PT  - JOURNAL ARTICLE
AU  - R. V. Chudyk
AU  - R. F. Crowther
AU  - O. A. Bradt
TI  - Use of Meteorological Data to Estimate Field Sugar Levels in Concord Grapes
AID  - 10.5344/ajev.1979.30.3.253
DP  - 1979 Jan 01
TA  - American Journal of Enology and Viticulture
PG  - 253--255
VI  - 30
IP  - 3
4099  - http://www.ajevonline.org/content/30/3/253.short
4100  - http://www.ajevonline.org/content/30/3/253.full
SO  - Am J Enol Vitic.1979 Jan 01; 30
AB  - This study explored the use of regression analysis involving meteorological data to estimate field sugar levels in Concord grapes. The appropriate type of regression depended upon the starting date for grape heat unit (GRHU), corn heat unit (CHU), or sunshine hour (SUN) summations.Two successful regressions were developed using first bloom as the starting date. The regression of sugar (Y) on CHU had an R-value of 0.952 and accurately (± 1.0°Brix) estimated 100% of the field sugar samplings during the 1978 vintage. The regression of sugar (Y) on GRHU had an R-value of 0.872 and accurately estimated 90% of the field sugar samplings during the 1978 vintage.A successful regression developed using April 1 as the starting date was the multiple regression of sugar (Y) on (CHU + SUN). This multiple regression had an R-value of 0.924 and accurately estimated 100% of the field samplings during the 1978 vintage.Results suggest that regression equations can be useful in estimating the extent of grape sugar production during vintage.