occur.

All that has changed with genetic or bioengineering. Over the last twenty years scientists have discovered that all living organisms have genetic information that is interchangeable, even between plants and animals. Unlike traditional breeding, bioengineering has made it possible to select exactly the traits desired from nearly any living organism and insert them into a plant and create a genetically modified organism (GMO).

In Part I we talked about how the bacterial disease, crown gall, played a role in bioengineering by providing a biological model for scientists to use to insert desirable genetic information permanently inside plants. It was known that the crown gall organism, a bacterium, could infect a plant and insert its own information causing the plant to do something it normally would not do. In the undesirable case of the crown gall disease, produce a tumorous swelling of plant tissue that housed and protected the disease.

More on Crown Gall Disease Organism

Scientists realized that packets of new, desirable genetic information might be inserted into plants following the same method that crown gall bacterium used. Early in the development of this technology the crown gall bacterium, modified with desirable genetic information, was used as the vehicle for transferring genetic information to plants. The crown gall model of gene insertion eventually led to the development of new more efficient technologies like “gene guns” which could “shoot” new information inside of plants.

Terms like “gene splicing”, which scientists use to recombine genetic information inside plants in an attempt to bioengineer a new organism with more desirable traits, results in “transgenic organisms”. This is a term that can be daunting at first until it is realized that it just means an organism that was altered or changed as a result of new genetic information which was purposefully inserted by some method.

More on Gene Splicing

Transgenic organisms usually have some sort of benefit passed on to it from genetic engineering resulting in an economic benefit to the horticulturist and ultimately the consumer. These might be new plant traits such as improved resistance to plant pests like viral yellows or ringspot diseases, acquired resistance to pesticides such as the Roundup Ready^® line of crops, some dwarfing characteristics in agronomic crops like wheat, the preservation of food flavors such as in Flavr Savr^©  tomato lines, and improved resistance to insect pests by inserting genes from biological organisms that produce toxins poisonous to insects such as the bacterium Bacillus thuriengensis (Bt).

Bt pesticide sprays for controlling insects have been available to commercial applicators and homeowners as a form of “natural” or “biological” pest control since the early 1960’s under a variety of different names. The first release of a Bt spray had a very narrow range of insects that it would control. Larvae of moths and butterflies with an alkaline gut pH and that fed largely on leaf surfaces were the only targets. This narrow range in pests that it controlled was both good and bad. It was good since it was very safe for humans and other animals that weren’t larvae of moths and butterflies such as beneficial insects. It was bad since it controlled such a narrow range of insects and these only in their larval stages.

We now recognize this particular strain of Bt as the variety kurstaki. Since the 1980’s there have been 50 strains of Bt developed that are specific to not only moth and butterfly larvae but larvae of other insects such as the elm leaf beetle (Bt var. tenebrionus), fungus gnats (Bt var. israelensis), and a wide range of agricultural pests including beetles. All the different Bt’s had the same basic scenario however; the susceptible juvenile insect eats plant foliage that has the bacterium on its surface, Bt spores are ingested by larvae, the spores grow and reproduce inside the insect producing toxins, toxins paralyse the digestive tract of the larvae causing it to cease eating, insect death. Death can range anywhere from a few hours to 5 days after ingestion. This depends on the amount of Bt ingested, the size and variety of the larvae and variety of Bt used for control.

Bt became popular in the past because it had some distinct advantages over other pesticides: it had a low hazard to humans; there was no waiting period from time of application before re-entering the field; different strains of Bt didn’t harm beneficial or non-target insects; insects that died from Bt were not dangerous to predators; Bt was not known to cause injury to plants on which it had been applied and was not considered harmful to the environment; and, little or no insect resistance had been reported.

More on Bacillus thuringiensis or Bt

The major problem with Bt applied as a pesticide was its lack of persistence in the environment (sunlight and rain shortened its life) and it had to be eaten by the insects to work and only the larval stages of the insect were susceptible. Multiple applications needed to be applied with just the right timing or its chances of success were limited.

