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Seasonal Production and Pest Management

by Donn Johnson - March 5, 2018

Seasonal Production and Pest Management of Primocane-Fruiting and Floricane-Fruiting Blackberries

In our experience, a commercial primocane crop is not possible in the planting year when tissue-cultured plants are established (0.6 m in the row). However, commercial crops should be expected the year after planting. A simple, two-wire trellis is recommended to prevent the vigorous canes from bending over and to prevent wind breakage (Strik and Thompson 2009).  Typically, unpruned or untipped primocanes produce a single inflorescence (flower cluster). Growers have used a combination of pruning back the primocanes and then tipping the lateral shoots prior to bloom to increase branching and plant yield (Thompson et al., 2009).

Trellis on Sta-N-Step Farm

The following floricane and primocane production and pest management practices should be followed:

  • October-February: while growers are less busy, cut all floricanes at ground level and remove cuttings from within the planting. Early removal of floricanes can reduce disease inoculum. Removal of last year’s dead floricanes (fruited) during spring can cause damage to green buds on current floricanes.
  • At green tip: apply pre-emergent herbicide for weed/grass control
  • At green tip, 6-inch shoot, prebloom and petal fall: implement disease management for anthracnose, but treat for cane blight only at prebloom (Bordeaux, copper-based products, Captan, Pristine, Tilt).
  • May and June: There are two types of canes that could be managed to produce fruit:
    • Primocanes production – to produce fruit on primocanes from mid-summer into fall, start double-tipping by pinching off soft-tip when any terminal reaches 20 inches tall and then pinch off soft-tip when lateral reaches 20 inches long. This double-tipping, where primocane branches are soft-tipped, shows great promise for increasing production (Thompson and Strik, 2007). This tipping will produce higher number of branches per cane, five on average that results in threefold more flowers and yield than per untipped canes (Strik et al. 2008, Thompson et al. 2007, 2008).
    • Floricane production – to produce fruit on floricanes next summer, pinch off soft-tips during the growing season when any primocane terminal reaches 5 feet tall to encourage branching. In the winter, the dead floricanes are removed and the branches of the new floricanes are pruned to about 20 inches in length or left unpruned (Strik et al. 2007).
  • Petal fall: apply one soil drench of Admire Pro for prevention of rednecked cane borer or apply weekly foliar spray of JMS Stylet Oil directed at the cane or keep Surround treated plots whitewashed. All these treatment will minimize egg laying and/or survival of the borer and delay broad mite buildup on primocanes (a research question being addressed).
  • Late May on:
    • Broad mites - walk planting weekly looking for terminal leaf bronzing or cupping that indicates presence of broad mites. If found, collect pinched off terminal tips and remove from field to minimize spread of broad mites from cane to cane. If broad mites are present and terminals are beginning to show bronzing apply Agri-Mek miticide to prevent fruit loss.
  • As needed in July: when you first detect flight and feeding by green June beetle and/or Japanese beetle, apply recommended insecticide or apply Surround (kaolin clay) as needed to maintain whitewashed appearance of plants that will repel beetles.
  • Green fruit to harvest: walk planting weekly looking for stink bugs on fruit. If mostly wingless nymphs are present, apply bifenthrin or pyganic or keep Surround treated plots whitewashed.
  • First Ripening Fruit through harvest: apply insecticide weekly and rotate modes of action (Brigade, Danitol, Delegate, Mustang Maxx) for prevention of spotted wing drosophila infestation of fruit. In 2017, the Surround whitewash of blackberry plants and fruit did not appear to reduce fruit infestation by spotted wing drosophila.
  • Late October: apply soil drench of insecticide (Brigade or Altacor) around blackberry plants to kill newly hatched raspberry crown borer larvae that overwinter on canes below soil surface.

December leaf fall: remove and compost all fallen blackberry leaves from planting to minimize numbers of overwintering broad mites.

Newly Emerged Stinkbugs

Sources or Citations

Drake, C.A. and J.R. Clark. 2003. Effects of pruning and cropping on field-grown primocane-fruiting blackberries. HortScience 38:260-262.

Smith, S. 2018. Arkansas small fruit management schedule. Univ. of Arkansas Division of Agriculture Res. & Ext. MP467.

Strik, B.C., J.R. Clark, C.E. Finn, and M.P. Bañados. 2007. Worldwide blackberry production. HortTech. 17:205-213.

Strik, B.C., J.R. Clark, C.E. Finn, and G. Buller. 2008. Management of primocane-fruiting blackberry to maximize yield and extend the fruiting season. Acta Hort. 777:423–428.

Strik, B.C., and E. Thompson. 2009. Primocane-fruiting blackberries: potential for extending harvest season and production regions. HortScience 44(1):23-24.

Thompson, E. 2007. Primocane-fruiting blackberries: the effect of summer pruning, tipping, and chilling on primocane morphology, fruiting season, and yield. M.S. thesis, Dept. of Horticulture, Oregon State University, Corvallis.

Thompson, E., B.C. Strik, J.R. Clark, and C.E. Finn. 2007. Flowering and fruiting patterns of primocane-fruiting blackberries. HortScience 42:1174–1176.

Thompson, E., B.C. Strik, J.R. Clark, and C.E. Finn. 2008. Flowering and fruiting morphology of primocane-fruiting blackberries. Acta Hort. 777:281-288.

Thompson, E., et. al. 2009. High tunnel versus open field: Management of primocane-fruiting blackberry using pruning and tipping to increase yield and extend the fruiting season. HortScience 44:1581-1587.


Donn Johnson

Donn Johnson