Herbicide Selectivity in Tropical Ornamental Species

Abstract

-This study evaluated the selectivity of herbicides applied post-emergence on ornamental plants of Alpinia purpurata, Strelitzia reginae and Heliconia psittacorum. The study was conducted in two seasons. The experimental design was completely randomized with four replications. The treatments were: fluazifop-p-butyl (87.5 g ha ), and a control without any herbicide. In general, all tested herbicides and doses were selective for the three studied species. Although plants of A. purpurata and H. psittacorum have shown symptoms of phytotoxicity, recovery occurred with subsequent satisfactory visual appearance at the end of the evaluations. However, the S. reginae plants showed the smallest dry mass values when the sethoxydim and quizalofop-p-ethyl herbicides were sprayed.Keywords: Alpinia purpurata, Strelitzia reginae, Heliconia psittacorum, phytotoxicity, landscaping. RESUMO -O objetivo deste trabalho foi avaliar a seletividade de herbicidas aplicados em pós-emergência sobre plantas ornamentais de Alpinia purpurata, Strelitzia reginae e Heliconia psittacorum. O estudo foi conduzido em duas épocas. O delineamento experimental utilizado foi inteiramente casualizado com quatro repetições. Os tratamentos foram: fluazifop-p-butyl (87,5 g ha -1), quizalofop-p-ethyl (75,0 g ha -1 ), sethoxydim (184,0 g ha -1 ), quinclorac (375,0 g h -1 ), chlorimuron-ethyl (15,0 g ha -1 ), clethodim + fenoxaprop-p-ethyl (37,5+37,5 g ha -1 ), bentazon (720,0 g ha -1 ), fomesafen (225,0

Weed Management and Herbicide Selectivity in Ornamental Plants

“…However, studies on herbicide selectivity are essential to decide on chemical control. Selectivity is the ability of an herbicide to eliminate weeds in the area to be worked without reducing any desirable phytotechnical or economic aspects such as development and visual beauty of plants (Queiroz et al, 2016a).…”

“…Freitas et al (2007) evaluated the selectivity and effectiveness of the herbicide oxyfluorfen to control P. microphylla in the production of crane flower (Strelitzia reginae Banks) and found that 7 weed control was higher than 90% from doses of 300 g ha -1 of oxyfluorfen and that the herbicide was selective for this species at all tested doses (300, 320, and 340 g ha -1 ), with few visual and transient injuries. Queiroz et al (2016a) worked with plants of crane flower (S. reginae), red ginger (Alpinea purpurata K. Schum.…”

“…In contrast, chemical weed control is a viable alternative, as it provides fast results and savings in the use of labor that performs the gardening practices necessary to maintain the visual beauty of a garden (Maciel et al, 2005). Herbicides are viable chemicals in the flower production and landscaping (Seixas et al, 2011;Queiroz et al, 2016a), but crops can also have some type of injury depending on the degree of selectivity of each herbicide used, and thus devalue the visual aspect sought in the landscape composition.…”

Allelopathy of extracts of Cyperus rotundus and Oxalis latifolia on snapdragon seeds germination

“…The most common weed species present in the field of ornamental plants are the Cyperus rotundus (purple nutsedge) and Oxalis latifolia (sour clover), often cited as causes of production losses due to competition or release of allelopathic compounds (RASTEGAR et al, 2016;QUEIROZ et al, 2016;PRASAD and SHIVAY, 2017). Both species are found in bromeliads production (RODRIGUES et al, 2007;SALA et al, 2007), but they may also be found in field of roses, chrysanthemum, gerbera, tango, lily and snapdragon.…”