CHAPTER XIV 



PLANT DISEASE LEGISLATION 



The subject of plant disease legislation, in the present connection, 

 has reference to the enaction and administration of laws for the 

 protection of plant industries against diseases and pests. It 

 divides naturally into consideration of protection against external 

 sources of infection and of the limitation of affections already 

 more or less established. 



Plant Importation. 



In island communities such as these of the West Indies, the 

 question of protection against outside infections resolves itseli 

 into that of the admission and inspection of plant material at the 

 one or more ports of entry. Such material may be seeds or 

 cuttings for planting, rooted plants with or without soil, fruit, 

 forage, grain or seed for feeding or manufacturing purposes, 

 cordwood, litter accompanying animals, and packing or wrapping 

 of various kinds. When these things, in their nature and origin, 

 constitute a possible source of infection, it may with confidence 

 be stated that the only method approaching safety is that of 

 total exclusion, and even this is qualified by the impossibility 

 in practice of strictly enforcing it. Any system of inspection, 

 however rigorous, is very fallible. Many examples might be 

 quoted in illustration of this statement. The mosaic disease of 

 sugar-cane is highly infectious and is carried by cuttings, yet 

 after careful and long-continued search no visible organism has 

 been found to be associated with it. It can be introduced in 

 material which might be examined with the utmost care and 

 passed as healthy. Citrus canker so closely resembles the com- 

 paratively inoffensive and widespread scab disease that it was 

 passed over as such until its characters became known as a result 

 of a disastrous outbreak following its introduction into Florida. 



The dangers of admitting unknown and therefore unrecognised 

 diseases, of the introduction of infection on resistant plants 

 which do not show the presence of disease, and the impossibility 

 of determining beforehand what effects a disease or pest may 

 have under new conditions, should by this time, in view of the 

 many instances which have become notorious, be well enougii 

 understood. The local besetting sin in this matter is the tendency 

 to regard the making of an ordinance as the end rather than the 

 beginning of action. 



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