19161 HORTICULTURE. 37 



on the station grounds. The varieties liere ilescrii)ed include the Perfect apple, 

 Rochester peach, Keine Hortense cherry, the Exupire State grape, and Herbert 

 raspberry. 



Fifteenth report of the Woburn Experimental Fruit Farm, Duke of Bed- 

 ford and S. U. 1'ickering {Woburn Uxpt. Fruit Farm Rpt., 15 (1916), pp. 83). — 

 This comprises a progress report on a number of long-continued investigations 

 with fruit trees and shrubs and other trees. 



Among other points being investigated, it has been sought to determine 

 whether apple trees have a tendency to produce alternate light and heavy 

 crops. One experiment favoring alternate cropping was recorded in a previous 

 report (E. S. R., 17, p. 559). Subsequent experiments have led to the conclusion 

 that the tendency toward alternate cropping is very feeble and that there is 

 at the same time an equally potent tendency to consecutive cropping, tluit is, a 

 tree bearing particularly well or badly during one season will probably do the 

 same in the succeeding seas(m. It is believed that the chief factor in determin- 

 ing good or poor bearing is tlie atmospheric conditions ratlier than any iimate 

 tendency of the individual tree to either alternate or consecutive fruiting. In 

 the experiments conducted at Woburn the principal factor influencing bearing 

 has been spring frosts. 



Several series of experiments were made to ascertain the distribution of 

 new rootlets forming on trees after transplantation. In the case of api»les less 

 than half of the new rootlets originated within the last half inch of the old roots 

 which had been trimmed bef<ire planting, whereas with currants and goose- 

 berries more than half originated from this half inch. Roots originating from 

 the stems were found to be on the average 20 per cent gi-eater in stoutness 

 than that of roots forming elsewhere. This result explains the habit of deeply 

 planted free-rooting stocks of flourishing better after a time than similar stocks 

 planted at the ordinary depth. With reference to the effect of trimming the 

 roots of the tree at the time of transplanting on the siTbsequent formation of 

 new roots, the results showed considerable variation in different seasons and 

 with different plants. The general conclusion is reached that trimming is of 

 no importance. 



Further tests of orthodox and careless methods of planting trees (E. S. R., 

 20, p. 1034) have continued to show no bad effects. In the case of two series 

 of experiments in which the ground was rammed around the trees after the 

 trees were planted the advantage gained by this procedure persisted through- 

 out the succeeding seven or eight years. In one instance, however, where the 

 trees were planted in a type of clay unsuited for fruit culture ramming proved 

 to be very deleterious, the soil around the roots developing sulphuretted hydro- 

 gen owing to the absence of aeration. Ramming experiments conducted witn 

 1,400 forest trees of various sorts resulted in only a slightly greater groAvth 

 for the rammed trees, but the subsequent mortality among the rammed trees 

 was only half as great as among those not rammed. 



Experiments were undertaken to ascertain whether apple trees in a heavy 

 soil suffered less from canker if they were planted higher than usual. Certain 

 varieties subject to this disease were planted at the usual depth and also with 

 their roots flush with the surface of the ground. Observations over a period 

 of ten years show that the high-planted trees have not flourished quite so 

 well as the others. No relation between their behavior in successive years and 

 the rainfall was observed. The high-planted trees have suffered somev.hat 

 less from the attack of canker. 



Experiments dealing with the ciitting back of the branches of trees at the 

 time of transplanting have shown that such cutting back may be delayed up 

 to any time before active growth begins without any injury to the trees. 



