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Newly Grafted Trees

Young grafts should be treated closer to vegetable starts than to trees. A nursery bed for that first year, at least, is required. Although the tree will require different environmental and nutritional needs than an annual, they do need the same sort of babysitting. Consider water and warmth as the “fertilizers” of first importance. This latter point is all to often left out of the equation. This also means keeping the humidity up, especially if the union is not healed so well. (Drying out the scion may not simply kill it, it may be just crummy growth). Also, make sure it is the growing conditions and not the grafting procedure that is causing slow growth. This especially means aftercare for proper heal. When they are growing, give them the attention you would give to your little tomatoes, including mulching and weeding.

There will be a disconnect in how the baby is treated in this first year or two, and how it will receive nutrition as an adult. Later in life in a healthy system, it will do well with gradual release through organic matter, in conjunction with good mycorrhizal fungal connections. Now, in a bed that has been prepared with forethought (fungal connections partially in place) and living soil, good growth is possible. Even in this situation, some supplementation is helpful. A foliar application is great, but a sustainably derived fertilizer in that bed is a good idea as well. They benefit from a bit of nitrogen which, being easily available in a mineralized form is an easy one, as is K. But, P and other micronutrients really should have been developed in that living soil. It is when the quick fix is needed that growers turn to industrial farming methods like triple superphosphate, miracle grow and 20 20 20 .

Having done this quite a bit commercially, I find that that first year never really is all that spectacular for growth, whether that is seedling plants or grafted fruit trees. I think they are pissed from being moved around and violated, and they need to be at peace again. That second year is always awesome, for most. But, if the soil is a mess and it is too late to fix it, foliar sprays, watering on time, and keeping things in the low 70’s will give the best growth rates.

If the little guys are stunted in that first year or two, it will take a few more to get things back on track, in my experience. That said, a small tree is not always a poor tree. (Charlie Brown knew this) As long as it is healthy, slower can also mean denser and more resilient wood. I would put our smaller gritty trees up against the overly succulent fertilizer pushed trees any day of the week.

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Ask the Farmer : Tree Irrigation ?

Do you see many orchards around here choosing to irrigate?

Irrigation of course, can mean a lot of things. What is being asked here I think is whether or not a constructed system is put in place to deliver the water.

Irrigation, as in drip-line, is used for high density dwarf systems. In these arrangements, whether they cultivate or not, it is usually recommended due to the meager root system. Trees using size reduction rootstocks (dwarf), require a good deal more pampering with respect to water. Traditionally this was delivered through open canals, overhead sprinklers, etc. Modern techniques include soil drenching through plastic emitters in miles of plastic tubing. It is an absolute must in many of the dryer regions of the northwest and California, but is popular throughout the country.

In the wet northeast, with standard  trees it is unnecessary. Trees obtaining their natural large stature will have roots mining for water over a very large area. Roots can extend meters down and in circumference at least twice the distance of the canopy. This means resilience during dry spells, and buffering against extreme cold.

Irrigation can confine roots to the pampered area in many cases. If the rooting mass is confined to shallow, smaller areas due to trickle irrigating, later stresses like cold or drought can lead to mortality. The mechanism here (and backed up with numerous studies) is the tendency for roots to amass in areas of ideal culture. That is, where it has good nutrition and soil moisture content. While this is good for the tree in general, it does limit the yardage the roots will occupy. This is pronounced if the outlying area is dry. Roots do not really grow toward ideal soil, they just don’t proliferate where it is poor. An example of the possible danger is when irrigation is confined to a shallow depth by continuous light applications. Roots will be largely clustered in this same shallow zone. In colder areas, this can lead to root damage or death . It can also have such consequences in warmer, dryer areas if there is a pause in irrigating (ie- broken lines or power outages).

Some alternatives include:

  • Increase the organic matter in your soil. Fully composted materials are advised if you are incorporating it directly.
  • Surface application of organic materials. This is the place to put the coarser materials, and higher carbon detritus. If it is a continuous application, we call it mulch. Bark, hay, straw, leaves and wood chips all fit in this category.
  • A 5 gallon pail of water really isn’t all that heavy. At 8 pounds a gallon, that’s 40. One in each hand (filled 4/5 so it doesn’t spill on you) is 64 pounds. That’s all you need to deal with during the occasional drought for your young tree.
  • Grow standard trees. These are those with a natural seedling rootstock that will let a tree grow to its full size. They can be pruned to be less tall and still have a large canopy and extensive root system. Think of this route as raising self sufficient children.

