362 Winter Cover Wa.^hes 



The whiting wash, though it gave good results as regards sticking, 

 presented difficulties owing to the large amounts of hot water required. 

 In order to get the starch and glue into solution about half the total 

 quantity of water had to be hot. This was a serious drawback and 

 a way was sought to overcome it. The fact that starch could be jellied 

 by caustic soda seemed to suggest a possible solution. It was found 

 that starch jellied by caustic soda gave the required thickness to a 

 whiting mixture but that at the same time it had no coherence and 

 gave a very thin coat. With lime, however, not only was the mixture 

 well thickened by this process but it also retained its coherence. 



The following mixtures were therefore tried. They avoid the use 

 of hot water: 



How made 

 The soda added before straining the 



mixture. This resulted in too thick 



a mixture to strain but it was worked 



through and applied to trees 

 (2) 2 J I J ttV 10 Lime mixed with half full quantity of 



water mixture, strained and then the 



soda added 

 (S) 2 ^ ^ tV TTf 10 Lime mixed with full quantity of water 



and strained. Soda then added 

 (4) 2 i i — 75L 10 Starch jellied by the heat of the freshly 



strained milk of Ume 



Of the first three (2) was distinctly the best but (4) proved better 

 than all, having a good thick smooth coat. It showed however some 

 tendency to flake. It is hoped to extend these experiments this season. 



Action of lime wash on insect eggs. 



It seemed desirable if possible to ascertain the nature of the action 

 of a lime coating on Psylla eggs since it certainly does have some 

 checking action. 



To do this, apple twigs abundantly covered with Psylla eggs were 

 cut off the trees in March. These were covered with various washes 

 and placed in a beaker of water till the eggs of the controls hatched. 

 The mixtures tried were 



On the control twig the Psylla hatched in abundance by April 18. 

 (1) showed only two larvae hatched. On dissolving off the whiting 



