14 CIRCULAR 926, U. S. DEPARTMENT OF AGRICULTURE 



Table 4. — Tolerance of two varieties of peas to insecticides ap- 

 plied to the soil prior to planting, as indicated by yields on 360 

 feet of roiv 1 



Insecticide 

 (pounds per acre) 



Untreated check 



Aldrin 4 



Chlordane 20 



Toxaphene 20 



Ethylene dibromide 54 



Laxton Progress (1949) 



Green pods 



Pounds 



Vines 



54 

 60 

 50 

 49 

 56 



Pounds 

 28 

 32 

 28 

 28 

 30 



Wyola (1951) 



Green pods 



Pounds 



51 



54 



61 



1 ! 43 



_ 1 46 



Vines 



Pounds 



35 

 38 

 43 

 30 

 36 



1 Not significant according to the F test. 



Potatoes 



Seed potatoes of the Bliss Triumph variety were planted 20 

 inches apart in rows on April 19, 1949, February 17, 1950, and 

 March 8, 1951, and were harvested on August 2, June 22, and July 

 9 in the respective years. At harvesttime the potatoes were plowed 

 up and handpicked, and all were weighed regardless of size (fig. 5). 



In 1949 there was an exceptionally good stand of potatoes in all 

 plots despite the delayed planting. None of the treatments affected 

 the rate of emergence of the plants, and there was no significant 



Figure 5. — Harvesting potatoes in experimental plots. 



