1920.] Insect and Fungus Pests during Winter. 775 



although a sHght scorching of the edges of any exposed leaf may 

 follow. The reason appears to be that the eggs of insects or 

 resting spores are but Httle affected by the wash. The pests 

 are most vulnerable and are easily killed. The best results 

 are obtained when the spores have germinated or the eggs 

 have hatched, which is usually about February. 



Lime spraying done late is often effective, and not only 

 cleans the trees but, when properly done, encases insect eggs 

 and so prevents hatching. Even when hatching takes place 

 the insects have difficulty in moving about in the particles of 

 Kme. 



In conclusion, attention should be paid to the general health 

 of trees. Too Httle care is given to the roots of trees, although 

 the branches may be well attended to. Many growers appreciate 

 the fact that the leaves breathe and must have light and air 

 to do their work properly, but few realise that the roots also 

 respire and cannot function properly unless the soil is well 

 drained and kept open, so as to allow the air to circulate between 

 the particles of soil. It has sometimes been held in the past 

 that old-established trees require no manure, but it is now recog- 

 nised that a tree cannot do its best unless it is supplied from time 

 to time with sufficient food which the manure supplies. In this 

 connection it should be remembered that plums in particular 

 require lime, and that probably other fruits need similar special 

 constituents, although little is known at present as to the require- 

 ments of particular plants. 



F 2 



