March, 1938] Agricultural Research in N. H. 15 



Delicious and Spy only a fraction as much. The removal of petals had a 

 greater effect in reducing fruit set, no fruit setting at all on Golden 

 Delicious and Spy receiving this treatment. {Purnell Fund) 



Orchard Fertilizer Tests 



On certain orchards a "scorch" of the leaves such as might be at- 

 tributed to potassium deficiency has been investigated by G. F. Potter, 

 who has compared applications of nitrogen only with a similar quantity 

 of nitrogen supplemented with potassium. Soil samples taken in mid- 

 season have shown that the replaceable potassium has been significantly 

 increased down to a level of 8 inches beneath the surface of the soil. 

 Examination of the leaves has also indicated a higher potassium con- 

 tent in the leaves of the potash plot. However, the increased supply of 

 potassium in the foliage has failed to reduce this trouble significantly. 

 It seems clear that it is not a potash scorch. 



Growth and production of Mcintosh trees fertilized with a complete 

 fruit fertilizer of 5-8-7 composition has been compared with that of con- 

 trol trees fertilized only with an equivalent amount of nitrogen carried 

 in cyanamid, nitrate of soda, or sulphate of ammonia. In the culti- 

 vated plot of 18 year old trees at the University of New Hampshire no 

 significant differences were found for 1937 in yield, size of fruit, per 

 cent, of red color, per cent, of spurs producing flowers, and per cent, of 

 flowers setting fruit. The same is true of averages for the period 1930- 

 37. However, the percentage of drops at harvest time was significantly 

 higher in the complete than in the nitrogen plot both for 1937 and as an 

 average for 1936-37. The percentage of drops has been tabulated only 

 for the last two seasons. 



Similar studies over a six-year period in a sod mulch orchard at Pitts- 

 field. N. H., show a slightly lower set and slightly better color for the 

 complete fertilizer plot. {Hatch Fund) 



Strawberry Fertilizer Tests 



Investigating the reasons for the decreased yield of strawberries fol- 

 lowing application of sodium nitrate and other salts, L. P. Latimer con- 

 ducted experiments in 220 plots. Sodium nitrate, sodium phosphate, 

 and sodium sulphate all reduced the yield of fruit, while the same salts 

 of ammonium and calcium did not. The total leaf area per plant and 

 the area of each individual leaflet was cut in half. The length of petioles 

 or height of plant was reduced about 50% by the treatment although 

 there was no significant reduction in the total number of leaves per 

 plant. The damage seems to have been a dwarfing of plant parts. Al- 

 though no measurements were made of the size of fruit, it was evident 

 that the fruit was considerably smaller in the sodium plot. It is be- 

 lieved that reduction in yield was due to smaller fruit rather than the 

 production of fewer fruits. Figures on yield, height of plant, total 

 leaf area, number of leaves per plant, and area per leaflet showed a very 

 high correlation between the various factors except as to number of 

 leaves per plant. Nevertheless there was some correlation between 

 total leaf area per plant and number of leaves per plant. (Hatch 

 Fund) 



