B. P. I. — 182. V. P. P. I. — 142. 



THE PRINCIPLES OF MUSHROOM GROWING AND 

 MUSHROOM SPAWN MAKING 



INTRODUCTION. 



For a number of years there has been an increasing demand in the 

 United States for information concerning- mushroom growing. In 

 the horticultural and agricultural press mau}^ individual practices 

 have been presented; but in order to give rational encouragement to 

 mushroom growing in favorable sections of this country it was recog- 

 nized at the outset of the investigations undertaken by the writer that 

 much experimental work would be required. Bearing upon the cul- 

 ture of Agaricus campestris " a number of physiological questions 

 were demanding attention, for it was desirable to ascertain (1) the 

 conditions of spore germination, in order that " virgin " spawn might 

 be propagated and the principle of selection attempted; (2) the 

 relation of this fungus to nutrients, or a determination of the sub- 

 stances or compounds which might best serve as food materials ; and 

 (3) the relation of the growing mycelium and of mushroom jjroduc- 

 tion to temperature, moisture, and other conditions of the environ- 

 ment. In the next place it would be necessary to determine the 

 application of any physiological principles established to the practice 

 of mushroom growing and mushroom spawn making. 



In connection with a presentation of the results of the experimental 

 work '' it seems desirable to include also a more or less comj^rehensive 

 account of the present status of mushroom growing at home and 

 abroad. 



« Throughout this puper the writer has employed the generic name Agaricus 

 in the sense in which it is usually understood hy those interested in the praetical 

 side of the worl<. 



6 During 1903-4 the writer was assisted in the experimental work by Mr. A. 

 M. Ferguson, instructor in botany in the University of Texas, at that time special 

 agent of the Department of Agriculture, and during 1904-5 similar assistance 

 has been rendered by Mr. L. F. Childers, student assistant. Through the assist- 

 ance thus given it has been possible to complete an unusual amount of 

 experimental work, only a portion of which can be described in detail, although 

 it has all been taken into consideration in the conclusions drawn. 



9 



