Budbreak, fruit quality and maturity of ‘Superior’ seedless grapes as affected by Dormex^®under Jordan Valley conditions

Abstract

Budbreak, fruit quality and maturity of 'Superior' seedless grapes as affected by Dormex ® under Jordan Valley conditions. Abstract-Introduction. In subtropical regions, the lack of or insufficient winter chilling has been one of the most important yield-limiting factors for table grapes. Winter chilling for several weeks is required to cause the transition of both vegetative and floral buds from the dormant to the active state. Thus, the effect of time of application of Dormex ® (hydrogen cyanamide) on fruit quality and ripening of 'Superior' seedless grape was evaluated under Jordan Valley conditions. Materials and methods. Five-year-old 'Superior' seedless vines were pruned on 20 December and sprayed to runoff with a 5% (v/v) concentration of Dormex ® at pruning (Dormex prun0), 7 d (Dormex prun7) or 14 d (Dormex prun14) after pruning in comparison with the pruned-only control plants. The date of vegetative budbreak and start of flowering were determined. Fruits were harvested at intervals of 7 d starting from 9 May, with four harvests. Studied data were fruit weight, total soluble solids (TSS), titratable acidity (TA) and maturity with the [TSS:TA] ratio. Results and discussion. All pruned and sprayed vines broke bud 23-46 d after pruning. The (Dormex prun0) and (Dormex prun7) treatments were the earliest. Compared with the control, Dormex ®-treated vines broke bud 4-26 d earlier. All pruned and Dormex ®-treated vines started flowering 55-64 d after pruning, with 4-13 d earlier than the control. Fruits of the (Dormex prun0) treatment had significantly the highest fruit weight, TSS and the least TA, and it was the only treatment that exceeded the [18:1] (TSS:TA) level. Additionally, higher TSS and lower TA were observed for fruits of Dormex ®-treated vines during all harvest dates in comparison with the control. Conclusion. Our study showed that, under southern Jordan Valley conditions, Dormex ® should be applied as early as at pruning time to obtain early budbreak and maturity. Jordan / Jordan River / Vitis vinifera / dormancy breakers / fruits / quality Effet du Dormex ® sur la levée de dormance, la qualité du fruit et la maturité de raisins aspermes 'Superior' dans les conditions de la vallée du Jourdain. Résumé-Introduction. Dans les régions subtropicales, le manque ou l'insuffisance de froid hivernal a été l'un des facteurs limitants du rendement le plus important pour le raisin de table. Un froid hivernal de plusieurs semaines est nécessaire pour provoquer la transition des bourgeons végétatifs et floraux du stade dormant à un état actif. De ce fait, la période d'application du Dormex ® (cyanamide d'hydrogène) a été évaluée quant à son effet sur la qualité du fruit et la maturation du raisin asperme 'Superior', dans les conditions de la vallée du Jourdan. Matériel et méthodes. Des vignes aspermes 'Superior' de 5 ans ont été taillées le 20 décembre et une solution à 5% de Dormex ® (v/v) a été appliquée par pulvérisation soit au moment de cette taille (Dormex taille0), soit 7 jours (Dormex taille7) ou 14 jo...

Effect of Summer Pruning and Some Bio-Stimulants on Bud Fertility, Vegetative Growth, Yield and Fruit Quality of Vitis vinifera cv. "Superior" Grapevines

“…Actress random samples of 6 bunches per vine were harvested when SSC reached about 16-17% according to Muhtaseb and Ghnaim (2007). The following characteristics were determined: -Yield/vine (kg) was estimated as number of bunches /vine multiplied by average bunch weight /vine and average estimated yield /vine was calculated.…”

Effect of Pre-Harvest Application of Hydrogen Cyanamide and Abscisic Acid (ABA) on Time of Ripening and Fruit Quality of Flame Seedless Grape (Vitis vinifera L.)

“…Similarly, Hyun et al, (1996) also found the higher bunch weight was recorded with ethephon treatments applied at veraison in "Kyoho" grapes. Muhtaseb and Ghnaim (2008) studied the effect of time of application of Dormex®. They found that Dormax treated vines had significantly higher fruit weight.…”

Enhancing Uniform Sprouting, Yield, and Quality in Grapevines: The Impact of Hydrogen Cyanamide (50% S.L) Treatment

“…The vines treated with Dormex (Hydrogen Cyanamide) broke bud 4-26 days earlier than the control. All vines that had been trimmed and given the Dormex treatment began to flower 55-64 days following the pruning, 4-13 days earlier than the control [17]. However, the period of maturity was only accelerated by 4 days when the same concentration was applied 53 days before natural bud break.…”

“…In addition, more TSS was detected from vines treated with Hydrogen Cyanamide (H2CN2) throughout every harvesting date as compared to the control. However, the TSS level of the fruit was modest or unaffected by delaying Hydrogen Cyanamide (H2CN2) treatment for longer than two weeks after pruning [17].…”