612 SCIENCE PROGRESS 



Of the several diseases and pests which affect flax only quite 

 a few make themselves sufficiently prominent to call for mention 

 here : nor need they in any way cause the farmer anxiety. At 

 an early stage of growth, when the plants are only about 

 two inches above the ground, they are sometimes affected by a 

 fungoid disease known as "yellowing " which is stated to be due 

 to the fungus Asterocystis radicis. 



At a later stage of growth Flax Wilt is sometimes manifest ; 

 it is a disease attributed to the joint activity of several micro- 

 organisms of which the most definitely identified is Fusarium 

 lini. This disease is hardly ever met with in Russia, although 

 it has long been known in Holland, Belgium and France. 

 Flax Rust {Melampsora lini) may become a serious trouble 

 in some localities where the wild purge-flax (JLinum catharticum) 

 flourishes, this particular plant being somewhat commonly 

 affected by the disease. 



Flax is subject to the ravages of several animal pests but 

 fortunately it suffers to no greater degree than do other farm 

 crops from similar causes. The grub of the silver Y-moth 

 (Pusia gamma) feeds upon the flax blossoms and the larva 

 of the two flies Thrips linaria Uzel and Haltica nemorum and 

 also the flax-flea-beetle {Longitarsus ater Fab.) may do con- 

 siderable damage to the young plants. 



It has been found in Ireland that a certain local condition 

 of soil occasions a sparsity of some of the plant's requisites, 

 causing small areas of young flax to become yellow and of 

 sickly condition. Rain showers frequently revive such flax but 

 when no rain falls a light dressing of muriate of potash has the 

 effect of restoring the flax to a healthy condition. Save in 

 exceptional cases, it is not customary to apply top dressings to 

 flax but should a spell of dry weather retard the early growth of 

 the crop it is well to apply a light dressing of nitrate of soda ; 

 but it must be used with moderation and is only to be given 

 with the object of preventing the crop from receiving an early 

 check to its development. When once the flax crop has made a 

 good start it requires no more attention until about harvest time. 



Harvesting 



Only when the crop is grown expressly for seed is it allowed 

 to become quite ripe before being harvested. When grown for 

 the fibre it bears, the matter of harvesting seed is either entirely 



