Green pruning of shoots to force new sprouting of buds, in fruit set and in pea size: vegetative, productive and maturation effects, in cv. Verdejo
The context of climate crisis leads to the acceleration of technological ripening of grapes, with unsuitable loss of acidity, so various vineyard management alternatives are being considered to delay the grape ripening. The delay of the vegetative cycle towards a period of milder temperatures affects ripening, but vine behavior can vary according to the area, conduction, watering, variety, etc. A work is proposed to know the response to the green pruning of shoots, executed in fruit set and in pea size, in cv. Verdejo. During the period 2020-2021, in Valladolid, the response of cv. Verdejo, to the application, in 2020, of the following experimental treatments: T, control (no green pruning); Fj6, pruning to 6 nodes in fruit set; Fj3, pruning to 3 nodes in fruit set; Fk6, pruning to 6 nodes in pea size; Fk3, pruning to 3 nodes in pea size. Pruning was done by eliminating all the green organs (leaves, laterals and clusters) of the respected part (6 or 3 nodes) of all 16 shoots per vine. The design is in 4 random blocks, with elementary plot of 12 vines, in a vineyard planted in 2012, conducted on a vertical trellis and winter pruned in a bilateral Royat cordon with 8 spurs per vine. The effect of green pruning shoots, increasing the number of nodes 3 or 6 times, produced a notable increase in grape production, around 60% in Fj6 and Fj3 and 30% in Fk6, and a notable decrease in winter pruning wood, with average of 50% reduction, negatively affecting the vegetative response, and, above all, productive in the following campaign. Qualitatively, the green pruning of shoots greatly delayed ripening, reducing sugars and increasing the acidity of the grape, with variable intensity that was highly dependent on the time of pruning of the shoots.
Acknowledgements: Project PID2019-105039RR-C42 (MCIN/AEI) and Junta de Castilla y León.
Issue: ICGWS 2023
1Instituto Tecnológico Agrario de Castilla y León, 47071 Valladolid (España)