146 Missouri Agr. Exp. Sta. Research Bulletin No. 8 



to the slow fall in temperature under such conditions rather than to 

 hardiness developed as the result of exposure to low temperature. 

 (Pages 266-269). 



21. In the peach growing district of South Missouri and Arkan- 

 sas, and probably other similar climates, the most important factor 

 influencing the loss of peaches from low temperatures in winter is 

 keeping the buds from starting into growth during warm periods in 

 winter. In that section the best means of accomplishing this end 

 is prolonging the growth of the trees in autumn, either by heavy 

 pruning or by fertilizing with nitrogen the spring before. Some 

 varieties of peaches have a much longer rest period than othei" varie- 

 ties and therefore are started into growth more slowly by warm peri- 

 ods in winter. (Pages 269-283). 



22. The killing temperature of peach blossoms when the tree 

 is just coming into full bloom, under Missouri conditions, seems to 

 vary from about 22 F. to 25 or 26 F. After the blossoms are old 

 enough that they are probably pollinated, and from that time on 

 until the peaches are as large as one-half inch in diameter, at least, 

 they continue to become more tender until they will withstand but 

 very few degrees below the freezing point, the seeds of young peaches 

 killing at a higher temperature than other peach tissue. (Pages 283- 

 286). 



23. So far the investigations at this station indicate that early 

 varieties of peaches are not started into growth more readily by warm 

 periods in winter than are later varieties. Some of the very early 

 varieties of the Chinese Cling group are the most slowly started into 

 growth in early winter and bloom as late as any of the varieties. How- 

 ever, after blooming time these early peaches grow much more rap- 

 idly and are much more liable to be killed by a freeze after the fruit 

 is set. (Pages 286-293). 



24. Killing of wood of the apple is of considerable importance 

 in some apple growing sections. Among the most common injuries 

 are root killing, crown rot, crotch injury, sun scald, trunk killing 

 and killing back of top and branches. (Pages 293-297). 



25. Killing of apple buds from low temperatures is not common 

 but has been observed. (Pages 297-298). 



26. The blossoms and young fruit of the apple will not generally 

 withstand as low temperature as will the blossoms or young fruit of 

 equal age of the peach. (Pages 298-302). 



27. While the killing of cherry and plum buds is less common 

 than the killing of buds of the peach, such killing is often to be ob- 

 served in some sections. The young fruit of the Wild Goose plum 

 is among the most resistant to late frosts in spring. (Pages 302-303). 