We suggest watering during that planting year, especially during dry spells, for better growth. Sandy soils of course will need more attention than heavier ones. Mulching is a great way to conserve that moisture ( keeping  it away from the trunk) and do it initially after the soil is wet.

Here is something to consider : The US Geological Survey posts on their site that a mature oak can transpire 40,000 gallons of water in a year. That’s one tree. Now, an apple tree is a whole lot smaller than an oak, so in the interest of fair play, let’s reduce that figure 40 times. That leaves us with 1000 gallons for a mature apple. However, if the tree is transpiring that much as water, it must also be absorbing  more to use in metabolic processes. Then there is the issue of delivery versus root uptake. That is, the soil must contain more than this amount of water to begin with. Irrigation through precipitation or human intervention must exceed the volume absorbed by the tree. To make an impact, it would seem a very large volume would have to be delivered indeed.

In conclusion, a plant with a small root system will require a good deal more attention as regards water. This lines up nicely, since a small root system stands the chance of benefitting from the amount of water we are likely to be able to deliver. This is why farms tend to irrigate their high end vegetable plots but not irrigate hay fields and cider orchards.

Water is the single greatest and most overlooked of fertilizers for plants. Time and money are the single greatest commodities of the human being. With proper decisions, nature can do a good deal of the work for us.

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Ants attack caterpillar – video

We shot a few minutes of footage of ants attacking (and eventually killing) a caterpillar many times their size. Ants are problematic in the orchard in many instances, from farming aphids to biting humans. They do occasionally shine, however, as is shown in this video dispatching a hungry caterpillar. Lepidopteran larvae can be a large orchard problem, and every little bit counts when it comes to keeping their numbers in check.

 

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Rootstock Crowding Study

I wanted to bring attention to a study we are doing at Walden Heights. In both research and direct observation, there is evidence that crowding of root systems leads to some dwarfing effects. Apples in particular tend to avoid growing in the same soil regions that other members of their species do. ( Atkinson D, Naylor D, Coldrick GA (1976) The effect of tree spacing on the apple root system. Hortic Res 16: 89-105 ). Additional consideration is that direct competition of many other species in the vicinity should lead to an overall size reduction. By creating a full block planting, roots will be forced to compete 360 degrees.

We have planted two sections to standard stock apple, one as an 8×8 foot grid, one as an 4×8 foot grid. We also, for comparison have standards at 15 x 15, and 30 x 30. We also have apples (part of another test) in a high tunnel at 8 foot spacing. Since we alot of scionwood collection for the nursery, if the fruit production is, well, unfruitful, there is still merit in the exercise. We are forced by necessity since we need to find room for what is closing in on 500 varieties, without resorting to dwarf stock or excessive topworking. It gives us an opportunity to run such a test without risking too much. We will keep everyone posted on the progress. There are about 500 trees in the two blocks, of 6 standard rootstocks and roughly 300 scion varieties.

Obviously precocity isn’t necessarily being addressed, at least at first glance. Since stress often leads to early bearing, who knows. If excessive pruning is needed in the early years, this may actually delay bearing. Our goals here have never been for rushing the crop- thats what berry bushes are for. Tree longevity and low maintenance plants are. If we can couple this with a tree that can more within reach for spraying, harvesting and scion collection, it may have a place in many a farm plan. Not as a replacement, but as an addition to the overall system.

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Bacteria and Freeze Damage

Freeze damage and the presence of pathogens in the orchard can apparently be linked.    George Sundin  and Nikki Rothwell at the Michigan State University Extension, Department of Plant, Soil and Microbial Sciences published at article entitled, “ Bacterial canker, ice nucleation, frost injury and blossom blast in sweet cherries”, outlining how in this example, a bacterial pathogen worked in tandem with frost events to cause or further damage in a prunus species.

The phenomenon occurs when bacterial cells act as nucleation sites within the flowers. The presence of the bacteria facilitates freezing which in turn allows the plant tissue to be damaged, and thus permits the pathogen to invade the plant tissue more effectively. An ingenious, if insidious maneuver.  How effective the process is depends upon the temperature (the cooler it is, the less bacterial cells are necessary to cause freeze damage). The bacterium acts, in a way as a catalyst.

The entire article can be read here.

