Considerable segregation is taking place. Some plants tend to make 

 swollen roots. Others have no noticeable root swelling, but they produce- 

 much foliage. Some plants also have much thickened, succulent leaf stems. 

 Thus there is opportunity to select plants for root characters and for any- 



desirable foliage or leaf stem characters. 



E. M. Meader, A. F. Yeager 



Phosphorus Needed for Quality Lettuce. 



In northern New Hampshire, heavy application of superphosphate com- 

 bined with moderate application of nitrogen resulted in the highest percent- 

 age of marketable heads. Increasing nitrogen applications reduced the per- 

 centage cut due to increased softness or failure to head properly, unless 

 phosphorus was also increased to balance the increased nitrogen applica- 

 tion. One ton of lime per acre was sufficient to adjust the soil pH. Doubling 

 or trebling the lime application produced no further change in pH. 



L. P. Latimer, R. Paulson 



Beneficial Effects of Hay Mulch. 



Hay used as a surface mulch continues to prevent leaf scorch on Mc- 

 intosh apple trees, as contrasted with the inability of sawdust to control this 

 disorder. Mcintosh and Northern Spy trees mulched with hay continue to 

 outyield trees grown in sod and fertilized with ammonium nitrate. The use 

 of ammonium nitrate during the last four years has not altered this effect. 



Young Clapp's Favorite, Bosc, and Gorham pears growing on a shallow, 

 dry soil and mulched with hay have made much better growth than un- 

 mulched trees. In a block of Northern Spy trees, fertilization of hay mulched 

 trees with superphosphate plus muriate of potash has, during 1950-51, de- 

 pressed the yield as compared to hay mulch without additional fertilizer. 

 With the addition of ammonium nitrate, to this formula, the yield equalled 

 that of trees mulched with hay but not fertilized. The amount of red color 

 on the fruit at harvest time was the greatest with mulched trees fertilized 

 with superphosphate and muriate of potash, apparently because this treat- 

 ment hastened maturity of the fruit. The least amount of red surface color 

 and the deepest green ground color at the time of harvest occured in all 

 cases where nitrogenous fertilizer was used. The advantage of the mulch with- 

 out fertilizer was the improvement of fruit color without any sacrifice of 

 yield. 



L. P. Latimer, R. Eggert 

 G. P. Percival, S. Dunn 



Radioactive Phosphorus Is a Tool for Testing Uptake of 

 Phosphorus Fertilizer by Apple Trees. 



Phosphorus fertilizers appear to be fixed by New Hampshire soils to 

 such an extent that many growing plants can get only a small fraction of that 

 fertilizer or none at all. The question arose as to whether apple trees, because 

 of that action, fail to give more response to phosphorus fertilizers because 

 they do not need more of the element or because they cannot get it. Phos- 

 phorus fertilizers tagged with radioactive phosphorus were applied as foliar 

 sprays and to the soil to compare the uptake of the element from both sources. 

 The first experiments under both greenhouse and field conditions show that 



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