Blackberries


Experts have long warned that weeds may compete with cultivated crops for nutrients and water.

But now research by a team from Washington State University and the United Kingdom has found that weeds may reduce the amount of plant-based nutrients in raspberries, according to a news release.

WSU weed scientist Tim Miller worked with fruit researchers in the United Kingdom last summer on a series of trials that examined weeds and herbicides and their relationship to plant-based or phytonutrients.

The UK team had already developed a method to measure the amount of several compounds in raspberries and black currants, two fruits that have been dubbed superfruits because of large amounts of antioxidants.

The 2012 trial in Scotland linked some hard-to-control weeds, such as broadleaf dock, fireweed and quackgrass, to reduced sugar, vitamin C, color and juice content in the berries.

Tim MillerCourtesy Washington State UniversityWashington State University weed scientist Tim Miller will travel to Scotland to work with colleagues on trial gauging the affect of weeds on raspberry and black currant nutritional content.

And the trials will be repeated this year to determine whether environmental responses during 2012 may have affected the outcome or whether the quality factors respond the same two years in a row.

“A better understanding of the potential effects of management decisions will give growers one more tool to improve not only the yield of their fruit, but also the quality of those fruits for consumers,” Miller said in the release.

 

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Blackberrries come in 3 forms.  Trailing, semi-trailing and bush.  Trailing can develop canes as long as 15 feet and require specialized trellising.  The semi-trailing are about 6-8’ and can be grown on a post or a trellis.  The thornless bush types do not require any support although a side wire may be helpful to hold canes upright when they have a full fruit load. There are many bramble crosses which are often listed as blackberries such as boysenberry, loganberry and tayberry and we are not covering those here.

Central New Mexico is at the top end of cold hardiness for the bush blackberries and they may benefit from covering the canes over the winter with straw or mulch in the colder areas.   Blackberries with the exception of the newly released Prime Jim, Prime Jan and Prime Ark series produce fruit on second year canes.  We have trialed Apache, Navajo and Ouchita, all thornless bush varieties from The University of Arkansas breeding program.  (the leader when it comes to blackberry releases and research). 

All three varieties withstood our record cold February 2010.   Navajo showed the most cane damage and plant loss over the last two winters, therefore we are recommending it for Albuquerque, Los Lunas, Belen and like areas only.  Navajo is the earliest to fruit and this may be linked to its relative lack of vigor in our climate.  Apache is next to produce starting harvest this year July 20.  Apache has also impressed with it’s general vigor over some others types.  Ouchita seems to grow a slightly smaller bush (36-48”) and its production starts in early August.  The health and vigor seem to match Apache along with flavor.  Berry size is comparable in both, so for a continuation of the season plant both varieties.  Production starts the second year after planting and increases as bush size increases and more canes develop.  Both varieties will sucker to fill in the row but at a much slower rate than raspberries.

This is our first year growing Triple Crown, a semi-trailing variety.  So far it has exceeded expectations and seems to be living up to the hype.  It is reputed to grow up to 30 lbs on a single plant and while that is hard to believe, I would be more than happy with 10 – 15 lbs!  So far some of the new canes have reached the 4-5’ range by the end of July.  These will be next year’s producers. Currently all have fruit that looks to start ripening about the first week of August.  For small plants and expecting no fruit this year they seem very productive.  With these they should be trellised. Grow 5-6 canes in a vertical fan formation and plant 4-6’ apart.  After fruiting these canes should be removed.  When the current year’s canes hit the top wire placed at 5 or 6 feet off the ground, snip them off.  They will then develop lateral branches which can be tied to the top wire.  These laterals will dramatically increase your fruit production.

A difference between raspberries and blackberries is when picked ripe, raspberries pull free from the core. Blackberries start out red and then change to a purple and then rapidly to a glossy black.  At this point when they turn black is when most people pick them.  Don’t, if you do you will get a berry similar to the grocery store product, beautiful and black but somewhat tart.  Allow the sugars to develop by leaving another few days to a week.  When the glossy black just starts to dull a little is the optimum time.  The sugars will have developed to give an unbelievable sweet flavor, rich and full. A few days and you have a totally different animal, so to speak. At this point I defy anyone to bring back to the house half of what you have picked because you will be eating them as fast as you can gather them.

As we start our third growing season at Road’s End Farm it is time to write about some of our observations and results with the many types of fruiting plants that we grow.  As you know our mission is to develop and promote varieties that are suited to culture in the central New Mexico mountains and similar locales.  We want you to be successful by helping you choose varieties that will profitably produce for you.  Our method is simple in that we take our best educated guess from years of growing, listening to others experiences and add some of the latest varieties to the mix.  We then grow these and see which do best or in some cases do poorly.

