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J. E. Shelton

Abstract

Surface applications of dolomitic limestone raised the pH from 4.3 to 6.2 with diminishing effect to 15 cm. Although the pH was affected to 15 cm the available Ca was raised only to a depth of 7.5 cm. When the lime was applied in discrete zones as subsurface applications, the pH was raised to 6.1 and maintained at 5.8 to a depth of 30 cm. When lime and superphosphate were applied on the surface the distribution of Ca and P with depth was improved. Concentrations of Ca and P in leaf tissue of ‘Delicious’ and ‘Golden Delicious’ (Malusdomestica Borkh.) apple trees were increased more by subsurface than surface applications of lime and superphosphate. However, the greater effectiveness of subsurface over surface applications in maintaining leaf concentrations was not sustained and did not result in increased growth.

Growth responses were obtained from applications of superphosphate and lime, regardless of method of application. Leaf Ca and P concentrations of 0.95–1.10 and 0.20–0.25, respectively, were associated with maximum growth.

Free access

T.R. Konsler and J.E. Shelton

Soil applications of dolomitic limestone and P fertilizer before seeding American ginseng (Panax quinquefolium L.) affected root weight (RW) gain during the first 4 years of growth. At the end of each growing season, root size was greatest with the intermediate liming rate and with the high P rate. Lime resulted in positive linear responses in soil pH, K, Ca, and Mg and in root N, P, Ca, and Mg and curvilinear responses in soil Mn and Zn and in root K, Mn, and Zn. Applied P had a positive linear effect on soil Na and on root N, Ca, and Fe and a curvilinear effect on soil P and on root P and Ca. Terminal RW was positively correlated with soil pH, K, Ca, Mg, and Na and with root P, K, Ca, and Mg; RW was negatively correlated with root Mn and Zn. Regression analyses implicated only soil Ca and Na and root Mg and Zn as significant terms in prediction equations,

Open access

D. C. Zeiger and J. E. Shelton

Abstract

Mn in apple leaves rose to a late summer maximum prior to or at abscission. The average levels, or the maxima, were not related to the severity of IBN symptoms. There are indications, but no conclusive evidence, that some withdrawal into the bark of shoots may occur. If such movement does occur, the resulting increase in bark Mn concentration is not great and cannot account for levels of bark Mn associated with IBN by Berg, et al. (1). No redistribution of Mn between bark and wood appears to occur during the winter.

Open access

D. C. Zeiger and J. E. Shelton

Abstract

‘Red Prince Delicious’ apples/‘M7’ rootstocks, growing in sand culture and receiving ½, 5 or 50 ppm Mn, developed internal bark necrosis (IBN), and an Fe-deficiency chlorosis in its severest expression, at the highest level of Mn supply. Fe was as high in leaves of chlorotic as in those of non-chlorotic plants, but the chlorosis was cleared up by increasing the Fe supply.

Ground twigs showed a brownish coloration which had a max reflectance at 700 mμ. Differences in coloration were correlated with the Mn supply, the severity of IBN symptoms and the Mn/Fe ratio in the leaves and bark, but not with the Mn/Fe ratio in the ground twigs.

Open access

J. E. Shelton and D. C. Zeiger

Abstract

‘Red Prince Delicious’/East Mailing (EM) VII trees were grown in sand culture and fertilized with a complete nutrient solution containing 0.5, 5.0 or 50.0 ppm Mn. 54Mn was supplied to provide the same specific activity in all treatments. Autoradiographs showed “islands” of radioactivity in bark patches from all treatments 2½ months after initiation of the experiment. These “islands” disappeared after 8 months in the 0.5 ppm treatment, and after 10 months in the 5.0 ppm treatment, but continued to exist in bark patches from the 50.0 ppm treatment through the last sampling at 15½ months. Typical, and some aberrant, symptoms of IBN first appeared after 5½ months in the 50.0 ppm treatment. Pimples occurred at sites where autoradiographs indicated Mn concentrations. As the pimple stage of IBN progressed to necrotic lesions, radioactivity was concentrated around the periphery of the lesions. Data is presented which suggests that, as Mn supply is increased, alteration of mechanisms for regulating uptake and distribution of Mn occurs.

Free access

T.R. Konsler, S.W. Zito, J.E. Shelton, and E.J. Staba

Soil-applied dolomitic limestone and fertilizer affected the level of certain root and leaf ginsenosides in 4-year-old American ginseng (Panax quinquefolium L.); however, ginsenoside accumulations in the roots and in the leaves often were not similar. Root and leaf ginsenoside production tended to differ in its response to soil fertility (SF) factors and root tissue nutrient (RN) elements. Leaf ginsenoside production was more often correlated with SF factors and RN elements than that of root ginsenosides, the response of both ginsenoside sources was greater to RN than SF status. Leaf ginsenoside content was positively correlated with the SF factors and RN elements to a greater degree than that of root ginsenosides. Leaf ginsenoside production was more often affected by the same chemical element in the soil and in root tissue than that of root ginsenosides. There was no correlation between the level of any ginsenoside measured in root tissue and the same ginsenoside in leaf tissue.