Nov. i6, 1914J 



Pecan Rosette 



161 



It will be noted from Table I that rosette occurred on all but two of 

 the plots receiving an application of lime. In the five unlimed plots 

 there were only two doubtful cases of rosette and these two trees directly 

 bordered a limed plot. Care was taken in spreading the fertilizers on 

 the side bordering a contiguous plot not to distribute to the middle, but 

 the lime was spread to the dividing line, and, hence, there was a chance 

 of its afifecting the adjoining unlimed plot. The largest number of cases 

 and those showing the most advanced stages occurred on the two limed 

 plots, Nos. 9 and 10, treated, respectively, with acid phosphate and 

 muriate of potash and with acid phosphate and nitrate of soda. Thus, 

 while the results of this test have so far been partly negative, they have 

 at least tended to show that some relation exists between pecan rosette 

 and the constituents of the soil. 



A fertilizer test was started in April, 191 2, in the badly rosetted part of 

 a 7-year-old orchard belonging to Mr. G. W. Saxon, at Tallahassee, Fla. 

 The soil here is a sandy loam underlain by a stiff red clay. Thinking that 

 possibly the lack of proper drainage might be a factor predisposing to 

 rosette, the subsoil around six badly diseased trees was dynamited. 

 Three 6-foot holes were bored at 10 to 12 feet from the trees and X to K 

 pound of dynamite was used to each hole. Applications of sulphur flour 

 and of copper sulphate to the soil were also tried, each at the rate of 6 

 pounds to the tree. With the exception of lime, which was applied at the 

 rate of one-third of a bushel to the tree, the fertilizers were used at the 

 rate noted for the preceding experiment. The results of this experiment 

 are given in Table II. 



Table II. — Summary of results from a fertilizer test with pecan trees at Tallahassee, Fla. 



Plot 



No. 



10 

 II 



12 

 13 

 14 

 15 



Lime, muriate of potash, nitrate 

 of soda, and acid phosphate . .. 



Muriate of potash 



Acid phosphate 



Control, subsoil dynamited 



Control , untreated 



Nitrate of soda 



Muriate of pota,sh 



Acid phosphate and nitrate of 

 soda 



Muriate of potash, nitrate of soda, 

 acid phosphate 



Stable manure 



Thomas phosphate 



Linie 



Cottonseed meal 



Copper sulphate 



Sulphur flour 



August, 1912. 



Number 

 of trees 



with 

 rosette. 



Number 



of normal 



trees. 



August, 1913. 



Number 



of trees 



with 



rosette. 



Number 

 of doubt- 

 ful cases.o 



"i 

 b I 



Number 



of normal 



trees. 



* As these trees were badly affected with rosette at the beginning of the experiments, it is probable that 

 their death was at least in large measure due to tliis disease. 

 i> Dead. 



62697°- 



