Pregermination of Italian Ryegrass and Tall Fescue Seed1

Abstract

Repair and improvement of sports turfs are difficult because of continuous use and damage to the turf ground cover. Sowing pregerminated rather the dormant seed is a possible means fo reducing establisment time. A series of experiments with seed of cool‐season turfgrasses were conducted under diferent temperature regimes to identify pregermination treatments that effect fast rates of germination. Italian ryegrass (Lolium multiflorum Lam.), which has a relatively fast germination rate, was compared to ‘Kentucky 31’ tall fescue (Festuca arundinacea Schreb.), which has a relatively slow germination rate. Seed was either treated by soaking for 24 or 48 h in aerated water, unaerated, in gibberellic acid (GA3) at 50 or 100 mg L−1, or by not soaking. Germination rates were compared 14 days after seed sown on blotters in petri dishes were incubated in controlled environments at optimum temperatures of 25 to 15°C or at suboptimum temperatures of 20 to 10°C and 15 to 5°C with an 8‐h photoperiod during the daily high temperature cycle. Fifty percent viable seed (Germ50)of Italian ryegrass germinated in 7 to 17 h depending on temperature, if pretreated with GA, at 100 mg L−1 and kept moist for 48 h at 25°C. Untreated, dry seed had Germ50 values of 4.2 to 7.1 days, respectively, depending on temperature. Germ50 values for viable seed of Kentucky 31 tall fescue were 1.8 to 5.9 days depending on temperature, if seed was pretreated with GA3 at 50 mg L−1 and kept moist for 48 h at 25°C. Untreated, dry seed had Germ50 values of 5.9 to 10.8 days, respectively, depending on temperature.