Touch of Gold

Cornell breeder's gave the working number NY04-722-N to the cross Marketmore 97FF x Boothby's Blonde F2.  I suspect that the F1 hybrid resulting from the original cross probably produced only green cucumbers since green color is dominant in cukes. The F2 seed I received resulted from the crossing of two of those F1 sibs.  So, out of this second generation seed, I saw a percentage of plants producing the recessive white trait in cucumber skin color of the Boothby's parent, a nice heirloom cuke from Maine.  We grew the F2 in 2005 as a participant farm in the Organic Seed Partnership with the understanding that we would work with the breeding material Cornell furnished to us as an "unfinished" project and finish the selection process on our farm.  The idea is that having the farmer do the selection on the basis of the particular stresses that the crop faces in the farmers field will result in a selection more adapted to the farmer's field instead of Cornell's field.  Since most modern day varieties were developed on fields of conventional agriculture with a chemical fertilizer and pest control regimen dominating the growth conditions;  the organic farm community correctly felt that if selection is done on an organically managed field then the resulting variety will be more adapted to the regimen of an organic farmer.  In addition, since the organic farmer often sells directly to the consumer; additional selection criteria include the acceptance by the farmers customers.

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Notice that the original F2 produced the long greenish fruit very suggestive of the Marketmore parent but also similar long fruit in the Boothby's shade of cream.  There were other variations that appeared in the F2 generation which was noteworthy; for example, the gynoecious trait of some plants.  These few plants produced masses of female flowers and the most fruit and a some of the unfinished selection"Touch of Gold" has this trait.  After several generations, we have selected a productive, nice tasting cuke.


Above is a selection after two years of working on the project. We were a bit premature when we showed the above slide and declared it's powdery mildew resistance.  The selection process after several more years yielded the cukes is below.   We sent to several friends to taste-test sliced fresh as well as pickled.  The fruit is a distinctive productive pickle cuke which is just so beautiful.  When the cukes develop the "gold touch" they are at their peak in flavor.  Unfortunately, although it is bears cukes through several weeks of early summer, "Touch of Gold" will succumb to powdery mildew.  We probably could have traded off some of the qualities that we like in order to maintain the PM resistance.  We could have also done an effective screening of young seedlings by spraying with the powdery mildew (select powdery milder infested plants from a friends greenhouse and blend with some water into a sprayable solution.  What seedlings survive are planted into the field.  You are still welcome to do a pm screen if you want since "Touch of Gold" is not stabilized and may still be segregating.
 

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Our Other Cucumbers:

At the farm, "Touch of Gold" is the most striking cuke but we continue to work with our "green pickle", a selection from a mass cross of kirby cukes that we planted a number of years ago.  Of all the cucumbers, "green pickle" was the favorite of the deer who plucked all but a few from the vines this year.  We highly recommend the technique of a mass cross.  First, a little history of "green pickle".  We grew about 10 varieties of kirbys that we were evaluating for a pickle cuke including heirlooms and hybrids and let them cross.  Instead of settling on one we liked, there were three or four kinds that had admirable traits (one being that they survived the summer in our unimproved sand lot without irrigation and maintained good shape).  Saving the fruit from those different kinds which had undoubtedly been crossed by pollinating insects and growing them out the next year revealed more survivors and more qualities to select for.  Selection for flavor, texture, looks (the classic pickle ratio); productivity, pest and disease resistance and vigor on our sandy soils is our mandate.  Sure, there may be lots of pickling cucumber varieties available but this one will become; in time, uniquely ours and adapted to our soils, our weather, our pests and our preferences.  Last year we planted out some forty plants of our Long Island Green Pickle Cuke and saw every single plant trashed by our marauding herd of deer who favored these above all other cukes in the garden.


The year after we did the mass kirby cross we planted a dozen commercial hybrid slicing cucumbers in a friends field.  Since some of these were only available as treated seed hybrids it was an opportunity to produce fresh clean F2 seed.  I really don't like chemically treated seed.  I know many in the agriculture community believe that treated and even encapsulated seed (in the future) is the way to go;   I just don't see the need.  I have light soils that warm up and dry out early in the season.  I rather like the fungus hyphae that mingle with the roots of my plants and give them the resiliance and vigor that I notice in my crops.  I don't particularly like absorbing fungicides from treated seed through my skin and I don't like the idea of poisoning my benificial mycorrhizae fungus along with the fungi that cause seed planted too early to rot in cold, wet ground.  Maybe I digress.

The next year we planted our slicer cross, we interplanted "sweet" asian slicers with the F2's and allowed them to cross pollinate.  We saved seed from the best performing, healthiest vines that also produced normal looking dark green slicing cucumbers.    We didn't get a chance to grow them out for the last two summers; but this year we did and we can say that we're optimistic that we have some very interesting breeding material to work with in the years ahead.    That's what a mass cross can do for you and despite what some people say about introducing hybrids into the mix, we say go right ahead and maximize your diversity.  Diversity is what the breeder wants;  here is where the desired traits will be selected from.
 