            But what if the Bt toxin could be inserted into the plant? The toxin would always be present so timing was not a problem. Persistence was not a problem since the plant protected and even produced the toxin. To insert the Bt toxin gene (lets call it X gene) the scientists first identify the right Bt. Next they isolate the X gene and remove it from the Bt bacterium. They then attach a second gene, a gene that provides resistance to a toxic chemical such as an antibiotic or herbicide, to the Bt gene. Lets call the second gene the Y gene. The X gene, with the attached Y gene, is inserted into plant cells. Any plant cell that has the toxic X gene now is given resistance to an applied toxic chemical due to the presence of the Y gene.

Researchers then multiply the plant cells in the presence of the antibiotic or herbicide and kill all cells that do not have the Y gene. Because the X and Y genes are attached, the resulting cells will contain the Bt toxin. These genetically transformed plant cells are then grown into whole plants by a process called tissue culture. The modified plants produce the same lethal Bt protein produced by Bt bacteria because the plants now have the same gene.

The insertion of the toxic genes from Bt into plant lines so that plant itself becomes toxic is under quite a bit of controversy. First and foremost is that growing plants that continually have the Bt toxin present increases the chance that insects feeding on these plants may become resistant to the Bt gene.

There is some recent research that has demonstrated that this has already happened. Problems arise primarily because the Bt toxin is always present through the plants life cycle and that it is in all plant parts. Because susceptible insects must ingest the Bt toxin to be poisoned, genetically engineered cells could be directed to plant parts that only the target pest will eat or at certain times of the year. Scientists have been working on a Bt gene that will “switch on” in plant parts that are green (leaf tissue) or “switch off” in other plant parts that are not green (flowers, pollen and seed). Plants receive genes with a genetic “promoter switch” that results in production of the Bt toxin only in certain plant parts.

My article was previously published in Southwest Trees and Turf

Science in Action: Part I. Engineering Plants Using Crown Gall Disease

Science in Action: Part I. Engineering Plants Using Crown Gall Disease
By Robert Ll. Morris

Ever since Mendel discovered that characteristics in pea plants could be inherited, scientists have been improving plants through hybridization; two related plants were crossed and the resulting offspring had characteristics of both parent plants. Breeders then selected and reproduced the offspring that had the desired traits. These conventional plant breeding techniques were relatively imprecise because they shuffled thousands of genes around and distributed them to the offspring just to get one important change in a plant that was economically worth pursuing.

One challenge encountered in Mendelian breeding is that generally only closely related species of plants could be crossed. If no closely related species with desirable traits existed, breeders had no way of passing on these traits to the other plant. Another problem was that some of the genes were linked to each other. This is seen today in tomatoes that have been bred so that they can be shipped long distances but with a substantial loss in flavor.

Since the early 1980’s scientists have been using the tools of modern biotechnology to insert a single gene, or just two or three genes, into a plant giving it new, advantageous characteristics. With this technology a single gene could be inserted into a plant giving it a desired characteristic instead of the mixing all the genes from two plants through traditional plant breeding and hoping for the best. This technique could develop a new plant with much more control and precision and at a rate much faster than ever before.

The bioengineering of plants emerged from discoveries by researchers in previous years on how bacteria caused plant tumors, how viruses protected plants from other viruses and what enabled some bacteria to kill insects. Some first major step toward biotechnology occurred early in the twentieth century with a plant disease called crown gall. Crown galls are tumor-like plant growths that occur on many woody plants including fruit trees, grape vines, and ornamentals. In 1907 researchers at the USDA discovered that the cause of crown galls was a soil bacterium, Agrobacterium tumefaciens. Other bacteria were known to cause plant diseases but A. tumefaciens had the unusual ability to cause the plant that was hosting it to grow a disfiguring tumor.

Forty years later in 1947 researchers at the Rockefeller Institute for Medical Research (now named Rockefeller University), curious about the crown gall bacterium and using it for insight into how tumors developed, grew crown gall tissue culturally free of any associated bacterium AND free of the plant host as well. They found that these uninfected crown galls could continue to grow, as crown gall tissue, independently of the crown gall bacterium and of the plant host for many years. It was concluded that normal plant growth in some unknown way had been permanently and irretrievably transformed by A. tumefaciens. Understanding how would have to wait nearly another thirty years.

