660 STATE BOARD OF AGRICULTURE. 



Table IV. Departures from Normal Tempsrature, Precipitation and Sunshine in Michigan 



-f = above normal; — = belcw normal 



1919 1920 1921 



T. +0.3° —4.9° +6.3" 



April P. +1.12" +0.65" +1.15" 



S. —2% —6% +3% 



T. —0.7° —1.1° +3.6° 



May P. N —1.91" — 1.4S" 



S. +6% +11% +7% 



T. +7.0° +1.4° +5.3^ 



June P. — 0.75'' +0.9" —0.92" 



S. +11% +1% . +7% 



T. +2.4° —3.1° +7.0° 



July P. —0.86" —0.01" . —0.02" 



S. +8% —1% +5% 



T. +0.5° —0.4° +7.0° 



Aug. P. —0.5" +0.09" +1.29" 



S. +1% +1% +1% 

 T = Temperature; P= Precipitation; S = Si:nThlne 



The 1919 season was considered approximately normal so far as the 

 spring advance was concerned. Duchess apples were in bloom at Ease 

 Lansing on May 14 and leafhoppers emerged at their normal period. 

 The season made rapid progress in June, and, as is .seen from the table 

 of departures shown above, the temperature and sunshine were mucii 

 above normal while the precipitation was below normal for the month. 

 Similar conditions prevailed during July but in August these became 

 more nearly normal. Favorable weather conditions were presented 

 during June and July for the development of leafhoppers and resulted 

 in serious damage from hopperburn during the season. 



Contrasted with 1919, the 1920 season was backward. Apples were 

 in bloom at East Lansing on May 21, a week later than the preceding 

 year. The season did not advance rapidly in June owing to the fact that 

 the temperature and sunshine were only slightly above normal, while 

 the precipitation was almost an inch above normal. July was charac- 

 terized by cold, cloudy weather with average rainfall, while August as 

 in the preceding year was more nearly normal. The weather conditions 

 during this year were not favorable to leafhoppers. The backward spring 

 resulted in late emergence of the over-wintering adults, which coupled 

 with the cold, wet weather of July prolonged the incubation periods 

 of the leafhoppers so that these insects did not become abundant and 

 hopperburn was not an important factor during the season. 



The 1921 season was the most advanced of the three seasons and 

 apples were in bloom at East Lansing on April 26, approximately two 