Of course results may vary depending on the care, location, microclimate etc. that you give a certain plant.  In those cases we will make recommendations for location and culture.  Our plantings are not babied as you might do at home. They are planted in the field with no shade and treated as a commercial crop would be.  In many cases the planting stock we have purchased has been very small, maybe suitable for a 4” container or was a 4-6” bare root plant.  Such is the way of dealing with new or rare varieties, they just may not be available in a size we would prefer.  Often is the time we felt a larger plant would have survived or thrived whereas the smaller one could not adapt. We will discuss these possibilities as we go through our series of posts.

For those of you more detail oriented, the soil ph at our farm is 8.2 which is considered very alkaline.  Our water comes from fractured limestone and also has a high ph and is very “hard”.  February 2010 recorded minus 34f and summer 2011 recorded a high of 102f.   Most research on “hardiness” of plants is focused on the coldest temperature they can live with and very little research has been done on the warmest temperature they can take.  When we make selections to trial we find ourselves choosing from varieties that may do well in the upper great plains or in Russia’s colder areas. In the case of heat we will discuss it when it applies.  I hope to be able to cover at least 1 fruit type a week in an informal and unscientific manner, but this time of year is always short on “spare writing” time so don’t hold me to it.

On a recent trip to Lowes early in the month, I was confronted by a large display of berry plants strategically situated in the main aisle.  As a former retailer I was extremely impressed.  To say the least, the packaging cups were unique and a new ”invention”.  I was drawn to the

Raspberry cups

graphics which had top notch clarity with vibrant colors.  The shipping boxes were designed to convert to a point of purchase  display.  The product (plants)were tissue cultured and consistent sized.  All in all this product kit and its components were first rate.  I’m sure thousands of hours of design, testing and prototyping went into it and I wouldn’t be surprised if it wins a “Product of the Year” award.

However as a grower and nursery owner, I was extremely dismayed to see this.  Not from a competition point of view but from the knowledge that probably every one of these plants will soon be dead.  The customer will have lost their money, but worse,  will be left with a bad taste in their mouth about growing and supplying their own food. 

Raspberry display

Often in the retail nursery world but especially in the big box arena,  it’s a race to see who can get the first sales of the year.  It’s all about product turns and dollars generated per square foot of selling space.  I receive copies of the trade journals for the Nursery industry and it is estimated that 25% of the vegetable plants and flowers purchased in the spring season will be repurchased since they were planted too soon and lost. 

Mind you I am not against the quality of these plants or their appearance.  My complaint is they are being promoted to an unsuspecting consumer to plant out now.  It is fully 2 months too early for these to be planted outdoors in Albuquerque and 3 months too early for the East Mountains.  To have a chance they would need to be babied indoors and repotted into a larger container. When the weather gets warm enough, they would need to be hardened off for at least a week.  This entails taking them outside on warm days, keeping in the shade, gradually exposing them to longer periods of direct sun and bringing them back in a night.  I notice that Lowes was keeping them indoors, not in the outer garden section.

A plant such as a raspberry can take -10 degree temperatures when fully dormant. However, it is most susceptible to damage or death from freezing when it just budding out new leaves.  These tiny, young plants are not near as tough as an older established plant (which is also susceptible to frosts).  At this point it can suffer damage at just a little below freezing and probable death at 25-29 degrees.  What are the chances we will see these temperatures before spring or the frost free season beginning?  I am not a real gambling man but I would wager about 100%.  Or to say it another way,  if you buy these plants and plant them out they will die! 

This is not the same as planting out bareroot stock which is still dormant.  We do not use greenhouses or force our plants in any way. They are grown here and come out on their own when Mother Nature tells them it is OK.  I know its tempting to want to get some green going after a bleak winter, but your patience will pay off in live plants that perform for you and in a monetary savings also, if you wait until the appropriate time.

The last few Saturdays have been exceptionally warm and gave us a chance to do a little catch up work.  Amazing the things you need to get done in the fall but never quite get to.

For us one of those things is adding compost to our berry rows. 

Dormant Raspberries

In theory the compost  can sit all winter and the melting snows will carry the nutrients down to the roots where they need them for the new spring growth.  Let’s hope we haven’t missed out on all the snow for this year!   February is a good time for cutting down Primocane, also known as fall-bearing or everbearing raspberries.  This is easy since you cut all the canes down, unlike summer bearing where you only cut the 2 year old wood.  I like to leave about 2” above ground as I feel the sun will rapidly callous off the cut and prevent any possible infections at the site. 

Raspberries after cutting canes

This is just my feelings, no proven fact.  It was surprising to see just how green they were this year when cutting.  It makes you think the warm weather is working on them.  Cutting all of the canes makes it simple to add compost.  We are trying to put on a one inch layer in about a foot  wide band. 

