Title page for ETD etd-63197-21517


Type of Document Dissertation
Author Detoni, Cezar Ernesto
Author's Email Address cdetoni@vt.edu
URN etd-63197-21517
Title Grain Sorghum Field Emergence and Seed Vigor Tests
Degree PhD
Department Crop and Soil Environmental Sciences
Advisory Committee
Advisor Name Title
Brann, Daniel E.
Welbaum, Gregory E.
Wolf, Dale D.
Abaye, Azenegashe Ozzie Committee Chair
Parrish, David J. Committee Co-Chair
Keywords
  • seed tests
  • osmotic
  • heat shock
  • electrical conductivity
  • sorghum
Date of Defense 1997-06-30
Availability unrestricted
Abstract
Poor emergence of sorghum [(Sorghum bicolor (L) Moench] affects the stand and

potential yields. The major objective of this research was to find correlations

among field emergence data and laboratory seed vigor tests. Thirty-two and 30

hybrids of sorghum were planted at three Virginia locations in 1995 and 1996,

respectively. Field emergence was subsequently compared with results from

laboratory tests that included: 1) standard germination; 2) osmotic-stress using

polyethylene glycol 8000 (mw); 3) heat-shock using 2 hr at 50?C stress; 4)

electrical conductivity of steep water of germinating seeds; and 5) seed mass.

Field emergence of grain sorghum differed among hybrids, years and locations.

Mean emergence across years and locations was 67.5%, whereas mean

germination in the laboratory was 87.8%. There were interaction between hybrid

and location and between hybrid and year. Germination under optimal conditions

(standard germination test) and with osmotic or heat-shock stress differed among

hybrids. Regression analyses showed a weak correlation between laboratory

germination (with or without stress) and field emergence in both years. The fresh

weight of seedlings whether from standard germination or stress tests also

differed among hybrids in both years, and the associations with field emergence

were weakly correlated in 1996. Hybrids showed significant differences in radicle

length when grown under laboratory stress in both years following standard

germination. There was a weak correlation with field emergence and radicle

length following heat-shock treatment in 1996. The measurement of electrical

conductivity in the seed steep water showed significant differences among

hybrids. A weak correlation with field emergence was seen in 1996.

Conductivity values per gram of seed and per cm2 of seed area revealed

differences among hybrids. The correlation of these parameters with field

emergence was higher than conductivity per seed. Seed mass varied among

hybrids in both years , but was no correlation between seed mass and emergence.

Of the laboratory parameters examined, germination proved to be the most

consistent predictor of variations in field emergence of sorghum hybrids.

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  ABSTRACT.PDF 79.51 Kb 00:00:22 00:00:11 00:00:09 00:00:04 < 00:00:01
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