Document Type

Thesis - Open Access

Award Date

1984

Degree Name

Doctor of Philosophy (PhD)

Department / School

Agronomy

Abstract

As initial testing, this research aimed to screen, describe and evaluate annul native clovers as potential forages. Pure clover stands were studied at three Ethiopian highland locations with introduced species used for comparison (checks). Intraspecific differences in T. tembense were studied as a spaced plant. Interspecific differences were evaluated with and without added phosphate on: dry matter yields at different harvest times, self-reseeding, seed yields, leaf tissue mineral contents, proportions of plant organs, and forage quality. Yields of clovers sown during short (SR) and long rainy seasons (LR) were compared. Native clovers performed significantly better than checks. Screening was best done in a spaced plant. Each of the significant differences (p<0.01) in T. tembense (stem, leaf and floral characters) had less than 50% intraclass correlation suggesting high non-genetic variability among strains. Ecotypic differences in flowering suggested intraspecific heterogeneity. Collection sites based on geographical references were perfectly discriminated according to regions using soil factors, but appeared asynchronous with strain classification into regions on similar edaphic basis. Differential yields among species indicated valuable agronomic interspecific diversity. Plant organic matter synthesis appeared to be greatest at reduced amounts of P despite overall yield increases over a wide range of P applications (5-30 kg P/ha). Native clovers showed relatively low tissue P suggesting efficient nutrient use under low soil availability Tissue mineral contents appeared unaffected by P addition alone. Differential yields in clovers were influenced by time of sowing (SR vs. LR season) and of clipping, in relation to increase in temperature, radiation and moisture stress. Seed yields and forage quality were improved by P application. Both inter- and intraspecific variability suggested the presence of valuable germ plasm for direct forage utilization or for future plant improvement.

Library of Congress Subject Headings

Clover -- Ethiopia

Clover as feed

Forage plants -- Ethiopa

Format

application/pdf

Number of Pages

222

Publisher

South Dakota State University

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