CIRCULAR 5 9, U. S. DEPARTMENT OE AGRICULTURE 



Table 2. — Comparison of mushroom yields from beds cased 



spawning 



[Tests made in 1931] 



and 4 weeks after 





Yield per 10 

 square feet 



Plot No. 



Yield per 10 

 square feet 



Plot No. 



Yield per 10 

 square feet 



Plot No. 



Cased 

 2 weeks 



after 

 spawn- 

 ing 



Cased 

 4 weeks 



after 

 spawn- 

 ing 



Cased 

 2 weeks 



after 

 spawn- 

 ing 



Cased 

 4 weeks 



after 

 spawn- 

 ing 



Cased 

 2 weeks 



after 

 spawn- 

 ing 



Cased 

 4 weeks 



after 

 spawn- 

 ing 



1 and la 



2and 2a 



3and3a 



4 and 4a 



5and5a 



6and6a 



Ounces 

 288 

 257 

 261 

 238 

 139 

 343 



Ounces 

 274 

 189 

 259 

 168 

 141 

 223 



7 and 7a 



8 and 8a 



9and9a 



10 and 10a 



11 and 11a 



12 and 12a 



Ounces 

 304 

 227 

 246 

 202 

 382 

 279 



Ounces 

 230 



247 

 215 

 88 

 212 

 200 



13 and 13a 



14 and 14a 



15 and 15a 



Mean yield » . 



Ounces 

 252 

 383 

 300 



Ounces 

 237 

 275 

 259 



273.4 



214.4 



i The standard error of the mean of the differences is 13.9 ounces per 10 square feet 



Here again, when considered as a whole, the results of the yield 

 tests were in agreement with general commercial practice. With a 



Figure 1. 



-Effect of the reaction of the casing soil on the yield of cultivated 

 mushrooms: a, Neutralized soil; b, acid soil. 



normal run of mycelium in the beds the best yields were obtained when 

 the casing was applied 2 or 3 weeks after spawning. At this time the 

 mycelium had usually appeared on the surface of the beds in patches 

 6 inches in diameter. Earlier or later casing reduced the yields in 

 certain of the experiments. 



REACTION OF THE SOIL 



In the first experiment planned to test the effect of the reaction of 

 the soil on yields, a soil series was made with four different pH values. 

 This series was made from a Keyport clay loam with a natural reaction 

 of pH 6.0. The hydrogen-ion concentration was increased with 

 sulphuric acid and decreased with hydra ted lime. It is evident from 

 the yield data in table 3 that production was sharply reduced when 



