542 UKl'OKT OK OFiaCK OF KXJ'jaUMKiNT STATIONS. 



sliijrlitly sclf-tVrtilc. One Haldw in fi-tiit set <»iil <>t" l.">() blossoms cov- 

 ered, 1 Ivsopiis out of St; l>l(jssoins t'ovorcd, iiiid 1 Fiiincuso out of 228 

 l)Iossonis covorod. 



At the Kansas Station," (iriincs (loldcn. Arkansas Black, and Mam- 

 nioth Black Twitr failed to set a sin<(lc fruit without cross-fcrtili/ation, 

 and Huntsman was practically solf-stcrilc. The variet\' lion l)a\is, 

 which was found solf-storile in Vermont and also in Canada, proved 

 .self-fertile at the Kansas Station. 'Pwenty-six out of 100 blos.soms of 

 this vai'iety covered set fruit. The self-i)ollinated fruit, however, was 

 not so large or so vigorous as that from cros.<-fertilized blossoms. 

 There was also a greater tendency of the self-pollinated fruits to fall 

 from the tree before they attained the size of a hazelnut. They 

 responded readily, however, to the pollen of almost any other Aariety. 

 Jonathan, Huntsman, and Cooper Karly provi^l especially valuable :is 

 pollenizers in orchards. The varieties Cooper Early, Jonathan, Smith 

 Cider, Smokehouse, AMiite Pearmain, and Wine were all more or less 

 self-fertile. 



Experiments in intercrossing varieties of apples at the Delaware 

 Station'' indicate that Paragon, Stamen, Winesap, and Lil}' of Kent — 

 all weak pollen bearers except the latter — are intersterile and should 

 not be planted together in commercial orchards for the purpose of 

 cross-pollination. Fletcher^ found the varieties Bellllower, Priniatc 

 Spitzenburg, AMllow Twig, and Winesap to tend toward self-sterility. 

 The varieties Stark, LongHeld, and Tolman Sweet were self-fertile, 

 but much larger fruits of Stark and Longtield were obtained when 

 they were cross-fertilized. There appeared to be no increase in size 

 from cross-fertilizing Tolman Sweet. 



In Canada H. S. Peart'' reports that the varieties Alexander, 

 Baldwin, Chenango, Early Harvest, Greening, Holland, Twenty 

 Ounce, and Ontario showed a certain amount of self-fertility wh(^n 

 the blossoms were covered with paper bags. TAVcnty-one other 

 varieties were found self-sterile. The eight varieties which are men- 

 tioned specitically as being self-sterile are Blenheim, Ben Davis, 

 Canada Red, King, Mann, Fameuse, Spy, and liibston. The Sp3Mvas 

 found to bloom at the same period as Ben Davis and Princess Louise. 



The data secured at the above stations show that a ver}'^ large 

 number of varieties of apples are self-sterile. Further experiment 

 with other varieties is likely to increase the list of self-sterile sorts. 

 The practical conclusion that can be drawn from this work is that large 

 blocks of apples of a single variety should never be planted. Two or 

 more varieties should be mixed in alternating rows. Varieties stand- 

 ing next to each other should be such as will blossom at the .same 

 time and be capable of cro.ss-fertilizing each other. 



« IndvLstrialist, 29 (1902), No. 11, p. 163. cNew York Cornell Sta. Bui. 181. 

 «- Delaware Sta. Rpt. 1901, p. 83. ''Canad. Hort., 26 (1903), No. 9, p. 361. 



