Zoysiagrass has great potential for use in the Gulf Coast states as a turfgrass. There has been minimal research on the nitrogen (N) and potassium (K) fertility response of zoysiagrass and the effect on turf color, quality, and nutrient content. The objective of this study was to evaluate the effects of N and K fertility on zoysiagrass. A study was conducted on three zoysiagrasses: Zoysia japonica × Z. tenuifolia Willd. ex Trin. (`Emerald'); Z. japonica Steud. (`Meyer'); and Z. matrella. The N and K treatment combinations consisted of high (H) and low (L) rates of N and K at the following levels: N levels of 454 and 227 g N/92.9 m2 per month and K levels of 454 and 227 g N/92.9 m2 per month. The treatment combinations were (N and K): HH, HL, LH, and LL and were applied in two split applications monthly from July through November. The study was a randomized complete-block design with three replications. All plots received two applications of a micronutrient fertilizer (late June and August), were irrigated as needed, and maintained at a height of 3.8 cm. Color, density, texture, uniformity, and quality were determined visually for each month. Plant tissue samples were collected (September) and analyzed for macronutrient and micronutrient contents. There were significant differences for color, density, and quality in the following months: September (color and density); October (quality); and November (color and quality). There were differences in leaf texture for all months. There were significant differences for N, magnesium (Mg), and K contents but there were no differences for any micronutrient. This study indicated that all three zoysiagrasses provided acceptable color and quality during the summer and fall, and that N and K rates affected N, K, and Mg contents in the plant.
Production of a Phytotoxic Compound, 3-Phenylpropionic Acid by a Bacterial Endophyte, Arthrobacter humicola YC6002 Isolated from the Root of Zoysia japonica