WATER QUALITY AS A POSSIBLE LIMITING FACTOR IN LOUISIANA MAYHAW PRODUCTION
Ground water salinity is a major concern for crop diversification in Louisiana where mayhaw (Crataegus opaca) is being considered as a new fruit crop. Its saline resistance is unknown; thus, we evaluated it in greenhouse conditions. One-year-old seedlings were irrigated with tap water, 10 mm NaCl (+ 2 mm CaC12), and 25 mm NaCl (+ 5 mm CaC12) for 9 weeks. Leaf and stem dry matter accumulation were reduced by an average of 80% and 60% below controls, respectively, in seedlings irrigated with 25 mm NaCl. The fresh weight: dry weight ratios of stems and roots also were reduced by 25 mm NaCl (15% and 28% below controls, respectively). Notably smaller leaf growth suppression occurred when 25 mm NaCl was supplemented with 5 mm CaC12 compared to 25 mm NaCl in the absence of CaC12. The fact that CaC12 partially reversed the leaf growth inhibition may indicate that Ca fertilization could be of benefit for mayhaw orchards relying on saline ground water.