Variety: Thompson Seedless
Phenology models predict timing of events in an organism's development. For many organisms which cannot internally regulate their own temperature, development is dependent on temperatures to which they are exposed in the environment.
Information in this database comes from published articles. It may be used in conjunction with field monitoring and a degree-day calculator.
Note: Before using a model that was not field tested in your location, you should test the model for one or more seasons under your conditions to verify that it will work for you.
Model 1
Williams, D.W., H.L. Andris, R.H. Beede, D.A. Luvisi, M.V.K. Norton, and L.E. Williams. 1985. Validation of a model for the growth and development of the Thompson Seedless grapevine. II. Phenology. Am. J. Enol. Vitic. 36:283-289.
- Location of study: San Joaquin Valley (Ceres, Livingston, Biola, Parlier, Hanford, Shafter), California (field studies)
- Lower developmental threshold: 50F (10 °C)
- Method of calculation: Double Triangle
Degree-day accumulations required for each stage of development
Biofix: February 20
- 50% bud break 155.5 (°F) 86.4 (°C)
- 50% bud break to 50% bloom 741.4 (°F) 411.9 (°C)
- Fruit maturity (20-21.5 brix) 2880-3240 (°F) 1600-1800 (°C) (except Ceres)
Bud break is defined as the point at which green leaf tissue could first be seen between bud scales.
