Agricultural Research in New Hampshire 35 



occurred in greenhouse tests. In the case of oats none of the greenhouse 

 treatments caused any increase in growth over that obtained in the con- 

 trol. 



In orchard tests, hay mulch, seaweed mulch, and sawdust mulch have 

 not as yet reduced leaf scorch. Magnesium sulphate applied to the soil 

 has not benefitted trees affected by leaf scorch, although there w^as some 

 reduction in the University orchards as a result of spraying with it. 



L. P. Latimer, G. P. Percival 



Winter Injury Among Deciduous Fruits 



Continuous temperature measurements in different parts of a dor- 

 mant Northern Spy apple tree w^ere made with an automatic recording 

 potentiometer. Maximum cambium temperatures of 84° to 93 °F were 

 recorded during February and March, on days when peak air tempera- 

 tures were from 39° to 45 °F. 



A dormant tree of 70 pounds, cut off and stood in an erect position 

 with its base in a tub of standard nutrient solution, absorbed from .5 to 

 1.0 Hter of water on each of five days between March 1 and 13. Ab- 

 sorption was initiated by maximum air temperatures between 37° and 

 46° F for six days. Minimum temperatures for the period were from 19° 

 to 40°F and cambium temperatures of the trunk (south side) were above 

 40°F for 6.5 to 10 hours each day. Maximum cambium temperatures on 

 days during which absorption took place were from 69° to 93 °F. 



Red raspberry canes of Chief, Taylor, Marcy, Viking, and Indian 

 Summer varieties, infected with spur blight, contained from three to 

 eight per cent less moisture than healthy canes, on January 24. On Feb- 

 ruary 2, healthy parts of diseased canes (above the infected areas) con- 

 tained from .5 to 1.0 per cent more moisture than the diseased parts. 



Russell Eggert 



Translocation of Radioactive Elements in Horticultural Plants 



Dormant Red Maple and Mcintosh apple trees, respectively, were 

 cut off on December 1, 1944, and February 1, 1945, and supported in an 

 upright position with their trunks standing in nutrient solution in cov- 

 ered barrels placed in holes in the ground to prevent freezing. Hoag- 

 land's nutrient solution, slightly modified, was replaced by radioactive 

 phosphorus in the form KH2P04- 



Temperatures of the trees w ere recorded continuously with an au- 

 tomatic potentiometer recorder, and the volume of nutrient solution in 

 the barrels were measured daily. Samples for analysis were removed 

 frequently from various depths and heights in the trees. After growth 

 started in March, radioautographs w^ere made of longitudinal and cross 

 sections of the trunk and of sections of small twigs, including buds and 

 primary leaves. 



Analyses of maple samples indicate that movement of radioactive 

 phosphorus took place principally in the young xylem. Translocation 

 into the trunk and larger branches occurred whenever water was ab- 

 sorbed from the barrels. 



