per acre in each of the 2 applications. For young orchards, the 

 addition of 1/2 pound of Solubor per 100 gallons (dilute basis) 

 to the first 2 cover sprays meets the B requirements of these 

 trees. Reports of New York State indicate that sprays can be con- 

 centrated up to 8X with satisfactory results. 



Leaf samples from orchards treated with Solubor have indicated 

 adequate leaf boron levels but the fruit was deficient in this 

 element . Whether or not B applied as a fertilizer more adequately 

 meets the B requirement of apples than foliar applied B is not 

 known by us. 



Magnesium (Mg) : Deficiency symptoms of this element are char- 

 acterized by necrotic (brown) areas between the veins. The older, 

 basal leaves on shoots and spurs are usually affected first, and 

 as the season progresses the injury symptoms appear on the younger 

 leaves. The deficiency symptoms frequently become apparent in 

 late July and early August. By late summer, the shoots on which 

 leaves show Mg deficiency may be defoliated except for a few 

 leaves near their terminals. Mg deficiency increases fruit drop 

 at harvest. 



Weather conditions may have been responsible for the frequent 

 symptoms last year and the question is what to do if you suspect 

 or know that you had trees low in Mg. If you have been applying 

 a dolomitic limestone on a regular basis (dolomitic limestone con- 

 tains magnesium), no corrective procedures should be necessary. 

 However, take leaf samples again for analysis in 1983. 



If you have not applied dolomitic limestone recently and you 

 suspect low Mg levels in your trees, we suggest applying this kind 

 of lime this spring. 



Manganese (Mn) : Apple leaves from trees showing Mn deficiency 

 in 1978 had 12 to 15 ppm of this element which is much below the 

 desired levels of 30 to 60 ppm. Mn deficiency symptoms are char- 

 acterized by interveinal fading of chlorophyll with the veins re- 

 maining green. For those who are unfamiliar with the symptoms of 

 Mn deficiency, we refer vou to the photograph that appeared in the 

 May/June 1978 Issue of FRUIT NOTES. 



Mn deficiency should be corrected on trees sho\\ring considerable 

 foliage damage. Although we have no definite proof, Mn deficiency 

 appeared to be associated with excessive fruit drop on a few trees 

 in orchard in 1977. Mn deficiency can be corrected by foliar 

 applications of manganese sulfate or of a fungicide containing Mn. 

 Apply manganese sulfate at about first cover at the rate of 3 lbs. 

 per 100 gallons of water. If using a Mn-containing fungicide, 2 or 

 3 applications are necessary with timings about petal fall, first 

 and second cover. 



