Modified gibberellins retard growth of cool-season turfgrasses

• Published in: Crop science 1997-11, Vol.37 (6), p.1878-1883
• Main Authors: King, R.W. (CSIRO Plant Industry, Canberra, ACT, Australia.), Blundell, C, Evans, L.T, Mander, L.N, Wood, J.T
• Format: Article
• Language: English
• Subjects: ACIDO GIBERELICO; Agronomy. Soil science and plant productions; Biological and medical sciences; BIOSINTESIS; BIOSYNTHESE; BIOSYNTHESIS; BOUTURE; CONTENIDO DE MATERIA SECA; Cropping systems. Cultivation. Soil tillage; CUTTINGS; DERIVATIVES; DRY MATTER CONTENT; ESQUEJES; FESTUCA ARUNDINACEA; FEUILLE; FOTOPERIODISMO; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; GIBBERELLINE; Grasses; Growth; GROWTH RATE; GROWTH RETARDANTS; HOJAS; INDICE DE CRECIMIENTO; LEAVES; LOLIUM PERENNE; NEW SOUTH WALES; NOUVELLE GALLES DU SUD; NUEVA GALES DEL SUR; PESO; PHOTOPERIODICITE; PHOTOPERIODICITY; Plant growth; Plant growth inhibiting substances; POA PRATENSIS; POIDS; RETARDANTES DEL CRECIMIENTO; RETARDATEUR DE CROISSANCE; SEASONAL VARIATION; STEMS; TALLO; TAUX DE CROISSANCE; Tending. Growth control; TENEUR EN MATIERE SECHE; TIGE; Tillage. Tending. Growth control; Turfgrasses; USO DEL AGUA; UTILISATION DE L'EAU; VARIACION ESTACIONAL; VARIATION SAISONNIERE; WATER USE; WEIGHT
• ISSN: 0011-183X; 1435-0653
• DOI: 10.2135/cropsci1997.0011183X003700060036x

Several modified gibberellins which inhibit shoot elongation have been assessed as turfgrass growth retardants. Dichloro-methano 16,17-dihydro GA, (DMDGA5) effectively inhibited growth of the cool season grasses, Festuca arundinacea Schreb., Poa pratensis L., and Lolium perenne L. Turf growth (weekly cutting dry weight) was reduced by up to 70% in three separate field trials over three seasons. This inhibition lasted up to 5 wk before recovery to control growth rates and, often, there was then a transient enhancement of growth. DMDGA, inhibited turf growth to the same extent as did the commercial turfgrass retardant, Trinexapac-ethyl (commercially formulated as Primo, Novartis, Inc., Basel, Switzerland). Daily water use was also 25 to 30% less over at least 4 wk in studies with mini-swards growing in controlled environment conditions. With isolated plants of two cultivars of P. pratensis (cvs Holt and Bronco) grown in controlled conditions leaf elongation rates were more than three-fold greater in long than short daylengths. Both Trinexapac-ethyl and DMDGA, blocked most of this growth increase as did a related derivative, 16,17-dihydro GA5. Since these compounds inhibit gibberellin biosynthesis it appears that the extra growth in long days arises from an increase in gibberellin content