The Effect of Borax in Fertilizers. 113 



whether mixed or unmixed with the soil, caused greater tip 

 and marginal injury than where it was applied above the seed- 

 piece. Mixing fertilizer with the soil resulted in greater leaf 

 injury, unless it was mixed with the soil above the seed-piece. 

 Abundant watering increased the amount of leaf injury. Stated 

 in another way, the most severe leaf injury was obtained where 

 the fertilizer was mixed with the upper 6 inches of soil or with 

 the 3 inches of soil below the seed-piece and the plants heavily 

 watered. 



It will be remembered that with the remaining 5 lots, the 

 fertilizer was applied only in the drill, both above and below 

 the seed-piece. Half of the pots in each lot were abundantly 

 watered and the other half scantily watered. As has been 

 stated very healthy, vigorous plants were obtained with No. 

 5409 which contained no borax. The other 4 lots which rep- 

 resented varying applications of borax gave results in general 

 agreement, as far as they went, with those given above for No. 

 5549. The most severe injury of both types resulted from the 

 application of the fertilizer below the seed-piece, and abundant 

 watering — as a rule — produced more tip and marginal injury. 



On account of the relatively small rainfall in Aroostook 

 county in June, 1919, the water supply for the plants, previous 

 to the appearance of the injury in the field, where most of the 

 more serious cases were seen, was largely from below upward. 

 A desire to duplicate field conditions as nearly as possible was 

 what led the writer, in planning the greenhouse experiments, to 

 decide to make all applications of water to the pots from below. 

 The results obtained indicate quite clearly that the method of 

 watering adopted, materially influenced the relative amounts of 

 leaf injury which resulted from the variation in the methods of 

 fertilizer application. Continued watering from above has still 

 greater objections as it would have a tendency to carry the borax 

 away from the plants. Alternate watering from above and 

 below, such as was decided upon in the case of the cooperative 

 experiments now in progress, undoubtedly is the nearest ap- 

 proach to field conditions that can be obtained in the green- 

 house. It is granted that, in the confined conditions imposed 

 by the pot, there is less opportunity for the plant to escape from 

 the poisonous action of the borax, but in spite of this fact and 

 the objection to the method of watering mentioned above it is 



