270 



the head of wheat is a total loss, but the soil is usually not suspected as 

 the source of the trouble. 



When grain is grown continuously on the same fields the soil tends 

 to accumulate germs of this character. Such an infested soil may be 

 likened to a house long used by sick people without cleaning. What is 

 needed is a thorough disinfection. Unfortunately, at present we know 

 no satisfactory way of disinfecting soils, and we do not even know the 

 kinds and virulence of the diseases to any extent. Our chief reliance so far 

 has been in crop rotation. Possibly something might be done by disin- 

 fecting the seed, which is known to harbor the germs. Mr. Hoffer found, 

 as reported in last year's Proceedings of this Academy, that out of thirty- 

 four varieties of wheat examined by him twenty showed germs of this 

 sort, most of them being Fusarium. 



The subject is a large one of the highest economic importance, and in 

 very great need of study. 



Diseases Not Associated With the Soil. — There is no need of specify- 

 ing where work is needed in this class of troubles, the subject has been 

 before the public too long. Many such diseases are now well understood 

 and efficient remedies already put into use, as in the case of oat and wheat 

 smut, corn smut, and some fruit rots. P>ut there are many rusts, mildews 

 and blights yet to be worked out. and their economic importance rated. 



Weeds. — As a rule weeds have not been regarded with sufficient seri- 

 ousness. But many farmers appreciate the advantages of clean culture, 

 and would like to exterminate the more pernicious kinds. There is a group 

 of weeds, including especially the bindweeds, wild sweet potato, horse 

 nettle and trumpet creeper, that need careful investigation as to the best 

 methods for their control. Field experiments along this line are needed. 

 Horse nettle is now infesting thousands of acres of land in the southern 

 and central parts of the State and is gradually gaining ground northward. 

 Trumpet creeper is becoming so pestiferous on account of its heavy, 

 woody roots, as to make the work of cultivating the infested laid a dif- 

 ficult and tedious task. Bindweeds and wild sweet potato are proving to 

 be a bane to corn culture, especially on bottom lands. Large fields can 

 _>e found where nearly every corn plant is entwined by some one of theso 

 kinds of weeds. It is safe to say that in such cases the crop yield is re- 

 duced by at least one-third. Aside from reducing the yield such weeds 

 also increase the cost of field operations and harvesting and in other ways 

 depreciate the value of land. 



