Growth Responses of Various Ryegrass Cultivars to Different Salt Types.

Various ryegrass (Lolium perenne L.) cultivars (Covet, Galileo, Michelangelo, and Newton) were studied in a greenhouse to evaluate their growth responses in terms of shoot and root lengths, shoot (clippings) fresh and DM weights, and grass general quality under salinity stress, using different salt types. Grasses were grown hydroponically using Hoagland solution No. 1. Treatments included control, CaCl₂, NaCl, and 1:1 ratio of CaCl₂+NaCl, each at EC 10 dSm^-1. The grasses were grown with 4 replications of each treatment in a RCB design trial. Shoot and root lengths, clippings fresh and DM weights were determined weekly. After the fresh weight determination, clippings were oven-dried at 65º C and DM weights recorded. At the last harvest, roots were also harvested and fresh weights were determined, then oven-dried at 65º C and DM weights were recorded. Grass general quality was weekly evaluated. The results showed shoot and root lengths and clippings fresh and DM weights of all the cultivars decreased under any salinity treatment compared with the control. However, these parameters were higher under the CaCl₂+NaCl and CaCl₂ treatments compared with NaCl treatment. There were some numerical differences found in the measured parameters between the grasses treated with CaCl₂ and CaCl₂+NaCl salts. Grass general quality followed the same pattern as the shoot lengths, clippings fresh and DM weights. General quality of all the cultivars scored the lowest under NaCl salinity and the highest under control followed by the CaCl₂+NaCl and CaCl₂ treatments. No significant differences were detected in the studied parameters among the various cultivars. Based on the results of this study, the various cultivars exhibited a similar response to these salt sources, were adversely affected under any salinity treatment with the most sever effect under NaCl salinity, but less severely affected under the CaCl₂+NaCl and CaCl₂ treatments compared with the control.