Effects of Humic Acids on the Germination and Early Growth of Two Varieties of Wheatgrass Grown Together.

As a continuation of our research for the more rapid establishment of native plants in western and eastern US military lands, two varieties of slender wheatgrass, the native cv. Pryor and the germplasm line SERDP-select developed by ERDC-CRREL, were comparatively germinated and grown in the same pots in the presence of various humic acids (HAs). The objective was to ascertain the possible different effects exerted by HAs on the two varieties grown in competition. Three HAs isolated from two Wyoming soils (GN and GS) and one Utah soil (D) were used in suspension at two concentrations (10 and 100 mg/l) to measure seed germination and seedling early growth of the two varieties. After 6-days of seed germination in Petri dishes in the dark in thermostated chamber at 20°C, the seedlings were grown for 21 days in controlled temperature, humidity and illumination conditions in a Fitotron chamber. All experiments were conducted in five replicates. Statistical analysis of data by ANOVA and LSD showed that, with respect to the control: (a), no HA treatment influenced statistically the germination % of either varieties, however the number of germinated seeds of SERDP-select slender was slightly greater than that of cv. Pryor slender; (b) the three HAs at both concentrations had variable and slight effects on the primary root and shoot lengths of the two varieties, with the exception of GS-HA at 100 mg/L that apparently promoted the primary shoot length of SERDP-select more than that of Pryor; (c) HA treatments increased roots length and roots and shoots fresh and dry weights of cv. Pryor more than those of SERDP-select. In conclusion, HA treatments generally appeared to promote the germination of SERDP-select slender with respect to that of cv. Pryor slender, whereas the opposite effect was apparent for early growth.