Adding compost after cutting canes on raspberries

I would like to go about 18-24” wide but good compost is always in short supply.  Probably the reason gardeners call it “Black Gold”.  The batch we used was 2 years in the making and we used about 6 large wheelbarrow loads per 100 foot of row length

 Last week Matt and I took a short road trip to Alcalde, NM. to attend a workshop on Jujubes.  A tiny hamlet on the road to Taos, just north east of Espanola, it is home to maybe 100 families.  It is also home to the NMSU Sustainable Agriculture Science Center.  At this location some research has been done into different fruit varieties in an organic growing situation.  Mostly this has been trials with blackberry and raspberry in 2003 thru 2006.  After that several varieties of Jujube were planted and monitored. One of the interesting things is that even though the location is 90 miles north of us the weather and temperature parameters are almost identical to our location.

The fruit production there is now under the care of Dr. Shengrui Yao. She received a M.S. in Horticulture/Pomology from Beijing Agricultural University and her Ph.D. in Horticulture/Pomology from Cornell University.  She hosted this workshop and tasting event for about 40 growers, gardeners and other government agency employees.  Shengrui is the perfect person to teach about this rare and unusual fruit from China.  She has the unique perspective of having been raised with a fruit that many in the western world have never even heard of, much less tasted.

 

Even with most picked this jujube tree's branches are bending under the fruit load

The Science Center has an orchard of about 40 trees of maybe 10 varieties that are 6 years old. They have just planted 100 young trees, 25 each of 4 varieties. She is trying to get grant money to fund research for these as a commercial crop for New Mexico and seems to be the only person at any university or research facility in the U.S. that is studying them.   There are about 700 cultivars in China today, however there are maybe only 40 in the United States.  With relations and import rules being what they are it is unlikely that we will be seeing new cultivars anytime soon.  The good news is that many of the varieties here are every bit as good as any of the commercial crops in China, so we may not really need any new types.  Another interesting note is there are no developed hybrids of Jujube, all named varieties are cultural selections. 

Our main purpose for going to the workshop was the tasting session.  Not only did we hope to try some varieties we don’t have, but also to test them in different stages of development to see where

Jujube in various stages of ripening, the side facing the sun turns mahogany colored first

is the ultimate ripeness for fresh eating.  More about that later.  The jujube is not really broken into classes and there are many ways it could be.  For example some varieties are good only for fresh eating, some only for dried and some work for both.  Another way is the fruit shape.  There are elongated, oval, round, gourd, teapot and apple shapes. However I think the best way to classify them might be by maturity: early, mid and late season varieties.  Some of the late season varieties require a longer growing season to mature than we can provide in the mountains.  Albuquerque or further south like Los Lunas would be fine for them though.

Even though jujubes have been cultivated in China for more than 4,000 years their use on the mainland is changing. In 1990 almost 90 % of the jujubes were sold as dried fruit. That has changed to 60% dried, 30% fresh and 10% processed.  This may be in response to the cultural changes that have happened in China more than the fruit’s development.  As China gains a middle class more people have refrigeration and so don’t require a dried product for storage and also more have a disposable income to buy a processed product.

For our purposes here inNew Mexico the benefits to growing the Jujube are many.  I won’t say that they thrive on neglect, but they are hardier than many fruit trees.  Once established they are very drought tolerant.  The bright glossy leaves are like citrus in that they hold in moisture and seem to have a shiny, waxy coating. 

Jujube trees have light branching. This one has good horizontal branches

They like our alkaline soil which most fruits do not.  The amount of heat they can tolerate seems to have no upper limit.  We know they are cold tolerant to -25f and just have not been really tested past that point although I suspect they can live way below it once established.  Most varieties are self fertile but will set a larger crop if you have two and that is what we are recommending at this point. They flower very late and avoid any freezes so you always get a crop. No known New Mexico pests or diseases.  Minimal to no pruning required.  This is about all you could hope for in a fruit tree!

As for taste: most have a sweet apple-like flavor and texture with a hint of almond aftertaste.  The fruit is not quite as juicy as an apple and of course if dried it is different altogether.  It is also called the Chinese Date because of the size and appearance when dried, however they are not quite as sweet or  gooey and sticky as palm dates.

I think if the United States got behind this as a commercial crop, our plant breeders could improve jujubes the way the crabapple was changed to modern grocery store apples.  In 30-50 years we could see a new fruit crop completely.  After all the blueberry got it’s start that way after WWII and now is a major crop and staple item in our diet.

See The Upcoming Part 2 for Tasting and Variety pictures.

