NC State Extension Publications

Problem

Skip to Problem

Nutritional disorder – zinc (Zn) deficiency.

Symptoms

Skip to Symptoms

Unlike the macronutrients, micronutrient deficiencies are rare. Zinc (Zn) deficiency has not been reported under field conditions. Most of the time, the soil will have enough micros to supplement any gaps in the chosen fertilizer plan. To present a more robust set of data, we induced zinc deficiency under controlled greenhouse studies for accurate diagnosis if the problem should arise.

In NC State University trials, ornamental tobacco developed a silver cast to the leaves as the initial symptom of zinc deficiency.

(Descriptions based on the book, Hunger Signs of Crops, 3rd Edition, edited by H.B. Sprague.) Under controlled greenhouse conditions, tobacco plants are stunted when zinc is limited. The middle to lower foliage of the plant develops a chlorotic leaf spot which (Figure 1) can later turn necrotic. These chlorotic spots can take on a metallic appearance, and will eventually become larger if the deficiency is not treated.

Initial symptoms of zinc deficiency on ornamental tobacco.

Figure 1. Initial symptoms of zinc deficiency on ornamental tobacco with a silvery coloration.

©2017 Forensic Floriculture

Zinc deficiency of ornamental tobacco.

Figure 2. Zinc deficiency of ornamental tobacco.

©2017 Forensic Floriculture

Similar Problems

Skip to Similar Problems

Symptoms appear to be similar to when phosphorus is limited. Submit a tissue sample for analysis to help diagnose the problem.

Additional Information

Skip to Additional Information

Zinc is required is very low concentrations, so deficiencies under field conditions is unlikely. First try and diagnose the problem with the symptomology of the macronutrients in mind. If none of the macros seem to fit the symptomology being exhibited by the plant, submit a tissue sample or contact your local extension office.

Diagnostic Tips

Skip to Diagnostic Tips

The sufficiency range for zinc is between 20 and 60 ppm for burley tobacco. A slight refinement of the range is available for flue cured tobacco, with 20 and 60 ppm zinc being recommended from planting until maturity, and a lower range of 18 to 60 ppm recommended at harvest for the upper, middle, and lower leaves.

Corrective Measures

Skip to Corrective Measures

Provide zinc with your fertilization program.

Management

Skip to Management

Provide zinc with your fertilization program.

Funding Source

Skip to Funding Source

Funding was provided in part by the North Carolina Tobacco Foundation.

Project Team

Skip to Project Team

Josh Henry (NC State M.S. student in Horticultural Science), Paul Cockson (NC State B.S. student in Agroecology), Ingram McCall (Research Technician in Horticultural Science), Rhonda Conlon (Extension IT at NC State), Matthew Vann (Tobacco Extension Specialist, Dept. of Crop and Soil Sciences), and Brian Whipker (Professor of Floriculture and Plant Nutrition in Horticultural Science).

Authors

Assistant Professor & Tobacco Extension Specialist
Crop and Soil Sciences
Graduate Student
Horticultural Science
Undergraduate Researcher
Horticultural Science
Professor: Commercial Floriculture Production
Horticultural Science

Find more information at the following NC State Extension websites:

Publication date: Jan. 1, 2017

NC Cooperative Extension prohíbe la discriminación por raza, color, nacionalidad, edad, sexo (incluyendo el embarazo), discapacidad, religión, orientación sexual, identidad de género, información genética, afiliación política, y estatus de veteran.

The use of brand names in this publication does not imply endorsement by NC State University or N.C. A&T State University of the products or services named nor discrimination against similar products or services not mentioned.

Recommendations for the use of agricultural chemicals are included in this publication as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services in this publication does not imply endorsement by NC State University or N.C. A&T State University nor discrimination against similar products or services not mentioned. Individuals who use agricultural chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage regulations and examine a current product label before applying any chemical. For assistance, contact your local N.C. Cooperative Extension county center.

N.C. Cooperative Extension prohibits discrimination and harassment regardless of age, color, disability, family and marital status, gender identity, national origin, political beliefs, race, religion, sex (including pregnancy), sexual orientation and veteran status.