Vine performance following preveraison shoot trimming is well document, the consequences of such treatments later in the season are poorly understood. Therefore, a 4-yr study was conducted in a mature vineyard of Sangiovese (clone 12T) grafted onto Kober 5BB rootstock at a spacing of 1 m × 2.8 m (intra- and interrow) to analyze the influence of postveraison shoot trimming on vine growth characteristics, cluster architecture (cluster compactness), and yield from a physiological viewpoint. The treatments consisted of shoot trimming during postveraison in a randomized block design with eight replications; each replication comprised of six vines. Three shoot trimming treatments consisting of light trimming (14 nodes), severe trimming (10 nodes), and an un-trimmed control were imposed when the soluble solids reached 15 Brix in August (40–45 day before expected harvest). Following the treatments, various vine growth characteristics, cluster morphology, and fruit quality attributes were measured. Postveraison shoot trimming, especially severe trimming reduced cluster weight along with cluster compactness, productivity, and total yield. In terms of fruit quality attributes, these reductions were manifested as lowering of Brix and pH with minor effects on TA, yeast assimilable nitrogen, the anthocyanin profile, and total anthocyanins. These results demonstrated that postveraison shoot trimming can be a valuable production practice in reducing cluster compactness without compromising overall fruit quality attributes in Sangiovese.

Articulo de publicación ISIBackground and Aims: The control of iron (Fe) chlorosis by synthetic Fe chelates is costly and their application can have adverse environmental impacts. We investigated the effectiveness of alternative vineyard strategies to prevent Fe chlorosis in grapevines. Methods and Results: An experiment was conducted over two consecutive seasons on Vitis vinifera L. cv. Cabernet Sauvignon grafted on the Fe-chlorosis susceptible Vitis riparia grown in pots filled with calcareous soil. Intercropping with Festuca rubra enhanced leaf chlorophyll index and reduced the root activity of phosphoenolpyruvate carboxylase enzyme, a physiological marker of Fe deficiency. This response was similar to that of supplying Fe-ethylenediamine- N,N’-bis(2-hydroxyphenyl)acetic acid to soil. Application of ammonium with 3,4-dimethylpyrazole phosphate (a nitrification inhibitor) increased leaf chlorophyll index and stomatal length, and induced root biochemical responses similar to those with Fe-ethylenediamine-N,N’-bis(2-hydroxyphenylaceticacid) application. Leaf-applied Fe-ethylenediaminetetraacetic acid induced a high root citric acid concentration, suggesting a limited translocation of Fe from leaves to roots. Intercropping with Festuca rubra decreased the leaf fluorescence-derived parameters in the first year and increased the leaf stomata conductance in the second year of the experiment. Conclusions: The results demonstrate the potential for preventing grapevine Fe chlorosis more sustainably through managing ammonium nutrition and adopting intercropping with Fe-efficient grasses. Significance of the Study: The data provide evidence of the effectiveness and physiological responses of agronomic strategies, alternative to synthetic Fe chelates, for preventing Fe deficiency in the grapevine

The aim of this investigation was to study the effect of sustainable strategies to correct iron deficiency in blueberries, based on Fe-heme applications or intercropping with graminaceous species, on yield, and berry quality variables. The experiment was conducted in a blueberry orchard established in a sub-alkaline soil. The association with grasses increased the crop load and yield (only Festuca rubra), and decreased the skin/flesh ratio. In addition, these treatments increased anthocyanins as well as some hydroxybenzoic acids, hydroxycinnamic acids, flavanols, and flavonol concentrations in skins with a similar effectiveness as Fe-EDDHA, whereas the Fe-heme applications did not influence such parameters. Moreover, data revealed that the association with both grasses decreased the firmness of the berries, whereas none of the treatments assessed changed the soluble solids, pH, acidity, and the soluble solids/acidity rate compared to the control. These results suggest that Fe nutrition is crucial for yield and berry quality in blueberry, and that intercropping with grasses may be an effective and sustainable alternative to counteract Fe deficiency in blueberry, with a similar effect on berries to that achieved with Fe-EDDHA.