 

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Bacterial Canker in Prunus Species

Here at Walden Heights, we are having trouble with plum trees. The plums in our orchard are relatively young and generally healthy and vigorous. They flower beautifully and are surrounded by pollinators, yet they bear no fruit. As we pruned this winter, we noticed some bacterial canker on the branches, characterized by gumosis and orange mold-looking spots. In the spring, the flowering stems were hit with blossom blast immediately after flowering. The blossom blast caused rapid brown dieback, often overnight. These symptoms were showing up on plums, cherry plums, and Hanson’s bush cherries, all closely related Prunus species.

After some research, we learned that these symptoms stem from the same bacterium- Pseudomonas syringae. This bacterium has over 50 pathovars, affecting a wide variety of plants including tomatoes, maples, wheat, mangoes, kiwi and more. Prunus stone fruits are affected by the P. syringae pathovars syringae (causing blossom blast) and mons-prunorum (causing bacterial canker).

P. syringae is  present in the air, water, and on plant surfaces all around us. This bacterium causes water to freeze at high temperatures and is responsible for a majority of frost damage in plants. It also plays a big part in the Earth’s hydrological cycle. When airborne it serves as a cloud condensation nuclei and ends up in raindrops and hailstones. 

Here in the orchard it’s a big nuisance. The pathogen lands on healthy stems, overwintering on healthy dormant buds. Because it causes ice to form at high temperatures it creates severe frost damage. In the spring when the damaged tissue thaws out, P. syringae colonizes that tissue. It colonizes especially quickly in cool, wet conditions. The pathogen will kill flowering stems immediately after flowering (blossom blast),  move into the wood and create cankers. The pathogen will multiply and overwinter in these cankers, spreading further in the tree the following season.

There are no good treatments for this bacterium and prevention is the best strategy.  Remove diseased stems, leaves, and cankers immediately to prevent it from spreading. Healthy trees can fight off the bacterium more successfully so invest in the health of your tree from the start. Make sure that the soil around the tree is full of microbes and that the tree is not stressed due to lack of nutrients or water. However, be sure not to over-fertilize. Too much fertilizer will create an abundance of succulent shoots, which are favorite overwintering spots for for the P. syringae bacterium. Prune the branches to ensure lots of air flow and quick drying of the tree’s surfaces, which reduces opportunities for the bacterium to colonize. 

Foliar sprays that inoculate the shoots and leaves with probiotics are another way to invest in the health of the tree and help it fight off the bacterium. We are going to experiment with these sprays  to improve the health and production of our plums.

Several extension agencies recommend spraying with copper, a common treatment for fungal and bacterial diseases. While there are some organic copper sprays available, they are harmful to beneficial populations and it is expensive to maintain full coverage of the tree. Full conventional orchards go so far as to spray with methyl bromide, but we do NOT recommend this treatment as it is highly toxic and not getting to the root of the problem.

Experiment with different varieties of plums! Plums tend to be very capricious- flourishing in one micro-climate and suffering in another- even when they are fairly close by. Talk with local growers and gardeners to find out what varieties do well for them try them on different areas of your property.

There’s nothing like a the deep flavor and juicy goodness of a plum in the summer, so we will continue to experiment and learn so that we can grow them successfully in our orchard. Please let us know if you are growing plums and what varieties are doing well for you!

Sources. 

Bacterial canker.  2009. http://www.which.co.uk/documents/pdf/bacterial-canker-151467.pdf (June 11, 2012)

Eastwell,  Kenneth C. et. al. 2005. Field Guide to Sweet Cherry Diseases in Washington. Washington State University Extension. http://cru.cahe.wsu.edu/CEPublications/eb1323e/eb1323e.pdf (June 11, 2012)

Kennelly, Megan et. al. 2007. Psudomonas syringae Diseases of Fruit Trees. Plant Disease.  http://www.agroquimicosgaspar.com.ar/wp-content/uploads/2011/12/Pseudomonas-en-frutales.pdf (May 31, 2012)

UC Management Guidelines for Bacterial Canker on Plum, 2009. University of California Davis. http://www.ipm.ucdavis.edu/PMG/r611100111.html (June 11, 2012)

prepared by Sarah Claassen (staffmember, apprentice, and friend) 2012

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Wood chips and pruning debris

Having used a chipper in the past, I have since retired it. Here’s why:

I don’t need it. Orcharding like many other endeavors, requires a  cost-benefit analyses.

 1.The unit we could afford, for one, took an awfully long time to run material through (along with all the stink and exhaust we breathed). Sure, running softwood boughs through is a joy, but try apple or poplar with all those funky angles. I love long hours with outdoor tasks, this I would not number among them.

