Blackberries are a viable commercial fruit crop for farmers in Missouri and other states in the Midwestern region of the United States. Recent advances in blackberry cultivar development and production practices have greatly enhanced the profit potential of this crop for farmers, and several markets (on farm sales, farmers markets, wholesale markets, and institutional markets) are clamoring for locally grown blackberries.
A blackberry planting was established at the University of Missouri Southwest Research Center (SWRC) in Mount Vernon, Missouri, USA in March 2016. Funding for the project was provided by a MDA Specialty Crop Block Grant. The planting highlights recent blackberry cultivar and production technology developments and is a powerful demonstration site for adult learning. The planting features:
The planting consists of 3 rows that are 12 feet apart, oriented east to west. Plants are planted 5 feet apart in plots of 3 plants per cultivar, with 3 plots per cultivar in the planting. The plants are on raised beds that are 36" wide and 8" high. We covered the beds with woven landscape fabric, and placed a single 18mm dripline per row, with 18" emitter spacing. We followed standard cultural practices with regard to preplant soil testing and soil modification, planting establishment, pest management, and weed management between rows (which were in sod). The planting was fertigated weekly from April to September, for an equivalent of 80 total lbs/acre of nitrogen per growing season.
The RCA trellis system offers huge benefits as described above, but we learned that timely management is critical to see these benefits. We carried out the following practices:
The demonstration blackberry planting at SWRC, including the seven thornless blackberry cultivars trained to the RCA trellis, produced an initial, significant fruit crop in 2017, just one year after establishment. Data collected on the 2017 fruit yield, fruit size, and harvest season are presented in Table 1 and Figure 1. Floricane harvest began on June 9 ('Natchez', 'Prime-Ark® Traveler') and continued through August 1 ('Apache'). Primocane harvest commenced on July 26 and continued through October 6 for both 'Prime-Ark® Traveler' and 'Prime-Ark® Freedom'. Impressive first year floricane yields were noted for 'Natchez', 'Ouachita', and 'Prime-Ark® Traveler'. 'Apache' and 'Prime-Ark® Freedom' produced the largest floricane berries. First year primocane yields were modest for both 'Prime-Ark® Traveler' and 'Prime-Ark® Freedom', though the berry size of 'Prime-Ark® Freedom' was impressive. Figure 2 illustrates a peak volume of floricane berries produced among the cultivars in early July, followed by a second peak (though of less volume) in early August. A peak in volume of primocane berries was noted in late September. Worth noting is that while 'Prime-Ark® Traveler' produced berries that were smaller than several cultivars, it produced a continual summer-long harvest (June 9 to October 6), with floricane and primocane fruit production overlapping, resulting in season-long fruit yields that were the highest among all cultivars.
|Cultivar||2017 Yield (lbs/plant)||2017 Berry Size (g)||2018 Yield (lbs/plant)||2018 Berry Size (g)|
|Prime-Ark® Freedom||1.03 e*||8.8 a||7.72 d||7.3 a|
|Prime-Ark® Traveler||14.72 ab||4.9 e||17.25 ab||4.0 c|
|Apache||9.50 d||8.1 b||10.63 cd||6.4 ab|
|Natchez||16.76 a||7.4 c||20.28 a||6.2 b|
|Osage||10.34 cd||5.1 e||15.62 abc||4.7 c|
|Ouachita||13.64 abc||6.2 d||12.17 bcd||4.5 c|
|Triple Crown||11.37 bcd||4.6 e||20.31 a||4.0 c|
* Means within columns with the same letters are not different according to Fisher's Least Significant Difference test (P < 0.05).
Data collected on the 2018 fruit yield, fruit size, and harvest season are presented in Table 1, and represent what we would consider to be a full crop. The sequence of ripening and the length of season were similar to 2017 (dates not shown). We noted impressive floricane yields for 'Natchez', 'Osage', 'Triple Crown', and 'Prime-Ark® Traveler'. As in 2017, 'Apache' and 'Prime-Ark® Freedom' produced the largest floricane berries. 2018 primocane yields were disappointing for both 'Prime-Ark® Traveler' and 'Prime-Ark® Freedom', and data were not collected.
The RCA trellis requires a lot of attention from a management standpoint, and practices must be done in a timely fashion. In particular, training the primocanes to the horizontal position must be done when the shoots are small and flexible. We also strive to remove the floricanes as soon as possible after harvest, and transfer the primocane laterals to the fruiting side of the trellis. Among the cultivars under trial, 'Natchez' and 'Triple Crown' have a growth habit that works well with the RCA system. Based on two years' harvest information, 'Natchez', 'Prime-Ark® Traveler', and 'Triple Crown' would be good choices for Missouri blackberry farmers. Other challenges noted during the trial include management of SWD and Japanese beetle. Our experience with the primocane crop has been disappointing. Additional information on the study is available from the author. Farmers are welcome to visit the demonstration planting at the SWRC. Check the website http://www.webbcityfarmersmarket.com/grower-training.html for upcoming blackberry production workshops.
REVISED: February 21, 2017