206 AGRICULTURE 



than the English ones. Oriental pears are not so subject to blight 

 as European varieties. 



Fruit and grain should be stored dry and in good condition. 



Fungi require food in a moist state, and are apt to attack fruit and 



.rtMMyK*^ ^a^mmmM^ grain when they are 



^m ^'\ jp B^ P ut awa y damp. 



I / Spores should be 



fi mm removed from seeds 



^ilijfjjfr 'JiQfnmfBr to which they ad- 



here. Grain affected 



HEALTHY POTATO POTATO WITH SCAB .,, 



with smut, and po- 

 tatoes with scab, should be treated with formalin just before 

 planting. The preparation is inexpensive and easily applied. 



Usually, fungi feed in and on the tissue, and are protected by 

 the thickened outer skin of the host plant. The fungi already 

 established in a plant cannot be killed except by treatment which 

 would destroy the host also. Therefore, treatment for fungous 

 diseases must be largely preventive, destroying the spores before 

 they enter the plant cells. 



Fungicides. Fungi, unlike higher plants, are made up of ab- 

 sorptive tissue. This tissue will absorb flowers of sulphur or salts 

 of copper, either of which is destructive to it. Sulphur is usually 

 applied as a dust-spray to the plants to be protected. Copper 

 sulphate, or bluestone, is the cheapest and most effective form of 

 the salts of copper. The copper sulphate, dissolved and diluted in 

 water, is used on bark, limbs, and unopened buds. But it should 

 not be used on foliage which its acid will burn and injure. 



Without affecting its value as a fun'gi fide, or fungus- destroyer, 

 the copper sulphate may have its acid neutralized by an alkali, 

 such as lime. Two thirds of a pound of unslaked lime will 

 neutralize the acid in one pound of copper sulphate. A mixture 



