Leaf Tissue Sampling Time for Blackberry Crop

Illustration of leaf numbers for sampling. Use leaves 3-5. Photo  courtesy NCDA &CS.

Now is a good time to take leaf tissue samples for floricane- and primocane-fruiting blackberries.

For  floricane fruiting types should be sampled 2 weeks after harvest is over.

See illustration above for leaf number. You want to try to pick the most recently mature leaf (MRML)  The MRML is usually 3rd to 5th leaf from top of the primocane.

For primocane fruiting types, leaves should be sampled when most of the fruit is in the green stage. Again try to pick a MRML. (It is a bit harder to illustrate, with all the laterals on a primocane fruiter. I will work to get a good image this season).

For both fruiting types, collect 1–2 leaves per bush from 20–40 bushes; 20-40 leaves total. Put them in a paper bag.

Since we don't know about each individual cultivars nutritional needs, it would be a good idea to keep cultivars and field locations separate. Keeping an accurate report for each cultivate each year will allow you to fine tune the fertility for that cultivar and location.

In North Carolina send your samples to:

NCDA&CS Agronomic Services—Plant Lab Mailing address:
1040 Mail Service Center, Raleigh, NC 27699
Physical address: (If you are dropping off samples):

4300 Reedy Creek Rd, Raleigh NC 27607 

If you are not in NC, check with your local Cooperative Extension Agent to find the best local source for tissue sampling.

For more information on how to collect samples and how to read the report go to:
http://www.ncagr.gov/agronomi/documents/BlackberryRaspberryTissueSamplinghandout.pdf