Physiological and Color Aspects of Turfgrasses with Fall and Winter Nitrogen¹

Abstract

Fall and winter N fertilization was studied on bentgrass and fescue to investigate the possibility of maintaining green foliage during winter. Research also involved the effects of this N on top growth, reserve carbohydrates, and photosynthesis. Desirable turf color was maintained throughout the winter in Virginia latitudes without adverse physiological changes. Green foliage during winter was not the result of residual color from fall but was induced even during the coldest periods of winter. Although no measurable top growth occurred during winter, turf fertilized with high N was very dense. Reserve carbohydrates generally increased from fall to winter and then decreased slowly until spring when there were sharp declines. Stem carbohydrates varied from 44% dry matter in late fall or winter to 5% in spring. More carbohydrates were found in stems than in leaves and similar trends for sugar occurred in both separates. Higher N rates generally lowered the available carbohydrates, but the opposite was found with certain winter conditions. With determinations made on five dates, net photosynthesis appeared to be higher during winter than spring or summer; however, dark respiration increased with temperatures. Photosynthetic and respiration rates during winter or spring were increased with N fertilization.

Effects of Nitrogen Application Timing on Growth and Quality of a Turfgrass Mixture

“…However, there was no visible sign of injury or winter kill for any treatment during the course of our experiments, probably due to mild winters in the region. These data are in close agreement with findings of several studies conducted in maritime or transitional regions (2,5,7,15,16). On the contrary, SF or F applications in the fall led to improved fall color retention and early spring coloration (Table 3).…”

ROOT AND SHOOT PERFORMANCE OF THREE CREEPING BENTGRASS CULTIVARS AS AFFECTED BY NITROGEN FERTILITY*

“…Nitrogen fertility rate has shown direct relation to creeping bentgrass shoot density, growth and color (6,7,8,9). Increases in creeping bentgrass shoot growth are observed as N fertility levels exceed zero.…”

Influence of Rates and Frequency of Nitrogen Application the Year Previous on Spring Color in Kentucky Bluegrass

“…Although the effects of fall applications of nitrogen have been demonstrated with Kentucky bluegrass (Poa pratensis L.) by Wilkinson and Duff (1972) and with Agrostis and Festuca species by Powell et al (1967) (Tromp and Ovaa 1971;Cooper et al 1972), and lilac (Meyer and Splittstoesser 1969). Work on this phase is beins initiated.…”