fits from soil and foliar treatments, from soil treat- 

 ments applied every 3, 2, or 1 year, and from differ- 

 ent rates of both soil and foliar applications. The 

 experiment was replicated 7 times, and both leaves 

 and fruit were sampled for analysis. Fruit quality 

 also was assessed in some years. Treatments were 

 applied in 1987, 1988, and 1989. In 1990, no tree 

 received any B, to assess the carry-over effects of the 

 treatments in previous years on leaf B concentra- 

 tions. 



Leaf analyses recorded during this experiment 

 are presented in Table 2. All soil applications of 

 borate sharply increased leaf B in the year of appli- 

 cation. It made little difference whether application 

 was at a rate of 1, 1 1/3, or 1 2/3 lbs per tree. Foliar 

 applications were considerably less effective than 

 were soil applications, even at twice the recom- 



mended rate. (This probably was 

 due to the small amount of leaf 

 surface for absorption at this time.) 

 Clearly, there was very little 

 carry-over effect on leaf-B concen- 

 trations from treatments in previ- 

 ous years. All trees had received 1 

 lb of soil borate in 1986, but in 1987 

 trees that were in the first two treat- 

 ments, and thus received no B that 

 year, contained much lower leaf B 

 levels than those that received soil 

 B in 1987. Trees in Treatment 2 

 received B in 1988 but not in 1989, 

 and in 1989 their leaf B concentra- 

 tions fell by 34 ppm. When no tree 

 received any B in 1990, all trees had 

 similar B concentrations in their 

 leaves, the concentration having 

 fallen as much as 38 ppm. 

 Therefore, our recommendation that soil B he ap- 

 plied only every third year apparently does not pro- 

 vide adequate protection against B deficiency . 



Effects of B treatments on fruit B and Ca concen- 

 trations are shown in Table 3. Fruit B concentra- 

 tions tended to reflect leaf B concentrations. Thus, 

 all soil treatments increased fruit B similarly, and 

 considerably more so than did foliar B treatments. 

 Furthermore, there was little effect of B applications 

 except in the years of treatment. 



It has been suggested at times that since B 

 affects movement of Ca in plants, high rates of B 

 application might be desirable to increase fruit Ca 

 levels. In 1987 and 1988, B treatments had no effect 

 on fruit Ca, but in 1989 soil B treatments signifi- 

 cantly increased fruit Ca levels. Since B application 

 rates were the same each year and both leaf and fruit 



Fruit Notes, Spring, 1991 



11 



