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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #223167
Title: Management of Primocane-Fruiting Blackberry to Maximize Yield and Extend the Fruiting Season

Author
item STRIK, B - OREGON STATE UNIVERSITY
item Finn, Chad
item CLARK, J - UNIVERSITY OF ARKANSAS
item BULLER, G - OREGON STATE UNIVERSITY

Submitted to: Acta Horticulturae
Publication Type: Proceedings
Publication Acceptance Date: 9/1/2006
Publication Date: 2/1/2008
Citation: Strik, B.C., Finn, C.E., Clark, J.R., Buller, G. 2008. Management of Primocane-Fruiting Blackberry to Maximize Yield and Extend the Fruiting Season. Acta Horticulturae. 777:423-428.

Interpretive Summary: Primocane fruiting blackberries are a new phenomenon, and we are in the process of trying to understand the best ways to manage them. The two newly released cultivars, 'Prime-Jan' and 'Prime-Jim,' were studied in a field planting established in June 2003 in Aurora, Ore., USA. Primocane management treatments studied were: 1) primocane-only cropping with no manipulation [un-tipped]; 2) double cropping with no primocane manipulation [primocane + floricane crop]; 3) primocanes "soft-tipped" at 1 m to encourage branching; and 4) rowcovers used in late-winter to early-spring to advance primocane growth; treatments 1, 3, and 4 were a primocane crop only. 'Prime-Jan' had a higher floricane yield than 'Prime-Jim' (6.1 vs. 4.0 t/ha) but a smaller berry size (4.0 vs. 4.6 g; P = 0.01). Primocanes that grew in the presence of floricanes were significantly longer (2.5 m) than un-tipped canes (2.1 m) in both cultivars. On average, the un-tipped primocanes of 'Prime-Jan' were shorter than those of 'Prime-Jim'. On 14 July 2004, primocanes in most treatments were just starting to flower and fruit harvest began on 16 Aug. Use of rowcovers in 2005 advanced bloom 14 d (24 June) compared to un-tipped canes. The 50% yield date was 7–14 Sept. for 'Prime-Jim', depending on treatment and 14 Sept. for 'Prime-Jan'. Rowcovers increased yield, compared to un-tipped, non-covered plots. Soft-tipped primocanes had up to three fold the yield of un-tipped canes (5.2 vs. 1.8 t/ha). We stopped picking in mid-Oct. due to poor weather, but at that time there were still flower buds, flowers, and unripe fruit present on most treatments.

Technical Abstract: 'Prime-Jan' and 'Prime-Jim' were studied in a field planting established in June 2003 in Aurora, Ore., USA. Primocane management treatments studied were: 1) primocane-only cropping with no manipulation [un-tipped]; 2) double cropping with no primocane manipulation [primocane + floricane crop]; 3) primocanes "soft-tipped" at 1 m to encourage branching; and 4) rowcovers used in late-winter to early-spring to advance primocane growth; treatments 1, 3, and 4 were a primocane crop only. 'Prime-Jan' had a higher floricane yield than 'Prime-Jim' (6.1 vs. 4.0 t/ha) but a smaller berry size (4.0 vs. 4.6 g; P = 0.01). Primocanes that grew in the presence of floricanes were significantly longer (2.5 m) than un-tipped canes (2.1 m) in both cultivars. On average, the un-tipped primocanes of 'Prime-Jan' were shorter than those of 'Prime-Jim'. On 14 July 2004, primocanes in most treatments were just starting to flower and fruit harvest began on 16 Aug. Use of rowcovers in 2005 advanced bloom 14 d (24 June) compared to un-tipped canes. The 50% yield date was 7–14 Sept. for 'Prime-Jim', depending on treatment and 14 Sept. for 'Prime-Jan'. Rowcovers increased yield, compared to un-tipped, non-covered plots. Soft-tipped primocanes had up to three fold the yield of un-tipped canes (5.2 vs. 1.8 t/ha). We stopped picking in mid-Oct. due to poor weather, but at that time there were still flower buds, flowers, and unripe fruit present on most treatments.