Chlorine, Bromine and Sodium As Nutrients for Sugar Beet Plants

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Abstract
Sugar beets (Beta vulgaris) were grown in nutrient solns. pre-pared from low halide salts of reagent grade. The first de-ficiency symptoms developed on the blades of the center leaves. These appeared as a netted mosaic pattern by transmitted light. As symptoms developed, interveinal areas appeared as smooth flat depressions, light green to yellow in color, whereas veins were green and had a "raised" appearance. A feature of Cl deficiency was stubby growth of secondary roots. Both leaf and root symptoms were absent in solns. with 6.7 m. eq. of Cl or with 20 m. eq. of Br per three plants. Addition of Mn, Na, Si, as well as those salts contained in Hoagland''s soln. No. 1 failed to correct the symptoms. Cl was necessary for top and root growth and was associated with sugar formation rather than with sugar utilization. Petiole Cl values of 4.9 to 7.9 [mu]eq. and blade Cl values of 3.3 to 5.4 [mu]eq. per g. of dry tissue were indicative of extreme Cl deficiency. Petiole Cl values of 200 [mu]eq. or above and blade (without mid-ribs) Cl values of 50 [mu]eq. or above per g of dry tissue were indicative of Cl adequacy. Petiole Cl concns. but not those of the blades, increased with the age of the leaf. For plants well supplied with Cl, the Cl concns. within the upper blade tissues of the leaf were less than one-tenth those of the corresponding petioles. Cl recovered from untreated plants was in excess of the Cl present as an impurity in the nutrient solns. and that contained in the transplanted seedlings, whereas complete recovery of Cl was indicated for plants treated with 20 meq. of Cl after correcting for the Cl found in the untreated plants. The addition of Na to low K plants increased growth significantly but had no effect upon high K plants. The effects of Si were not conclusive.