ALASKA PIONEER FRUIT GROWERS NEWSLETTER Spring 2013 http://www.apfga.org Volume 27, Number 1

President: Kevin Irvin, president@apfga.org Vice President: Mark Weaver, weavrm@yahoo.com

Secretary: Dan Elliott, dmelliott@mtaonline.net Treasurer: Debbie Hinchey, Debbie Hinchey, dhinchey@alaska.com

Board Members at Large: Doug Ott, driftedn@mtaonline.net Fred Deiser, fdeiser@mtaonline.net

Newsletter Editor: Tami Schlies, editor@apfga.org

Membership information and dues payments contact Debbie Hinchey

Association News Congratulations to our 2013 board members.

President Kevin Irvin

Vice President Mark Weaver

Secretary Dan Elliott Treasurer

Debbie Hinchey

Directors: Fred Deiser Doug Ott

Tami Schlies, Newsletter Editor

NEXT GATHERING Pruning workshop at Bob Boyer’s greenhouse

Saturday, March 23, at 1:00pm

649 E 81st Ave. Anchorage AK.

Near Midas Muffler on corner of 81st and Old Seward approx. 2 blocks north of Dimond Blvd turn West onto 81st Ave. Just before dead end on right is Bob Boyer’s Greenhouse.

April Saturday, April 13, at 1:00pm Annual grafting workshop. The workshop is open to the public and is located at: Dimond Greenhouses, 1050 W. Dimond Blvd. Anchorage, AK

May Saturday, May 11, at 1:00pm Top working demonstration on members’ trees. Directions will be sent to members.

June Saturday, June 1, at 1:00pm Tour of David Ballard’s and then Peter Raiskum's Orchards in East Anchorage - Cherry and Apple trees on dwarf and semi-dwarf rootstock. - Solar heated soil garden - Small winery Directions will be sent to members.

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Membership Loss... Our deepest sympathies go out to the families of Clair Lammers and Alice Brewer, life time members and true Pioneers of fruit growing in Alaska.

Clair passed away on December 24, 2012 and Alice on December 30, 2012. They both will be greatly missed.

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President’s Message By Kevin Irvin

Spring certainly seems to be coming early this year to South Central Alaska. Hopefully this means we will have a warm and sunny summer for growing fruit! Now is the time to think about collecting scion wood for our upcoming grafting workshop that will be held on April 13th at Dimond Greenhouses in south Anchorage at 1 pm. We always need a good selection of scion wood. Please make sure you label and keep wrapped in damp paper towel or newspaper. The best scion wood (for those who are unsure) is last year’s vegetative growth also called new wood. Old wood doesn’t work as well and usually has blossom buds which takes some time to produce vegetative buds to produce a new tree. Old wood will work if you have that special tree you want to propagate it just takes longer the first year to get a whip growing into the new tree. Vegetative buds are more rounded at the tip whereas blossom buds are more pointed. The State of Alaska Division of Agriculture has rekindled a Horticulture program at the Plant Materials Center in Palmer. Horticulture has been absent for many years at the PMC. Now is a good time to contact them and express your wishes for fruit trials. As of now they aren’t exactly sure what the Horticulture program will entail as they are in

the planning stage. The more people to express their wishes in fruits would be beneficial to getting a fruit program started. Their website is www.plants.alaska.gov Also remember our website www.APFGA.org we are looking into advancing our website to include a forum where we can ask questions and gain answers to those questions or simply report your success in growing fruit and making it more interactive between our members. There is no time line to when this will happen but is a goal of mine to get this up and running in 2013. Any ideas or suggestions are welcomed. I will keep you posted how we progress on this.

Reminder; all formal business meetings of the Assn. are suspended from March through September for workshops and tours. Looking for a volunteer to show off their orchard and garden for July. Please volunteer your orchard for a tour. You can email me at president@APFGA.org you can always email me with your wants, ideas or questions and topics for future meetings. Enjoy the fruits of your labor.

Kevin Irvin

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The Importance of Chilling Hours Reprinted with permission from www.GrandpasOrchard.com

Flower buds require sufficient chilling hours during the winter to break

dormancy and bloom in the spring.

Chilling hours is a complex and confusing issue. Because so many customers have asked about chilling hours, Grandpa has compiled some charts from the best sources that he has to help customers concerned about chilling hours. Many varieties have not been researched sufficiently as to their specific chilling hour requirements. Where Grandpa lives in the “banana belt” of Southwest Michigan, accumulating sufficient chilling hours never has seemed to be a problem, so Grandpa has never been too concerned, but too many questions have come his way, and here is his spin on the subject.

