Optimizing Eastern Gamagrass Forage Harvests Using Growing Degree Days

Stacey A. Gunter,Corey A. Moffet,Tim L. Springer,Jason J. Goldman

doi:10.4236/as.2016.710066

Abstract

Tripsacum dactyloides (L.) L., commonly known as eastern gamagrass, is useful for grazing, stored forage, soil amelioration and conservation, and as a biofuel feedstock. Our goal was to calculate accumulated growing degree days (GDD) from existing datasets collected for eastern gamagrass forage production experiments in northwestern Oklahoma, and discuss the use of GDD, instead of calendar harvest dates, in the production of eastern gamagrass forage. Growing degree days were calculated from 1 January each year using the “optimum day method”. For 10 harvest years, the first eastern gamagrass harvest required 690 ± 26 cumulative GDD. Based on long-term weather data from Woodward, Oklahoma, this would place the first harvest on or near 1 June. The second harvest required 635 ± 27 cumulative GDD which would place the second harvest on or near 15 July and the third harvest required 690 ± 23 cumulative GDD placing it on or near 30 August. Each of the 30 harvest required an average of 670 ± 15 cumulative GDD. Using GDD to predict harvest events is a useful tool that forage producer can use in the production of eastern gamagrass forage in the USA and possibly elsewhere.

Highlights

Tripsacum dactyloides (L.) L., commonly known as eastern gamagrass, is a perennial, native, warm-season forage grass distributed throughout the eastern, central, and southern USA [1]
Our goal was to calculate accumulated growing degree days (GDD) from existing datasets collected for eastern gamagrass forage production experiments in northwestern Oklahoma, and discuss the use of GDD, instead of calendar harvest dates, in the production of eastern gamagrass forage
Each of the 30 harvest required an average of 670 ± 15 cumulative GDD

Summary

Introduction

Tripsacum dactyloides (L.) L., commonly known as eastern gamagrass, is a perennial, native, warm-season forage grass distributed throughout the eastern, central, and southern USA [1]. These experiments were conducted by the late Mr Chet Dewald to gain a general knowledge about the crop and to improve the selection and breeding of eastern gamagrass. The highest TDN per acre was found using 45 day intervals [3]” Information like this was not reported in the mainstream journals, it became the starting point for more detailed agronomic research of eastern gamagrass

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