30 SHADE IN COFFEE CULTURE. 



shaded in elevated localities where the moisture is already ample and 

 the temperature sufficiently low, have been found to be especially sus- 

 ceptible to inancha de hierro and other diseases due to parasitic fungi, 

 and even a shade tree (Inga laurina) has been similarly attacked. 

 Thus, from the present as from other standpoints, it nuiy be said that 

 the use of shade is warranted only under conditions and to the extent 

 of contributing- to normal vigor and healthful growth of the coffee; 

 no general principle can be laid down. 



THE EFFECTS OF UNWONTED EXPOSURE. 



In addition to reasons drawn from the preceding facts regarding the 

 local, incidental, and indirect advantages of the use of shade, other 

 arguments require notice. These may be grouped under the present 

 heading because they have reference to the general fact that coffee 

 plants nurtured in the shade are at a disadvantage Avhen the protection 

 is removed, though it appears, even in such instances, that the coffee 

 suffers because of an exaggeration of its normal susceptibility to 

 drought rather than from injuries due directly to increased sunlight. 



In countries where, as in Porto Rico, the shade method is carried to 

 an unreasonable and suicidal extreme, it is obvious that the general 

 impression in favor of shade is not based on any experimental realiza- 

 tion of the possibilities of open or at least of more open culture. 

 Custom and tradition influence the majority of the planters, but those 

 who are sufficiently thoughtful and intelligent to seek a reason for a 

 cultural method not in use in some of the principal coffee-growing 

 countries, are often misled through failure to realize that the effects 

 of sudden and unwonted exposure in plantations which have grown up 

 under heavy shade furnish no criterion applicable to plantations sub- 

 jected from the first to rational methods of culture. 



THE USE OF VOLUNTEER SEEDLINGS. 



There can be little doubt that the overshading practiced in Porto 

 Rico, and probabty also in some districts of Central and South America 

 is partly the result of the habit of transplanting chance-sown seedlings 

 instead of raising new plants in special seed beds or nurseries. In 

 countries where rain is prevalent during the ripening season, or where 

 heavy shading is in vogue, the berries which are accidentally dropped 

 by the pickers or which fall from overripeness, germinate readily and 

 produce quantities of young plants. The use of these precludes, of 

 course, anything like the selection of good seed, and often tends in 

 the contrary direction, since the berries which are unripe at the time 

 of the harvest or those sparingly produced by unhealthy or unfruitful 

 trees are much more likely to have the opportunity of germinating 

 than good and seasonably-ripened seeds. The indefinite repetition of 

 this process of reversed selection can bring about only a deterioration 