Unless you live in a region where it is VERY WARM all year around, such as Southern California, Florida, the Desert Southwest, or the Gulf Coast regions, you likely get enough chilling

hours in most years for many varieties to properly break dormancy and bloom.

Enough chilling hours are required during the dormant season to satisfy the plants need for dormancy. Insufficient chilling hours may delay bloom or even the breaking of dormancy and growth of the tree in the spring. Chilling hours are typically calculated at an optimum temperature of 40 degrees F. Temperatures over 50 degrees F mean NO chilling hours are accumulated as the tree is attempting to break dormancy and may be losing

some of its cold hardiness at that time. Also, if the temperature is under 32 degrees F NO chilling hours are accumulated because the plant is fully dormant with no cellular activity.

The total number of hours during the winter that the plant accumulates hours in that 32-50 degree range will determine whether it has accumulated enough chilling hours. Because accumulated chilling is such a variable thing, the requirements are not hard firm numbers, but rather soft areas and ranges.

Chilling Hours Map

Micro-climates and regional variations will also affect chilling hours, as well as hardiness zone issues. For the most part it is more important to make sure that you have selected varieties that are sufficiently hardy for your zone. Higher altitudes and elevations often are colder and will accumulate more chilling hours than lower elevations, such as valleys or sunny slopes, and their hardiness zone may differ slightly also.

Even so, many varieties vary in their response to chilling hours and there seems to be little pattern. Therefore, Grandpa takes them with a "grain of salt!" Unless you are in a region with very low chilling hours, you should not get too worried about this issue. This is typically around Zone 9.

Hardiness zones and chilling hours also seem to show little relationship. This is likely due to the genes that control winter hardiness and cold tolerance not being the same or linked to the genes.

that control when a plant will come out of dormancy and bloom (chilling hour requirement). In regards to chilling hours and hardiness, Grandpa foresees only two possible problems:

1. If you grow a LOW-chill hour variety in a high-chill hour climate, your variety will reach its chilling hour requirement early during the dormant season, and thus if an untimely warm spell comes along (example “January Thaw”) or if spring comes excessively early (like last year!) then that variety may be likely to break dormancy too early. Once dormancy is broken, frost and cold tolerance decreases and so the chance for losing some of the crop is much higher.

2. If you grow a HIGH-chill hour variety in a low-chill hour zone where the variety may not accumulate sufficient chilling hours each year, you may likely see difficulties some

years in the tree breaking dormancy or blossoming.

For the most part, if you live in or near an area that has 600 or more chilling hours, you will likely be able to grow almost all varieties that we offer. If you live in a zone with less than 400-600 hours of chilling in a typical year, then you may want to examine varieties that are in the lower chilling hour requirement range. It helps to also talk with experienced gardeners and/or orchardists in your area and find out which varieties do best for them. Local experience is a very good guide. Use the attached chilling hour map as a helpful reference, but don't assume that it is hard, cold fact. Ranges vary greatly within regions based on your own micro-climate and can vary greatly from one season to the next.

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Ranetka is a Ranetka is a . . . ? (Some Inconvenient Observations about Apple Rootstocks)

By Mark Weaver — December 2012 In the last 20 years, productive apple trees and productive home orchards have proliferated in Southcentral Alaska to an extent once thought impossible. In large measure, this has happened because of the willingness of a few Alaskan and Canadian growers—real pioneers in the pomological wilderness — to share their hard-earned apple experiences, and often as not, their scion wood. Perhaps the most significant pearl of wisdom passed on by these pioneer orchardists has been the importance of using “ranetka” rootstock — the ranetka having proven itself in the far north as vastly superior to antonovka, and to many other supposedly hardy rootstock apples, most of which fail to survive our cold summer soils and sub-zero winter frosts. The beneficial impact of ranetka rootstock on Southcentral apple growing can hardly be overstated. It has acted as a catalyst, almost single-handedly enabling the production of hundreds of viable bench grafts each year at the APFGA spring

grafting workshop, and a remarkable increase in the trees and cultivars represented at our autumn apple-tasting event. At the same time, because of the relative success of northern growers using ranetka, there is a corresponding risk that we will become complacent in our thinking about rootstocks. I, at least, have been guilty of subscribing to a convenient myth — a myth so easily conceived and so compelling that it may have attracted the allegiance of others also. By way of warning (the faint of heart should stop reading here!), I choose to call this “The Ranetka Myth.”

