PT - JOURNAL ARTICLE AU - James A. Taylor AU - Terence R. Bates TI - Sampling and Estimating Average Pruning Weights in Concord Grapes AID - 10.5344/ajev.2012.12069 DP - 2012 Aug 17 TA - American Journal of Enology and Viticulture PG - ajev.2012.12069 4099 - http://www.ajevonline.org/content/early/2012/08/16/ajev.2012.12069.short 4100 - http://www.ajevonline.org/content/early/2012/08/16/ajev.2012.12069.full AB - Pruning weights are a useful indication for growers of the state of vine size within their production systems. However, pruning weights are rarely collected in commercial situations as there is little information to help growers determine how many samples to measure. An intensive study of individual vine pruning weights was undertaken over three years in a Concord (Vitis lambruscana, Bailey) block at the Lake Erie Research and Extension Laboratory, Portland, NY. The population variances associated with individual and then aggregated neighboring vine measurements were used to determine random sample schemes to assist growers. Several approaches are presented and a sampling scheme based on 23 random inter-post (3 vine) samples is suggested as a good compromise to minimize the time associated with sampling, the accuracy of measurement and value of the information. A spatial analysis of the variance indicates that the same sampling scheme could be extrapolated to block sizes larger than the survey area (0.93 ha) provided that the management and environmental conditions can be considered uniform over the larger block.