76 



THE WHEAT PLANT 



sown out of the ordinary English season, namely in April, May, or June, 

 that the greatest effect of time of sowing is seen. 



Winter wheats, or varieties with a long vegetative period, sown at any 

 date after the end of April, and spring forms of short growing period, 

 sown after the middle of June, go on tillering throughout the year in 

 which they are sown into the next before sending up ear-bearing straws, 

 the number of short unexpanded shoots or " tillers " produced diminish- 

 ing more or less regularly as the date of sowing advances from the periods 

 named. 



In a series of experiments, in which grains of four varieties of wheat 

 were sown at the University College Farm, Reading, every week through- 

 out the year, the following results, as shown on page 77, were obtained. 



Another factor which very materially modifies the stem and ear pro- 

 duction in wheat is the space allotted to the individual plants of the crop. 



Extensive tillering can only take place when each has ample room for 

 its development ; the roots especially must be free from competition with 

 the roots of other plants, and allowed to permeate the soil in all directions 

 without hindrance, if maximum tillering is to be attained. 



Where the crop is crowded, owing to thick seeding of the grain, 

 branching is much reduced ; on the other hand, it is increased by thin 