The Ranetka Myth goes like this: Malus ranetka is a species of crabapple having M. baccata as one parent and M. prunifolia, or possibly Dolgo, as the other. It is hardy, it is vigorous, it is almost perfectly reliable as the rootstock of choice for Alaskan conditions, and it is conveniently available in seedling form, at low prices, from various nurseries in the lower 48 and from APFGA at the

April grafting workshop. Use ranetka, and your orchard will prosper!” I will move on to a key point of this article, which I call:

Heresy #1: Believing in the Ranetka Myth is a bit like believing in the Tooth Fairy. Or, to be more botanical, like believing that all brown mushrooms are edible. Why? Because the Ranetka Myth is dangerously overstated. It defies common sense and several well-established genetic, taxonomic, and economic principles. It ignores, or misinterprets, a considerable body of local experience. And, most significantly, it is potentially lethal — at least to apple trees. Let me add some related points, each of them troublesome: Heresy #2: As far as I can tell, none of the rootstock imported by APFGA and others in recent years is M. ranetka, or even M. x ranetka. Careful scrutiny of Westwood’s Temperate Zone Pomology (3rd ed.,

Timber Press, Portland, 1993) suggests there is no such species as M. ranetka. But if, by ranetka, we simply mean crosses of M. baccata x M. prunifolia, or possibly M. baccata x Dolgo, the rootstocks that we have been calling “ranetka” in recent years are not those either! Most likely, they are seedlings of open-pollinated crabs that may themselves be seedlings of open-pollinated M. baccata. Or they are seedlings of open-pollinated seedlings of open-pollinated seedlings of open-pollinated M. baccata ... etc., etc. Heresy #3: It is a mistake to give any domestic, seedling-propagated population of apple rootstocks a formal name, other than seedling #1, seedling #2, seedling #3, and so on. A formal name implies uniformity of characteristics like hardiness and onset of dormancy, and uniformity in apple seedlings (except in some wild populations) is a perilous illusion. Apple seedlings are inherently diverse.

Cloned Ranetka: More Alike Than Peas in a Pod. Not So Ranetka Seedlings!

One year old cloned “ranetka” whips photographed in early September. The color of the plastic marker in each pot identifies a clone group. It is easy to see that siblings cloned from a single ranetka seedling are look-alikes that can be visually distinguished from the clones of

a different ranetka seedling. Winter tests show that differences between seedling ranetka are more than cosmetic.

Hardiness, like vigor and branching habit, is genetically determined and highly variable in a seedling population.

As apple-growing readers doubtless realize, apples which are full siblings can be quite different in key characteristics. Norland and Parkland, for example, are full siblings--they are both Rescue x Melba

crosses. Yet they differ in tree structure, taste, appearance, and other traits, including hardiness. Seedlings derived from trees that are open-pollinated, and that flowered in places where many

cultivars — and species! — of apple are potential pollen donors, are likely to be even more diverse.

Heresy #4: The imported “ranetka” seedlings many of us have been using for rootstock are, not just theoretically but in fact, genetically and phenotypically diverse. They are variable in a number of observable traits, including leaf color, vigor, tree form, onset of dormancy, and most significantly, winter-hardiness. Moreover, a significant percentage of them are not hardy enough to withstand a Southcentral Alaska test winter — a winter with precipitous drops in temperature and little or no snow cover.

For emphasis, I will present the last statement in the form of a prediction:

Heresy #5: If we get a Southcentral Alaska test winter in the foreseeable future, there will be, come spring, an unfortunately large number of dead apple trees. Many will fail because of “ranetka” rootstock. Trees grafted on to the APFGA “ranetka” class of 2010 and 2011 will be particularly vulnerable, but some from earlier years will also die — if they are not already dead. One more point, before I offer support for these pomological heresies (or am besieged by emails from angry apple-grafters): I sincerely hope I am wrong. Or, if not wrong, I hope that global warming will mean no test winters and thus few rootstock failures — in which case, my predictions can be laid to rest as the debunked rantings of an amateur. And I will not be offended; I will be tending my apple trees. But now, the observations that I believe support the previous points: Observation #1: “Malus ranetka” appears to be a misnomer, unless somewhere there are wild native populations of ranetka apples which have been taxonomically catalogued and named. Moreover, any seedling resulting from a cross between Malus baccata (which is a species, having a wild population with remarkably uniform characteristics and botanical descriptors that have been catalogued) and any other apple, should not be considered a species. It should be considered, like many apples, a seedling hybrid, and unless clonally propagated, it can be expected to vary substantially in both

genotype and phenotype from other siblings resulting from the same cross. Observation #2: Decades ago, Robert Garner, dean of grafting and longtime chief propagator at the East Malling Research Station in England, noted the disadvantages of seedling rootstock: “The chief disadvantages of seedlings are their propensity for variation and the impossibility of predicting the limits of this variability” (emphasis added). Garner went on to suggest that “the unpredictable variability of seedling rootstocks will probably not much longer be tolerated” (The Grafter’s Handbook , 5th ed., Cassell, London, 1988, 70, 76).

