Effects of shade on the cultivated strawberry (Fragaria X anassa Duch.)

Greenhouse and field studies were conducted to determine the effects of shade on photosynthetic, growth and yield responses of "Redchief" strawberries. Plants were exposed to 0 , 30 , 47 and 63 percent shade in the greenhouse. Net photosynthesis (Pn) as measured under the shade treatments demonstrated a curvilinear decrease. Pn as measured under saturating light levels of 790 μ-tmol· m-2 · s·1 began to decrease in plants grown under 30 percent or higher shade levels. Light saturation curves for leaves expanded in full sun and then transferred to shade treatments for seven days showed a decrease in Pn saturation rate and light saturation point at 63 percent shade. Saturation curves for leaves expanded under the shade treatments exhibited a decreasing trend in saturation rate and point at all shade levels. Heavy shade (63%) reduced leaf thickness and depth of the palisade cell layers. Individual leaf area was not affected by shade treatments. As percent shade increased, total plant dry weight decreased linearly as did specific leaf weight. Shade treatments of 0, 30, 63 or 95 percent were applied over field-grown plants either in the fall during flower bud initiation, or in the fall and spring, during flower bud initiation and spring vegetative growth. Berry number was reduced as percent shade increased. Plants shaded only in the fall had higher berry number than plants shaded both in the fall and spring. Berry weight was also reduced as percent shade increased. Sugar concentration, pH and titratable acidity were not affected by shade levels or time of shade application.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Horticulture

Department dc:contributor.department

Horticulture

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1990

Author dc:creator

• Garrison, Susan Elizabeth

Chair dc:contributor.committeechair

• Williams, Jerry Michael

Committee members dc:contributor.committeemember

• Barden, John A.
• Lyons, Robert E.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-04142009-040805

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/42099