June, 1939] Agricultural Research in N. H. 25 



now on the heavily pruned trees will be pruned by the thin-wood 

 method and the others according to the conventional method. 

 Although it is too early to note any changes, Mr. Smith expects that 

 this will be a real test of the thin-wood method for which so much 

 is claimed. {Hatch Fund) 



Pollination Project 



During the past year the pollination work in charge of L. P. Lati- 

 mer has been concerned principally with the interesting case of 

 cross-incompatibility observed between Early Mcintosh and Cort- 

 land apples. As the result of pollination tests made at the New 

 Hampshire station it was discovered that Early Mcintosh will not 

 pollinate Cortland, nor will Cortland pollinate Early Mcintosh satis- 

 factorily because pollen tube growth is inhibited in the style. 

 {Purnell Fund) 



Premature Dropping of Mcintosh Apples 



This is a problem of great economic significance since many grow- 

 ers have occasionally suffered considerable loss of profits because of 

 premature dropping of Mcintosh fruit. The drop is known to be 

 heavier in some localities than in others and varies from year to 

 year. In a given orchard individual trees may difl'er in this respect. 

 It has been found over a period of seven years that certain Mcintosh 

 trees at the university farm are consistently heavy droppers and 

 others consistently light. 



Work was begun on this project in 1938, under the direction of 

 L. P. Latimer. Trenches were dug down to the impervious till layer 

 of soil in order to study the soil profile and root distribution of the 

 eight heaviest and eight lightest dropping trees in the orchard. So 

 far extreme difi'erences in soil structure found in the orchard do not 

 seem to be correlated with the amount of dropping. Root samples 

 are being examined to determine how different root stocks might 

 affect the trouble. {Purnell Fund) 



Strawberry Fertilizers 



Experiments were continued by L. P. Latimer on the effect of 

 sodium on strawberries. In 1937 one acre of land to which 15 tons of 

 stable manure had been applied and disced in was planted to Howard 

 17 strawberries. No further fertilizer was used until May, 1938, 

 when sodium, ammonium and calcium ions in combination with 

 nitrate, phosphate and sulphate ions were applied broadcast about 

 two v/eeks previous to bloom. Results were somewhat different than 

 in other years when the same amount of fertilizer was applied in 

 August of the year preceding bloom. Sodium applied in the spring 

 did not cause the same reduction in yield as when applied the fall 

 following planting, except where nitrogen was used in the fertilizer. 

 Then a considerable reduction in yield occurred. Ammonia nitrogen 

 causes more excessive leaf growth that nitrate nitrogen, but both 

 types decrease the yield to approximately the same degree. Other 

 ions did not seem to cause injury or improvement to the crop. Fur- 

 ther investigations are needed to solve this problem. {Hatch Fund) 



Variety Tests on Several Fruits 



L. P. Latimer was in charge of the following fruit variety tests : 