Observation #3: Many seedlings labeled “Malus ranetka” and/or “Malus x ranetka” (suggesting they were open-pollinated seedlings of a species named “Malus ranetka”) have been imported and distributed by APFGA and others from Lawyers Nursery in Montana. Two years ago, in December 2010, I telephoned Lawyers and inquired about the source and the parent material of the rootstock they had been selling as “ranetka.” I received a written reply, the complete text of which is (exact quote): “Thank you for your call. The Malus ranetka source is the Kiev region in the Ukraine. No additional information is available.” (Again, note the use of “Malus ranetka” as an apparent genus/species indicator, although as far as I can discover, no such species exists.) Observation #4: Bernie Nicolai, an Edmonton apple grower, has on more than one occasion pointed out that the term “ranetka” is a source of semantic confusion. He wrote the following in 2004 (emphasis his, quote taken from NAFEX online correspondence, Feb. 24): “[A]ccording to a friend in Siberia, ranetka is the generic term for ANY seedling that has Siberian Crab as one parent. They usually take the extreme hardiness from the Siberian Crab, and have small inedible fruit, and make great rootstocks in cold climates. The ranetka seeds Lawyers Nursery in Montana sells come from the Ukraine, and are simply Siberian x Domestic apples.”

I believe that Nikolai is correct in his assertion about what “ranetka” means, and what Lawyers sells. But I also believe he misses a key point about hardiness, which is:

Observation #5: Pomologists who study winter hardiness in apples have found that cold tolerance is genetically determined and additive. That is, in any population of apple seedlings, a majority will inherit cold hardiness traits that range between those of the two parents in a distribution curve centered on the mean (Janick, Cummins, Brown, and Hemmut, Apples; from Janick & Moore, Fruit Breeding; 1996, http://www.hort.purdue.edu/newcrop/pri/chapter.pdf, 40). Thus, a few seedlings will inherit traits that are approximately the same as one or the other parent. A very few may be hardier than the hardiest parent or less hardy than the least hardy parent. But almost all of the apple seedlings originating in Kiev — or in any other place — will be less hardy than their hardiest parent, and about half of the seedlings will be less hardy than the average of their parents. Hardiness is obviously a complex cluster of traits, more complicated than simple cold tolerance, and more difficult to measure. Nonetheless, the implication of the above genetic principle as applied to imported seedling rootstocks is staggering. Consider the following: Observation #6: Recent plant hardiness maps indicate that the Kiev region of Ukraine — the apparent source of many of our “ranetka” — is generally comparable to U.S. zone 5. If this is accurate, winters in Kiev are much like those in Iowa and southern Wisconsin. They are less severe than those in most of up-state New York and in most of the apple-growing areas of Minnesota. Obviously, many cultivars of apple (and hence, many pollen donors and many mother trees) that survive in Kiev that would not survive in Southcentral Alaska. Moreover, part of the Kiev region, less than a hundred miles south of the city of Kiev, is mapped as zone 6! Observation #7: In the mid-1980s, Catherine Wright, an experienced plant propagator at the State Plant Materials Center in Palmer, Alaska, performed apple rootstock trials. Her results are published and available on the Internet. Notable findings include these: Survival rate of “M. ranetka”: 48% (more than 40 specimens tested). Survival rate of M. baccata: 61% (more than 70 specimens tested). Most fatalities were on three-

year-old plants after the winter of 1985-86, which Wright considered a test winter. As far as I can tell, the rootstocks tested were seedlings obtained either from Lawyers Nursery or from government plant facilities in British Columbia and Washington state, but I have been unable to locate Wright to confirm this. Observation #8: (complicated but critical) Several years ago, I began to apply principles of “forward funding” to my apple rootstock supply. Instead of immediately cutting and bench-grafting onto the bare root seedling “ranetka” I obtained from APFGA each spring, I simply planted the bareroot whips in pots, let them grow outside for a summer, discarded any weak or obviously problematic plants, and wintered-over the rest by tipping the pots before freeze-up to prevent ice damage. I planned to use them for rootstock the following spring. My thinking at the time was that I would get more reliable and vigorous graft growth on ranetka that had developed well-branched root systems and proven their vigor.

