عنوان

Germination, yield, and yield components of tef (Eragrostis tef (Zucc) Trotter) as affected by environment, tillage and weed control practices

TLpq304011710

انگلیسی

Germination, yield, and yield components of tef (Eragrostis tef (Zucc) Trotter) as affected by environment, tillage and weed control practices

[Thesis]

A. Debelo

Oklahoma State University

1992

162

Ph.D.

Oklahoma State University

1992

Scope and method of study. Field and controlled environment experiments were conducted in Ethiopia and at Oklahoma State University, respectively. The field experiment was conducted on Sirba-Godetti (Adaa) and Arsinegelle farmers field in 1988 and in 1989 on clay and loamy soils, respectively. The objective of the field experiment was to study the effect of tillage and weed control practices on yield and yield components of tef. The purpose of the controlled environment experiment was to study the effect of environment (temperature, light, soil type, planting depth, drought, salt stress, and seed age) on germination response of tef cultivars. Findings and conclusions. There was no significant yield increase because of extra tillage beyond one time plowing when field was sprayed with either paraquat (1,1-dimethyl-4,4bipyridinium ion) or glyphosate (N-(phosphonomethyl) glycine) before plowing. Number of panicle per unit area, grass and broadleaf weed distribution were the most affected by tillage. Supplemental hand weeding or chemical herbicide (2,4-chlorodiphenoxy acetic acid) once at early tillering stage of tef significantly increased yield. The effect of either tillage or weeding on soil moisture was not consistent. Study of the environmental effect on germination of tef cultivars conducted under laboratory condition indicated that tef seed can fully germinate within 48 hours at 25/35C night/day or 30C mean temperature. Tef seed can germinate under continuous or alternating light or dark treatments. Germination significantly increased when seeds were planted at depths between 5 and 20 mm in clay loam than sandy loam soils. Germination decreased as drought or salt stress increased to 0.6 and 0.9 MPa of PEG and NaCl solutions, respectively. Two early maturing cultivars, Dabbi and Gealami, were found to be more drought and salt tolerant at germination. High temperature and relative humidity enhanced tef seed aging as a result germination decreased significantly. Solute leakage, described as a sign of seed deterioration, increased significantly before germination was significantly decreased and continued in a quadratic relation (r2 = 0.80) with aging.

Agronomy

Agronomy

Biological sciences

Plant propagation

A. Debelo

p

[Thesis]

276903

a

Y