자료유형  

 학위논문

Control Number  

0016933471

International Standard Book Number  

9798380608800

Dewey Decimal Classification Number  

630

Main Entry-Personal Name  

Davidson, Maria Teresa.

Publication, Distribution, etc. (Imprint  

[S.l.] : University of Florida., 2023

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2023

Physical Description  

1 online resource(210 p.)

General Note  

Source: Dissertations Abstracts International, Volume: 85-04, Section: B.

General Note  

Advisor: Perez, Hector;Ruiz-Menjivar, Jorge.

Dissertation Note  

Thesis (Ph.D.)--University of Florida, 2023.

Restrictions on Access Note  

This item must not be sold to any third party vendors.

Summary, Etc.  

요약Seed production is an essential agricultural practice for seed security, crop production, and restoration of native species. However, in many regions, smallholder farmers rely on unorganized, informal seed systems that limit options for seed availability. The lack of information and technology available to farmers within informal seed systems can lead to poor-quality seeds due to non-optimal harvest and storage practices that reduce yield and seed viability. Variable climatic factors represent another challenge posed to seed production. I aimed to identify seed developmental markers that help characterize the best harvest times to obtain high-quality seeds.Moreover, I determined influential factors affecting the intention of southeastern U.S. farmers to adopt seed production practices. I found that 'Mississippi Purple' (Vigna unguiculata L.) seeds reach mass maturity by 35 DAA, and the study of aging under stress demonstrated high seed vigor. I concluded that producing high-quality cowpea seeds is possible in regions such as north central Florida. Two main aspects resulted from studying 'Butterfly milkweed' (Asclepias tuberosa L.) grown in on-farm conditions for seed production. First, recent transplants may require two years of acclimatization to overcome transplant stress and produce seeds of acceptable quality. Second, seeds stored in a climate-controlled room (i.e., 23 to 26°C; 45 to 50% Relative Humidity RH) may be exposed to aging stress that reduces seed viability. I was able to demonstrate that 50 DAA is the minimum time to harvest 'Bellevue Butternut' (Cucurbita moschata) seeds since germination performance improved greatly by this time. Nonetheless, moisture content, water potential, and chlorophyll levels continue to decrease, suggesting that seeds may require longer periods of time to complete with the developmental program. Yet, seed vigor essay indicated that seeds at 50 DAA are highly tolerant to stressful conditions. Seed production of 'Yukina Savoy' (Brassica rapa L.) with high-quality and vigor is also achievable in hot and humid conditions. Results displayed that after 45 DAA seeds can be harvested although at 55 DAA seeds reached lower moisture and water potential levels. In both, 45 and 55 DAA, seed vigor was high as only after 125 days of exposure to stress seeds started to show deterioration, demonstrating a great capacity to tolerate stress and storage conditions. One of the main aspects learned in this study with 'Yukina Savoy' was that seeds may acquire dormancy at harvest. The results of the social study generated two constructs: perceived benefits and perceived challenges of engaging in seed production. The salient perceived benefits are locally and regionally adapted seeds, reliable seed availability, and independence from external suppliers. The salient perceived challenges are a lack of knowledge, skills, and training in seed production, financial constraints, and adverse climatic conditions. Data shows that farmers producing seeds intend to continue the practice. Still, about half of the non-seed producers participating in the study are not. Education about biology and technology related to seed production may motivate engaging in the practice.

Subject Added Entry-Topical Term  

Agriculture.

Subject Added Entry-Topical Term  

Biology.

Subject Added Entry-Topical Term  

Horticulture.

Index Term-Uncontrolled  

Farmers intention

Index Term-Uncontrolled  

Physiological maturity

Index Term-Uncontrolled  

Seed development

Index Term-Uncontrolled  

Seed production

Index Term-Uncontrolled  

Seed viability

Index Term-Uncontrolled  

Seed vigor

Added Entry-Corporate Name  

University of Florida Horticultural Sciences

Host Item Entry  

Dissertations Abstracts International. 85-04B.

Host Item Entry  

Dissertation Abstract International

Electronic Location and Access  

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Control Number  

joongbu:643251