What I got—quite unexpectedly—was a high rate of winter mortality. This was not due to icing, or voles, or moose. It was due to simple winter-kill, resulting from a lack of hardiness. In the spring of 2011 (the wintered-over seedling class of 2010), the survival rate was only 50% on a group of about 20 whips. (Is an exposed-pot a tough winter test? Of course. But so is a winter in which the temperature drops below zero in late October with no snow cover.) Observation No. 9: In 2011-12 (last winter), I again wintered over a “ranetka” seedling class from the previous spring (2011). In addition, I deliberately wintered-over more than 20 clonally propagated rootstock whips which I obtained by layering two 3-year-old “ranetka” (APFGA class of 2008) that had survived several winters in untended pots in a neglected part of the garden (think “well winter-tested” here). This gave me two additional groups of whips that were physiologically the same age as the new class of “ranetka” seedlings, but were genetic copies of winter-tested survivor “A” and survivor “B” of the class of 2008.

I treated the three groups identically throughout the growing season. As late fall 2011 approached, the pots of the clonally propagated whips were placed

next to the pots of the seedling whips, so that winter conditions, especially amount of snow cover, would be identical. Visually, the three groups of plants—the two groups cloned from winter-tested plants and the new seedlings—were quite similar in size and apparent vigor.

In late March of 2012—last spring—I dug the three groups out of the snow and put them into the garage to warm up. The survival rate of the 2011 “ranetka” seedlings? Exactly 15 percent. Only 3 of 20

seedlings had survived. (The group originally numbered 25. Five were discarded for poor vigor before winter even began.) The survival rate of the “ranetka” clones, from my two winter-tested plants? 100 percent. Every single clone survived. The conclusion is obvious: Not all “ranetka” are created equal. Some are significantly hardier than others, and those hardiness traits can be selected for and replicated through cloning.

Not All Ranetka Are Created Equal

Late September: Close-up of two cloned ranetka whips from Group A and two from Group B. Again, note the similarity of each plant to its clonal sibling (due to the identical

genotype); also, the contrast to the siblings from the other group in form, vigor, and now, leaf color.

Observation #10: One added point of interest with respect to the two clone groups: the members within each group appear, in branching habit and vigor, remarkably similar to each other — that is, all the “A”s look alike, and all the “B”s look alike, as one would expect because of their identical genotype. However, as can be seen in one of the accompanying photographs, when Group A ranetka are compared to Group B ranetka, differences in habit and vigor become obvious. There are also differences in the timing of seasonal adaptation. Last autumn, all the plants in Group A turned color and lost their leaves at exactly the same time. Ditto

in Group B. However, leaf fall in Group B was two weeks earlier than in Group A. This suggests that even in the winter-tested plants, there is a significant genetic difference that affects the rate at which the plants transition into dormancy. Obviously, this could have important implications for survival in an early winter.

Since this article is already long, I will not review other details nor belabor the fine points of logic that led to my opening heresies. Astute readers can analyze the observations and compare them to their own experiences and research. If observations or

logic are found wanting, readers are welcome — encouraged! — to point out errors.

Meanwhile, I will state as succinctly as possible what I (tentatively) think this all means:

Many of the seedlings we have been calling “ranetka” are not particularly hardy — and are a poor rootstock choice for Southcentral Alaska. Many of the seedlings we have been calling “ranetka” are hardy — and are a good rootstock choice for Southcentral Alaska.

Some of the seedlings we have been calling “ranetka,” especially from older importations which have been winnowed in the orchards of various apple-growing pioneers, are very, very hardy, have been tested repeatedly by harsh winters, and have for years supported strong grafts and produced good apples. We should

identify these, clone them, propagate the clones, call them something like Alaska Pioneer No.1, Alaska Pioneer No.2, etc., make them available for rootstock, and begin to minimize the use of seedling ranetka in Alaska except for experimental purposes or landscaping situations where significant winter mortality is acceptable. I am not suggesting that the value of “ranetka” to the Alaska orchardist is in any way diminished. Far from it! But it is time to refine our thinking — and our propagation techniques — and to begin the next step in our selection of Alaskan rootstock materials. Cloning individual rootstocks that are productive and have been winter-tested is a means to accomplish this. As Robert Garner pointed out years ago, seedlings are variable; it is impossible to predict the limits of this variability; and seedling rootstocks should not much longer be tolerated!

