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Abstract
African violets (Saintpaulia ionantha Wendl.) are propagated commercially by leaf cuttings with or without a petiole (3). Laurie and Kiplinger (4) reported that leaves propagated without petioles produce more crowns. Developing shoots or crowns (plantlets) with roots usually are divided and handled as young plants. In one variation of this method the roots are removed from the shoots, the shoots are graded and the graded shoots are rerooted to obtain uniform plants. This method requires numerous shoots.
Abstract
Paclobutrazol drenches were more effective in retarding chrysanthemum (Chrysanthemum × morifolium ‘Charm’) plant height than paclobutrazol incorporated in plaster-of-paris tablets, injected hydrogels, and gelatin capsules applied at the same rate (0.5 mg a.i./15-cm pot) in three experiments. Capsules containing paclobutrazol also controlled plant height effectively in all three experiments. Drenches consistently reduced plant area, whereas a 50-ppm paclobutrazol spray did not. Paclobutrazol tablets, gels, and capsules reduced plant area in two of three experiments. Drenches were the only treatment to reduce flower number per plant. Chemical name used: β-[(4-chlorophenyl)methyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).
Abstract
All fungicides applied as dips to polyurethane propagation cubes prior to propagation of poinsettia (Euphorbia pulcherrima Willd.) cuttings inhibited rooting at the concentrations employed. Least inhibition of rooting resulted from dips containing (per liter) either 37 mg metalaxyl [N-(2,6 dimethylphenyl)-N-(methoxyacetyl) alanine methyl ester] 25 WP plus 300 mg ferbam (ferric dimethyldithiocarbamate) 76 WP, 500 mg ferbam 76WP, or 599 mg benomyl [methyl l-(butyl-carbamoyl)-2-benzimidazole-carbamate] 50 WP. Treatments containing fenaminosulf (p-dimethylaminobenzenediazo sodium sulphonate) 35 WP inhibited rooting most. The PCNB (pentachloronitrobenzene) 75 WP treatment also caused low root counts.
Abstract
Cuttings of poinsettia (Euphorbia pulcherrima Willd.) treated with a basal dip of 0.1% indolebutyric acid (IBA) alone (control) or in combination with 5% ferbam (ferric dimethyldithiocarbamate), benomyl [methyl 1-(butyl-carbamoyl)-2-benzimida-zole-carbamate], metalaxyl [N-(2,6-dimethylphenyl)-N-(methoxyacetyl) alanine methyl ester], PCNB (pentachloronitrobenzene), and ethazol (5-ethoxy-3-tricloromethyl-l,2,4-thiadiazole) did not differ in rooting index or weight. Increasing the percentage of fungicide above 5% generally reduced rooting. However, rooting was similar to the control with combinations of ferbam at 5% to 67% or metalaxyl at 20%. Fenaminosulf (p-dimethylaminobenzenediazo sodium sulfonate) at 5% to 67% reduced rooting.
Growers of greenhouse ornamentals in New York State (NYS) have identified the need for improved diagnosis and management of diseases, insects, and media/fertility problems to reduce crop loss and improve crop quality. With the objective of using an interactive small-group format to encourage active learning of topics, our team developed a hands-on workshop model that we termed integrated pest management (IPM) In-depth. In addition, we wanted to deliver the workshop in several locations around NYS to reach growers who traditionally have not attended on-campus programs. Each program consisted of three modules focusing on an insect, disease, or plant culture topic. Participants were divided into small groups that rotated through the areas. From 2009 to 2013, we present 20 In-depth workshops in 14 NYS counties reaching 309 attendees. The project succeeded in its intent to reach growers who had limited access to previous IPM programming; 59% of attendees had not previously attended any type of IPM programming. The majority of attendees (66%) reported that they had learned information they intended to implement at their operations. Additional impacts and challenges of offering this hands-on program are discussed.
Procedures were developed to determine if live, adult two-spotted spidermites (Tetranychus urticae Koch) could be surface disinfested before being introduced into in vitro cultures of torenia (Torenia fournieri L.). Three time periods (5, 10, and 15 minutes) and five levels of sodium hypochlorite (0.05% to 0.25%) were evaluated. Surface disinfestation was accomplished by agitating 2 × 3 cm pieces of infested bean leaves in sodium hypochlorite solutions and then drying in a mite drier apparatus. All sodium hypochlorite concentrations disinfested the mites completely, however high concentration levels were lethal to the mites. Exposure periods of 10 and 15 minutes also significantly increased mortality. For optimum disinfestation of two-spotted spidermites with minimum mortality, a concentration of 0.05% sodium hypochlorite and 0.05% Tween-20 for 5 minutes should be used.
Abstract
An isolate of Thielaviopsis basicola (Berk. & Br.) Ferraris from Ilex crenata Thunb. was highly pathogenic to susceptible hollies while the isolate from Pelargonium × hortorum L.H. Bailey was less pathogenic. Various ratios of pine bark and sphagnum peatmoss did not suppress T. basicola on susceptible hollies. Of the cultivars tested, I. crenata ‘Helleri’ and I. pernyi Franch were most susceptible, while I. aquifolium L. × I. cornuta Lindl. and Paxt. ‘Nellie R. Stevens’, I. cornuta ‘Burfordii’ × I. peryni ‘Lydia Morris’, and I. cornuta ‘Burfordii Nana’ were the most resistant to T. basicola. I. crenata ‘Helleri’, grown in a medium with a pH of 5.0 or 6.0, had less black root rot development than similar plants in a medium with a pH of 6.5.