Why didn't I take a picture of the diversity of our "slicer mass cross"?  The cucumber "slicer mass cross" seed still hadn't been planted at the time of this photo since we wanted to space the cucumber varieties out in separate fields but also in time/space.  Flanders Bay Farm is in zone 7 and we have the luxtury of a long growing season so we can prevent crossing by planting many of our projects several weeks apart.  We will tag the last fruit from one patch of cukes that will be allowed to mature as a seed crop by the time another cuke patch is allowed to produce it's first fruit.  Here you can see our drip lines that we extended to the front garden which really increase what we can do with our sandy soils and have turned our interests away from selecting for drought tolerance out of necessity.

We grew the fifth generation of what was marketed as an Asian hybrid which is still the same cuke it was in year one which only goes to show you thateven though it might be marketed as a hybrid; it may not act like a hybrid or indeed actually result from a cross of dissimilar parents.  I have heard that quite a few marketed "hybrids" are really not true hybrids.  Folks expect to pay more for "hybrid" seed which may require expensive hand pollination techniques.  People also don't grow seed crops from "hybrids" so they are safe from being propagated by other seed producers unless the parentage is made known by the breeder.  There are reasons a company might want to call their product a hybrid and generally, there is no one who will bother to verify that it is or isn't.  My Asian white cucumber is probably a case in point.  The retailer assumes that the wholesaler has correctly described the cultivar as an open pollinated type (standard) or an F1 Hybrid.  It may not be a correct assumption.  The long white fruits of our Asian cuke are very attractive but the productivity and plant vigor while good, doesn't match the other cukes we grow and we will probably stop growing crops of it unless we decide to use it as a parent in a future breeding project.  We have become excited about a group of cucumbers from China that are rampant climbers and bear long, crispy and sweet warty fruit.  There are a half dozen selections that we have that show a very pretty gradation in color from green to white at the blossom end.
 

An Improved White Cucumber

With the input of other participants in the Organic Seed Partnership, Cornell breeders crossed Boothby's Blonde to Marketmore 97, a long green cucumber and the newest cucumber in the Marketmore line. Marketmore is highly praised for flavor and disease resistance.  Yes, it laughs at fungus diseases that can cause the vines of an ordinary cucumber to wither during cooler and wetter weather especially.

I received the packet marked with the breeder's working number NY04-722-N (Marketmore 97FF x Boothby's Blonde) F2.  I suspect that the F1 hybrid resulting from the original cross probably produced only green cucumbers since green color is dominant in cukes. The F2 seed I received resulted from the crossing of two of those hybrids. So, out of this second generation seed, I should see a percentage of plants producing the recessive white trait in cucumber skin color.   My job since I volunteered, was to select a perfect Boothby's Blonde. A disease resistant plant that keeps on turning out little creamy white cucumbers all season long.

One of the Cornell Crosses that we continue to work with at Flanders Bay Farm is indeed the selections we made in 2005 from NY04-722-N.  Why?  You see, this was a cross of a New England heirloom favorite, Boothby's Blonde, a handi-sized white snacking cucumber acclaimed for it's mild flavor and crunchy texture. Those that like white cucumbers for novelty and flavor appreciate the Blonde.  Fedco Seeds, a seed cooperative that is a major seller of seed to organic farmers in the northeast have sold Boothby's for many years and the stumpy white cucumber has a loyal following.  What would be better for organic farmers selling for market though might be more productivity and disease resistance.  If only those vines would keep on cranking out cukes like the disease resistant Marketmore.

A Disease Resistant Boothby's?  So far, the vines are healthy and the yield is much better than the original Boothby's Blonde that we are growing for comparison. It's always nice to be able to compare what you hope is an improvement to the original. You can see that the fruit is a bit more streamlined than the original.   It has a nice length to width ratio that picklers look for. It also has a pleasant fresh eating quality. It's black spined like the original.

The siblings of the F2 Boothby's Blonde Cross (Boothby x Marketmore 97) produce loads of mostly striped yellowish-green kirby-sized and shaped fruits and the white fruited kinds that we want. Interesting, the dominant green trait was not the uniform dark green of the Marketmore parent.  Since we're only selecting for "whites", we pick off the male blossoms and nip back the vines of these so they do not cross with the white. We'll let the bees do the crossing of the white. The fruit that result from developing females on the non-white sibs will make great salads and oh yes, we'll let some mature for seed because they do have great genes from the outstanding Marketmore 97 and the little heirloom from Maine.  The seed will also produce quite a few white fruit since they carry the recessive white genes and will cross with the white selections.

