Plants of Euphorbia pulchenima Wind. 'Gutbier V-14 Glory Annette Hegg Dark Red', and 'Annette Hegg Brilliant Diamond' were treated with 37 iw a.i. of XE-1019 applied in 102, 204, or 408 ml-m⁻² foliar sprays. Half of the plants received overhead irrigation and the remaining received soil-surface irrigations. No spray carrier volume effect or irrigation effect was observed for final plant height, bract canopy diameter, or for days from start of short days to bloom. The results obtained do not support the hypothesis that spray carrier volume or irrigation method affect the efficacy of XE-1019 on poinsettias.

Plants of Lilium longiflontm Thunb. 'Nellie White' recei,yed the following treatments during forcing: 1) control; 2-3) gne or two sprays of 50 mg-liter ancymidol 4-9) one or two sprays of 5, la, or 15 mg-liter XE-1019; or 10) one spray of 20 mg-liter XE-1019. All growth retardant treatments reduced plant height compared to controls. Plant height decreased linearly with increasing concentration of XE-1019 for both one- and two-spray treatments. High concentrations of XE-1019 delayed anthesis; ancymidol treatments did not. Individual corolla length was not affected by treatments. Treatments did not affect daughter bulb depletion or new daughter bulb growth. Total leaf area and leaf dry weight decreased as XE-1019 concentration increased; ancymidol treatments did not affect leaf area, but did reduce leaf dry weight. Leaf total soluble carbohydrate decreased with increasing concentration of XE-1019.

XE-1019 (2 foliar sprays of 10, 2Q or 30 mg-liter⁻¹) was applied to plants of Hydrangea macrophylla Ser. 'Rose Supreme' during greenhouse forcing. Doses applied resulted in excessive reductions in shoot elongation and inflorescence diameters and delayed anthesis. Shoot growth was reduced with increasing XE-1019 concentration. Shoot length was reduced 46 %; stem dry weight was reduced 31 %; leaf area per shoot was reduced 44 %; inflorescence height was cut by 45 %; and inflorescence mass was reduced 48% with the 30 mg-liter⁻¹ XE-1019 treatment. Specific leaf weight increased with increased XE -1019 concentration (192% increase with the 30 mg-liter⁻¹ treatment) resulting in thicker leaves at anthesis. XE-1019 is an effective height control agent for florists' hydrangeas, and shows significant activity at very low (less than 0.2 mg a.i. per plant) doses.

Plants of Chrysanthemum moifolium Ramat. 'Ovaro' received 0, 10, 20, or 30 mg-liter ⁻¹ XE-1019 applied as a 204 ml-m⁻² foliar spray. Treatments did not affect time from start of short days to bloom or inflorescence height lunge. Inflorescence height and inflorescence display diameter both were reduced with increasing concentration of XE-1019.

Plant of Chysanthemum morífolium Rymat. 'Ovaio' received 0, 102, 204, 304 or 408 ml-m⁻² of 0, 40, 20, 13.3, and 10 mg-liter⁻¹ XE-1019, respectively. No treatment affected time from start of short days to bloom or inflorescence display diameter. All XE-1019 treatments resulted in shorter plants than controls did. No carrier volume effect on plant height was observed. The inflorescence height range per pot decreased with increasing carrier volume. The greater inflorescence height uniformity achieved with the high carrier volume is beneficial and warrants further investigation.

Floral initiation was successfully stimulated for plants of Hydrangea macrophylla 'Rose Supreme' under non-inductive environmental conditions by spraying plants with XE-1019 or paclobutrazol. Effective treatments were 10 weekly of 5 biweekly sprays of 100 mg-liter ⁻¹ paclobutrazol; 5 biweekly sprays of 11 or 30 mg-liter⁻¹ XE-1019, and 4 triweekly (once every 3 weeks) sprays of 15 or 30 mg-liter⁻¹ XE-1019.

