24 



BULLETIN 1410, U. S. DEPARTMENT OF AGRICULTURE 



TESTS AT WINDSOR, CONN. 



The plats located at Windsor, Conn., were essentially a duplica- 

 tion of those at Whately, so far as the plan of the experiments 

 and treatment are concerned. The soil was known not to be affected 

 with brown root rot. It was believed, however, that it might de- 

 velop the disease under one or the other system of cropping; but 

 this did not prove to be the case. The soil in the plats at Windsor 

 varied from a light sand to a light sandy loam. Unfortunately, part 

 of plats 18 to 22 lay in a corner of the field affected with black 

 root rot, and consequently the yield of tobacco from these plats is 

 probably not so high as it otherwise would have been. This, to- 

 gether with other soil variations, probably accounts for the differ- 

 ences in yield of duplicate plats placed on opposite sides of the 



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Fig. 18. — Tobacco growing after fallow on plat 17-B at Whately, Mass., August 24, 

 1923. Compare with Figure 15 



experimental area. The land had been seeded to timothy several 

 years prior to 1922. 



There seems to be no good reason for discussing in detail the 

 results of the three years in which these plats were conducted, so 

 far as brown root rot is concerned. They served the useful purpose 

 in this connection of acting as a control upon the Whately plats. 

 The yields on these plats are presented in Table 3, which adequately 

 serves to show that on this particular land and in the absence of 

 brown root rot, timothy, corn, or clover had no such injurious action 

 on subsequent crops of tobacco as was shown in the Whately plats. 

 This statement is, of course, superfluous in the light of practical 

 experience and other experimental data; yet it should be made clear 

 that it is only on certain soils or under certain conditions that brown 

 root rot occurs and that the cropping system probably bears a con- 

 tributing rather than a causal relationship. 



