-5- 



unsprayed trees. If the pistil is killed before the pollen tube has grown 

 doimward far enough to escape the toxic effects of' the spray, no fruit cam 

 be set. It still seens that pistil killing is an important factor in blos- 

 som thinning. They recommend that a 2-day period between pollination and 

 fertilization of the egg cell is enough to insure set of the apple. It will, 

 of course, depend on temperature. If the weather is cool, it will take long- 

 er than in warmer weather. (Proc . Amer. Soc. Hort. Sci., Vol. 45, page 53.) 



— J. K. Shaw 



BLOSSCM THINNING YJITH ELGETQL 



In Virginia, 33-year-old York Imperial trees which were quite defi- 

 nitely in alternate bearing were sprayed with Elgetol in concentrations of 

 from approximately one to three pints in 100 gallons of spray. A concentra- 

 tion of a little under 2 pints gave the best results on this variety. On 

 thinned trees, there was some reduction in the percentage of N.umber One apples 

 on account of roughness, stippen on oversize apples, etc., but no color dif- 

 ferences were apparent in the harvested fruit. T/ith stronger concentrations, 

 size of fruits increased and total yields decreased. (Proc. Amer. Soc. Hort, 

 Sci., Vol. 45, page 45). —J. K. Shaw. 



FURTHER TESTS WITH BLOSSai THIMIN G MTERIAI3 . Tests of the effectiveness 

 of various materials for reducing TEe set of Delicious, Gano, Staynan, and 

 Arkansas Black apples were made in 1942 and 1943 in New Mexico. Elgetol re- 

 duced set but caused considerable injury. The chemicals commonly used to make 

 apples stick to the trees in the fall were also tried. It may seem foolish 

 to expect such a chemical to make apples drop in the spring, but we know that 

 a high nitrogen fertilizer maJces apples stick in the spring and also may in- 

 crease drop in the fall. ¥/hen these materials were used in strong concentra- 

 tions, the set of fruit was practically eliminated. Napthalene acetic acid, 

 the active principle in many preharvest sprays, used at very weak concentra- 

 tions, thinned the fruit successfully and did not cause severe injury. Cer- 

 tain chemicals related to napthalene acetic acid were not effective. Borax 

 at ,h% and \% concentrations reduced set without visible injury. These ma- 

 terials are not yet recommended for thinning apples, but further study may 

 show a way to reduce set without injury such as that caused by Elgetol. (Proc. 

 Amer. Soc. for Hort. Sci., Vol. 45, page 63). —J. K. Shaw. 



Hew Bulletin . A nevi bulletin in the series on the identification of 

 fruit varieties by vegetative rather than fruit characteristics has 

 been written by Lavn-ence Southwick, A. P. French, and 0. C. Roberts 

 of the Pomology staff. It is expected that this Experiment Station 

 Bulletin No. 421 will be available for general distributicn by the 

 time this copy of Fruit Notes is received. The title is ''The Identi- 

 fication of Pear Varieties from Non-Bearing Trees." Special con- 

 sideration is given to the characteristics by which nursery pear trees 

 may be identified. Descriptions and photogrcphs of some 40 varieties 

 are given. As with other Station or Extension ''oulletinfi, copij" will 

 be sent to those requesting them. 



