REFERENCE SUFFICIENCY RANGES
VEGETABLE CROPS

Spinach, Greenhouse

C. R. Campbell

• Critical Values

  None established.

• Sampling Procedures

  The most recent mature or fully expanded leaf is the best indicator sample for all growth stages. This is generally the 3rd or 4th leaf from the growing point.

  Depending on size, 8 to 10 leaves are adequate for a sample.

  Problem samples can be taken at any time during the growing season. Monitoring samples should be taken at two-week intervals as soon as the plants are large enough.

  Samples are shipped to the laboratory in paper containers.

• Sufficiency Ranges
  
  
  • Most Recent Mature Leaf
    All growth stages
    
    

    Macronutrients
    N	P	K	Ca	Mg	S
    4.0–6.0%	0.3–0.5%	3.0–8.0%	1.0–1.5%	0.4–1.0%	0.2–0.8%

    
    

    Micronutrients
    Fe	Mn	Zn	Cu	B	Mo
    50–200 ppm	25–200 ppm	20–75 ppm	5–15 ppm	25–60 ppm	0.2–1.0 ppm

• DRIS Norms

  DRIS norms have not been reported for greenhouse spinach.

• Remarks

  Sufficiency ranges were developed from available references and experience reviewing analytical results.

• References

  Mills HA, Jones JB Jr. 1996. Plant analysis handbook II: a practical sampling, preparation, analysis, and interpretation guide. Athens (GA): Micro-Macro Publishing. 365 p.

Electronic Document Prepared by:
Catherine Stokes, Communication Specialist
Agronomic Division of the N.C. Department of Agriculture and Consumer Services. July 2000.