EFFECT OF BORAX ON POTATOES. 7 



Table 2. — Precipitation at Presque Isle, Me., for June, July, and August, 1920. 





Rainfall record (inches). 



Day. 



Rainfall record (inches). 



Day. 



June. 



July. 



August. 



June. 



July. 



August. 



1 





0.45 



0.17 



17 









2 



0.13 

 .50 



18 





0.03 

 .42 

 .05 





3 



.37 



.43 



1.10 



.63 



19 



0.20 





4 



20 ' 





5 





21 



.06 

 .57 

 1.02 

 .10 

 .12 





6 





22 



.06 

 .03 

 .02 



0.23 



7 



.73 



.11 

 1.00 





23 



1.32 



8 



24 





9 





25 





10 







.43 

 .12 



.46 



.01 



.01 



26 



.01 



11 



.49 





27 



.03 







12 



28 







13 





.04 



29 



1.09 

 1.01 







14 





30 



.08 



.08 



15 







31 



.15 



16 



.04 



.09 















SUMMARY. 



This bulletin presents the results of borax experiments conducted 

 on Caribou loam, the principal soil type in Aroostook County, Me. 

 Injury definitely occurred with an application as low as 5 pounds 

 of borax per acre, when put in the furrow and when the planting was 

 done immediately, which is the method customarily followed in this 

 section of Maine. The other methods of applying- the fertilizer, 

 broadcasting at the time of planting and applying in the furrow 

 some time before planting, did not show injury in as low concentra- 

 tions of borax as showed injury when the fertilizer-borax mixtures 

 were applied in the furrow at the time of planting. As the quantity 

 of borax was increased the injury in all cases became progressively 

 worse, until, with the larger quantities of borax per acre, great in- 

 jury ensued. 



The moderate and fairly regular rainfall during the month of 

 June was not sufficient to carry the borax out of the reach of the 

 growing plant, so that no alleviation of the injurious action was 

 noticeable. 



The types of injury observed in the commercial fields during 1919 

 were similar to those found in the borax experiments of 1920. Some 

 of the reactions with borax, observed in both seasons, were as fol- 

 lows: Failure of the seed piece to germinate, the killing of sprouts, 

 the absence of roots at seed pieces, general weakness of plants which 

 came through the ground, bleaching of the foliage (or at least a 

 marginal yellowing of the leaf) , a poor stand, and low yields. 



