Effect of zinc applications on the crop of grapefruit trees affected with mottle-leaf

Parker, E

Effect of zinc applications on the crop of grapefruit trees affected with mottle-leaf

Author

E. R. Parker

Author Affiliations

E. R. Parker was Assistant Horticulturist in the Experiment Station.

Publication Information

Hilgardia 11(2):35-53. DOI:10.3733/hilg.v11n02p035. December 1937.

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Abstract

Abstract does not appear. First page follows.

Introduction

The superficial effects of mottle-leaf are readily apparent in the character of the foliage and in the vigor of citrus trees (Fawcett, 1936).4 The reduced size of individual leaves and the retarding of growth causes an obvious decrease in leaf area. According to (Reed and Dufrénoy (1935)), the condition of partial chlorosis involves a reduction in the number of chloroplasts and in the photosynthetic capacity of the leaves.

Such abnormalities might be expected to alter the carbohydrate metabolism of plants and to affect their reproductive activities. In the case of citrus, such an effect might result in a decreased yield and possibly in an effect on the quality of the fruit. In extreme cases of mottle-leaf, these effects are clearly evident on casual inspection. Not only is the crop light, but fruits produced on severely affected branches are small and abnormal; the nature of the abnormalities varies with the species of citrus observed. Where trees are slightly to moderately affected with mottle-leaf, however, it is difficult to tell by casual observation what, if any, influence this disorder has on the amount and quality of the fruit produced.

Literature Cited

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