540 REPORT OK OFFICK OP' EXPERIMENT STATIONS. 



spriiii,'' i)l<)\viii<r :ui(l fr('(|ii('iil sIkiHow cultivjitioii will ])rosorv<' a j^ood 

 supply of inoistiMT in tlu' soil, which is so essential to the j^rowth of 

 healtiiy leaves and Imds. In seasons of exeessi\-e rainfall the ji^round 

 may l>e left unculti\ated to hasten evaj)orati<)n. In the Northern 

 States it is desirable for the formation of flower buds that wood 

 growth come to an end al)out July 1. Should growth continue after 

 this date it may bt' checked by moderate root })runing. This can be 

 accomplished by plowing a furrow down the I'ows each way, followed 

 by a subsoiler, so that the small roots on etu-h tree can be cut off. 

 Plowing should be followed l>y a cover crop to evaporate any excess 

 moisture in the soil. 



At the Rhode Island Station" a study was made of the effect of light 

 on l)ud develo])ment. An examination was made of the num))er of 

 Hower l»u(ls on limbs exposed to suidight as compared with those on 

 limbs partially shaded. The proportion found was 182 clusters on 

 limbs in sunlight and only 136 on limbs partially shaded. This sug- 

 gests the desirability of thinning out the tops of trees that become too 

 luxuriant in wood and leaf growth, so that more flower buds may be 

 produced. 



The Canada Experimental P'arms'' report some experiments in which 

 whitewash covering the trees appeared to have 1>ut little effect in 

 retarding the swelling of apple ])uds in the spring. Mulching apples 

 with strawy manure in winter when the ground was deeply frozen and 

 covered with 8 to 12 inches of snow did not retard leafing and blos- 

 soming the following spring. 



Some of the conditions controlling the germination of apple pollen 

 have been studied and reported upon by the Wisconsin Station.'' In 

 a saturated atmosphere under a bell jar apple anthers failed to burst 

 after fift^'-six hours, while in dry air the anthers on duplicate twigs 

 had practically all burst. The experiment is believed to indicate that 

 during periods of protracted rain, or as long as the trees are wetw^th 

 rain or dew or enveloped in fog, practically no anthers burst and there- 

 fore no pollen is wasted. The anthers were not found to swell per- 

 ceptibly until the maxinmm temperature reached 70^ F. Other 

 laboratory experiments with blossoms indicate that pollen is discharged 

 freely onh' in warm and dr}- weather. At a temperature of 40^ to 

 51^ F. pollen germination was very feeble, a fact which indicates that 

 the vitality of the pollen is not likely to be injured by exposure to a 

 prolonged rainy period if the weather remains cool. If it rises to 65^ 

 or 70^ F. the vitality of the pollen may be destroyed. 



Observations at the New Jersey stations '*' showed that no apples set 

 when the fruit blossoms were not permitted to get dry during the 

 period of pollination. 



« Rhode Island Sta. Bui. 37. ■ « Wisconsin Sta. Rpt. 1901, p. 289. 



6 Canada Expt. Farms Rpts. 1899, j). 94. <^New Jersey Stas. Rpt. 1899, p. 221. 