During the 1950s and 1960s, scientists discovered DNA’s role in transmitting information from plant to plant and ultimately controlling plant growth. Armed with this new information, scientists began looking more closely at DNA’s role in the formation of crown gall. The crown gall mystery was attacked again when several investigators began, logically, looking for the tumor-inducing factor in the bacterium's DNA.

Bacterial DNA is relatively simple compared to other types of organisms since it can be normally found on a single chromosome. It wasn’t found there. Instead it was found by Flemish researchers on a smaller, mobile DNA unit called a plasmid that was not part of the bacterium's single chromosome. In a series of experiments at the University of Washington ending in 1977 researchers found that this bacterial plasmid was spliced into the chromosomes of plant cells when the bacteria infected the plants.

This was at the same time that researchers in other fields were just beginning to understand how to manipulate genetic information by a technique called, in lay terms, gene splicing – to cut and splice foreign DNA into the genetic code of an organism.

It became clear now that A. tumefaciens transmitted the genetic information needed to cause a plant to produce tumor-like growth through the transfer of a “packet” of information called a plasmid.  This plasmid altered the genetic makeup of the plant so that the infected cells of the plant were induced to divide continually, developing galls containing the genetic information from A. tumefaciens.

What if scientists could manipulate A. tumefaciens so that it no longer transferred the genetic information for creating crown gall but instead transferred genetic information into plants that produced desirable traits such as resistance to insects or disease?

To convert the A. tumefaciens plasmid into a beneficial plasmid (now called a vector) researchers first had to locate and then replace the tumor-inducing genes. By 1983, plant molecular biologists had developed the first plasmid vector for plants susceptible to crown gall from A. tumefaciens. The crown gall disease had changed plant breeding forever.

A tool for introducing genes into plants is useful only if scientists have found genes that they want to transfer. Enter Monsanto. In the late 1960’s researchers at Monsanto wanted to know what made the nonselective herbicide glyphosate (Roundup^TM) a potent killer of so many different kinds of plants; weeds and crop plants as well. It seemed reasonable that if you could alter crop plants so that they were resistant to glyphosate, then spraying an herbicide like glyphosate “over the top” of a mixture of emerging combination of resistant crops and weeds would kill the weeds but not the crop.

Through combined research starting early in the 1970’s glyphosate’s genetic “mode of action’, destruction of an enzyme vital to all plants, was specifically identified by research performed at Monsanto and by German researchers.

In 1983 researchers at Calgene and Monsanto identified the gene, and Monsanto modified the gene, so that the enzyme it produced was no longer sensitive to glyphosate. The A. tumefaciens plasmid vector was used to introduce the modified gene into crop plants. The new tomatoes, petunias and other modified plants were resistant to damage from glyphosate which was reported in the research in1985.



Gene gun. More on this subject at

http://users.comcen.com.au/~biodynamic/pages/what_is_it.html

The USDA requires field testing of genetically modified plants for several seasons before its release and that testing includes potential changes in food safety, nutrient levels, development of potentially toxic substances and safety to the environment. In 1996, the first glyphosate-resistant soybean, cotton, canola, and corn seeds were made available to farmers.

During the1980s and 1990s other ways were developed to introduce beneficial genes into plants. One is called a "gene gun," which literally shoots DNA-covered particles attached to metal “bullets” through plant cell walls and membranes to the cell nucleus. Inside the nucleus the foreign DNA combines with the plant's own DNA and transforms the plant. Other techniques involve electrical or chemical treatments assisting DNA molecules to pass through plant cell walls and membranes barriers and combine with a plant’s genetic information, a high-tech form of plant breeding. Wouldn’t Mendel be impressed?

Previously published in Southwest Trees and Turf

My Beans Emerged From the Soil and Died

A good indicator of collar rot is when the plant shows less vigor than it
should or less vigor than its neighbors

Q. I recently planted bean seeds in pots on my porch here in Las Vegas.  However, after the bean stalks were half a foot tall, they bent over, turned dark and died.

A. This is probably crown rot. If you plant beans when the soil is too cold they have a huge chance of developing crown rot at the point where the bean stem enters the soil. This causes the stem rot, the plant dies or we say “collapses”. If you plant them when the soil is warmer, they have less chance of this happening.

Once the plant is lifted from the soil you can inspect the stem at the soil
level. Where the brown part of the stem and the green part starts was
the soil level. This is also the place where the bean stem was attacked
by collar rot fungi. Avoid planting in soils that are too cold.

