Teff Growth and Yield As Affected by Day Length, Temperature and Soil Moisture.

ABSTRACT

Teff is an annual tri- purpose grass crop becoming important in many parts of the US. Although the crop is drought tolerant, it is not well understood how teff reacts to different soil moisture regimes. Similarly, teff responses to day length and temperature are not well documented. This study was designed to establish the response of teff growth and yield to day length, temperature, and soil moisture. A growth chamber was initiated in 2011 and repeated in 2012. Experimental design was a split-plot arrangement of a completely randomized design. Whole plots were growth chamber set to deliver one of six environmental treatments resulting from the factorial combination of two day lengths (14/10 or 16/8 hours day/night) and three day/night temperature regimens (24/19, 27/16, or 30/24 C day/night). Sub plots were individual pots hand-sown to teff within each growth chamber and consisted of a factorial combination of four soil water contents (100%, , 75%, 50%, or 25% of field capacity) and three watering intervals ( 3, 5 or 7 days). Tillering decreased by approximately 16% as daytime temperature increased from 24 to 30 C.  Increasing temperature regime from 24/19 to 30/24 C day/night resulted in a 35% decrease in biomass yield and a 100% decrease in grain yield in 2011 and a 56% decrease in biomass yield and a 53% decrease in grain yield in 2012. Increasing day length from 14h to 16h decreased tillering by 10% both years of the study. Increasing day length from 14h to 16h decreased biomass by 24 and 5% and grain yield by 40 and 59% in 2011 and 2012, respectively. The results of this study clearly indicate that teff is responsive to both day length and temperature; however, additional work is required to determine how these responses will affect the feasibility of teff as a cash crop under Oklahoma environmental conditions.