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© 2009 Plant Management Network. Forage Yield of Teff is Low in the Southeast and is Only Marginally Responsive to Nitrogen Dennis W. Hancock, Forage Extension Specialist, and R. Gregory Durham, Forage Research Technician, Department of Crop and Soil Sciences, University of Georgia, Athens, GA 30602 Corresponding author: Dennis W. Hancock. dhancock@uga.edu Hancock, D. W., and Durham, R. G. 2009. Forage yield of teff is low in the Southeast and is only marginally responsive to nitrogen. Online. Forage and Grazinglands doi:10.1094/FG-2009-0819-01-RS. Teff (Eragrostis tef Zucc. Trotter) is a high quality, warm-season annual grass that is reportedly tolerant of drought and warm temperatures and is increasingly used as a summer hay crop (3). Unfortunately, there is a lack of published research on teff as a forage crop, yield expectations in various regions, and its response to N fertility. Recent press releases from the Northeast have indicated teff yields were about 80% of that produced by sorghum and sorghum-sudan varieties (1). More detailed reports from South Dakota indicated the yield potential of teff is greater than 10,000 lb DM/acre (3). The objective of this research was to assess the forage yield of teff in the southeastern USA and its response to increasing N fertility. To accomplish this objective, a small plot trial was conducted on a Cecil clay loam (fine, kaolinitic, thermic Typic Kanhapludults) soil over two years at the University of Georgia’s Plant Sciences Farm near Watkinsville, GA. In both years, the previous crop had been pearl millet under uniform fertility. Teff was planted 1/8 inch deep into a firm, well-prepared seedbed using a cultipacker-seeder at a rate of 10 lb PLS/acre on 31 May 2007 and 26 April 2008. Five levels of N fertilization (0, 25, 50, 75, and 100 lb/acre) were applied as treatments to 5 × 25-ft plots (6-ft alleys) in a randomized complete block design with four replications. Soil tests indicated no other nutrients were limiting. The N was applied as urea at planting and subsequently watered in with sprinkler irrigation. Rainfall was supplemented with irrigation to provide a minimum of 0.75 inches of water each week. Harvests were taken on 6 September and 19 September each respective year, when visual assessments indicated the forage growth entered a stationary growth phase (virtually no reproductive development was observed). Plots were harvested using a flail-type plot harvester (leaving a stubble height of 3 inches) on these dates. In 2007, a second harvest was made on 5 November after a killing frost but regrowth after the first cutting in 2008 was not significant. Grab samples were dried at 140°F, weighed, and total DM yield was calculated. Data were analyzed via regression analysis and orthogonal contrasts in SAS (SAS Institute Inc., Cary, NC). The forage yield of teff in these experiments was low (< 4250 lb/acre). In both years, the forage remained in the lag phase of growth for approximately 45 days. This conflicts with reports of excellent seedling vigor in other regions (3). High nighttime temperatures during this 45-day period (average minimum temperature was 66° and 61°F, respectively) may have contributed to the lack of vigor and low yields of teff in the two years of this study (2), though additional research is needed to confirm this hypothesis. The response of total forage yield to N treatment did not differ (P > 0.10) between years. When averaged over both years, total forage yields exhibited a significant linear response (P < 0.01) to N addition (Y = 8.55x + 3092; R² = 0.16). Higher order polynomial regression equations did not improve the fit. Though the response to N was significant, the increase in yield was marginal. Orthogonal contrasts showed the forage yield response plateaued when the N was 50 lb/acre or greater, and the yield increase at 50 lb/acre over the nil control was not substantial (+470 lb DM/acre). This work is the first to report teff yields in the Southeast USA and demonstrates that its yield in this region is much lower than yields reported in press reports from other regions, even when supplied ample N fertilizer. Further, since teff yields in this study were only 30 to 50% of the yield typically provided by other summer annuals in this region and the teff exhibited poor vigor in the first 30 to 45 days after planting, we conclude that teff may not be a suitable forage crop in this region. Literature Cited |
