Designer Zucchini

When Cornell asked the organic farming community what they would like in a zucchini, I can imagine the response.  We want a prolific zucchini that bears fruit as fast as you can pick them.  A nice nutty sweet flavor with dense flesh that doesn't cook up mushy or taste bland.  How about an eloquent stream-lined shape or with subtle ribs which are so favored by gourmet chefs.  How about some striping or mottling that won't show blemishing or scars on the fruit like some of the new zucchini hybrids?  Make it open-pollinated so we can save seed for another crop.  Give it a vigorous plant that resists squash borers and beetles like the yellow summer squash.  Make it drought tolerant.  Most of all give it disease resistance so the plant stays healthy and productive the whole season.

NY04-833-1L is the name of a routine breeding line that Cornell University plant breeders produced.  One of hundreds of breeding lines that they produce every year.  It's novel in that it addresses a part of the wish list of the organic farmer and gardener.  NY04-833-1L is the second generation from a cross between a farmstand favorite in New England, "Costata Romanesco" and a special strain of "Early Prolific Straightneck" which is Mildew Resistant.  Both parents produce a large vigorous plant.  "Romanesco" is a zucchini of flavor and class but can be a frugal bearer.  "Early Prolific" is a workhorse that can keep on going and going but is prone to some of the faults of it's crookneck ancestry.

I didn't get to see the F1 Hybrid which was produced by the Costata Romanesco x Mildew Resistant Early Prolific Straightneck.  When a first generation hybrid is produced all the offspring will have the same characteristics and generally there will be some characteristics of both parents.  Dominant traits will show up, recessive traits may not; if you remember Mendels Laws from High School Biology.  The F1 generation consists of uniformly similar plants.

We received seeds from the F2 generation resulting from the crossing of those identical hybrid plants.  It was the F2 that was given the name NY04-833-1L.  All I knew was to expect the unexpected.  When somebody of gardening authority tells you not to save the seed of F1 hybrids, it won't be Cornell breeders.  It's precisely theunexpectedyou want.  Every plant may produce a different kind of fruit and may have differences in disease and pest resistance, productivity and vigor that will allow it to compete with weeds orkeep going in wet and cold summers.

The predominant chartreuse overtones in the 2007 crop of Romanesco x Success PMR

The predominant chartreuse overtones in the 2007 crop of Romanesco x Success PMR

This Cornell cross has probably been one of the most exciting breeding lines that I've worked with.  For me, I'm seeing many nice features in the plants and fruit of this cross.  I imagine I could be quite happy working for the next couple of years with just the seeds from the fruit of this generation in order to develop a variety that my farmstand customers will ask for (they'll say, "I need a bushel of that chartreuse zucchini, the one you had the other day") and that I can grow and harvest with ease.  Actually, I may be able to develop a useful product in much less time if I'm willing to accept some variability in the fruit.  But each year I select out that perfect chartreuse squash to save the seed of,  I'll be closer to a sustainable, consistant performing, open pollinated variety.

Since I'm participating in the Public Seed Initiative, I know that my selection of F2 plants will be important to the project.  Selection often means tearing out inferior plants and allowing only the superior to cross breed and save the seed of.  Only I really don't know which plants will have the best qualities.  I have ideas, but I'm not sure because I haven't observed the plants under disease attack yet.  As a result, I "self" each plant if I can.  Hopefully,  there will be a male flower ready to pollinate an open female on the same plant.  Then, the night before they will open, I will tie both blossom buds closed.  Next day I'll open the blossoms, remove the corolla (petals) and pollinate the female. Then I label the tie (a piece of survey tape) with a permanent ink Sharpie which simply reads "x self".  When the fruit ripens to "gourd or a pumpkin-like" ripeness and the skin is a hard "shell" I will cut open the squash and save the seed. Seed from this kind of cross (the F3 generation from a "self") stands a good chance of producing plants and fruit which have a greater similarity to it's parent.  This is especially good if I find that one of the F2 plants had truly superior qualities.  If I allowed that plant to "sib" or cross with others in the same row, those qualities would be diluted or covered and possibly lost.  Sibbing the F2 generation could be a good thing if some of the plants had good qualities but also drawbacks and the other plants had good and bad characteristics which were complementary.  Giving it another generation to make sure disease resistance was effectively imparted to the population might be a good reason to sib.  Not catching a female flower before it opens and can be tied shut and then seeing it open the next morning being visited by bees is the reason for most of my sibs.  They aren't very controlled.  I might consume the fruit or allow it to produce seed, again depending on the trait I see in the plant and it's fruit.

