240 



FUNDAMENTALS OF FRUIT PRODUCTION 



with these figures the total heat units for the last 6 months of the pre- 

 vious growing season he secured a closer approach to uniformity as ex- 

 pressed in percentage of the smallest yearly total to the greatest yearly 

 totals for any variety (see Table 5). Sandsten interprets his data as 

 showing that other factors besides the heat units from Jan. 1 have a 



Table 



-Number of Positive Temperature Units (above 32°F.) Received 

 From Preceding July 1 to Date of First Bloom 



Variety 



1901-1902 



1902-1903 



1903-1904 1904-1905 



Wealthy . . . 

 Borovinka . 

 Charlamoff 

 Hibernal . . . 

 Grimes. . . . 



5,106.5 

 5,133.5 

 5,133.5 

 5,081.5 

 5,081 . 5 



4,827.5 

 4,801.5 

 4,918.5 

 4,827.5 

 4,801.0 



4,601.5 

 4,576.0 

 4,601.5 

 4,556.0 

 4,601.5 



48,01.5 

 47,10.5 

 48,24.5 

 47,10.5 

 47,63.5 



bearing on the time of flowering and enumerates as possible factors the 

 stage of advancement of the buds at the time of growth cessation in the 

 fall, the size of the crop borne in the previous year, "soil conditions and 

 the amount of plant food present in the soil; and fifth, the individual 

 characteristics and state of health of the tree or plant." General observa- 

 tion on peach trees shows a sequence in opening blossoms corresponding 

 to the stage of advancement of these buds in the fall, the difference in 

 time of flowering on the same branch amounting sometimes to several 

 days, which would make a difference occasionally of 50 units or more on 

 the Fahrenheit scale. Magness makes an interesting suggestion in this 

 connection which is referred to under Fruit Bud Formation. 



Seeleyi^" applied the method of temperature summations to the Late 

 Crawford peach, as recorded in the Mikesell data for Wauseon, Ohio. 

 His summary of results, shown in Table 6, indicates no close agreement 

 from year to year for the same locality. Somewhat closer tallying was 

 secured when maximum figures were used (line 4) . Seeley shows that air 

 temperatures as recorded by thermometers in the conventional shelter do 

 not indicate at all closely the actual temperatures of the leaves. 



Table 6. — The Least and the Greatest Temperature Summations in the Life 

 Phase of the Late Crawford Peach 



{After Seeleij''^) 