 

What to do When Your Indoor Palm Has Sticky Leaves

Q. My indoor palm plant has developed a sticky-looking, shiny appearance on the leaves.  Also, small, 1/16" brown spots/bumps on the leaves and stems.  What is this?

Scale on palm leaf but unfortunately the plant also has spider mites
judging from the yellow speckled appearance of the leaf

A. This is probably one of the scale insects. It is living under this brown bump and sucking plant juices while totally protected by this bump or shell they build on top of themselves.

            This brown bump is what keeps them alive when pesticides are sprayed on the plant. BUT they are susceptible to poisons or insecticides that are taken up into the juices INSIDE the plant.

            So, systemic insecticides, those that are applied to the soil or sometimes sprayed on the leaves and taken up through the leaves, can be quite effective on these protected insects. Since it is a palm and you are not eating anything from it you can use these types of poisons on these plants.

            You will have to try to find one at a nursery or garden center that carries a systemic insecticide that has a label specifically for houseplants and controlling scale insects. The shiny stuff on the leaves is sticky since this is the sugary excrement of these scale insects falling on the leaves. Frequently it attracts ants.

Is Now a Good Time to Fertilize Shade Trees?

Apply fertilizer to the irrigated areas and just
outside the irrigated areas, just below the
soil surface, no deeper than this

Q. There are six trees on our property; a Raywood ash which is 10 years old, Arizona ash also 10 years old, California pepper (taller than our 2 story house and 8 years old), Bradford pear also 10 years old, a young African sumac and a young palo verde. Is now (October - November) a good time of year to deep feed these trees? Also, we've got a three foot long tree root from the pepper that's growing along the top of our lawn. Can I cut that part out this time of year?

A. You can deep root feed these trees (put the fertilizer in the root and watered area at about half a foot, no more) now that the trees are preparing for winter and stopped growing but they should still have green leaves on the tree.

            If there is no grass there then apply it to the surface of the soil and water it in. Water the fertilizer in the root zone three times over the period of one week and then continue to cut back on your irrigation for these trees as you normally would for the winter.



            The living green leaves on the tree will help move the water laced with fertilizer into the trees and into storage for next spring's growth. It also places fertilizer in the area of the roots for next season provided you don’t water too much. You can then skip a spring application of fertilizer.

            If the leaves have turned yellow or are starting to drop, you missed it for this year. Wait until next spring. There is no advantage to applying it in the fall vs. spring except possibly convenience.

Not All Cactus Fruit Are Desirable for Eating

Bird damage to nopal fruit called tunas in Mexican Spanish.
Bird damage to cactus fruits is a good indicator tunas will
have good quality for human consumption. Tunas are high
in vitamin C.

Q. I have a large cactus garden in my front yard and much fruit.  My cactus are the"bunny ears" type.  Is the fruit of this type good to eat and does it have health benefits?  I am a retired teacher and just read your article on cactus fruit.  I have made jelly from them in the past.  I suffer with Crohn's disease and wonder if this fruit is comparable to the Nepolia (sp?) health drink that costs so much. Since Crohn's is an auto immune illness, I wonder if this fruit has some good anti-inflammatory properties? Thank you for your time and any help you can give me.

A. Sorry to hear about your health concerns. The fruit would definitely be edible BUT not all Opuntia type cacti are as desirable as others for eating. The nopal cactus is also a “bunny ears” type but the fruit may not be as edible.

            In some nopal cactus the sugar content may be as high as 30% which would rival fully mature wine grapes in sugar content. I normally will get about 16 to 18% which would rival a really good apple or peach.

            A good indicator about whether it is going to be a good one is how the birds use the fruit. If birds are devouring the fruit then it will have some really good characteristics for human consumption. If the birds leave it alone, well… it probably has low desirability.

            So look for bird damage to ripe fruit. Nopal or bunny ears cactus is selected for edibility so not all of these cacti are as desirable as others for food.

            As far as health benefits goes, I have heard that it is of course high in fiber content, helps to lower cholesterol, helps reduce high blood pressure, is normally high in Vit C (reds are the best) but I have not heard anything about auto immune system benefits unless you want to count the Vit C content as part of that. But I am no health expert and you would probably have to do some digging in the literature online for that information. There are some good papers out of the University of California with the University of Sonora on this subject in the past.

