Hydrogen cyanamide levels and mineral oil to budbreak induction of 'Baigent' apple trees under anti-hail net in southern Brazil

L.S. Paim, F.J. Hawerroth, G.A.B. Marodin, D.S. Mauta, F. Simões
This study aimed to evaluate hydrogen cyanamide (HC) concentrations in combination with mineral oil (MO) to budbreak induction of 'Baigent' apple trees under anti-hail net, in southern Brazil. The study was carried out in a commercial apple orchard under black anti-hail net, during 2017/18 and 2018/19 growing seasons, in Vacaria, RS, Brazil. A RCB design was adopted, according to a 7×2 factorial structure, with seven levels of budbreak promoter - 1) control (no application); 2) MO 3.5%; 3) MO 3.5% + HC 0.17%; 4) MO 3.5% + HC 0.34% (standard application); 5) MO 3.5% + HC 0.51%; 6) MO 3.5% + HC 0.69%; 7) MO 3.5% + HC 0.86% - and two levels of tree's canopy portion - 1) lower and 2) upper portion. The flowering dates and duration, axillary and terminal budbreak, fruit set and production parameters were evaluated. The flowering dates were advanced by MO 3.5% + HC concentrations, particularly in tree's canopy upper portion with HC above than 0.34%. The axillary budbreak was intensified by MO 3.5% + HC concentrations with low chilling accumulation during the winter, particularly with HC above than 0.34%. The MO 3.5% and MO 3.5% + HC concentrations effects on fruit set data were probably masked and the highest fruit set values were provided by tree's canopy upper portion. The fruit production variables were not affected by MO 3.5% and MO 3.5% + HC concentrations in the study conditions. The use of MO 3.5% + HC above than 0.34% is an alternative to budbreak induction of 'Baigent' apple trees under anti-hail net, in southern Brazil.
Paim, L.S., Hawerroth, F.J., Marodin, G.A.B., Mauta, D.S. and Simões, F. (2020). Hydrogen cyanamide levels and mineral oil to budbreak induction of 'Baigent' apple trees under anti-hail net in southern Brazil. Acta Hortic. 1268, 319-326
DOI: 10.17660/ActaHortic.2020.1268.43
https://doi.org/10.17660/ActaHortic.2020.1268.43
Malus domestica Borkh., insufficient chilling, dormancy overcoming, budbreak promoter, protected cropping
English

Acta Horticulturae