4 CIRCULAR 867, U. S. DEPARTMENT OF AGRICULTURE 



Table 1. — Effectiveness of different forms of dinitro thinning sprays 

 when applied during the bloom period on certain varieties of apples 

 in certain areas — Continued 



Varietj- 



Jonathan 



Do_ 



Winesap- 



Do_ 



Do_ 



Year 



1947 



1948 

 1945 

 1947 

 1948 



Treatment 



Check 



Elgetol 



DN No. 1_ 

 DN No. 2. 



Check 



Elgetol 



DN No. 1_ 



Check 



Elgetol 



DN No. 2. 



Check 



Elgetol 



DN No. 1. 



\ Check 



Elgetol 



DN No. 1_ 



Concen- 

 tration 

 per 100 

 gallons 



Quantity 







2.0pt___. 

 1.01b.. _. 

 1.01b____ 







2.0pt___. 

 1.01b___. 







1.0pt___. 



.5 1b 







2.0pt___. 



1.01b 







1 .5 pt 



.751b__. 



Fruits 

 per 100 



Reduc- 

 tion 



blossom- 



fruit 



ing spurs - 1 



set 



Number 



Percent 



54 





49 



9 



20 



63 



33 



39 



67 





34 



49 



49 



27 



42 





24 



43 



23 



45 



30 





21 



30 



29 



3 



63 





26 



59 



36 



43 



State and 

 literature 

 reference 



> Washington . 



Do. 



Washing- 

 ton (5). 



Do. 

 Do. 



i Description of the commercial preparations listed in the treatment column : 

 Elgetol, a slurry containing 20 percent sodium dinitro-ortho-cresylate ; DN No. 

 1, a powder containing 40 percent dinitro-ortho-cyclohexylphenol ; DN No. 2, a 

 powder containing 40 percent dinitro-ortho-cresol ; DN No. Ill, a powder con- 

 taining 20 percent dicyclohexylamine salt of dinitro-ortho-cyclohexylphenol. 



In any given experiment the various materials were used at approximately 

 equivalent concentrations of toxicant. 



2 Fruit-set records presented in all tables of this circular were obtained 

 following the June drop. 



It seems evident from the data presented in table 1 that no definite 

 conclusion can be drawn as to the relative effectiveness of the various 

 forms of dinitro chemicals as thinning agents for apples. When 

 results are considered on the basis of extent of thinning obtained they 

 are so variable as to preclude the establishment of one form of dinitro 

 as superior to another. In general, the DN No. 2 (used at equivalent 

 toxicant concentration) has resulted in somewhat more thinning than 

 Elgetol in most of the cases where the two materials have been 

 compared. However, DN No. 2 is more prone generally to result in 

 greater foliage injury than Elgetol, particularly when applied 

 under conditions of cool, humid weather. As near as can be judged 

 from the data in table 1, DN No. 1 is about as effective as Elgetol. 



Results in New York, where these two materials have been com- 

 pared (22), indicate that DN No. 1 is generally less likely to result 

 in as much foliage injury as Elgetol. For this reason it is sometimes 

 considered preferable to Elgetol in that locality. However, Elgetol 

 or Krenite 2 is used commercially almost exclusively in the fruit areas 



2 Krenite is a commercial preparation similar to Elgetol. 

 approximately 20 percent sodium dinitro-ortho-cresylate. 



It also contains 



