Xtremehorticulture

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.

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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

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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

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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?

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This Clover-Looking Weed is Hard to Get Rid Of

Q. I have clover growing at the base of my spike plants. I pull them, and pull them, and pull them. Do we all just enjoy each other and smile or is there some way to get rid of them I’ve split off babies from the base of the plants and have four separate pots with spikes in them now and they are about one and a half feet tall now. I cleaned around the roots and put them in new potting soil, but their “friends” are hanging right in there with all four plants also. We do have other larger clover growing with our main clutch of aloe vera and have no idea how to approach that type (and tight) group without starting a full scale aloe army throughout our garden. Symbiotic yin and yang or what, Professor? A. I am not sure what you are calling Spike plants. The common name, spike plant, usually refers to a house plant called bcdefghi DY’`IY{L8n you may be referring to aloe as a spike plant.  Oxalis or wood sorrel.             I am also not sure the plant you’re calling clover is really a clover at all. I am wondering if this is oxalis, a plant whose leaves are very similar to clover in appearance. But this plant is much more difficult to control or eradicate than clover. It is also called wood sorrel.             Oxalis can be spread through seed from the flowers, bulbs from the roots and also by bulbils. If you are going to control this weed you will need to clean all soil from your “spike plant” roots thoroughly and sterilize any soil you are using when you’re a replanting these plants.             Clover is not that difficult to control but oxalis is a terrible weed to control particularly among nursery plantings and in landscapes in our climate. An easy way to tell if this is oxalis is to taste a few of the leaves. Clover leaves will be slightly sweet to the taste. Oxalis leaves contain oxalic acid, the same chemical in rhubarb, spinach and brussels sprouts and will be sour to the taste. But my guess is you have oxalis.

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Should I Cut Back Bareroot Apricot After Planting and Leafing Out?

Q. I planted several bare root fruit trees about three weeks ago.   They were shipped to me about four foot tall. I did not want to trim them until I could see some growth. They have started to leaf out except for the apricot. The apricot is the one that concerns me. It has no branches below the 2 ft level, six branches above 2 feet, and no visible growth yet.  Everything else looks good. My question is will it harm them if I cut them down to the 2-1/2 ft level at this time.  Or, should I leave them alone to establish themselves, then prune and cut them down to size in the winter when they are dormant. A. They all appear like they can handle being cut back somewhere between your knee or no more than a foot above the knee. Use your judgement as to the exact location as it should be just above a branch or a bud.                      It would have been better to cut them back before they leafed out.             Limb up branches at the bottom that are too close to the ground (bend the branch and if it can touch the ground then eliminate it). On spur producing fruit trees (pear and apricot) cut the branches back to about 18 inches in length or no closer than 18 inches to the closest spur if any have been produced.

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Sap Dripping from Tree Trunk a Common Problem

Q. We love your advice. Please explain and tell us any info about our trees. We sent you some pictures. I removed the dried area and flushed with water. We lost large cottonwoods years ago having same condition. Slime flux or wetwood on a large established tree which is not the readers. A. The pictures show a liquid coming directly from the trunk of the tree. This may be a disease called wetwood or slime flux that can infect many different types of trees. The liquid coming from this disease will have a putrified, yeasty smell which quite often attracts flies. In many cases, the liquid does not seem to be coming from any cut or damage to the tree. It seems to come directly from the limb or trunk.             This particular disease is normally not lethal. However, there are some trees where it seems quite deadly. One of them is Navaho globe willow. In this case it has been noted that it has killed trees. In any regard, this disease in poplars, elms, mesquite and other trees is usually not deadly. It is considered more of a nuisance than anything else.               Check to see if there is an odor to the liquid. See if flies are attracted to the liquid on a warm day when flies are present. If this is the case, there is nothing you can do about the situation but have the tree live with it. There are no fungicides or other pesticides that will make any changes. Hopefully the tree will have a long life living with this problem.

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Yellowing of Apricot Leaves and Possible Causes and Cures

