Sulfur Requirement of Eight Crops at Early Stages of Growth
- Kiyoko Hitsuda *a,
- Mitate Yamadaa and
- Dirceu Klepkerb
Sulfur deficiency symptoms are more often observed in crops at early stages of growth since S can be easily leached from the surface soil. The objectives of this study were to evaluate some of the popular rotation crops grown in Brazil for tolerance to low external S levels and to determine the critical tissue concentration for S deficiency during early stages of growth. Germinated seedlings of soybean [Glycine max (L.) Merr.], rice (Oryza sativa L.), maize (Zea mays L.), field bean (Phaseolus vulgaris L.), wheat (Triticum aestivum L.), cotton (Gossypium spp.), sorghum (Sorghum bicolor L.), and sunflower (Helianthus annuus L.) were transferred to water culture with 0.0 to 32.0 mg S L–1 and were grown for 29 d. The minimum S concentration required in nutrient solutions was 2.0 mg L−1 for sunflower; 1.0 mg L−1 for cotton, sorghum, wheat, and soybean; and 0.5 mg L−1 or less for field bean, rice, and maize. All crops achieved optimum growth at 2.0 mg S L−1 Critical shoot S concentration at early stages of growth was 0.8 g kg−1 in maize and soybean; 1.1 to 1.3 g kg−1 in cotton, sorghum, and rice; and 1.4 to 1.6 g kg−1 in wheat, sunflower, and field bean. Our results demonstrate that the tolerance to low external S (<2.0 mg L−1) and the critical tissue S levels for deficiency varied significantly among crop species tested.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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