2. This one isn’t for everyone, but central to our mission: Environmental impact. Yes, it takes longer to trim things down by hand or remove them (ie prunings), but we find it is worth it. Trying hard to model our system on nature, we let natural decomposition run its course. There is also a disturbing trend I am noticing, even in thoughtfully managed landscapes and farms- the need to rush things to decomposition. The earth has a system for breaking things down, yes even big things. How many hundred foot ginko and monkey puzzle trees do you see lying in a pile? So do we really have to worry about a branch half an inch thick? It is also important to have different levels of matter out there to decay at different times. This way if you cannot add material each year with your regime, different caliper wood will become available to microbes in different years as they take different amounts of time fully decay. Also, different physical specimens attract different creatures, from fungi to ants. Additionally, nitrogen will not be tied up as dramatically at a given time since decomposition is spread out, which will reduce need for supplemental nitrogen additions.  Diseased tissue needs to be dealt with, but there are other ways. This leads to the next point:

3. Although not necessarily the case with many commercial operations, chipping, like lawn mowing and sidewalk edging is really about tidiness. I have used chipped mulch and alternatively coarse brush on berries, and man does the chipping look nice. There is nothing wrong with this distinctly human reaction, and we still have a bit of it here, but most of us can get around this tool if we want to.

4. Another engine equals another expenditure, routine maintenance, and emotional stamina (when it doesn’t start). Add fuel and oil and health and safety issues. And oh are they loud.

So what do we do? When we prune, all wood larger than an inch gets cut and stacked for the wood stove. Smaller dimensions get pulled into windrows some distance from same species live trees. This often winds up as kindling, but this pile a few years later will be a beautiful crumbly mass. Much of the smaller stuff is actually trimmed and dropped in the dripline while contemplating the next pruning cut. What Todd?! You have time for that?! To answer, the day I do not is the day I have too many trees to take care of in a wholesome manner. Again, this is my deal, and will only make sense to those who have a kinship with such silly ideas. And I enjoy doing it this way. When this is completed, I apply wood ash, and other debris including hay, bramble prunings, you name it to try and smother any erupting pathogen spores and the like. It also keeps the wood moist to improve decomposition. This last point will attract more folks to this method, you can dress up the area by covering the rats nest with a tidy carpet of hay or leaves. (We reserve the nicer piles for the nursery area ). We have a thousand or so trees, and as many bushes of various ages and so far, so good.

So, not the answer, but an answer for those who think in that direction.

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Pruning Cherry Trees

Cherries are a bit different from some other fruit tree species as regards the method of pruning. To understand why, we need to understand how they grow. Cherries have a habit of producing a large length of unproductive (vegetative) area along the branch. When the tree grows…(more to come)..

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Hardy Cherries

After you are done sulking that you can’t grow a sweet cherry in your frigid and inhospitable locale, take solice in the fact that you can grow one heck of a cherry pie. Those wonderful confections aren’t the product of bog oxeye cherries of Bing and the like. No, they are the oft neglected and unfortunatley named sour cherries. Prunus cerasus is perhaps a bit tart right off the tree for the modern palate (not mine mind you), but boy can it hold its own between a flakey crust. The growth and culture are nearly the same as the sweet cherry, but easier to grow and self pollinating. What really seperates the two, though is their attitude toward the cold weather. More to come…

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Pear Blister Mite

Phytoptus pyri    In a nutshell, it is a mite, and it causes blisters. These cause blisters not to humans (unlike the common blister beetles which do) but to the foliage. Damage can include both leaves, especially younger growth, but also the fruit itself. Introduced from Europe, this tiny arachnid often moves about undetected due simply to its size. Damage will often occur before any of the actual creatures are observed. More to come…

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Pears and Fireblight

erwinia amylovora on pear (image : Ninjatacoshell)

No demon could ever conjure up a worse fate for the pear grower than that manifested in the fireblight bacterium. Erwinia amylovora. It nearly sounds like the latin words a midieval priest might give such a sordid beast.

Fireblight can affect a host of species, including amelanchiers, hawthorns, apples, but pears so often seem the worst molested. There is no cure for the infected area once it is attacked, the protocol is to cut off or cut out the infection  and then some. It is a more successful strategy to keep it from occurring in the first place. Following are several strategies to lessen your chances of encountering this unwanted visitor. More to come…