_________________________ Pest Problems:

If you have pest or disease issue this spring and summer, please take samples to the Cooperative Extension office to get them ID’d. Corlene Rose with IPM says that she can ship off samples of what we think or believe to be fireblight to get tested. Many believe we have seen it up here including Corlene, but we have no testing to definitively say it is. There is a disease that is similar but not fireblight.

*** Looking for apple wood:

Jeff Brace is looking for fruit tree wood to make traditional Latvian style cold-smoked salmon (lachs.) He uses a process passed down in his family which requires apple wood 1 inch in diameter and greater. If you have a dead or damaged fruit tree you need to prune, give Jeff a call and he’ll pick up the wood. (907)360-4726 brace@coffman.com

*** Remembering Alice and Clare:

A member of the NAFEX Apricot Interest Group as well as of the APFG, sent me back a report on the 2012 growing season in Anchorage, and also told me about the recent deaths of both Clare Lammers

and Alice Brewer. I first met Alice in 1982 and Clare, several years after that. Alice was a tremendous encouragement to me during the first 4-1/2 years of the APFG when I was president of the group. The first time I learned of the Brewers was from Lenore Hedla's book, Gardens for Alaskans, and it was Joe and Alice who gave us Latham red raspberry bushes for the yard of our newly purchased house in Anchorage in 1982. They also told me that Country Gardens in South Anchorage sold field-hardened apple trees, and it was the Wealthy and Red Duchess trees I got there that were my first apple trees to survive the Alaskan winters without injury. Seeing the 10-year-old Yellow Transparent apple trees in the Brewers' yard in 1982 as well as their North Star cherry trees convinced me that it was possible to grow fruit trees successfully in Anchorage. An even greater accomplishment was her showing that Goldcot apricot (a tree from Gurney's Nursery that she bought from me in 1988) could survive and fruit in Anchorage in a sheltered location. No doubt if I went back through my journal entries from 1982-89 I could tell you about some of the times I spent with Joe and Alice and about the one or two times I visited Clare's orchard in Fairbanks. Best wishes for the 2013 growing season, Bob Purvis

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Gluten Free Rhubarb Cream Cheese Tea Cake Reprinted with permission from You Can Eat This! 22 Gluten Free Comfort Recipes

This cake is a bit involved to assemble, but well worth the effort. The cake portion has a pastry-like texture, and the layers of fruit and cream cheese give the confection a complexity that makes it hard to stop eating. If you want to make this with regular flour, replace the sorghum, potato, tapioca, almond flours and the xanthan gum with 2 1/2 cups of all-purpose flour.For the rhubarb filling: 3 cups chopped, fresh rhubarb 1 Tablespoon water 1/4 cup sugar 1 Tablespoon cornstarch – Wet ingredients: 1 egg 2 teaspoons cider vinegar 3/4 cup milk –

Dry ingredients: 3/4 cup sorghum flour 3/4 cup potato starch 1/2 cup tapioca starch 1/2 cup almond flour 1 teaspoon xanthan gum 1 teaspoon cinnamon 3/4 cup sugar 1/2 teaspoon baking powder 1/2 teaspoon baking soda 1/8 teaspoon salt

– 3/4 cup butter – For the cream cheese filling: 3 ounces cream cheese, softened 1 egg yolk 1 Tablespoon sugar – 1/2 cup walnuts (optional)

Stirring constantly, cook the filling on stove until soft, and the cornstarch thickens - about 3 minutes. Set aside to cool.

Line the bottom of a spring form pan with parchment paper and butter the sides. Preheat oven to 350˚F. Combine the dry ingredients in a large bowl. Using a pastry blender cut in the butter until it resembles course crumbs. Reserve ½ cup of this mixture for topping. In a two cup measuring cup, mix the wet ingredients, then add to the bowl all at once. Mix only until combined. The batter will be lumpy.

Pour 1/2 to 2/3 of the batter into the prepared spring form pan. Over the top, spread the rhubarb sauce. Mix the softened cream cheese with the egg yolk and sugar, and drop over the top of the rhubarb, then sprinkle the nuts, if desired. Pour the remaining batter over the top and sprinkle with the reserved crumb topping. Place the spring form pan on a cookie sheet to prevent leaks during baking and bake for 45 to 50 minutes until the cake is set. Allow cake to cool before running a thin bladed spatula around the edge and releasing the spring form. Leave it on the spring form base to serve. This cake is wonderful warm or cool. Yield: 12 to 14 servings.