ANNUAL REPORT, 1938 89 



apples on this tree was only mediocre. This has been propagated under the name 

 "Galbraith Baldwin" to see whether the high color is maintained and whether 

 it is a superior strain. 



Fruit Bud Formation in the Strawberry. (R. A. Van Meter.) To study the pos- 

 sibility that winter injury might be responsible for continued failure to get a 

 response to differential soil treatments, 24 plots of about 175 plants each were 

 established in the spring of 1937 and fruited during the past year. Six differential 

 mulching treatments were used, each replicated four times: 



1. No mulch. 



2. Light mulch applied November 12. 



3. Light mulch applied December 16. 



4. Light mulch November 12, more applied December 16. 



5. Heavy mulch applied November 12. • 



6. Heavy mulch applied December 16. 



The crowns of plants in all plots were damaged in varying degrees, suggesting^, 

 the desirability of applying the mulch earlier. Plots not mulched were damaged 

 most and yielded least. They had, however, the largest number of mature leaves 

 when the fruit was setting, which suggests the desirability of removing the mulch 

 early. A heavy mulch applied early resulted in the least crown damage. 



Plots given a light mulch early followed by more at the time of the late applica- 

 tion gave highest yields, followed by those receiving a heavy mulch applied early. 



In the spring of 1938 a duplicate of this plot arrangement was established with 

 five replications. Five additional plots were mulched heavily with the first cold 

 weather and the mulch will be removed from these plots very early. 



Nutrition of the Highbush Blueberry, Especially in Relation to Soil Reaction. 



(J. S. Bailey.) As in previous years chlorotic plants in blueberry- Plot D were 

 treated with various chemicals to cure the chlorosis. Again the plants treated 

 with sulfate of ammonia were the only ones to show marked improvement. 

 Plants sprayed with ferrous sulfate, 2 gm. per liter, developed green spots where 

 drops of spray had collected. 



Plants growing in three-gallon crocks, treated in 1936 with 40 gm. of lime per 

 crock, all died in 1937; only one of five plants treated with 20 gm. of lime sur- 

 vived. This one plant is slowly reco\ering under a soil acidification treatment; 

 lOcc. of N/10 H.jSO^ added from time to time when plants ware watered. Plants 

 receiving 10 gms. and those receiving 5 gms. each of lime are all alive but chlorotic. 

 A 1.0% solution of ferric citrate was injected into the stem of one of these chlorotic 

 plants. The solution was so strong that all the leaves dropped. A new set of leaves 

 formed which had the normal green color. This experiment was repeated with a 

 0.25% solution of ferric citrate with the same results except that not all the leaves 

 dropped. Chemical analyses of the tops and roots of blueberry plants growing in 

 soil treated with phosphoric acid (H3PO4) were made by Mr. J. N. Everson of 

 the Department of Agronomy. These analyses indicated that the occurrence of 

 chlorosis is related to a change in the H-ion concentration of the plant tissue. 



During the hurricane of September 21, twelve blueberry plants were blown out 

 of blueberry plot D. These were all of the variety Rubel, were among the largest 

 plants, and were broken ofT from one to three inches below the surface of the soil. 

 During the heavy rains preceding the hurricane there was a great deal of soil 

 erosion on this same plot. This erosion has rapidly become so serious that it 

 would be unwise to start a fertilizer experiment before the erosion is stopped. 



Blueberry Culture. (J. S. Bailey.) Clean cultivation with cover crops has not 

 been a satisfactory method of culture for blueberry plot D where the land slopes 

 from three sides toward the center. Soil erosion is excessive. After the berries 



