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IVES 9 IVES Conference Series 9 Influence of the number of CPPU applications on growth, mineral composition and Bunch Stem Necrosis incidence in table grape clusters

Influence of the number of CPPU applications on growth, mineral composition and Bunch Stem Necrosis incidence in table grape clusters

Abstract

The forchlorfenuron (CPPU) application is recommended in table-grape after fruit-set to boost berry sizing, albeit growers also apply CPPU during pre-flowering with controversial advantages. We examined the effect of single (BBCH 15) and double (BBCH 15 and 57) CPPU applications (2.25 mg/L a.s.) in a commercial vineyard. At each time, 75-100 bunches belonging to 6-9 vines were sprayed, and compared with unsprayed (CTRL). Leaf stomatal conductance (gs), cluster stem diameter and length were measured. At harvest, 25 berries/repetition were sampled for chemical composition, BSN incidence was counted (N° necrotic laterals/10 cm of stem) in 40 bunches/repetition. To test the role of air VPD on mineral composition, at BBCH 77, 50 CTRL clusters were bagged to induce a low VPD.

Preliminary results showed a significant effect of CPPU on stem diameter when compared to that in untreated being 5.49 ±0.22 SE, 6.05 ±0.20 and 6.17 ±0.24 mm in CTRL, single and double CPPU applications, respectively. Cluster length and gs remained comparable across treatments. The number of CPPU applications did not affect berry Ca content (0.84 ±0.08 –single- and 0.85 ±0.03 mg berry-1 -double), whereas BSN incidence was significantly higher (2.63 ±0.33a) in the double CPPU applications than single (1.29 ±0.18b) and comparable to CTRL (1.75 ±0.24ab), leaving some open questions.

Based on the significant effect of VPD on berry Ca content (0.39 ±0.04 –bagged-, 1.81 ±0.84 mg berry-1 -CTRL), the use of management options (i.e. training systems, plant distances, covering, canopy manipulation) to increase Ca accumulation is discussed as alternative to chemical spray.

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DOI:

Publication date: June 14, 2024

Issue: Open GPB 2024

Type: Poster

Authors

Antonio Carlomagno, Giuseppe Montanaro*, Giuseppe Flores, Vitale Nuzzo

1 DiCEM – Università Degli Studi della Basilicata, Via dell’Ateneo Lucano 10, Potenza

Contact the author*

Keywords

PGRs, hormones, cytokinin, pre-anthesis, Vitis vinifera L..

Tags

IVES Conference Series | Open GPB | Open GPB 2024

Citation

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