FIELD SI^UDIES OF THE DISEASE. 57 



believed that the copper sulphate would affect seriously the woody 



tissues with which it would come in contact. Two trees showed the 



following conditions : 



Tree No. 286. 



March 11: Nine spikes of nuts and good open flower spike. 



May 28: Same. 



June 6: Practically the same. 



June 29: Appeared unheallhy. 



July G: Had dropped 15 immature nuts; 5 spikes of few nuts; and above were 5 or 

 6 spikes of no nuts; 3 good swords and good middle leaves. Placed 1 kilogram of 

 copper-sulphate crystals at the bases of the leaves. Rains were so frequent that the 

 crystals were soon dissolved. 



July 21: Showed 1 open discolored flower spike. 



August 6: Only 2 nuts and many empty spikes on tree; a dead flower spike, 

 opened some time ago, and 1 just opening. 



October 21: Central leaves bent over dry and dead; swords dead; many empty 

 spikes; all leaves yellow. 



Tree No. 288. 



March 11: Sixteen spikes of nuts in good condition. 



May 28: Eleven spikes of nuts and 3 good swords. 



June 10: General appearance unhealthy. 



July 6: Middle leaves healthy and numerous; the second, third, and fourth swords 

 from center were good; fifth and sixth diseased. The seventh and outermost sword 

 was good; the next outward and the adjacent spikes were also good. The 10 or 15 

 other spikes had no nuts. The lower leaves were yellow. 



July 21: Showed from the ground a dead sword and also 2 dead leaves. Applied 

 1 kilogram of copper sulphate directly to the base of the leaves. 



August 8: Very yellow; only 1 green sword left; the tree apparently very far gone. 



October 21: Middle leaves bent over, dry, and dead; all the remaining leaves yellow. 



Thus from the application of copper sulphate no, good result was 

 obtamed. 



Two trees treated with Paris green, another poison, progressed as 

 follows : 



Tree No. 102. 



March 7: Seven spikes of nuts and 1 good open flower spike, also 1 good sword; an 

 excellent tree. 



May 28: Thirty-six fallen green nuts, 9 spikes of nuts, and 2 good swords. 



June 8: Practically the same. 



July 8: About 40 fallen 'mmature nuts; 8 good spikes of nuts; 3 spikes with no nuts 

 above the others; 1 good ' ^en flower spike on one side and 1 bad open flower spike 

 on the diseased side; 2 goi ^ swords and the middle leaves were healthy. About 250 

 grams of dry Paris green a' ^re applied. 



July 21: Only 8 nuts left on 4 spikes; a dead sword just breaking open; 1 green 

 sword visible; all leaves green and healthy. Removed 1 spike with 13 3-centimeter 

 nuts, 1 spike with 6 8-centimeter nuts, 1 spike with 1 15-centimeter nut, 1 spike with 

 1 20-centimeter nut, 1 spike with 1 5-centimeter nut, and 7 spikes with no nuts. The 

 bases oi the spikes and of the leaves were well covered with water-soaked areas both 

 on the upper side and on the lower side of the leaf base and spike base. This tree 

 was treated with Paris green, but the spots on the under side could not be caused by 

 228 



