PT  - JOURNAL ARTICLE
AU  - R. P. Smithyman
AU  - G. S. Howell
AU  - D. P. Miller
TI  - The Use of Competition for Carbohydrates Among Vegetative and Reproductive Sinks to Reduce Fruit Set and Botrytis Bunch Rot in Seyval blanc Grapevines
AID  - 10.5344/ajev.1998.49.2.163
DP  - 1998 Jan 01
TA  - American Journal of Enology and Viticulture
PG  - 163--170
VI  - 49
IP  - 2
4099  - http://www.ajevonline.org/content/49/2/163.short
4100  - http://www.ajevonline.org/content/49/2/163.full
SO  - Am J Enol Vitic.1998 Jan 01; 49
AB  - Three pruning severities and two times of cluster thinning were applied to Seyval blanc grapevines to vary the quantity of vegetative and reproductive sinks at fruit set. Vines were balanced pruned to either 10, 30, or 60 nodes per 454 g of cane prunings. Half were flower cluster thinned and half post-fruit-set thinned to 15 clusters per 454 g of cane prunings. Increased sink competition created by a greater number of apical meristems influenced canopy morphology and reduced cane maturation, but had no effect on Botrytis bunch rot. Delaying cluster thinning until post-fruit-set decreased fruit set, yield, and Botrytis bunch rot while increasing berry weight and °Brix. Decreasing cluster thinning severity eliminated losses in yield from reduced fruit set. Post-set cluster thinning to increase reproductive sink competition and reduce fruit set appears to be a viable cultural practice to reduce Botrytis bunch rot and improve yields.