Sweet Pea Diseases 337 



accurately. In relying on guesswork the general re- 

 sults are likely to be the application of an overdose 

 of fertilizers or manure. 



In order to gain an approximate idea of the total 

 amount of plant food as well as the available plant 

 food furnished by horse manure when mixed with 

 the soil for greenhouse use, Haskins has prepared 

 the following data: 





Pounds of Total 

 Plant Food per Acre 



Pounds of Plant Food 

 Likely to he Available 

 the First Season 





A* 



B* 



C* 



A* 



B* 



C* 



Nitrogen 



5.800 



3 863 



2.900 



2.320 



1-545 



1 . 160 



Phosphoric acid 



2.800 



1.850 



1 .400 



2.380 



1.585 



1. 190 



Potash 



5 300 



3 530 



2.650 



3.971 



2.648 



1.985 



*"A" represents one-half manure, one-half soil; "B", one-third 

 manure and two-thirds soil; "C", one-fourth manure and three- 

 fourths soil. 



In greenhouses when the ill effects of overfertili- 

 zation become apparent, the soil should be leached 

 out with hot water as soon as the crop is removed. 

 This may also be done with lukewarm water, while 

 the crop is still growing. In either case good drain- 

 age should always be provided in order to carry off 

 the salts in solution. Where conditions for leaching 

 are not favorable as may be the case with a cucum- 

 ber crop, about 3 inches of fresh loam should be ap- 

 plied to the surface of the bed and thoroughly 

 worked in. 