 Q. I have an Apricot tree I planted in January (bareroot from the farm).  It has been doing really well until a couple of week ago I noticed something was eating some of the leaves.  More recently I have noticed yellowing of some of the leaves.  Any ideas as to what is causing this and how to remedy the problem?  I have attached pictures.  Thanks.   Typical of iron chlorosis is that the newest leaves will have a lighter green leaf than older leaves AND the veins remain a dark green compared to the leaf itself. (Newer leaves are farther out on the limb than older leaves). A. Photos 2, 3 and 4 looked like a nutrient or watering problem. The leaf or leaves were light green with some scorching around the edges. There might also be some wind damage. In photo it looks like a critter could have been eating the leaves but that is no big deal if it only affects a few leaves and doesn’t bother the fruit. In the photos 2 – 4 it does appear to be a nutrient problem.   Not a clear picture from the reader but you can see the scorching of the leaves on apricot. See how the leaves on the ends of the branch are yellowing more than the older leaves coming from the thicker part of the branch? This is a good indicator it is most likely an iron or irrigation problem. Irrigation, too much, can also mimic iron shortages or actually cause an iron shortage. This is what you need to do. If there is mulch, pull the mulch away from the trunk. If there is no mulch, then pull the soil away from the trunk until you start to see the roots that were in the original container. I am concerned you might be developing collar rot. Planting the tree a little too deep can also cause similar looking problems. Again not the best picture but it does look like an insect could have taken a chunk out of the leaf but chances are, if there were strong winds recently, it was wind damage. If you are on a watering pattern that is every day, try to get off of it. Go at least every other day or even best every third day in the summer but add enough water to get the water down at least 12 inches into the soil. If it is hard to do this, build a donut around this young tree at least 18 inches from the trunk. Two feet from the trunk is even better. One of the many iron sprays. Just make sure you adjust the chemistry of the water to be on the acidic side so that the iron is not lost when you mix it with water. To be on the safe side I would use distilled or RO water and use it all up. Don’t keep it premixed for any length of time. This donut or moat should be high enough to hold about three to four inches of water. Fill it twice until the next watering. Because we are now in July, spray the leaves early in the morning with an iron fertilizer spray. Pick an iron product made for correcting iron chlorosis, an iron chelate is best. I usually recommend EDDHA iron but that is for applying to the soil. It is expensive and you do not need this chelate for spraying on the leaves. Any iron spray made for applying iron to the leaves should work fine. However, some plants, in fact many plant leaves will not turn green from an iron spray without multiple applications. So I would make a fresh spray of iron for the leaves about four times and apply the iron on four separate applications a few days apart. Remember to apply it in the cool of the morning. I would use distilled water or RO water. I would also put a tsp of liquid dish detergent (one with no addatives like scents or lotions) in one gallon of spray mix. Shake it to mix the spray and detergent together but not allow it to foam. Spray immediately.  Do not hold it overnight. Make a fresh spray each time you spray. Next January make your normal fertilizer application to the tree and include an iron chelate to the soil that contains EDDHA chelate.

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Pruning Citrus: How to do it

Q. I have a dwarf lemon tree that is about 14 years old. It produces plenty of fruit and I keep it relatively small. I trim it in the winter but have never professionally pruned it. Could you recommend to me a source on how to properly prune this tree? A. I don’t know of a source to help guide you in pruning your citrus tree except the one I wrote and posted below this entry.  It was published by the California State Parks; Citrus State Historic Park. I will try to give you some basic directions but read below for more specifics.  Light pruning can be done anytime but heavier pruning should be done right after harvest.              Light pruning would include the removal of small branches that are interfering with growth or causing too much shade inside the canopy. You can judge if there is too much shade in the canopy by looking at the ground beneath a canopy. There is enough light passing through the canopy if you can see speckles of light throughout the shadow of the canopy on the ground.              First of all, remove branches that are crossing or any branches growing back toward the center of the tree.  Next, remove branches which are growing straight up or straight down.  Once you have done this, stand back and look at the shadow of the canopy on the ground.  Is light passing through the canopy and causing speckles to form throughout its shadow on the ground?  If this is now happening, perhaps you should stop pruning until after harvest.              Citrus does not require much pruning but getting rid of problem branches such as those that are crossing, growing to close together or growing back to rid the center of the tree would be recommended. Open publication – Free publishing – More citrus

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Lets Hope for a Gradual Drop in Temperatures This Fall

            Normally we enjoy very nice fall weather in Las Vegas until about the first week of December and oftentimes without frost. This would be pretty normal. To have freezing weather before this, or unusually cold weather, would be a bit odd. As long as the temperatures continue to drop slowly to our winter minimum lows our perennial plants that can withstand some light freezing weather will survive the winter. Cold temperature damage to cycad. Notice there is more damage closer to the ground where cold temperatures lay.             If November temperatures drop suddenly, or we have snow before trees drop their leaves, then we can have problems. If we are enjoying, for instance, night time temperatures just falling below 50F and then it suddenly drops to 30F the next night, then we might see major freezing damage in plants that normally might tolerate temperatures to 20F. To survive the winter minimums, winter-tender plants need time to acclimate to these low temperatures so that they can create their “antifreeze” if they are to survive.             Decreasing fall and winter temperatures also helps leaves to drop. One good cold snap in the fall can cause tree leaves to drop prematurely. One day the leaves are there and in just three or four days after the freeze, they are on the ground. Trees like ash and Chinese pistache don’t please us with their winter colors when this happens. Reader’s African Sumac with snow damage during the snow of December 2008. You will need to get out and hit the limbs with a broom during heavy snow falls.             There is a good side to this early leaf drop. If we have one of our “every five year” snow events, and it comes after early leaf drop, we miss all the damage snow can cause that time of year. If snow comes early and these trees have not dropped their leaves, then we can have massive limb breakage due to the snow load on limbs.             How we manage winter-tender plants going into the fall months can make the difference between their survival and death from winter freezes. It is important to withhold fertilizers, particularly nitrogen, during and after the month of August. It is also important to change the irrigation clock so that water is delivered less frequently that time of year.             If winter-tender plants are still pushing new growth or they are still succulent at this time of year, there may not be enough time for them to begin their adjustment for winter cold. This adjustment takes them a couple of months of decreasing temperatures and longer nights to accomplish this.

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