20 SUPPRESSION OF INSECT PESTS AND PLANT DISEASES. 



The parasites which trouble the horticulturist belong to three different categories, 

 viz, fungi, weeds, and insects. Now as to the first class, ten years of practical 

 experience as an experiment station botanist has convinced me that only State laws 

 and local ordinances are of any use. The best that a national law can do for us is 

 to prevent the sale of apparently diseased nursery stock, but none of the more 

 destructive diseases, such as peach yellows, plum knot, or pear blight, appear with 

 sufficient distinctness to be recognizable upon young trees or such as are usually 

 sold by nurserymen. Laws against this class of pests must be directed against 

 orchards on the lines of orchard hygiene and management. Such laws fall within 

 the sphere of State influence alone. 



Against weed pests a national law would be more effective than in the case of fungi, 

 'but it is doubtful if the results would be worth the expense. Most of our more 

 troublesome weed pests are of foreign origin, and were originally introduced in foul 

 samples of clover, grass, and field seeds. Of recent years the experiment stations 

 have devoted much attention to seed testing, and the official association at its last 

 meeting arranged for a uniform system which will have the effect of driving foul 

 seed samples out of our markets. 



Our third category includes insect pests, and here, I think, we have abundant 

 grounds for governmental intervention.' Insects possess greater powers of adapta- 

 tion than plants. They pass through various changes of structure during the period 

 of their life history, and in some one or more of these phases they are capable of 

 remaining dormant and without food for an indefinite period. This enables them to 

 secure dispersion, with and upon the plants they infest in their original homes, to all 

 countries to which such plants or their fruits are carried by commerce. An efficient 

 quarantine law by Congress to enforce entomological inspection of all imported 

 plants, fruits, and seeds by a competent entomologist will go very far toward pre- 

 venting the further introduction of foreign insect pests. A similar law regulating 

 interstate commerce in plants and allowing free circulation only of such as have 

 been examined and certified as free from insect parasites, will prevent the further 

 spread of pests already existing in one or more of our States. The deplorable 

 results of the absence of such a law is only too readily seen in case of the recent 

 spread of San Jose scale in the Atlantic States. 



The need of such a law is peculiarly felt in the new fruit-growing sections of the 

 South. Hitherto, and until a comparatively recent tune, the highways of commerce 

 had not so extensively penetrated the Southern as the Northern States. Along with 

 the disadvantages entailed by the lack of commerce, we have enjoyed the blessing 

 of immunity from many of the most destructive pests which affect Northern fruit 

 growers. We realize the danger of speedy infection unless we can secure protection 

 by an enactment of Congress the only possible source of an efficient law. North 

 Carolina has already tried State laws, and so have other States, but when such 

 laws promise any good their provisions are pronounced unconstitutional by the 

 United States courts. 



To recapitulate: (1) Pests of crops belong to three categories fungi, weeds, and 

 insects; (2) only the last class can be effectively dealt with by a national law; 

 (3) insect pests can not be effectively or economically dealt with by State or local 

 laws alone; (4) a national quarantine law against foreign insect pests and the 

 enforced inspection and certification of plants which are objects of interstate com- 

 merce are the principal desiderata in such a law. 



A general discussion followed the reading of the papers. The discus- 

 sion brought out the various interests represented, and was continued 

 until 1 o'clock, when a recess was taken until 3 p. m. 



