FERTILIZERS 51 



of nitrogen is usually the cause of yellow color in 

 citrus orchards. 



A careful record of previous applications, namely : 

 The amount and analysis of the fertilizer, time of 

 application, and its effects on growth and crop will 

 be a guide to selection. 



TIME TO APPLY FERTILIZERS. 



75. In the book of nature we read that growth is 

 dormant for some months preceeding the blossom 

 and fruit setting period. This is naturally the time 

 of most moisture in soils, which with root acids and 

 fermentation, are rendering available the unavail- 

 able plant foods natural to the soil. So, when the 

 important time of blossom comes, the plants have 

 their greatest store of available plant food to draw 

 upon, so that fertilizers should be applied long 

 enough before the blossom time to become avail- 

 able. 



76. Nitrate of soda requires the least time. Blood 

 requires more time than nitrate, and raw bone more 

 time than blood. Coarse bone, and hoof and horn 

 meal, are slowest in their action. Acidulated phos- 

 phate acts more quickly than any other form (that 

 is the soluble portion.) Steamed, fine ground bone, 

 used with some ammoniate, is next in order, while 

 fatty, raw bone takes still more time to decompose. 

 (46-48). 



Many apply a part of the fertilizer in early sum- 

 mer. This is intended to feed the latter growth of 

 tree and crop. It is a practice that undoubtedly 

 gives better results arid is gaining in favor. 



77. Acidulated forms should always be applied 

 just before an irrigation or rain, for then the water 



