Effects of hot water treatments on dormant grapevine propagation materials used for grafted vine production

Abstract

Agrobacterium vitis is responsible for the crown gall disease of grapevine which breaks the grapevine trunk vascular system. Nutrient flow is prevented by crown gall and it leads to weak growth and death of the plants. It can be destructive disease often encountered in vineyards and it can be spread in cuttings for propagation. Thermotherapy treatment is an alternative method for eradicating A. vitis from grapevine cuttings but effects of thermotherapy treatments on dormant vine tissue, bud vitality, rooting and shooting of the propagation materials are not yet fully understood. In this research, it is aimed to determine the effects of thermotherapy treatment (Hot water treatment) on callus formation (at the basal part and grafting point), grafted vine quality (shoot length, shoot width, root number, shooting and rooting development, fresh and dry weight of shoots and roots) and final take in the grafted vine production. Experiment was conducted in the nursery of Manisa Viticultural Research Institute. Rootstocks (Kober 5BB, Couderc 1613 and 41B) and scions (Sultan 7 and Manisa sultanı) were hot-water treated at 50 • C for 30 minutes which is the most common technique against Agrobacterium vitis. After thermotherapy treatment, all rootstocks were grafted with Sultan 7 and Manisa sultanıvarieties. They were kept for 22 days in callusing room for callus development and then they were planted in polyethlyene bags for rooting. At the end of the study, significant treatment x rootstock interaction were observed for the final take of Sultan 7 variety. Thermotherapy treated of 1613C/Sultan 7 combinations had more final take than the control (untreated) group. For instance, hot water treated cuttings of 1613C/Sultan 7 combinations had 75% final take while the control group had the 70%. Also there were not observed any adverse effects of HWT on bud and tissue vitality.

Hot water treatment: an effective method for disinfecting Castanea sativa mill. dormant scions against Dryocosmus kuriphilus Yasumatsu

“…found only a slight reduction in grapevine shoot weight in the third and fourth years following HWT. Soltekin and Altindisli treated two grapevine cultivars and three rootstocks, and found differences in shoot development following HWT depending on the rootstock involved. In our experiment, scions treated at 52 °C were significantly longer than the control treatment.…”

“…Hot water treatment (HWT) was first employed in 1882 to prevent mildew in potato . This method is currently used for pathogen control with the seeds of several crops, and it is known to be an effective method for the control of the fungi that cause trunk diseases, as well as Scaphoideus titanus eggs, mealybugs, mites, Agrobacterium vitis and Xylella fastidiosa in grapevine; Xanthomonas arboricola in hazelnut; and Neonectria dittisima in apple . Post‐harvest HWT has been also evaluated in chestnut fruits, where positive results in terms of the reduction of weevil and fungal contaminations have been reported …”