ATTEMPTS TO RAISE THE CALCIUM LEVEL IN APPLES 



W.J. Bramlage, Mack Drake, and John H. Baker 

 Department of Plant and Soil Sciences 



It has long been recognized that insufficient calcium can lead 

 to development of cork spot of apples in the orchard, and bitter 

 pit development on the fruit both on the tree and after harvest. 

 Recently, there also has been a rapidly increasing awareness that 

 low calcium levels are contributing to a greater rate of deteriora- 

 tion of apples after harvest, probably through a hastening of the 

 aging processes in the fruit. 



With this recognition comes the question of how to raise the 

 calcium level in the fruit. Answering this question has proven to 

 be yery difficult. Soil applications have been generally ineffec- 

 tive, because apple roots do not absorb calcium very readily, the 

 tree does not translocate it efficiently, and because it appears 

 that what calcium is available is drawn away from the fruit by the 

 vegetative growth. 



1 evel 

 an ex 

 Horti 

 with 

 woul d 

 f erti 

 were 

 3 , an 

 (10 1 

 from 

 were 

 eval u 

 ferti 

 of ca 

 1 evel 

 inter 

 Mulch 

 appl e 

 inter 

 Analy 

 t a s s i 

 potas 



Last 



in a 

 p e r i m 

 cul tu 

 hay ( 

 impr 

 1 i z e d 

 spray 

 d Jul 

 bs hi 

 m i d - J 

 store 

 ated 

 1 i z e r 

 1 c i u m 

 sign 

 nal b 

 ing t 

 s , an 

 nal b 

 ses s 

 um, a 

 sium 



year , 

 pples 

 ent i 

 ral R 

 100 1 

 ove c 

 with 

 ed wi 

 y 16; 

 gh ca 

 une t 

 d in 

 and a 

 nor 

 in t 

 i f i c a 

 reakd 

 he tr 

 d the 

 reakd 

 howed 

 nd it 

 that 



we CO 



with 



n a bl 



esearc 



bs/tre 



al cium 



c a 1 c i 



th cal 



and s 



1 cium 



hrough 



regul a 



nalyze 



the ca 



he app 



ntly a 



own th 



e e s si 



re was 



own , a 



that 



is 1 i 



i nterf 



n t i n u e 

 severa 

 ock of 

 h Cent 

 e) in 



absor 

 um nit 

 cium E 

 till 

 hydrat 



1 ate 

 r stor 

 d for 

 1 ci um 

 1 es . 

 nd al s 

 at dev 

 g n i f i c 



a str 

 nd dec 

 these 

 kely t 

 ered w 



d our a 

 1 new e 

 40, 10 

 e r , in 

 hopes t 

 ption f 

 rate at 

 DTA at 

 ther tr 

 ed 1 ime 

 August, 

 age unt 

 cal cium 

 EDTA sp 

 Lime-wa 

 reduc 

 eloped 

 antly r 

 ong tre 

 ay in t 

 fruits 

 hat the 

 i t h cal 



ttempt 

 X p e r i m 

 -year- 

 which 

 hat re 

 rom th 



5.4 1 

 1 lb p 

 ees we 



per 1 

 At h 

 i 1 Jan 

 . Nei 

 rays h 

 ter sp 

 ed the 

 during 

 educed 

 nd tow 

 he f ru 

 were s 



hay r 

 cium a 



s to rai 

 ents. F 

 old Mcln 

 some tre 

 d u c t i n 

 e soil; 

 bs per t 

 er 75 ga 

 re spray 

 00 gal ) 

 arvest , 

 uary, wh 

 ther the 

 ad any e 

 rays rai 

 amount 

 and fol 

 the cal 

 a r d i n c r 



se th 

 irst , 

 tosh 

 es we 

 of wa 

 other 

 ree ; 

 1 on 

 ed wi 

 at 2- 

 sampl 

 en th 

 cal c 

 ffect 

 sed t 

 of bi 

 1 w i n 

 ci um 

 eased 



its from 

 i g n i f i c a 

 el eased 

 b s r p t i 



thes 

 ntly 

 1 arge 

 n by 



e cal 



we e 

 trees 

 re mu 

 ter s 



tree 

 other 

 June 

 th li 

 week 

 es of 

 e app 

 ium n 



on t 

 he ca 

 tter 

 g sto 

 1 evel 



bitt 

 e tre 

 h i g h e 



amou 

 the t 



CI um 

 stabl 



at t 

 1 ched 

 tress 

 s wer 



tree 

 18, J 

 me-wa 

 inter 



frui 

 1 es w 

 i trat 

 he am 

 1 ci um 

 pit a 

 rage . 



of t 

 er pi 

 es . 

 r i n 

 nts 

 ree r 



i s h e d 

 he 



e 



s 



uly 



ter 



val s 



t 



ere 



e 



ount 



nd 



he 



t. 



Why? 



po- 



f 



oots 



This experiment will be continued for a number of years to 

 assess long-range results of the treatments. However, we are re- 

 placing calcium EDTA sprays with calcium chloride sprays this year. 



