April, 1935 J Agricultlkal. Research in N. II. 13 



Lime-sulphur Injury 



Experiments were made during the year for the purpose of studying the 

 conditions under which spray injury occurs, and the extent to which spray- 

 ing with lime-sulphur solution interferes with the clahoration of dry matter. 



It is not uncommon for the first formed leaves on the apple in orchards 

 sprayed with lime-sulphur to turn yellow towards the end of June and fall. 

 This chlorosis and premature fall is usually ascrihed to lime-sulphur injury, 

 but it would seem from observations made during the year, that this con- 

 clusion may need qualification. It has not so far been ])ossible to produce a 

 yellowing of the apple foliage at will, so that the other factors concerned 

 have not been determined ; but the evidence collected does not indicate that 

 spraying during very hot weather is as injvu"ious as currently believed. No 

 injury has thus far been caused to the apple by spraying at temperatures 

 ranging between 30 and 40° C in the shade. 



Besides work with the apple, experiments have also been made with the 

 bean and potato. In the experiments with the bean the object was to study 

 the effect of strength of lime-sulphur used on spray injury and elaboration 

 of dry matter. The dilutions of lime-sulphur solution used were 1-50, 1-100, 

 and 1-200. Spray injury was produced at all the strengths used and was on 

 the whole slightly less severe in the case of the more dilute solutions, though 

 the differences were not great. The injury produced, measured in terms of 

 dry matter formed, was, at all strengths used, quite immaterial. (0. Butler 

 — Adams Fund.) 



Effect of Weathering on Injury 



Experiments have also been made with the bean for the purpose of study- 

 ing the effect of weathering on injury, but no difference could be detected 

 between plants placed outdoors at night or during rain, and those protected 

 from dew and rain. 



An experiment was made using the potato to study the effect of spraying 

 with lime-sulphur solution 1-50 on plants grown at a mean temperature of 

 14.9° C and a mean temperature of 22° C. When the experiment was brought 

 to a close the sprayed potatoes grown at 22° C could not be distinguished 

 from the non-sprayed plants, while in the case of the potatoes grown at 

 14.9° C the lower leaves of the sprayed plants were chlorotic and obviously 

 maturing faster than the non-sprayed. Spraying reduced the yield, the 

 greater loss occurring in the plants grown at 14.9° C. 



Studies were also made during the year on the changes induced in lime- 

 sulphur solution by akmiinum sulphate and ferrous sulphate. Both these 

 substances reduce the active alkalinity and percentage of soluble sulphides 

 present. We know that in many cases a reduction in active alkalinity will 

 reduce spray injury, but in the case of lime-sulphur solution the reduction 

 of spray injury accompanying the use of ferrous sul])hate or aluminum 

 sulphate would a]:)pear to be due primarily to the more or less complete des- 

 truction of the sulphides present. (O. Butler — Adams Fund.) 



Dye Adsorption 



The effect of temperature, mineral nutrition, and selection on hardiness 

 and the extent to which the changes induced were measurable by the dye 

 adsorption test was studied during the year, with the following results : 



In the temperature tests cabbage and potato plants were used. It was 