Iron Chlorosis is the most common micro-nutrient problem of fruits in New Mexico.  It is the result of the inability to extract sufficient iron from the soil, but not usually caused from a deficiency of iron.  New Mexico soils generally have plenty of iron especially in the red soil or red rock areas.  Iron is required to produce chlorophyll which in turn is what feeds the plant and promotes growth.  It appears as a yellowing of the leaf tissue between the veins.  In severe cases it will cause the leaves to turn a very pale yellow and possibly even white if it is past “severe”.  At first glance it can resemble a nitrogen deficiency but is distinguished in 2 ways.  With iron chlorosis the veins of the leaf will remain green. Nitrogen deficiency will turn all of the leaf yellow.  Also iron chlorosis starts with new leaves and nitrogen deficiencies first appear on the older leaves.

 The underlying cause is a high soil ph, which is what most New Mexico soils have.  Different plants and varieties within a species have different levels of tolerance.  Fruit crops are among the most sensitive plants to this problem.  In our experience the most susceptible types in order are: strawberries, blackberries, grapes, raspberries and apples.  Mild cases will result in poor growth, poor runner or new cane/branch production and poor quality and flavor fruit. Severe cases will result in plant death.

 As the soil ph increases the solubility of many nutrients is reduced. As a result these nutrients are precipitated as solid materials that plants cannot use.  For example the solubility of iron is 100ppm at a ph of 4, but drops to only.01ppm at a ph of 6.  At ph levels above 7.5, the amount of iron is often too low to sustain healthy plant growth.  While generally we have more iron in our soil than needed it may be in an unavailable form due to high ph.

 Plants differ in their ability to tolerate high ph soils.  In moderately alkaline soils, some plants can secrete high amounts of acids into the soil.  This lowers the ph immediately around the roots and increases nutrient availability. As the soils ph increases to 7.8 even these plants experience nutrient deficiencies. 

 There are many contributing factors that can bring on iron chlorosis and the interactions of these factors are not fully understood.  Plant competition, winter injury, soil compaction, excessive soil salt levels, excessive organic material, extreme soil temperature and light intensity and over watering can all lead to or aggravate a chlorotic situation. One common cause is the incorrect application of N-P-K chemical fertilizers

  How to Prevent Iron Chlorosis –

 Start with testing a good soil test. If you don’t know your starting point you won’t know how to get to where you need to be.  Check the soil ph and also the ph of the water you will be using to irrigate with. If you are in the 7 – 7.5 range you probably will not have any issues. If above 7.5 do the following. 

  • · Start your bed 1 year ahead of when you will plant it
  • · Use vegetative compost, no animal manures as these increase the soils salts levels and can aggravate the situation.  Try to achieve about 5% organic matter. Stable compost and the associated biological activity have a buffering affect on the ph.  
  • ·Flood the bed several times to leach accumulated salts below the root line.
  • ·If your soil does not have free lime add elemental sulfur.  A simple way to test is to take a teaspoon of the soil and dampen with vinegar.  If the soil fizzes you have too much lime for the sulfur to be effective. The bacterial action on the sulfur produces sulfuric acid which lowers the ph.  Sulfur will take around 6 months to start to become effective.
  • ·Add peat moss to your bed and mix in thoroughly.  Peat moss has a very low ph and will help bring it down in your soil.
  • ·Choose varieties that are known to be less sensitive.  In strawberries we have seen Sparkle a June bearer and Albion an ever bearer to be very susceptible to chlorosis.  Honeoye as June bearer and Seascape as an ever bearer are much less susceptible and better choices for New Mexico.

How to Deal with Iron Chlorosis if it Shows Up –

 The vast majority of the cases are brought on by over watering! It gets 90 degrees and our plants wilt (which is normal) but we assume they need more water.  We keep adding even more water as the situation gets worse and create a vicious cycle.  At the first sign of chlorosis decreasing the water will usually bring on a cure. The additional water also leaches away the acid environment the roots had developed immediately around them and now they cannot uptake iron. 

  • ·Add liquid elemental sulfur, this will work faster than the granulated as it will immediately get to the root zone where bacteria can use it.
  • ·Add a chelated iron.  This is a form of iron that will stay available longer than iron sulphate.  This may give some immediate results usually within 5-10 days.  If soil is above 7.5ph this may not be effective. Then you will have to use a form chelated with EDDHMA or EDDHA instead of the normal EDTA chelate.
  • ·If the situation is desperate use the iron chelate as a foliar spray.  This is the least recommended as it will take several applications and is a fine line between using enough to be effective and too much that will burn.  Chelated sprays are inactivated by sunlight so application is late in the day or at dusk.

 Again the benefits of a professional soil test cannot be overstated if you are serious about growing good fruits.  NMSU and many private labs offer this service for a reasonable charge.  If you want names or recommendations for labs, email or call us.

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