6 BULLETIN 998, U. S. DEPARTMENT OF AGRICULTURE. 



Table 1. — Yield of potatoes in borax experiment at Presque Isle, Me., in 1920. 



Quantity of borax applied per acre. 



(Control 1). 



1 pound 



2 pounds 



3 pounds 



(Control 2) . . 



4 pounds 



5 pounds 



10 pounds 



(Control 3) . 



20 pounds 



30 pounds 



50 pounds 



(Control 4) . 

 100 pounds... 

 200 pounds... 

 400 pounds... 

 (Control 5) . 



Yield per acre (pounds). 



Section 1. a Section 2.6 Section 3. c 



21, 

 23, 

 22, 

 23, 

 20, 

 20, 

 19, 

 17, 

 20, 

 12, 

 7, 

 5, 

 20, 



760 

 200 

 880 

 440 

 560 

 480 

 720 

 600 

 880- 

 080 

 120 

 280 

 320 

 560 

 240 



18, 560 



19, 600 

 20. 960 



21, 760 



18, 320 



22, 560 



19, 840 

 18, 160 

 13, 680 

 21, 040 



9,040 

 3, 120 

 1,600 



17, 680 

 320 



80 

 <f40 



18, 960 



20, 240 

 19, 120 

 19, 440 



18, 240 

 19, 040 



19, 680 

 19, 760 

 15, 840 

 18, 800 

 12, 000 



4, 880 



3,400 



19, 300 



640 



160 



80 



14, 240 



a Fertilizer applied in the furrow about one week before planting. 

 b Fertilizer applied in the furrow planting. 

 c Fertilizer applied broadcast at planting. 

 <2 All culls. 



In section 3 the general trend of the results is similar to that in sec- 

 tions 1 and 2, the first sign of injury occurring, however, with the 10- 

 pound application. In this section the method of applying the fer- 

 tilizer-borax mixtures apparently depressed the yield of the last 

 contral as the yield dropped off considerably. In this connection, 

 in view of the fact that single rows were employed in the borax 

 experiments, it would seem that broadcasting a fertilizer-borax mix- 

 ture containing such a large quantity of borax might easily tend to 

 influence the yield of the adjacent control row. 



RAINFALL RECORD. 



The daily rainfall record for the months of June, July, and August 

 is given in Table 2. 



The rainfall, subsequent to planting on June 5, was well distrib- 

 uted during the remainder of that month, at least until June 29, 

 on which date 1.09 inches fell, followed by 1.01 inches on June 30. 

 It would seem that the rain, which fell between June 5 and June 29 — 

 a somewhat critical period in the early life of the potato plant — was 

 sufficient to keep the soil in good condition without much chance of 

 an} 7 great leaching of the borax to lower soil zones. 



