Research and IPM

Phenology Model Database

Rose

Flowering Shoots

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.

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 of 1

Pasian, C.C., and J.H. Lieth. 1994. Prediction of flowering rose shoot development based on air temperature and thermal units. Scientia Horticulturae 59:131-145.

Location of study: Davis, California (greenhouse studies)

Developmental thresholds

Lower:

41.4°F

(5.2 °C)

Method of calculation: Max-Min Method: Degree-days = [(Tmax - Tmin)/2] - To, where Tmax is the daily max temperature, Tmin is the daily min temperature, To is the lower threshold. Set Degree-days to 0 when To > (Tmax - Tmin)/2.

Degree-day accumulations required for each stage of development

	DD (°F)	DD (°C)
'Cara Mia'
Cutting to bud break	376	209
Bud break to leaf 1	171	95
Leaf 1 to visible bud	297	165
Visible bud to last leaf	149	83
Last leaf to harvest	364	202
'Royalty'
Cutting to bud break	362	201
Bud break to leaf 1	139	77
Leaf 1 to visible bud	313	174
Visible bud to last leaf	119	66
Last leaf to harvest	473	263
'Sonia'
Cutting to bud break	349	194
Bud break to leaf 1	167	93
Leaf 1 to visible bud	288	160
Visible bud to last leaf	153	85
Last leaf to harvest	310	172
Bud break: day on which a growing bud reaches length of at least 10mm. Leaf 1: unfolding of leaf 1