-fi- 



SOIiE FACTS ABOUT FRCST 



Critical temperatures for fruits at different stages of development are 

 indicated by the following figures. They represent temperatures endured for 

 30 minutes or less, v.dthout injury. 



Kind of Fruit 



Apples 



Belicious 

 Some Beauty 



Pears 



Beurre Bosc 

 ./inter i'lellis 



Peaches 



Cherries 



Plums 



Grapes 



Small Green Fruits 



29°F. 

 29 



29 

 29 

 30 

 30 

 30 

 31 



Records from various stations in New England reveal wide variation in dates 

 of the last killing frost. 



Average Date of last Date after which frost 



Station lulling Frost in Spring may occur 1 year in 5 



Amherst 



Concord, ii'ass, 



Fitchburg 



l.'estboro 



^'Villiamstovm 



Liiddleboro 



Ilew Bedford 



Blue Hill Observatory 



Concord, Nev/ Hampshire 



Burlington, Vermont 



Kingston, PJiode Island 



Hartford, Connecticut 



28 



ilay 12 

 May 8 

 April 

 I.Iay 6 

 May 2 

 May 12 

 April 14 

 April 

 May 7 

 April 

 April 

 April 



28 



29 

 28 

 23 



Aiay 21 

 May 15 

 May 18 

 May 17 

 May 11 

 May 23 

 April 

 May 7 

 May 16 

 May 8 

 May 6 

 Ma-^^ 4 



23 



A difference of as much as Q° has been recorded at different elevations in 

 the University Orchards during a single night. If a frost follows a period of 

 weather favorable for rapid grov/th more damage is caused than if the same tempera- 

 ture follovjs a period of cool cloudy weather. Also, more damage results from a 

 given temperature vfhen the humidity is lov; than vrhen it is relatively high. 



G-rovjers Urged to K eep Simple Spray Record . Any commercial apple grower 

 in iiassachusetts may obtain a form for recording weather conditions and 

 the details of the spray and dust program by contacting his county 

 extension office. Just ask for a Spray Record "Card, These cards pro- 

 vide space for noting rainfall, but stages, temperature and materials 

 used. Data of this kind will be of special interest to prospective 

 members of the Red Apple Club. 



