The effects of sulfur deficiency on citrus

Abstract does not appear. First page follows.

Introduction

In a preceding paper ⁽³⁾5 an account is given of the development of phosphorus deficiency in citrus trees growing in one of two soils potted in 55-gallon containers. In the other soil an acute deficiency of sulfur occurred. The purpose of this paper is to describe the effects of this sulfur deficiency on the growth, appearance, fruit characters, and inorganic composition of the orange trees of this experiment. To the knowledge of the authors, sulfur deficiency of citrus trees growing in the field has never been recognized or described. Haas ⁽⁷⁾ has given a very brief description of sulfur deficiency of young Valencia trees grown in sand cultures. He states that this deficiency caused a chlorosis of the leaves. Total sulfur determinations in the leaves, twigs, root bark, and rootlets showed less of this constituent in the plant grown without sulfate than in corresponding plants of the same age growing in an adjacent nursery. The leaf symptoms illustrated, however, are unlike those produced on the experimental plants described in this paper.

Experimental Procedure

The technique used in these experiments, as regards culture, differential fertilization, number of containers, and preliminary cropping, has been given in the accompanying paper ⁽³⁾, and only such details as appear necessary to an understanding of this paper are set forth herein.

The soil in which sulfur deficiency developed was obtained from a sagebrush-covered hillside on the property of the University of California Citrus Experiment Station at Riverside. It was derived from granite and is classified as a Sierra loam. This soil was initially used for purposes of comparison with the phosphorus-deficient Hanford fine sandy loam. Previous pot tests on the Sierra soil, while showing a low supply of total and available nitrogen, had given no hint of other deficiencies.