Huining Xu

Influence of crop load on belowground carbon allocation in Concord grape.

M.S. in Plant Biology, 2008

Collaborators: Alan Lakso, Rick Dunst, Kelly Link

Huining has been supported by an IBIOS fellowship, the Viticulture Consortium and NY Wine & Grape Foundation.

Large crops may substantially compete with root growth and activity in grapes and other fruit tress, possibly leading to a decline in plant vigor. I predict that high crop loads will reduce fine-root production, longevity, respiration and concentration of carbohydrates and nitrogen. My study site is a mature Concord grape vineyard in Fredonia, NY. In 2004, 2005, and 2006, at 30 days after bloom, crops were adjusted to four levels by cluster thinning, with targets of 100, 75, 50 and 25% of full crop in a completely randomized block design with 3 treatment vines and one buffer vine on each side of the treatment vines. Fine root production and lifespans have been observed using minirhizotrons beginning in 2004. I am also determining the effect of different crop loads on root respiration using a gas exchange system with an IRGA and carbohydrate and nitrogen concentration by colorimetric and elemental analysis, respectively (2006). I will estimate the total amount and spatial distribution of the vine root system by roots collected from soil cores in 2006 before veraison. These data will be used to calculate the total carbohydrate requirement and carbon allocation of the whole root system.


  • Xu, Huining. 2008. M.S. in Plant Biology. The influence of reproductive effort on root dynamics and physiology in Concord grape.