HYGIENE OF PLANTS. 



Nothing perhaps comes out plainer in a study of diseases of plants, bacterial diseases 

 included, than the fact that such diseases are very often introduced on species or varieties 

 brought in from other localities. No one, for example, would care to buy seed-potatoes 

 from a field subject to brown rot or basal stem-rot, cabbage-seed from plants affected by 

 black rot, sweet corn seed from fields subject to Stewart's disease, olive trees with olive- 

 knot, pear-trees with pear-blight, plum-trees carrying with them the black spot organism, 

 or peach-trees grown in nurseries subject to crown-gall, and yet without knowing it planters 

 are doing these things all the time. 



Viewed in this light, the introduction of new things from all sorts of places is not an 

 unmixed good. Many diseases are spread in this way. Especially is the importation in 

 bulk and the immediate general distribution of all sorts of seeds and plants to be deprecated. 

 It would be much safer to import seeds and plants in small quantities and multiply them 

 for a year or two under strict Government supervision in experiment gardens before making 

 a general distribution. The dissemination of many scales and other injurious insects would 

 also be prevented by this method. Up to this time, with local exceptions, e.g., France, 

 Germany, California, growers in all parts of the world have been allowed to import and 

 distribute at will. The growers in the United States in particular do almost exactly as 

 they please. The Department of Agriculture also has sometimes imported and distributed 

 without proper inspection. The machinery of inspection is not properly organized in this 

 country. To do such inspection thoroughly would require a small army of trained inspec- 

 tors (entomologists and pathologists) distributed at at least a dozen different ports of entry, 

 all subject to one efficient central inspection bureau. Universities are not turning out men 

 fast enough to meet the demands for this sort of work, and at the present time there are 

 not men available in this country to carry out properly any such system of inspection, 

 important as it is to have it instituted speedily, nor even to meet the ordinary requirements 

 of pathological research. 



As time goes on undoubtedly strict inspections will be required in all highly civilized 

 countries, and the propagators and distributors of trees, shrubs, herbs, tubers, bulbs, seeds, 

 etc., will be required to give some sort of guarantee as to where the plants were grown and 

 under what conditions. Then seedsmen will not be permitted to sell seeds raised in infected 

 districts and often harvested from infected plants, simply because it is convenient for 

 them to do so, nor will nurserymen be allowed to sell stock known to be infected, for no 

 better reason than simply because they have a large quantity on hand and wish to dispose 

 of it. Meanwhile, in the absence of proper inspections, intelligent buyers will deal only 

 with reliable firms, and will in addition seek for some specific assurance as to healthfulness. 

 In case of large orders a visit to the plantations themselves before the trees are dug, or the 

 seeds harvested, might occasionally prevent much subsequent vexation and loss. 



Some propagators of seeds and plants appear to be entirely indifferent to the welfare 

 of the community, sometimes distributing things known to be infected, and there should 

 be a severe law for such people.* The greater number, however, undoubtedly trespass 

 through ignorance, and we can not hope for a general improvement of the seed and plant 

 trade in these particulars until a knowledge of these diseases, particularly information as to 

 their dangerous nature and the exact methods of their dissemination, is broadcasted through 

 the trade, and made effective through the demands of the buyers for healthy stock. The 

 buyer must be on his guard continually. He knows theundesirability of cocklebur, ragweed, 

 and thistles, but in most cases he has not yet come to realize the greater undesirability of 



*The San Jose scale was disseminated through the eastern United States by nurserymen of this type. 

 1 88 



