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Abstract
A study of anthurium farms in Hilo, Pahoa, and Kurtistown, Hawaii was conducted to assess types of unmarketable anthurium (Anthurium andraeanum André cv. Ozaki) flowers. Of the 5000 flowers harvested from test plots on each farm during 1 year, total flowers rejected were 32%, 31%, and 26% at the three farms, respectively. At all farms, mechanical injury was the most common type of reason for rejection of flowers, followed by curved petiole; rejections due to insects, mites, and diseases were minimal. The incidence of sunburn, phytotoxicity, thrips, and mites differed among seasons at Hilo and/or Kurtistown.
Abstract
Dimethoate 4EC, fenpropathrin 2.4EC, fluvalinate 2F, oxamyl 2L, chlor-pyrifos 4EC, malathion 5EC, diazinon 4EC, and oxydemeton-methyl 2EC insecticides significantly reduced injury of anthurium (Anthurium andraeanum Lind. & Andre cv. Ozaki) flowers by the orchid thrips, Chaetanaphothrips orchidii (Moulton). Injury was characterized by white streaks and/or scarrings occurring primarily on the abaxial surface only or on both adaxial and abaxial surfaces of the spathe. Injury on the adaxial surface occurred only at 0.15% of all thrips-injured spathes observed during the study period. Thrips injury on anthurium flowers in control plots during Aug. 1984 to Sept. 1985 decreased to 3% during Feb. and Mar. 1985, and increased to 90% during Sept. 1985. Chemical names used: O,O-dimethyl S-[2-(methylamino)-2-oxoeth-yl]phosphorodithoate (dimethoate); (Rs)-α-cyano-3-phenoxybenzyl 2,2,3,3-tetramethyl cyclopropanecarboxylate (fenpropathrin); N-[2-chloro-4-(trifluoromethyl)phenyl]-DL-valine (±)-cyano(3-phenoxyphenyl)methyl ester (fluvalinate); S-{2-(ethyl suffinyl)ethyl}O,O-dimethylphosphorothioate (oxydemeton-methyl); methyl 2-dimethylamino)-N-[[(methylamino)carbonyl]oxy]-2-oxoethanimidothioate (oxamyl); O,O-diethyl 0-[6-methyl-α-(1-methylethyl)-4-pyrimidinyl] phosphorothioate (diazinon); O,O-diethyl O-(3,5,6-trichloro-2-pyridyl)-phosphorothioate (chlorpyrifos); and diethyl [(dimethoxyphos-phinothiovl)thio] butanedioate (malathion).
Burrowing nematode (Radopholus similis) causes severe stunting and yield reduction in anthurium (Anthurium andraeanum) cut flower production. Two field trials were conducted at commercial grower farms to test the efficacy of fluopyram or fluopyram + trifloxystrobin for managing burrowing nematodes. Nematode population densities in roots and cinder media were evaluated during the trial in addition to cut flower yield and canopy cover. In the first trial, the nematode population in roots was reduced by 57% after two applications of fluopyram 3 months apart. As plant health improved, the increasing anthurium root weight supported higher nematode populations. After 14 months, fluopyram-treated plots had 43% more green canopy cover and a 53% increase in flower production compared with the untreated control plots. At a second location, population densities of burrowing nematode were reduced in roots after one application of fluopyram + trifloxystrobin and remained low with quarterly applications. Nematode populations were initially reduced in fluopyram-treated plots followed by a resurgence as demonstrated in the other trial. Ten months after the initial treatment, flower yield was greater in fluopyram + trifloxystrobin-treated plots with more large and extra-large flowers produced. Canopy cover was 45% and 22% greater with fluopyram + trifloxystrobin and fluopyram applications, respectively. Fluopyram shows potential for management of burrowing nematodes in anthurium by improving plant vigor and cut flower production.