PT  - JOURNAL ARTICLE
AU  - Chock, Coby Kanaipono Keiichi
AU  - Trivedi, Manushi B.
AU  - Vanden Heuvel, Justine E.
TI  - Spatial Sampling of Fruit Maturity Reduces Sampling Costs for Winegrapes in California and New York
AID  - 10.5344/ajev.2024.23057
DP  - 2024 Jan 01
TA  - American Journal of Enology and Viticulture
PG  - 0750012
VI  - 75
IP  - 1
4099  - http://www.ajevonline.org/content/75/1/0750012.short
4100  - http://www.ajevonline.org/content/75/1/0750012.full
SO  - Am J Enol Vitic.2024 Jan 01; 75
AB  - Background and goals In winegrape production, clusters are sampled multiple times per growing season to assess fruit maturation. The economic cost of implementing a previously-developed spatial sampling method using normalized difference vegetation index (NDVI) images to assess block variability was compared to the economic costs of random sampling (R20) and of sampling via the four corners approach (4C). The objective was to compare the travel distance to sample blocks between the spatial sampling protocol (NDVI3), R20, and 4C, and the time and cost associated with the required travel distance of each sampling method.Methods and key findings Travel distances for each sampling method were calculated for six commercial vineyard blocks. The cost of required labor and travel was calculated for each travel distance. Travel distances per block for the R20, 4C, and NDVI3 methods ranged from 3.34 to 13.63 km, 0.68 to 2.41 km, and 0.36 to 1.58 km (all per sampling event), respectively. Total cost savings per sampling event using NDVI3 ranged from $5.54 to $32.40 when compared to R20, and from $0.33 to $4.61 when compared to 4C.Conclusions and significance The cost savings of using NDVI3 for maturation monitoring appears relatively small compared to R20 and 4C, but considering that most blocks are sampled multiple times leading up to harvest, and that larger wine companies have thousands of acres to sample for fruit maturity, savings may become more substantial. We conclude that adoption of the NDVI3 sampling protocol for fruit maturity may substantially reduce the cost of production for winegrapes grown in large blocks, compared to R20 and 4C sampling.