THE STIFFNESS OF STRAW 151 



secondly the losses caused by parasites, mainly 

 of a fungoid nature. The former factor hardly 

 appears to concern the plant breeder but in practice 

 it does, for supplementing the supplies of food 

 material present in the soil by the addition of 

 natural or artificial manures frequently leads to 

 over-vigorous growth of the foliage and of stems 

 which cannot withstand rough weather conditions. 

 The crop is then "laid" and not only is it expensive 

 to harvest but the yield is often seriously depre- 

 ciated. This is particularly the case in the Fens 

 where a season hardly ever passes without a great 

 proportion of the crop being so badly laid that 

 it is impossible to cut it with self-binders. Conse- 

 quently the production of a variety capable of 

 standing well under conditions of intensive cultiva- 

 tion is a matter of great importance. A comparison 

 of existing varieties whilst growing under the 

 same conditions of cultivation shows that consi- 

 derable differences exist in the stiffness of the 

 straw. Yet none are as rigid as one could wish. 

 But amongst the hybrids from some of the lesser 

 known varieties straws have been found which 

 are stiffer than any at present in cultivation. 

 These forms have been used successfully for building 

 up new types and in the immediate future several 

 varieties particularly suitable for intensive cultiva- 

 tion should be available. One indeed has already 

 been placed on the market. 



The losses caused by disease are far more serious 



