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Archive for the ‘Bluecrop’ Category

Improving Bluecrop production

Posted by blueberrytalk on November 3, 2016

For many years Bluecrop held the distinction of being the variety of choice for blueberry growers. Then came Duke! Duke was as easy to pollinate as Bluecrop was difficult to pollinate. Bluecrop invariably left 20-30% of the fruit as tiny undeveloped green berries. Duke berries tend to ripen in fewer pickings making it much easier for pickers to achieve  higher production. This says nothing about the overall production of the field.

We are attempting to meet all of the challenges posed by Dukes by using Mason bees to pollinate in the Bluecrop. Mason bees are trapped by their unwillingness to fly long distances so they can be forced to pollinate Bluecrop when they are placed next to Bluecrop. The first question is :”How many Mason bee cocoons does it take to pollinate an acre of Bluecrop?” We are close to an answer to this and probably after the 2017 season we will have a pretty good idea. Last year we used about 1500 cocoons per acre. Overall production is harder to pin down but we are collecting data in this area. We will have something to say about picker satisfaction that comes from compressed ripening later in this blog entry.

Let’s look at the challenge posed by Duke. This is what the second picking looks like to a picker!


The greater the density and size of berries the greater the productivity in picking.

Thanh is from Vietnam. He and his wife Lan have picked at our farm for about 20 years. Thanh knows the difference between a bush  he would like to pick from a bush he wouldn’t like to pick. His English is excellent and he doesn’t hesitate to share his thoughts. He has been with us through all the old “hard to pick” varieties that we no longer grow.

In 2015 we hand picked the Bluecrop in 3 pickings  In 2016 we did one hand pick and then finished the field with a machine pick. A couple of times before we machine harvested Thanh expressed his disappointment that he wouldn’t get a chance to pick the 2nd pick of Bluecrop. One anecdote can’t convince but we would like to pursue the idea  that Bluecrop , pollinated by Mason bees, can lead to a crop that produces higher picker satisfaction by the way the berries are presented on the bush.


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Bluecrop fruit set

Posted by blueberrytalk on June 6, 2015

With a sunny May the fruit set has been good in the Bluecrop blueberry variety. The blueberries on the left were pollinated with the help of Mason bees. Click on the pictures to enlarge.





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Bluecrop pollination

Posted by blueberrytalk on May 29, 2009

The Bluecrop variety of blueberry presents unique challenges in setting fruit. In a year when there are few bees it is not uncommon to see bees drawing nectar for the base of a flower that has become separated from the base. This, of course, subverts the whole process of pollination. In a year like this year, when there are lots of bees, foraging without pollinating is never seen. A plausible explanation is the following:

Dr. Gary C. Pavlis

County Agricultural Agent

Pollination: Unfortunately not all of the visitations to blueberry flowers by bees result in pollination. Pollen must be transferred from some parts of the bee’s body, usually the head to the tip of the pistil (stigma) in order to achieve pollination. There are three ways in which honeybees “cheat” the grower by not earning their rental fee. 1) Acquire nectar by feeding through hole in blossom made by a carpenter bee. 2) The distance from the edge of a flower petal to pistil is very wide, as in Earliblue. The bee can stick its tongue down and get the nectar without touching the pistil. 3)The bee does not thrust through the open end but gets nectar through the bottom – very important in Bluecrop and Jersey. In some years such a high percentage of the bees may work through the bottom of the corolla that the crop can be significantly reduced. Bees develop this bad habit mostly on Jerseys and Bluecrop. The probable reason is that both of these varieties can produce small seedless berries without pollination (parthenocarpy). These parthenocarpy berries begin to develop shortly after the flowers open and once it starts the corolla becomes loose at the base after a few days, enabling the bee to secure its nectar through the loose juncture of the corolla and ovary. Since the honeybees usually select older flowers which have more nectar it enables the younger ones to start the parthenocarpic process which does not occur once the flower is pollinated. The solution may be to use higher concentrations of bee hives.

The higher numbers of bees per bush forces them to accept younger flowers with the result that more berries are developed from bee pollination than by parthenocarpy.



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Bluecrop pollination

Posted by blueberrytalk on September 5, 2008

The tiny unripe berries on the Bluecrop blueberry bush is a result of  poor pollination. It would be easy to blame the weather but the fact is bees prefer any other blossom to Bluecrop blossoms. This is a persistent problem for Bluecrop. What is the solution? Our plan is to saturate the area with Mason bees. Mason bees forage close to their nests so a lot of Mason bee nests close to the Bluecrop is our plan for next year. We will check back a year from now.

late Bluecrop

late Bluecrop

unripe Bluecrop

unripe Bluecrop

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