2017 ASHS Annual Conference

Manilagrass (Zoysia matrella ‘nuan noi’), hybrid bermudagrass (Cynodon dactylon x. C. transvaalensis ‘Tifway 419’), and seashore paspalum (Paspalum vaginatum ‘salam’) are commonly used as fairway grasses on golf courses in Southeast Asia. There is little data about the growth and nutrient use of these grasses when maintained as fairway turf in a tropical environment. Our objective in this experiment was to measure the growth rate and associated water use and nutrient use of these species in response to three N:K fertilizer ratios. We filled 16-cm-diameter plastic pots with a sand typically used on golf course fairways in central Thailand. Then we planted stolons of these grasses in the pots and grew them in a plastic greenhouse in Pathum Thani, Thailand. Twelve pots were planted of each species, for a total of 36 pots. After a grow-in of 168 days, the fertilizer treatments were started. For 48 days, from 20 Nov. 2013 to 7 Jan. 2014, we applied weekly treatments of three different N:K ratios to four pots of each species. Nitrogen was supplied from urea at 1 g N m^-2 week^-1. Potassium was supplied from KCl at 0.5, 1, and 2 g K m^-2 week^-1. This gave N:K ratios of 2:1, 1:1, and 1:2. Irrigation was supplied twice weekly, and the pots were weighed before adding water. Mowing of the pots was done with scissors at 15 mm once per week, and the grass clippings were collected, dried, weighed, and analyzed for leaf nutrient content. Averaged across all N:K ratios and across the 48 day duration in which the clippings were collected, the daily dry matter clipping yield was 2.8 g m^-2 for bermudagrass, 3.4 g m^-2 for seashore paspalum, and 4.3 g m^-2 for manilagrass. There was a small effect of N:K ratios. Increasing the N:K ratio from 2:1 to 1:1 caused an 8% increase in clipping yield, averaged across species. Changing the N:K ratio from 1:1 to 1:2 had no effect. The species differed more among themselves than they did in response to N:K fertilizer ratios. The manilagrass produced 1.3 g dry clippings for each liter of irrigation water applied, seashore paspalum produced 1.1 g, and hybrid bermudagrass 1 g. On a dry matter basis, the bermudagrass clippings contained 2.9% N, 1.9% K, and 0.3% P. Seashore paspalum clippings contained 2.5% N, 2.8% K, and 0.3% P. Manilagrass clippings contained 2% N, 1.8% K, and 0.4% P.