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Growth and Environment Effects on Anatomy and Quality of Temperate and Subtropical Forage Grasses 1
Author(s) -
Silva J. H. S.,
Johnson W. L.,
Burns J. C.,
Anderson C. E.
Publication year - 1987
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1987.0011183x002700060036x
Subject(s) - cynodon dactylon , festuca arundinacea , biology , forage , temperate climate , subtropics , zoology , vascular bundle , dry matter , agronomy , plant morphology , cynodon , botany , horticulture , poaceae , ecology
The constituents determining the nutritive value of forage plants can be altered by short‐ and long‐term environmental changes. The objective of this study was to associate environmental effects on plant morphology and anatomy with cell‐wall composition and in vitro true digestibility (IVTD) and cell wall disappearance (IVCWD) of three grasses. ‘Kentucky 31’ tall fescue ( Festuca arundinacea Schreb.), flaccidgrass ( Pennisetum flaccidum Griseb.), and ‘Coastal’ bermudagrass [ Cynodon dactylon (L.) Pers.] were grown in a one‐third perlite and two‐thirds gravel media in controlled environment chambers with 18/14, 22/18, 26/22, or 30/26°C day/night temperatures (T) at either a 9‐ or 12‐h light period (LP). Successive harvests were taken at 1.5, 3, 4.5, or 6 weeks. Dry matter (DM) yield was highest at 22/18°for tall fescue (TF), but increased linearly with T for both subtropical species. The ratio of stem (plus sheath) DM to leaf blade DM (SLR) was positively associated with total yield in all grasses and increased T resulted in higher SLR for flaccidgrass (FG) and Coastal bermudagrass (CB). Cell‐wall constituents in TF increased with age and with T only to 26/22°C, whereas the age and T effects occurred for the subtropical species throughout the ranges studied. Only the bundle sheath area in TF stems (plus sheath) and the ratio of leaf thickness to average bundle diameter in FG was positively influenced ( P ≤ 0.01) by either T or LP. Quality measurements were negatively related to the ratio of leaf thickness to vascular bundle diameter in FG and to the schlerenchymatous sheath areas in TF stems. An index computed for leaf degradability was related to CB IVCWD ( r = 0.66**, significant at the 0.01 probability level) and for stem degradability was related to both IVTD and IVCWD for TF ( r = 0.46** and 0.63**) and FG ( r = 0.50** and 0.46**).