Foliar sprays of XE -1019 at 3, 4 9, 12, 15, l8 and 36 mg a.i. liter⁻¹ were found to be effective in controlling the height of Podroea ricasoliana However, at higher concentrations (greater than 12 ppm), undesirable leaflet curling and reductions in leaflet size were observed All treatments lost effectiveness in controlling internode elongation during week 4 and 5.

Plants of Lilium speciosum hybrids '101' and '298' received one 125 ml soil drench containing 1-3) 0, 0.125, or 0.25 mg ai. ancymidol per pot; or 4-6) 0.05, 0.10, or 0.15 mg a.i. XE-1019 per pot. Ancymidol treatments were less effective in controlling plant height (11 % and 16 % reduction of control plant height) than were XE-1019 treatments (18 %, 26 %, and 34 % reduction of control plant height). Treatments did not affect days from planting to visible bud; days from planting to anthesis of the first flower per inflorescence; the total number of flowers per inflorescence reaching anthesis; or the number of aborting buds per inflorescence. The treatments investigated allowed for rapid production of plants having a commercially acceptable height without a reduction in flowering quality.

Gossypium barbadense L. “algodón nativo” es oriundo de la costa norte del Perú y se caracteriza por presentar fibras de colores naturales. La evaluación del efecto de diferentes concentraciones de fitorreguladores de crecimiento en la inducción de callo embriogénico se realizó en explantes de hipocotilo de G. barbadense L. “algodón nativo” color pardo, bajo dos condiciones lumínicas distintas. La desinfección de semillas se llevó a cabo utilizando NaOCl al 2.5% en distintos tiempos de exposición (5-20 min) para obtener plántulas in vitro. Para la iniciación y proliferación de callos, se introdujeron explantes de hipocotilo (con 5 réplicas) en medios Murashige-Skoog (MS) suplementados con diferentes concentraciones de ácido 2,4-diclorofenoxiacético (2,4-D), kinetina (Kin) y agua de coco. Los callos friables de mayor proliferación fueron transferidos a medios MS con distintas concentraciones de Kin, 2,4-D y ácido indol-3-butírico (IBA) para la inducción de callo embriogénico. Los cultivos fueron mantenidos en condiciones de fotoperiodo 16 h luz/ 8 h oscuridad y oscuridad continua. Se logró el 100% de desinfección de semillas en 10 min de exposición al desinfectante. En 85% a 100% de explantes de hipocotilo se obtuvo la formación de callo en todos los tratamientos de iniciación de callo incubados en ambas condiciones lumínicas durante 21 días. La mayor proliferación de callo friable se obtuvo en 82.5% de explantes cultivados en medio MS enriquecido con 0.1 mg/l de 2,4-D y 100 ml/l de agua de coco e incubados en fotoperiodo 16 h luz/ 8 h oscuridad. En los medios MS suplementados con distintas concentraciones de Kin, 2,4-D e IBA no se logró la inducción de callo embriogénico. Sin embargo, en el medio MS sin reguladores de crecimiento y en el suplementado con 0.05 mg/l de Kin y 0.3 mg/l de IBA, en fotoperiodo 16 h luz/ 8 h oscuridad, se inició la organogénesis radical.Gossypium barbadense L. “native cotton” is originally from the northern coast of Peru and is characterized by its naturally colored fibers. The evaluation of the effect of different concentrations of plant growth regulators on embryogenic callus induction was performed in hypocotyl explants of Gossypium barbadense L. “native cotton” brown, under two different lighting conditions. Seed disinfection was carried out using 2.5% NaOCl in different exposure times (5-20 min) in order to obtain in vitro plants. For initiation and proliferation of callus, hypocotyl explants (with 5 replicates) were placed in Murashige-Skoog (MS) medium supplemented with different concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D), kinetin (Kin) and coconut water. Friable calli with the highest proliferation were transferred to MS medium with different concentrations of Kin, 2,4-D and indole-3-butyric acid (IBA) for induction of embryogenic callus. The cultures were maintained under conditions of 16 h light/ 8 h dark photoperiod and continuous darkness. 100% of seed disinfection was achieved at 10 min of exposure to disinfectant. In 85% to 100% of hypocotyl explants, callus formation was obtained in all callus induction treatments, incubated in both lighting conditions during 21 days. The highest proliferation of friable callus was obtained in 82.5% of hypocotyl explants cultivated in MS medium enriched with 0.1 mg/l 2,4-D and 100 ml/l coconut water, in 16 h light/ 8 h dark photoperiod. In MS medium supplemented with different concentrations of Kin, 2,4-D and IBA, induction of embryogenic callus was not achieved. However, in MS medium without growth regulators and supplemented with 0.05 mg/l Kin and 0.3 mg/l IBA, in 16 h light/ 8 h dark photoperiod, root organogenesis was initiated.