There is another kind of cross I might make at this point, a backcross.  I really like one of the plants that produced one of the fruit pictured here.  I won't tell you which one.  So far,  it has not succumbed to powdery mildew (one of the reasons that zucchini will rot and plants will die long before frost) but it might.  To increase the probability that disease resistance is imparted to the next generation (F3), I would cross this plant with the disease resistant parent, "Mildew Resistant Early Prolific Straightneck", actually a Cornell release named "Success PMR".
In 2007, the yellow stipes on pure white of the original "Yikes-Stripes" of 2005 and 2006 is gone and the color contrast is much less.  Working with such a small population as I do and without the best isolation technique, I may have lost the characteristic I valued the most.  A disappointment unless better colored fruit show up in the remaining plants that still haven't produced fruit.

This all seems very simple, there is really no mystery in plant breeding but it does take care in careful isolation technique and record keeping;  however, the years and hundreds of crosses between wild gourds and edible squash to just develop that one stabilized, open-pollinated parent, "Success PMR" makes me appreciate the work that our publicly funded breeders such as those at Cornell do on an on-going basis.

A New Romanesco Zucchini

Everybody likes the long, slender Costata Romanesco. Very close in it's genetics to it's relative, Cocozelle which by the way is one of the original zucchini introduced and grown in America initially by families of Italian immigrants around the turn of the 20th century. Cocozelle has a heritage but Romanesco is wilder, firmer with a flavor and shape that gourmet chefs really like. Romanesco produces flowers in great quantities but lacks disease resistance and fruit productivity.

This is one of two F2 crosses involving Romanesco as a parent designed to impart disease resistance to the popular Romanesco that Flanders Bay Farm received. One of many Cornell University crosses targeted at helping the organic farmer, this one was released unfinished to cooperating farms under the Public Seed Initiative which is administered by NOFA-NY.  I received seeds of a second generation cross (Costata Romanesco x PMR Caserta) F2 from Cornell via the Nofa sponsered OSP.  The initial hybrid of the cross of the two parents probably produced uniformity as F1 hybrids do, all the hybrid plants were uniform in fruit and plant habit. We received seed from siblings of that hybrid that were crossed. When you save the seed of an F1 hybrid you get diversity and true to our expectations every plant is a little different, their fruit is too. The F2 generation is what breeders really want to look at.  In the first year after planting the F2 cross only one plant was bearing fruit with the pronounced ridging of Romanesco but most had the attractive stripes of Romanesco.

We will pollinate the female flowers with males on the same plant so we get a "self" which will produce offspring more like this one parent than the variable plants we now see in a row. Which seed we save from this summer's "self" crosses will depend on our observations of the plants through the summer.  This produces the material to select from based on what characteristics you're looking for.  I'm sure that Cornell and other participants in the project are interested in primarily disease resistance.  Powdery mildew resistance is one of the primary reasons that this cross was made.  But breeders are always looking for a number of characteristics and so too, do we.

The idea is to let the organic farmer select the fruit qualities from the diverse second generation cross between Romanesco and a disease resistant strain of Caserta and select for the particular growing environment of the organic farm. The unique collaboration between the organic farming community and the professional breeders at Cornell could lead to an important gourmet summer squash coming soon to your neighborhood green market.  There have been a number of selections that we made from the cross.  There is a selection of very a productive vigorous plant that produces a gray with dark green mottled and striped skin that we like and have given a working name as "Super Caserta" and also an attractive very pale green with light green stripes that we find very appealing when harvested young.

The above picture shows the results of 3 years growing the Romanesco/Caserta cross.   I know that we should be looking to stabilize selections for uniformity but I continue to cross still yet unstabilized selections like Super Caserta with white zucchini and other long green zucchini from my collection.  It may not be suitable for the chain grocery stores, but my customers expect to see the assortment of zucchini that they can pick and choose from and so I continue to save and plant the dozen or so selections and crosses made from the original Cornell material.  It works for me.