HYDROGEN CYANAMIDE ON BUDBREAK AND YIELD OF 'O'NEAL' HIGHBUSH BLUEBERRY IN SOUTH URUGUAY

M. Arias, E. Darino, R. Astessiano, V. Severino, A. Borges
Southern Highbush Blueberry cultivars are becoming a high value crop in Uruguay since 2002. A rapid increase in surface area is due to the good prices of blueberries at the beginning of the off-season fresh market. The application of Hydrogen Cyanamide (Dormex, H2CN2,) in our mild and variable winter is one of the cultural practices that may improve yields and advance harvest. This study was conducted in two commercial blueberry orchards in the south of Uruguay (34°44’ south latitude). ‘O’Neal’ (V. corymbosum L. hybrid) plants were sprayed with 0, 1, 1.5 or 2% of Dormex (v/v) at two moments in (May and June). The experiments had a randomized complete block design with 6 plants per treatment with 3 replications in 2005 and 6 replications in 2006. Variables measured were: total length plant, nodes number per plant, reproductive and vegetative budbreak, fruit number and total fruit weight (picked up twice per week in harvest). June applications of H2CN2 accelerated vegetative and reproductive budbreak in both evaluated years, advancing fruit ripening. Dormex, the H2CN2 applied at 1%, increased by 13,2% and 8% the total kg/plant harvested in the first 10 days in 2005 and 2006 respectively. However, Dormex at the 2% H2CN2 sprayed in June injured apical flower buds mainly at stages 2 and 3. This removal of the apical dominance stimulated growth of lateral vegetative buds one month earlier than the control. Even though the final number of vegetative budbreak was higher, the fruit weight was improved only on the first harvest date. The effect on fruit number and total harvest weight were influenced by Dormex treatment depending on the doses and chill hours accumulated at each date of application moment.
Arias, M., Darino, E., Astessiano, R., Severino, V. and Borges, A. (2010). HYDROGEN CYANAMIDE ON BUDBREAK AND YIELD OF 'O'NEAL' HIGHBUSH BLUEBERRY IN SOUTH URUGUAY. Acta Hortic. 872, 245-252
DOI: 10.17660/ActaHortic.2010.872.33
https://doi.org/10.17660/ActaHortic.2010.872.33
Vaccinium corymbosum, Dormex, flower bud, vegetative bud, chilling hours
English

Acta Horticulturae