Stockpiling EliteTall Fescue Cultivars.

Stockpiling Elite Tall Fescue Cultivars

Rocky Lemus

Extension Forage Specialist

Department of Plant and Soil Sciences

Mississippi State University

  <>Abstract:

Tall fescue is an important cool-season forage in the central and northern part of Mississippi and it allows producers to extend their grazing season.  Producers are reluctant to utilize tall fescue in their pastures due to fescue toxicosis associated with the endophyte.  Several novel endophyte lines have been evaluated in Mississippi for yield performance during the regular grazing season, but no data has been collected about their stockpiling potential and management for winter feeding.  The objective of the study is to asses yield potential, changes in forage quality, and optimal fertilizer application and nitrogen use efficiency of different N sources when applied to tall fescue elite cultivars.  A study was established in the fall of 2007 and 2008 to study the stockpiling potential, optimal N application date and rate, management, and forage quality of different novel endophyte lines.  Six experimental Jesup tall fescue lines with different enphohyte strains were evaluated:  EIWT (endophyte-infected wild type), EF (endophyte free), 502, 514, 542, and 584.  Nitrogen application dates were mid-September and mid-October of 2007 and 2008.  Nitrogen treatment consisted of a control and two nitrogen sources (urea and ammonium nitrate) applied at two different rates (56 and 112 kg N ha^-1).  The experimental design was Split-Split-Split Block replicated four times with dates and N rates randomized within each experimental line.  The main plots were the experimental lines, the subplots were the application dates (September or October) and the sub-sub plots were the nitrogen rates.  Small random grab samples will be collected from each plot every four weeks to determine changes in forage quality.  Total yields were taken February of 2007 and January of 2008 to measure biomass potential using a flail-type harvester.  No yield differences were observed in 2007 between experimental lines, but total yields were influenced by date, N source and application rate.  Yield differences were observed in 2008 among the experimental lines. Ammonium nitrate was more efficient in increasing biomass yield than urea at both application rates.