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Wednesday, December 12, 2012

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.

Tuesday, December 11, 2012

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