Temperature, potassium nitrate, substrate, and harvesting time on the germination of zoysia grass seeds

Abstract

Zoysia japonica grass has commercial importance to Brazil due to its use in golf courses and football stadiums. The main concern about its commercial cultivation is the unevenness on seed germination as well as the ideal seed harvesting time. Therefore, the objective was to measure the effect of temperature and potassium nitrate on dormancy overcoming, and of substrate and harvesting time on germination of zoysia grass seeds (Zoysia japonica Steud). There were three experiments: 1) temperature and potassium nitrate treatments, with six temperature conditions (constants at 20 ˚C, 25 ˚C, 30 ˚C, and 35 ˚C, and alternating at 20-30 ˚C and 20- 35 ˚C), under absence or presence of potassium nitrate; 2) temperature and substrate treatments, with two temperature conditions (alternating at 20-30 ˚C and 20-35 ˚C) and three types of substrates (on paper, between paper, and on sand); and 3) harvesting time treatments, which seeds were obtained by manual harvesting comprising 11 harvesting periods. Seeds germinated more rapidly on the sand and paper, at the alternating temperature of 20-35 °C. The best period for seed harvesting was from 18 to 19 days after ear emergence in the production field.