Thursday, May 28, 2015

How can I tell the difference between a primocane and floricane leaf or cane?

So this time of year there is a lot of new growth in the blackberry field. Both floricanes and primocanes are present and providing the plant the food via photosynthesis that occurs in the leaves.  This food (carbohydrates) help to ripen the fruit.

Most of the floricanes are loaded with green fruit by late May, and look like this image below. shorter laterals, short internodes relatively small leaves with 3 leaflets. FYI, caneberries have compound leaves, meaning each leaf has more than one section or leaflet.
Picture 1. Floricane with fruit.

The primocanes usually have thicker stems, that gradually taper at the tips,  and long internodes (area on stem between each leaf). They look like this:
Picture 2. Primocane Note that each leaf has 5 leaflets.
Then there are these canes, at first they look like a primocane, but then with closer inspection, they have little flower buds and only 3 leaflets per leaf.
Picture 3. This is a floricane, note the leaf is comprised of 3 leaflets.
So, there are two types of floricanes, the ones that produce the majority of the fruit on the canes that developed last year. Then there are basal buds that are much more vigorous (and look like primocanes) and produce fruit later in the season (Navaho is probably the variety where we see if most often). Here is a picture of the basal floricane and the primocane. Note that not only does the floricane have fruit, it has 3 leaflets per leaf. Most blackberries and raspberry floricanes have 3 leaflets and primocanes with 5 leaflets.
Picture 4. Floricane with 3 leaflets/leaf  and small flower buds on left, primocane with 5 leaflets/leaf on right.

So, when you are wandering through your fields, take a look, can you tell the difference?

3 comments:

  1. Very good explanation of why new canes have 5 leaves and the 2nd year have three. Thank you.

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  2. Super great article. My blackberries went from having clusters of 3 leaves to clusters of 5 leaves. I now understand better. Thanks for the pictures and great explanations.

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  3. Very helpful to me, too! I saw a wild Rubus yesterday that I wasn't sure was Rubus at all, because (as I now understand) it was just a single, tall, primocane, with widely separated five-leafleted compound leaves

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