Growth Regulators and Irrigation Mitigate
Competition Between Intercropped Grass and Fraxinus nigra ‘Fall Gold’
Jeffrey H. Gillman[1] and
Department of Horticultural Science
Citation
Gillman, J. H. and C. P. Giblin. 2001.
Growth Regulators and Irrigation Mitigate Competition Between
Intercropped Grass and Fraxinus nigra ‘Fall
Gold’. Jour. Environ. Hort. 19(4): 195-198.
Abstract
Grass, intercropped with nursery stock, is beneficial to the
long term productivity of a field due to decreased erosion of topsoil and
increased soil organic material. The
primary disadvantage of using grass as an intercrop is supposedly due to a
reduction in nutrients and water available to nursery stock. In the spring of 1999 Fraxinus nigra ‘Fall Gold’ trees were planted in herbicide strips
with no intercrop (cultivated soil), an intercrop of untreated ryegrass, an
intercrop of mowed ryegrass or an intercrop of ryegrass treated with a growth
regulator. Half of the trees in each
treatment were irrigated and half were not.
Growth measurements were taken over two growing seasons. There were no significant increases in growth
with the addition of
irrigation with the exception of trees grown with an intercrop of
growth regulated ryegrass where the addition of irrigation resulted in greater
tree height. Trees grown with no
intercrop had the greatest increase in both caliper and height. Trees grown with grass treated with a growth
regulator and irrigated did not show significantly different growth from
non-irrigated trees grown without intercrops.
Trees grown with untreated or mowed grass had the lowest increase in
caliper and height.
Index words: intercrop, growth regulator, production
nursery, woody ornamentals, ryegrass, cover crop.
Species used in this study:
Lolium perenne L., Fraxinus
nigra (Marsh.).
Chemicals used in this study: Trinexapac-ethyl
(Primo) [4-(cyclopropyl-%-hydroxy-methylene)-3,5-dioxo-cyclo-hexanecarboxylic acid ethyl ester].