Presentation Type

Proceeding Paper

Publication Date

8-13-2018

Subject Category

Blueberry Culture

Description

The objectives were to identify the effects of late season fertilization on southern highbush blueberry (SHB) dormant floral bud cold hardiness, flower timing, and plant nutrient uptake. Treatments included two fertilizers 10-10-10 (Super Rainbow) and 46-0-0 (urea) and two cultivars, ‘Emerald’ and ‘Star’, grown in pine bark media. There were four late season fertilization treatments: 1) August: 10-10-10 fertilization (28 g/container applied in August); 2) September: 10-10-10 fertilization (20 g and 10 g/container applied August and September, respectively); 3) October: 10-10-10 fertilization (10 g/container applied monthly; August-October); 4) Urea: 46-0-0 fertilization (3 g/container applied August and September). Dormant root and shoot tissue were analyzed for mineral nutrients. Floral bud tissue was freeze tolerance (FT) tested and floral bud stages were recorded from 24 Jan. to 14 Mar. The FT of ‘Star’ was unaffected by fertilization treatments. In contrast, ‘Emerald’ on 17 Jan. was hardiest in October treatment (at -12.0 °C) and on 8 Feb., the hardiest floral buds of ‘Emerald’ were in September treatment (at -13.5 °C). Regardless of fertilizer, the treatments were similar in N concentration with some variation observed between roots and shoots. In both cultivars, late fertilization increased root N concentration. All fertilizer treatments in ‘Emerald’ bloomed earlier than ‘Star’. No significance was seen between treatments of bloom progression for ‘Emerald’. Treatment October advanced bloom progression in ‘Star’. This work demonstrates that urea and mid-October fertilization had no effect on floral bud cold hardiness and bloom timing was cultivar dependent.

Start Date

13-8-2018 10:20 AM

End Date

13-8-2018 10:40 AM

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Aug 13th, 10:20 AM Aug 13th, 10:40 AM

Floral bud cold hardiness of southern highbush blueberry (Vaccinium corymbosum L. interspecific hybrids) in response to late season fertilization

The objectives were to identify the effects of late season fertilization on southern highbush blueberry (SHB) dormant floral bud cold hardiness, flower timing, and plant nutrient uptake. Treatments included two fertilizers 10-10-10 (Super Rainbow) and 46-0-0 (urea) and two cultivars, ‘Emerald’ and ‘Star’, grown in pine bark media. There were four late season fertilization treatments: 1) August: 10-10-10 fertilization (28 g/container applied in August); 2) September: 10-10-10 fertilization (20 g and 10 g/container applied August and September, respectively); 3) October: 10-10-10 fertilization (10 g/container applied monthly; August-October); 4) Urea: 46-0-0 fertilization (3 g/container applied August and September). Dormant root and shoot tissue were analyzed for mineral nutrients. Floral bud tissue was freeze tolerance (FT) tested and floral bud stages were recorded from 24 Jan. to 14 Mar. The FT of ‘Star’ was unaffected by fertilization treatments. In contrast, ‘Emerald’ on 17 Jan. was hardiest in October treatment (at -12.0 °C) and on 8 Feb., the hardiest floral buds of ‘Emerald’ were in September treatment (at -13.5 °C). Regardless of fertilizer, the treatments were similar in N concentration with some variation observed between roots and shoots. In both cultivars, late fertilization increased root N concentration. All fertilizer treatments in ‘Emerald’ bloomed earlier than ‘Star’. No significance was seen between treatments of bloom progression for ‘Emerald’. Treatment October advanced bloom progression in ‘Star’. This work demonstrates that urea and mid-October fertilization had no effect on floral bud cold hardiness and bloom timing was cultivar dependent.