No. 6. DEPARTMENT C)F AGRICrLTURK. 547 



One of the most important foatnrcs of the work that has bf«»ii devfl- 

 oiKid to an extent but of which much more undoubtedly can and will 

 be discovered as time and experiment progress in the use of insecti- 

 cides and fungicides, is in uniting the two; w'e refer to what may 

 be called poisoned Bordeaux mixture. If Bordeaux mixture is 

 reijuired to prevent fungi, its application must be made at such 

 favorable times as will insure the best results as a fungicide; fortu- 

 nately it is known that arsenical poisons may be added to the Bor- 

 deaux mixture without deterioration either to the mixture or the 

 poison. The right time to apply Bordeaux is the right time to apply 

 the poison to reach many of the injurious insects of the apple, pear 

 and quince. 



The extensive use of the lime-sulphur-salt wash in 1903 as a rem- 

 edy for San Jos6 Scale has developed the fact that this preparation 

 is a most excellent preventive of the leaf curl of the peach, and one 

 c«se is known w^here the lime-sulphur-salt was a perfect check to pear 

 psylla. 



Many formulas for the preparation and method of applying them 

 have been recommended; but the following are such as have been 

 most satisfactory in New York State. Success in the use of fungi- 

 cides is dependent on their preventive effect. Rarely can any gain 

 come from an application after the affected plants show injury, for 

 by that time the fungus has penetrated beneath the surface and 

 consequently beyond the reach of sprays. Such poisons as the 

 arsenites remain upon the surface of the foliage or fruit and kill 

 the insects after they eat them. Insects which do not chew the sur- 

 face but pierce to the inner tissues from which they seek nourish- 

 ment are not affected by such poisons. 



For these sucking insects applications which kill by contact are 

 adopted. Thoroughness in application is essential with contact in- 

 secticides since the insects must be touched by the spray. The time 

 is also important as some insects are protected within rolled-up 

 leaves or in other ways and are then harder to reach than at earlier 

 periods. 



Gases kill by inhalation and can prove effective only upon insects 

 not in egg or pupal stages. 



INSECTICIDES: ARSENICAL COMPOUNDS. 



Paris Green. — One pound per 100 to 200 gallons of water to which 

 four pounds of quick lime should be added for each pound of Paris 

 green. Four to eight ounces of Paris green or other arsenical com- 

 pounds may be added to each 50 gallons of Bordeaux mixture with 

 perfect safety and without weakening the action of either. The 

 excess of life will take up the caustic property of the Paris green. 



Arsenite of Lirne^ is one of the cheapest and most effective of 

 the arsenical poisons. It should more generally take the place of 



