lOO STATE rOMOLOGICAL SOCIETY. 



In Plats I, 2 and 4, there is very little difference, — less than a 

 tenth of an inch in the averages. The slight advantage now pos- 

 sessed by the clean tillage alone is again probably connected 

 with its lower demand for moisture as compared with the cover 

 crop used in Plat 4. It is notable, however, that the net influ- 

 ence of the cover crops in this case has been to check rather 

 than to benefit the growth of the trees. Up to the close of the 

 fifth year, therefore, the cover crop has made no visible return 

 for itself, so far as the trees are concerned. It has consisted 

 chiefly in a mixture of red and crimson clover, sown about July 

 loth to 20th, and only the last three covers have been really 

 good. In Plat 2, the intercrops have been potatoes, peas, man- 

 gel wurzels, and sweet corn, with the fertilization considered 

 best for each. They were kept at a reasonable distance from 

 the trees, and the intervening spaces were cultivated until mid- 

 summer and again when the cover crops were sown, which 

 was after the intercrops were removed and hence was usually 

 rather late. None of the intercrops have proved especially 

 profitable, and neither have they proved any serious detriment 

 to the trees, as compared with the other tillage methods, since 

 their check to tree growth is slightly less than that of the cover 

 crops sown in the midsummer. These results are similar to 

 those obtained by Emerson at the Nebraska Station, and re- 

 ported to the close of the second year in 1903, in Nebraska 

 Bulletin 79, pages 14 to 17. 



RESULTS IN THE MERCER COUNTY ORCHARD. 



Additional data are available from another experiment 

 started by the Station in 1908 in Mercer County, the latter por- 

 tion of which is similar to the experiment just considered. In 

 the present experiment, the treatment of Plat 12 corresponds 

 with No. 2 in the experiment just considered. The usual tillage 

 and cover crops have been maintained on Plats i to 12, rye being 

 used chiefly as the cover on account of the lateness of some of 

 the intercrops. Plat 13 has received tillage alone, and 14 has 

 been mulched as in Experiment 331, although oftener. The 

 results on growth are shown in Table III. 