O presente estudo teve por objetivo avaliar características agronômicas e tecnológicas da fibra do algodoeiro mediante a antecipação da abertura das maçãs pelo uso de maturador em épocas distintas. O experimento foi conduzido na área experimental do Departamento de Produção Vegetal da USP/ESALQ em Piracicaba, Estado de São Paulo, no ano agrícola de 2005/06. O delineamento experimental utilizado foi em blocos ao acaso com 4 repetições. Os tratamentos consistiram na aplicação do maturador (ethephon/amads) em épocas distintas de abertura natural dos frutos, correspondendo a 7 tratamentos com a aplicação do produto aos 15, 30, 54, 75, 87, 92 e 100% de abertura natural, respectivamente. Em dois metros lineares de cada parcela foram realizadas imediatamente antes e 15 dias após a aplicação do produto, onde ocorreu a contagem de maçãs, capulhos e folhas, determinando as porcentagens de abertura dos frutos e as desfolhas ocorridas. Na área útil de cada parcela foi determinada a produção de algodão em caroço e, em amostras de 20 capulhos colhidos aleatoriamente por parcela, foram realizadas as análises das características agronômicas (massa de um capulho, massa média de 100 sementes, porcentagem de fibra e germinação) e das características tecnológicas da fibra (comprimento, uniformidade de comprimento, tenacidade e índice micronaire e maturidade). De acordo com os dados experimentais obtidos, pôde-se concluir que a melhor desfolha ocorreu aos 87% capulhos. A aplicação de maturador com 84% de capulhos garante maior produção. Quanto as características tecnológicas da fibra, houve redução significativa para índice micronaire quando a aplicação foi realizada aos 15, 30, 54% de capulhos e a maturidade foi menor quando a aplicação ocorreu aos 15 e 30 % de capulhos. / The present study had as objective, to estimate the agronomic and technological characteristics of the cotton plant by means the anticipation of open bolls using the harvest-aids applied in different time. The experiment was made at experimental area of Agricultural Departament at USP/ESALQ in Piracicaba, São Paulo State during the 2005/06 season. The experimental design was in randomized blocks with four replications. The trataments were made up of in application of harvesting-aids (ethephon/amads) in different time of natural opening and the experiment was composed of seven treatments, using the product at 15, 30, 54, 75, 87, 92, 100 % open bolls, respectively. Two linear meters in each plot were immediately available before and fifteen days after the application of the product, the bolls, the open bolls and the leaves were counted, estimating the parameters of percentage of opening and defoliation. The cotton yield was determinated in the useful area of each plot and samples of 20 open bolls randomized chosen per plot were analyzed for agronomical lab characteristics (average open boll mass, mass of 100 seeds, fiber percentage and germination) and fiber technological characteristics (length, length uniformity, strength, micronaire and maturity). According to the experimental data obtained, the best falling off of the leaves occurred to the 87% open bolls. The application of maturation with 84% open boll guarantees greater production. As the technological characteristics of the fibre, there was significative reduction to the micronaire index as the application was achieved to 15, 30, 54% open bolls and the maturity was smaller when the application occured to 15 and 30% open bolls.