Monitoring flower to fruit development of blackberries

Several of you saw the talk  that Daniel Shires gave at the Georgia Fruit and Vegetable Growers meeting in Savannah in January.  Last summer,  Daniel, me and an intern helped to set up a demonstration that could help growers determine when a variety would ripen. We set up the demonstration at Killdeer Farm in Kings Mountain and posted weekly updates here on Team Rubus Blog. Here is how you can do it this year at your farm.

All you need is some flagging tape and a permanent marker.

Step 1. When you think the field is in full bloom, find a flower that is on the outside upper portion of the canopy. This fruit will most likely continue to be easy to spot if not buried too far into the canopy.

Step 2. Cut a 12" piece of flagging tape and put the date on one end of the flag (we used numbers for our trials instead of dates as you can see below)

Step 3. Tie the flagging tape around the base of the flower. We suggest you do at least 3 flowers from the same variety at the same time. We lost many fruit to a number of mishaps before the fruit was ripe.

Step 4. Return to the flower on a weekly basis and monitor. Record stage of plant development. Examples of a few of the stages are below.

Step 5. Keep the records so you can compare how long it takes each year. After a few years, you will have a good idea how long it should take variety to ripen at your location once it is in full bloom.

If you don't want to keep track of all of the stages, make sure at the least that you have a date for full bloom and shiny/dull black.

We also suggest that you let your pickers know that they should NOT pick this fruit.

Example of a data sheet for recording the steps of blackberry development.

Flower full bloom

Green fruit

Red-green fruit

Red fruit

Shiny black fruit

Blackberry flowers to fruit: most fruit ripe or picked! (as of July 17)

For each cultivar, we tagged 5 flowers in the same field. As the season progressed, we had wind damage, picker damage and other sorts of damage. So in most cases, we ended up with less than 5 ripe fruit.  

As of July 17, most of the fruit we labeled in the field has been harvested. Only 2 Von samples were still in the field. 

Based on our guesstimates* of harvest dates, the number of days from flower to fruit are:

Natchez 51

Osage 44

Ouachita 51

Navaho 51

Von 58

* these are based on only 3-4 flowers, so what you may see in your field may vary. 

Thanks to Abby Whitaker and Daniel Shires for their help with data collection and taking pictures on all these dates. 

Flowers to fruit June 27 seeing red and black!

Natchez won the race, it is the first cultivar to produce a ripe fruit. Two of the five flagged berries are ripe. One was picked before the picture was taken and this one was fully ripe. It took 38 days for this berry to go from a fully open flower to a ripe fruit. We will calculate the number of days for the rest of the fruit as they ripen and post that list at the end of the season.

The flower below was actually at a stage we call petal fall, the flower has been pollinated (you can tell because the anthers are all brown, indicating that the pollen has been released).  It was probably in full bloom a day or so before the picture was taken.

Ouachita, Osage, Navaho are all at the red stage. Von was the only cultivar that still had only  green fruit.

In this little trial, we are determining how long it takes a group of five berries to progress from a flower to a ripe fruit. Fruit in the field are at a range of stages. We have been picking Natchez, Osage and Ouachita in our research plots for over a week.

Photo credits and big thanks to Abby Whitaker and Daniel Shires. Photos taken at Killdeer Farm, Kings Mountain, NC.

Flowers to fruit third week update

These are images taken on 3 separate dates, showing development from flower to fruit of 5 cultivars, starting at full bloom. Images taken by Daniel Shires, NCCES Agent and summer intern Abby Whitaker.