Plants, like insects, are ectotherms, which means that their rate of development depends on external conditions. Sure, most companies put ‘days-to-harvest’ on the seed packet, but we all know that is just an estimate, and can vary widely by region. It’s greatly influenced by temperature; especially if we encounter variations from the ‘normal’ levels of heat and/or rainfall.

Faculty at OSU Extension’s Small Farms Program and the Integrated Plant Protection Center have developed an online, predictive tool to help guide grower decisions and crop planning. The resource is called CROPTIME, and it provides models for a few of the crops grown in Oregon, with aims to develop 50 models (vegetables and weeds) eventually. Here is a 9-minute video that describes how to use the program.

This tool can greatly aid vegetable growers in estimating regional, temperature dependent phenology for a specific variety. For instance:

Broccoli Harvest Estimates - 2017

This information is collected from an online prediction tool, Croptime, from Oregon State University. The program is free to use and publicly available. Planting dates and varieties can be adjusted by the user and models are available for broccoli, sweet corn, cucumber, and sweet pepper.
*Estimates are accurate for W. Oregon only, these particular values are based off weather data near Keizer, OR.
VARIETYTransplant date50% head initiationFirst harvestEarly flowering
Imperial1-JUN26-JUL13-AUG23-AUG
15-JUN7-AUG26-AUG4-SEPT
1-JUL22-AUG11-SEPT21-SEPT
Arcadia1-JUN24-JUL10-AUG22-AUG
15-JUN4-AUG22-AUG4-SEPT
1-JUL20-AUG8-SEPT21-SEPT
Emerald Pride1-JUN21-JUL7-AUG18-AUG
15-JUN1-AUG18-AUG30-AUG
1-JUL16-AUG4-SEPT16-SEPT
Green Magic1-JUN17-JUL5-AUG16-AUG
15-JUN29-JUL17-AUG28-AUG
1-JUL13-AUG2-SEPT13-SEPT

For more information, visit http://smallfarms.oregonstate.edu/croptime

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