(119) Mycorrhizal Effects on Grape Acclimation

Abstract

Grape growers are interested in production systems that are ecologically sustainable. The positive effect of colonization by arbuscular-mycorrhizal (AM) fungi on water and nutrient uptake, and thereby plant growth, is well-documented, at least in greenhouse studies. However, we have only limited data on how this complex association between grapes and these fungi might affect entry into winter dormancy, a factor crucial to vine survival in the northern great plains. To test this relationship, we rooted cuttings of grape genotypes Vitis riparia and an F1 selection of `Seyval' × V. riparia in a soil mix containing either inoculum of the AM Glomus intraradices, or a control. These cuttings were then used in growth chamber, greenhouse, and field experiments. The inoculated rooted cuttings were successfully colonized; no significant differences were observed among treatments in initial cutting vigor, budbreak, or leaf number. In the field and greenhouse, periderm development (an indicator of entry into dormancy) occurred earlier in AM-inoculated plants, regardless of genotype. Growth chamber-grown plants did not display differences in the first year, but, after a dormancy cycle, buds from inoculated plants survived lower temperatures in freezing tests compared to controls.