            Also if you want to start growing cactus for food you will have to alter your irrigations to push new succulent growth starting in about March. A deep irrigation every two weeks is all that is needed along with a fertilizer application high in nitrogen in the spring. Compost applications at the time of planting and on the surface each year will also help push new growth.

How Far to Cut Back Ash Without Killing Them?



Example of a thinning cut made to peach. The cut is made
directly above a side branch going in a preferred direction
or a smaller one that will help to reduce the size of the plant.

Q. We have two fantex ash trees, 15 years old. They are spreading out too far. How far can we cut them back without killing them?

A. The problem with ash is that it does not have much ability to come back from cut limbs if you cut back too far. You can begin structuring the tree if you do it fairly early and stay on top of it but if you let it go too long and then cut it back you may have some problems.
 

            You can cut it back to side branches that are growing in a desirable direction but you cannot prune it back by what we call heading cuts (stubbing it back) and hoping these dead end cuts will resprout. You can cut back into about second or maybe three year old wood (there are still side buds remaining that can grow) but if you cut into a limb with no buds present it will probably die back to a major limb.

            So cut back to a branch at a crotch going in the direction you want it to grow. When limbs are growing the wrong direction, eliminate them back to a crotch or another limb. Do not leave any stubs (dead end cuts).

The Modesto ash on the right was "topped" and because of the nature of
ash it never came out of it but had to be removed. The one on the left was
cut back early enough so that it could resprout from young wood.
Consequently the one on the left developed swellings just under the cuts
that are full of tissue that can generate new growth. The one on the right
could not.

            I hope this makes sense. I attached a picture of a thinning cut made removing a larger limb going up…to a smaller limb going out and toward the camera. The direction of growth of the limb was changed without leaving a stub.

Marketplace at The Roots

~ Marketplace at The Roots ~

A new Saturday market is opening at the Vegas Roots Community Garden.

The first market day is November 24th, from 10:00 AM to 3:00 PM.

Please read the flyer and additional information below.

We really hope to meet you!

(Vendors, please see below)

Free Admission -

We have lots of room down here.  Parking and admission to the market are completely free.

Local Vendors -

We will strive to have between 25 and 30 vendors at each market.  Their wares will range from locally grown produce and honey to various artistic creations.  All local and all in need of your support.

We’ll try to provide a pre-market update of the vendors we expect, so you can plan your shopping accordingly.

Tour the Property -

We’d love to have you come down just to view the garden and its spacious four-plus acre grounds.  So, if you’ve ever been curious about the Garden or even if you’re just now hearing about it, our new Market will give you a great reason to pay us a visit!

You-Pick Garden -

Part of your tour of our sanctuary will include the chicken coops, the permaculture garden and the You-Pick garden.  Throughout the year, garden staff (volunteers) plant various crops.  Since Las Vegas has such favorable year-round growing conditions, local residents can usually find something to harvest.  There’s nothing quite like picking and enjoying a fresh tomato, squash or other vegetable right off the plant.

Kids Playground -

You are welcome to bring your children with you.  In fact, we encourage it.  Not only is it a great learning environment regarding food production and quality, but the young ones won’t get bored for a moment.  We have a very nice playground that frankly, doesn’t get enough attention.   Of course, we’ll need you to keep an eye on them, because the chicken coops are right beside the playground…

Music -

The Garden is a peaceful, restful and grounding place.  We’ll have some nice background music going, thanks to DJ Coco, to add to the enchantment.  Eventually, we hope to have some live musicians perform.  One step at a time…

Support Your Community -

This is a great way to make a difference locally.  A couple of times a month you can buy super-fresh produce and other perishables as well as various other goods, rather than shopping at your favorite grocery store or supermarket.  The Garden benefits, the vendors benefit, the community benefits.  Just the way we love it!

JOIN US! -

Please do!  This is a non-profit community garden.  It’s open to everyone.  The Marketplace at The Roots event is your official invitation to come on down and see the place.  Look around.  Shop.  Meet new folks.  Find out about all we have going on down here.  Maybe even volunteer?