New break dormancy spray treatments in nectarine peach (Prunus persica var. nucipersica), in warm areas

In the last decades, peach culture in warm areas presents adaptation problems due to the climate change effects. Among others, the main issues are the lack of homogeneity in the flowering, pistil abortion, difficulty for vegetative bud development and the drop of flower buds or premature fruits. All these problems are consequence of the non-satisfaction of the chill requirements of the cultivars that have been planted in these areas. To combat this issue, different chemical treatments for the compensation of not fulfilled chill requirements have been applied in stone fruits. CEBAS-CSIC has developed a new formulation that was compared with other commercial biostimulant products. This new formulation is known as 'Bloom-Tech (R) Spray'. In this work, dormancy breakers were applied to nectarine cultivar 'Garcima', grafted on 'Garnem' rootstock. The work consisted on five groups of treated trees and a control group in which phenology, bud drop, vegetation intensity and production were compared. The products used were 'Erger + Activ Erger', 'Broston + Nitroactive (1 and 2 application)' and 'Bloom-Tech (R) Spray (1 and 2 application)'. The application time for the products was when the 60% of the chill requirements of the cultivar had been satisfied. For the measurement of chill accumulation, the Chill Portions model was used. Treatment T5 (Bloom-Tech (R) Spray in 2 application) stimulated a greater number of flower buds and also produced a more synchronized flowering. It also led to a significant increase of yield compared with the two products applied. Treatment T3 (Broston in 2 application) showed the earliest flowering but caused a significant drop of flower buds that reduced yield moderately.