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Fruit & Nut Crop Chill Portions Requirements

Chill Portions Requirements, Calculated using the Dynamic Model

Compiled by Katherine Pope, Orchard Advisor, UC Cooperative Extension

Crop Cultivar Chill Portions
Almond Desmayo Largueta1 28
Ferragnes1 32
Nonpareil1,2 22-23
Apple Golden Delicious3 50
Apricot Bergeron4,5 62-65
Búlida4,5 54-56
Canino5 30-45
Currot4,6,5 34-40
Dorada4,5 56-58
Goldrich6 62
Murciana4,5 56
Orange Red4,5,6 55-69
Palsteyn5 32-37
Rojo Pasion4,5 48-51
San Castrese6 55
Selene4,5 57
Cherry Brooks7 37
Burlat3,7 48-53
Cristobalina7 30
Lapins3 35
Marvin7 58
New Star7 54
Rainier3 45
Ruby7 48
Sam3 70
Somerset7 48
Nectarine Aprilglo3 12
Fantasia8 42
Flavortop8 41
Mayglo3 18
Sunlite8 33
Peach Andross9 63
Big Top9 63
Earligrande3 12
Flordaprince3 8
Maravilha3 12
O’Henry9 63
Redhaven3 75
Pistachio Kerman2,10 54-58
Mateur11 36
Peters2,10 58-65
Sirora12 60
Prune Improved French10 55-60
Walnut Chandler10 45-50
Hartley13 54
Payne14 38

 Numbers next to cultivar name indicates information source.

1. Ramirez, L., K. X. Sagredo, et al. (2010). Prediction models for chilling and heat requirements to estimate full bloom of almond cultivars in the Central Valley of Chile. Acta Horticulturae 872: 107-112.
2. Pope, K., et al. (2014). Nut crop yield records show that budbreak-based chilling requirements may not reflect yield decline chill thresholds. International Journal of Biometeorology: 1-9.
3. Erez, A. (2000). Bud dormancy; phenomenon, problems and solutions in the tropics and subtropics. Temperate fruit crops in warm climates. A. Erez. Dordrecht, The Netherlands, Kluwer Academic Publishers: 17-48.
4. Ruiz, D., J. A. Campoy, et al. (2007). Chilling and heat requirements of apricot cultivars for flowering. Environmental and Experimental Botany 61: 254-263.
5. Campoy (2012) The fulfilment of chilling requirements and the adaptation of apricot (Prunus armeniaca L.) in warm winter climates: An approach in Murcia (Spain) and the Western Cape (South Africa)
6. Viti, R., L. Andreini, et al. (2010). Effect of climatic conditions on the overcoming of dormancy in apricot flower buds in two Mediterranean areas: Murcia (Spain) and Tuscany (Italy). Scientia Horticulturae. 124: 217-224.
7. Alburquerque, N., F. Garcia-Montiel, et al. (2008). Chilling and heat requirements of sweet cherry cultivars and the relationship between altitude and the probability of satisfying the chill requirements. Environmental and Experimental Botany 64: 162-170.
8. Linsley-Noakes, G. C. and P. Allan (1994). Comparison of two models for the prediction of rest completion in peaches. Scientia Horticulturae 59: 107-113.
9. Miranda (2013) Evaluation and fitting of models for determining peach phenological stages at a regional scale
10. Estimate based on chill accumulation in California’s Central Valley in the winter of 2013-2014, spring phenology and final yields.
11. Elloumi, O., M. Ghrab, et al. (2013). "Chilling accumulation effects on performance of pistachio trees cv. Mateur in dry and warm area climate." Scientia Horticulturae (Amsterdam) 159: 80-87.
12. Zhang, J. and C. Taylor (2011). "The Dynamic Model Provides the Best Description of the Chill Process on 'Sirora' Pistachio Trees in Australia." Hortscience 46(3): 420-425.
13. Luedeling, E., M. Zhang, et al. (2009). Validation of winter chill models using historic records of walnut phenology. Agricultural and Forest Meteorology 149: 1854-1864.
14. Luedeling, E., L. Guo, et al. (2013). "Differential responses of trees to temperature variation during the chilling and forcing phases." Agricultural and Forest Meteorology 181: 33-42.