CHARACTERIZATION OF NUTRIENT DISORDERS OF LETTUCE IN SILICA SAND CULTURE

Lactuca sativa cv. ‘SVR6006’ plants were grown in silica sand culture to induce and photograph nutritional disorder symptoms.
Plants were grown with a complete modified Hoagland’s all nitrate solution: (macronutrients in mM) 15 NO₃^–N, 1.0 PO₄^–P, 6.0 K, 5.0 Ca, 2.0 Mg, and 2.0 SO₄^–S, plus μM concentrations of micronutrients, 72 Fe, 18 Mn, 3 Cu, 3 Zn, 45 B, and 0.1 Mo.
A control group was grown using a complete nutrient formula containing all essential nutrients.
Each nutrient deficiency treatment was induced using a complete nutrient formula that lacked only one of the essential nutrients.
Reagent grade chemicals and deionized water of 0.18 dS/m purity were used to formulate treatment solutions.
Nutrient toxicity of boron was also induced by increasing the element 10X higher than the complete nutrient formula.
The plants were automatically irrigated every 2 hours and the solution drained from the bottom of the pot and recaptured for use.
A complete replacement of nutrient solutions was done weekly.
Plants were monitored daily to document and photograph sequential series of symptoms as they developed.
Typical symptomology of nutrient disorders are presented.

International Symposium on Soilless Culture and Hydroponics

C.C. Gunter, B.E. Whipker, I. McCall, J. Garzón

Lactuca sativa L., Hoagland¿s solution, nutrient deficiencies, romaine type

https://doi.org/10.17660/ActaHortic.2009.843.21