98 PRINCIPLES OF PLANT CULTURE 



160. Seeding of fodder crops. — The maturing of seeds 

 injures fodder crops. The food value of straw, from which 

 the ripe grain has been threshed, is comparatively small, and 

 that of grass and other crops intended for coarse fodder is 

 much reduced by permitting the seed to ripen before cutting. 



161. Ripening of fruits. — Green fruits assist the leaves 

 in food preparation to some extent, but as they begin to 

 ripen, the process is reversed. Carbonic acid and water 

 are then given off, while oxygen is absorbed. Fruits 

 first become sour from the production of acids which dis- 

 appear in part at a later stage, while sugar is notably in- 

 creased. Ripening is favored by warmth and in some 

 fruits by light. 



Some fruits, as the strawberry and peach, increase 

 rapidly in size during the ripening period, provided the 

 water supply is sufficient. 



Color is not always an index of maturity. Blackberries, 

 currants and certain other fruits improve in edible quality 

 for some time after assuming their mature color. 



Most fruits that have attained nearly normal size 

 ripen to a degree when detached from the parent plant. 

 Pears are usually improved in quality if picked before 

 maturity and ripened in-doors. The grape, however, 

 fails to develop its sugar if prematurely picked. 



After a certain stage of maturity is reached, all vital 

 processes in the pulpy part of the fruit cease, and dis- 

 organization (decay) begins, unless prevented by a pre- 

 servative process. 



THE GATHERING AND STORING OF SEEDS 



162. Time of germination. — The stage of maturity at 

 which seeds will germinate varies greatly in different plants 