The vines in 2007, now in the third year of selection show great promise.  We still select for the traits that we like.  They are still bee pollinated and so we waited until we were certain that there were all white fruited in our patch (by watching as they produced their first fruit).  If there was just one green fruited plant then we would have had to remove the vines of the green type and also all the fruit and female flowers already growing on the white vines.  These female flowers will produce white cucumbers but they could have crossed with the green plant which we are selecting against.  New flower buds that open will only be of the pure white genotype and can then be harvested for white fruit in the future.   It is a bit of work to go through the vines, one plant at a time to make sure that they are all producing white fruit.

Most plants in 2007 produced stubby creamy yellow fruit but one plant produced a fruit which looked a bit like a white variation of Marketmore 97.  A nice looking cucumber with a the very good Boothby flavor and good disease resistance.

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The over-ripe fruit of black spined cukes such as Boothby's Blond turn orange when they are ready for seed harvest. We allow them to start to rot and ferment in a tub so that the gel around the seeds break down and we are able to wash the seeds. The good seeds are heavy and sink allowing one to float all the waste off.  If there is sill some attached gel, lay a single layer of seed on a small mesh screen and use a forceful stream of water to remove the gel.  It usually works for us.  Then let the seed dry on the screen.  When the seed breaks with a snap (does not bend), it's dry enough to store in a sealed container.

 

Other White Cucumbers

This is a modern Italian White Cucumber.  Seeds of white cucumbers were in commerce in the 1700's and probably before that.  They had names like Turkish White, Dutch White and Paris Long White.  In America solid green dark green ones were favored but in Europe especially, white cucmbers were popular especially for pickling.   The Far East also have pure white cucumbers and pale green or white grading into green kinds.

"Miniature White" is smaller than "Boothby Blonde", only 2-3 inches when at the eating stage. It's marketed by the Seed Saver's Exchange, Decorah, Iowa. It rapidly swells with seeds though and turns orange when it's mature for the seed saver only a few days later (not illustrated).

An interesting white cucumber from Korea. Bright white fruit are long and wide and are fine slicers. It is a white spine type.

White cucumbers are probably better known in Europe and Asia where they are used in cooking and pickling. We're just beginning to see some of Asian varieties appear in retail seed catalogs.   White Stallion comes an importer of asian seeds, Dimension Trade Company, Scappoose, OR.   It's a real beauty. The fruit of the one above is about 9 inches in length, comparable to an American market type. It is a vigorous climber although we use cucumber clips (to right of the fruit stem above) that snap the vine to the netting so that the weight of the fruit doesn't pull the vine down. It's also a good greenhouse variety and produces large numbers of consistently marketable fruit but also does well in ground culture.

Cucumber Breeding and Seed Saving

Cucumber Breeding

The pollination of cucumber as well as various other cucubits such as cantaloupes and watermelons are very similar.  Cucurbit plants like cukes are typically monoecious;  that is, they produce separate male and female flowers but on the same plant (hence one plant= (mono)ecious)   The female blossoms have the attached ovary that will develop into the fruit. 

Male and female flowers

Male and female flowers

The top row of flowers in the photo above are males, bottom row females. Note the female flowers two days before bloom and one day before bloom (showing color).  The blossom can be taped shut the evening before bloom or place a large gelcap over it to prevent insect pollination then the blossom opens the next morning.  Do this for both the female and the male flower which you have selected to be the pollen donor.  On the morning the blossoms open uncap or open the taped blossoms and use the male with the pollen bearing stamen at center to dab pollen on the female stigma located at the center of the flower.  Then seal the female up again to prevent stray pollen from being brought in by ants, bees and other potential pollinators.

Cucumbers will cross with other cucumbers but not melons.  If you plant more than one kind of cucumber it will cross through insect pollination with others open at the same time and to same pure seed you will have to hand pollinate or isolate your plantings in some way.

Pickling cucumbers

Pickling cucumbers

Black Spined Cukes

Black Spined Cukes

The pickling cukes that we grow each year (above) were developed from a mass cross of half a dozen kinds including hybrids and were not the work of hand pollinating.  Insects worked the flowers of the different kinds of cukes and I simply selected out the fruit of the most productive, disease resistant plants with the type of fruit quality I wanted.  After four years of selection, I'm pleased with the result.  Black spined cukes (cucumbers have either tiny white spines or black spines if you look carefully at their bumps) like the one developed here at FBF, turn into bloated orange ripe fruit.

Seed Saving

Sometimes I will harvest the fully ripe and gourd-like fruit and dump them into a crate, leaving them there until I notice some degree of over-ripening or rot and then I break them open and scoop out the seed into a container such as the plastic pail here to allow a day or two for the gel covering each seed to break down if it hasn't already through the over-ripening process.  Then I add a squirt of dishwashing soap and water and agitate the slurry containing the seeds with my hands, dump them out in a strainer or over a screen where I will use a force of water to wash away the slurry and leaving the clean seed on the screen.  Out onto some newspaper they go or leave them to dry on the screen in a thin layer at normal summer temperatures.