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important factor in the east Mr. Burbank's records indicate that he found 

 'hybrids of certain oriental strains which appear immune to chestnut 

 blight.' How he arrived at this conclusion I do not know, except that 

 some of his hybrids may have been sent east for testing. 1 do not believe 

 at that time there was any chestnut blight anywhere near California. 



" Mr. Burbank's records state that he found crosses between the Oriental 

 Chestnut from Japan and our native Chinquapin were the most resistant 

 to chestnut blight. No doubt his later breeding experiments were con- 

 centrated on these crosses." 



We made many crosses with this Burbank pollen, but the most 

 important was a cross on our most resistant Japanese, from which 

 we obtained 5 nuts. 



Cross Pollination Work 



1940 was the poorest year for cross pollination that we have yet 

 experienced. The spring was cold, and continued cold right into 

 July. The Fourth of July, proverbially hot, was as " cold as 

 Christmas " — a statement which is literally true, at least for New 

 York Citv. The records at the U. S. Weather Bureau in lower 

 Manhattan give the minimum temperature on July 4. 1940, as 58°, 

 and the maximum, on Dec. 25, 1940, as 58°. The cold weather had 

 two important results. 1. 'The flowering of the chestnuts was de- 

 layed. Some were in bloom even on August 1 ! Usually every- 

 thing is finished (except for the ever-blooming Costarica Seguinii) 

 by July 15. 2. " Setting" of the nuts, i.e. fertilization as a result 

 of pollination, did not occur as regularly as usual. The months of 

 August and September were unusually dry — and thus a very poor 

 growing season ended. The oaks in the woods surrounding the 

 plantation were similarly affected, so that few acorns ripened. As 

 a result, the squirrels did not allow windfall chestnuts to remain on 

 the ground, as they have done in good acorn years. 1 Tow-ever, in 

 spite of these drawbacks we harvested 401 hybrid nuts. Fast year 

 we harvested 767, and in 1938, 930. 



Twelve of the combinations from which we harvested nuts were 

 new to science, making a total of 48 new hybrid combinations made 

 since we started out in 1930. Altogether, including the hybrid nuts 

 planted this fall, we have about 1,000 hybrid trees of various 

 pedigrees. 



