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United States Department of Agriculture

Agricultural Research Service

Research Project: Physiology and Genetic Improvement of Small Fruit Crops Title: Management of primocane-fruiting blackberry – impacts on yield, fruiting season, and cane architecture

Authors
item Strik, B -
item Clark, J -
item Finn, Chad
item Buller, G -

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 13, 2012
Publication Date: May 1, 2012
Citation: Strik, B.C., Clark, J.R., Finn, C.E., Buller, G. 2012. Management of primocane-fruiting blackberry – impacts on yield, fruiting season, and cane architecture. HortScience. 47-593-598.

Interpretive Summary: The University of Arkansas recently developed a whole new class of blackberries, the primocane fruiting blackberries that fruit on current seasons growth (primocanes). This study looked at primocane management systems for ‘Prime-Jan’® and ‘Prime-Jim’®, primocane-fruiting blackberry, grown in a field planting in Aurora, OR. Treatments studied were: 1) no manipulation of primocanes (un-tipped; no floricanes); 2) un-tipped primocanes growing in the presence of floricanes; 3) un-tipped primocanes grown with rowcover in late-winter to early-spring; and 4) primocanes “soft-tipped” at 1 m to encourage branching. The primocane management did not affect drupelet number per berry or percent drupelet set. Fruit harvested earlier in the season had more ovules and drupelets than later harvested fruit. Primocanes that grew in the presence of floricanes were longer and bloomed later, but did not differ in yield from un-tipped canes grown only for a primocane crop. Soft-tipping primocanes increased yield 114 to 150% compared to un-tipped canes through increasing branch and node number per cane and percentage of fruiting nodes; soft-tipping did not delay harvest. Yield per cane was negatively correlated with the number of fruiting canes per plot but positively correlated with branches per cane, total branch and cane length, number of nodes and percent fruiting nodes, percent fruiting nodes, fruit per cane, and berry weight. The proportion of fruiting nodes was greater on branches than on the main cane, illustrating the importance of managing this type of blackberry to increase branch number for high yield.

Technical Abstract: Primocane management systems were compared for ‘Prime-Jan’® and ‘Prime-Jim’®, primocane-fruiting blackberry (Rubus L. subgenus Rubus, Watson), grown in a field planting in Aurora, OR. Treatments studied were: 1) no manipulation of primocanes (un-tipped; no floricanes); 2) un-tipped primocanes growing in the presence of floricanes; 3) un-tipped primocanes grown with rowcover in late-winter to early-spring; and 4) primocanes “soft-tipped” at 1 m to encourage branching. Date of primocane first bloom and cane height at bloom were not affected by cultivar and were only affected by primocane management in 2005. The number of growing degree days to first bloom ranged from 1272 to 1390, depending on year. Primocane management did not affect ovule or drupelet number per berry or percent drupelet set. ‘Prime-Jim’ had more drupelets and greater weight per berry in 2005 than ‘Prime-Jan’. Fruit harvested earlier in the season had more ovules and drupelets than later harvested fruit. Primocanes that grew in the presence of floricanes were longer and bloomed later, but did not differ in yield from un-tipped canes grown only for a primocane crop. Use of rowcover in 2005 advanced bloom and harvest, improving yield 73% compared to un-tipped control canes. Soft-tipping primocanes increased yield 114 to 150% compared to un-tipped canes (5.6 vs. 2.4 t·ha-1) through increasing branch and node number per cane and percentage of fruiting nodes; soft-tipping did not delay harvest. Yield·cane-1 was negatively correlated with the number of fruiting canes·plot-1, but positively correlated with branches·cane-1, total branch and cane length, number of nodes and percent fruiting nodes, percent fruiting nodes, fruit·cane-1, and berry weight. The proportion of fruiting nodes was greater on branches than on the main cane, illustrating the importance of managing this type of blackberry to increase branch number for high yield.

Last Modified: 12/17/2014
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