20 EXPERIMENTS IN BLUEBERRY CULTURE. 



direction originally contemjjlated, and in the end have been fully 

 conclusive. 



On May 26, 1908, six blueberry seedlings were potted in six 14- 

 ounce drinking glasses in a good i^eaty blueberry soil, in which, 

 however, 1 per cent of air-slaked lime ° had been mixed immediately 

 before the potting was done. Six other plants were similarly potted, 

 but without the addition of lime. The unlimed plants grew 

 normally. The younger leaves of the limed j^lants, however, began 

 to wilt the same day on which they were potted. On June 1 all 

 the leaves on all six plants were withered, though parts of the stems 

 were still green and i^lump. Tlie leaves did not turn purplish or 

 yellowish, as is usual with sickly blueberr}' plants, but either re- 

 tained their green color after withering or turned brown. No new 

 root growth took place in any of the limed pots, and by July 10 all 

 the plants were dead. 



Another series of six plants, also potted on May 26, 1908, but m 

 a sterile soil containing no peat, by accident received a very small 

 amount of lime. Most of the leaves on these plants withered during 

 the first few days, but the plants subsequently recovered and made 

 as good growth as could have been expected from the general char- 

 acter of their soil. 



From these experiments the writer concluded that the blueberry 

 was exceedingly sensitive to lime and that the slightest admixture 

 of it in the soil would be immediately fatal to the life or at least 

 the health of a blueberry plant. This conclusion, however, was 

 erroneous, as subsequent experience showed. This first experiment 

 may therefore be dismissed with tlie explanation that in all proba- 

 bility the immediate collapse of the plants was due to a caustic effect 

 of the lime used. In none of the later lime experiments did this 

 immediate collapse occur and in none was the lime so applied that 

 it came into contact with the blueberry roots while in a caustic 

 condition. 



Still laboring under an erroneous conception of the supersensi- 

 tiveness of the blueberry plant to minute quantities of lime, the 

 writer, desiring to produce fresh examples of this phenomenon, in 

 November, 1908, placed a very small quantity, a few milligrams, of 

 air-slaked lime on the surface of the soil in each of three 2-inch 

 pots containing a small blueberry plant. No effect was produced 

 either at first or for several weeks. On December 19, 1908, a large 

 surface application of carbonate of lime was made to the same three 

 plants, a gram to each pot, and the lime was washed down with 

 water. The expected collapse did not occur. The limed plants con- 

 tinued to grow as luxuriantly as their unlimed neighbors. The con- 



° Computed ou the dry weight of the soil. 



193 



