THE EFFECT UPON THE GROWTH OF SOME CONIFEROUS 



SEEDLINGS OF VARIOUS CONDITIONS OF 



SHADE AND MOISTURE * 



BY PAUL C. KITCHIN. 



It has long been the practice, and still is in many places, to consider 

 the shading of coniferous seedlings, at least until the end of the first 

 year, as essential to their proper development. According to Toumey, 

 experiments in many locations have proved that this shading is not 

 essential, though the advantage or disadvantage of shading should be 

 proved for any specific locality before it is dispensed with. To prove, 

 then, the economic advantage, or disadvantage, of shading for the Forest 

 Nursery, located at the Michigan Agricultural College, is the object of 

 the work herein detailed. It was carried on under the supervision of 

 Prof. A. K. Chittenden of the M. A. C. Forestry Department. 



The experiment was run in three parts, using different seedlings in 

 each part. Up to the time when the work was started, all four sections 

 of each group had developed under similar conditions, hence the com- 

 parisons and contrasts on any one set should show the approximate truth. 

 The three species used were (1) Pinus strobus, (2) Pinus resinosa and 

 (3) Picea excelsa. With the exception of the fact that maximum and 

 minimum temperatures were determined for the air just above each of 

 the four parts of the Pinus strobus bed, all the species had identical 

 treatment as follows: 



The seedling bed (about twenty linear feet of ordinary four feet wide 

 seed bed) was divided into four equal parts of five linear feet each and 

 these parts will subsequently be known as I, II, III and IV respectively. 

 Bed I was given full shade by means of a burlap cover, and received no 

 water, except that rainfall which filtered through (see precipitation re- 

 ports appended). Bed II was given one-half shade by means of the 

 ordinary lath covering, and no water except as noted for I. Bed III was 

 treated as a check, receiving no shade and no water, excepting rainfall. 

 Bed IV was given no shade and watered well every evening, besides the 

 rainfall it received. (Plate XVII.) In the case of the Pinus strobus, 

 the maximum and minimum temperatures for each part for each 24 hours 

 were noted and tabulated. The fact that the temperatures of the air. 



*Subinitted for credit (in part) leading to the degree of Master of Science from the 

 Michigan Agricultural College. 



