BURKAU OF PLANT INDUSTRY. 189 



Effects of different lengths of day upon the growth and reproduc- 

 tion of the corn plant have been studied. It has been found that the 

 various types of corn react very differently and that such differences 

 must be "taken into account iii acclimatizing corn and determining 

 the adaptability of varieties. 



EFFECT OF BORAX ON FERTILIZERS. 



Investigations of the effect of borax on different crops and in dif- 

 ferent quantities under a variety of soil conditions and climatic 

 factors have been concluded. The results show that the injuries re- 

 ported during the war were primarily due to the borax contained 

 in the fertilizer in proportions exceeding 10 pounds per acre, although 

 in many experiments much smaller quantities often caused some of 

 the symptoms of borax poisoning to appear. Under moist soil con- 

 ditions or rains following the application of the fertilizers the 

 effect of the borax is much less than where dry conditions obtained. 

 The potash sources which carried this borax into the fertilizers are 

 now so purified that the quantity of borax contained in them is 

 negligible. The elimination of borax from fertilizers to a safe limit 

 has been accomplished, and no further damage need be feared from 

 this source. 



FOREST DISEASES. 



BLUE STAIN OF YELLOW PINE AND GUM 



" Blue stain," caused mainly by the fungus Ceratostomella, is the 

 most important degrading factor in air-seasoned southern yellow 

 pine and causes deterioration of many other kinds of lumber. In 

 the South, the control of staining and molding fungi is perhaps the 

 biggest problem in the industry. In air-seasoned pine and gum two.- 

 thirds of the stock becomes blued. Blued gum sells for $2.50 to $4 

 per thousand board feet less than "' bright " stock, and exporters will 

 not take stained stock at all. Anywhere in the country where^ lum- 

 ber is cut,, if the conditions of humidity and temperature are favor- 

 able, blue staining and molding will occur unless special preventive 

 measures are taken. 



DiECAY IN DOUGLAS FIR. 



In the States of Oregon and "Washington alone there is a stand of 

 Dourrlas fir a^gregatino- 505,000,000,000 feet board measure, which 

 amounts to nearly one-fourth of the remaining stand oi saw timber 

 in the United States. Much of this is overmature, and the loss 

 through decay in such stands is enormous. A loss of 20 per cent 

 from decay in overmature stands is common, and in some cases the 

 loss may reach 50 per cent or more, making profitable logging im- 

 possible. This large percentage of defect often leads to gross error 

 in cruising timber and scaling logs. 



It has been determined that all but a very small portion of the 

 loss through decay is caused by the ring-scale fungus {Trametes 

 pini). It has been found, contrary to the oreneral belief among 

 timbermen, that whenever this decay occurs in a living tree it is 

 accompanied by outward visible indications of its presence. Apply- 

 ing this knowledge makes it possible to cruise timber and scale logs 

 with much greater accuracy. 



