Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: April 10, 2008
Publication Date: June 1, 2008
Citation: Makus, D.J. 2008. Effect of Greens and Soil Type, Sulfur Addition and Lithium Level on Leaf Constituents. HortScience. 42(4):1243. Technical Abstract: A greenhouse experiment was conducted near Weslaco, Texas (Lat. 26o 8' N, Long. 97o 57' W) between Dec. 2006 and Feb 2007 to evaluate the effect of soil type, added sulfur and lithium level on the growth and leaf nutrients, particularly biofortified levels of Li and S, in spinach and mustard greens. Cultivars Samish (Spinacia oleracea) and Florida Broadleaf (Brassica juncea) were sown in two soils, Hebbronville and Hidalgo. Greens type exhibited differences in most attributes tested. Mustard greens (MG) grown in the lighter-textured Hebbronville soil produced plants with lower leaf and root dry wt., higher leaf transpiration and blade P, Mg, S, Li:K ratio, Zn, B and shoot and root Li. Spinach grown in the Hebbronville soil had a higher shoot:root dry wt. ratio and blade K, Ca, Mg and Li:K ratio. Sulfur addition (1 Mt / ha equivalent) had no affect on agronomic responses measured, but reduced leaf blade K (spinach, only), Ca (spinach, only) and increased P (MG, only) and S. The micronutrients Mn, Zn, Cu and B were reduced in spinach and Na, Zn and Cu increased in MG by sulfur addition. In MG (only), adding Li from 0 to 40 kg / ha reduced plant wt., leaf number, area, fresh wt., root dry wt., and the incidence of powdery mildew and increased leaf transpiration. In MG, increasing soil applied Li increased leaf blade N, K, P, Mg, S, Fe and Zn. In spinach, Li addition decreased leaf blade K, P, S, and B. Added soil Li increased shoot and root Li in both greens. All reported increases or decreases due to Li addition over the 0 to 40 kg Li / ha range were linear. The Li shoot to root ratio and shoot concn was higher in MG. Leaf blade S was reduced (r = -0.441**) by the presence of blade Li in spinach, but increased in MG (r = 0.496**). The ratio of leaf blade Li:K was approx. 4 X higher in MG, which may have interfered with somatal regulation (higher leaf transpiration in MG with increasing Li applied).