INDOOR COMPOSTING FOR MUSHROOM CULTURE 7 
perienced growers at the end of the conventional composting procedure. 
The manure must be friable, dark brown, speckled with gray fire 
fang, free from an ammonia odor, and the average pH should be less 
than 8.0. This condition usually will be reached some time between 
8 and 14 days. In the experiments at Arlington Farm the manure 
was chopped and moistened on the same day it was hauled from the 
stables, and in most cases it was placed in the beds the following day. 
Under these conditions the most satisfactory length of composting 
was 12 days. The results of tests conducted to determine the relation 
of length of composting and moisture content at time of filling to 
mushroom yield are summarized in table 1. It will be noted that the 
poorest yields on the average are obtained from the plots that received 
an excess of water and were composted only 8 days. The plots 
composted 12 days and 14 days with moderate moisture were uni- 
formly satisfactory. 
BONTROE OFSFUNGUS DISEASES AND INSECT PESTS 
No difficulty was experienced with weed molds, such as the olive 
green mold or the plaster molds, in plots that were composted a 
sufficient length of time within a proper temperature range. All 
cases of weed mold invasion could be traced to deliberate under- 
composting or overheating. In the experimental rooms at Arlington 
Farm insects were completely eradicated during the composting period 
without the usual cyanide or sulfur fumigation by maintaining an air 
temperature of 130° F. with auxilary heat and circulating the air 
with fans during the last 2 or 3 days of composting. It should be 
noted that the above statement applies particularly to the last 2 or 3 
days of composting, because it is only at this time, when the differ- 
ence between air temperature and the manure temperature is reduced 
to less than 5° F. (see fig. 3), that it is possible to raise the air tempera- 
ture to 130° F. without running a risk of overheating the manure. 
It is understood, of course, that after the compost cooled and the 
rooms were opened the usual control measures were observed to pre- 
vent the entrance and multiplication of insects and disease fungi. 
QUALITY AND YIELD OF MUSHROOMS 
The quality of the mushrooms produced from indoor composting 
was the same as from beds composted in the conventional manner 
(fig. 4). The experimental beds in the spring of 1940 produced 
mostly small mushrooms after the first break, but, as this frequently 
occurs in commercial culture, no special significance was attached to it. 
The yield of mushrooms per square foot of bed space averaged 
between 1% to 2% pounds on beds that were not deliberately given a 
treatment injurious to the crop. So many factors enter into the pro- 
duction of a good yield of mushrooms that it 1s difficult to judge the 
potential worth of a system, such as the one under discussion, from a 
few yield test figures without seeing the beds in all stages of production. 
In the writer’s opinion the yields per square foot were excellent con- 
sidering the conditions under which the crops were grown. 
