COMMON WEEDS 



PERCENTAGE CONTENTS OF DRY MATTER 



Weeds, therefore, take food material which would 

 have been equally available for the cultivated crop, but 

 which is thus lost to the farmer, at least for the time 

 being. Although the weeds may in some way be 

 utilised, or the food they have taken be in part returned 

 to the soil, it would be of greater benefit to the farmer 

 if the food removed by the weeds were immediately 

 utilised in building up larger and better grain, root, or 

 fodder crops. 



(2) For the most successful growth of any ordinary 

 crop an unrestricted amount of light is requisite, green 

 crops being unable to develop the green colouring 

 matter, or chlorophyll, necessary for their nutrition, 

 except in the presence of sunlight. This may be clearly 

 seen when a patch of grass is covered with a board or 

 a sack, the grass which grows beneath being of a sickly 

 yellowish-white colour. Further, even if the green colour 

 is developed, light is necessary in order that the process 



