Multiple ornamental uses of Costus stenophyllus standi. & L.O. Williams

Costus stenophyllus or bamboo costus, despite its high ornamental potential, is still little known in the cut flower and ornamental plant market. The bamboo costus is a spiral ginger admired for its beautiful stems that are lined with brown colored alternating bands. This costus has rather straight and upright stems. Conical red inflorescences, which resemble the head of a snake, emerge from the base of the plants. The flowers are light yellow and emerge between the red scales on the rather long-lasting, attractive inflorescences. This study was carried out to evaluate the possibility of using these species as a garden plant, cut flower and cut stem. Thus, the characterization was made based on 28 characters of the plant, the leaves, the flower stem, the flowers, as well as season blooming characteristics and flower postharvest longevity.

Multiple Ornamental Uses of Costus stenophyllus Standl. & LO Williams

Costus stenophyllus or bamboo costus, despite its high ornamental potential, is still little known in the cut flower and ornamental plant market. The bamboo costus is a spiral ginger admired for its beautiful stems that are lined with brown colored alternating bands. This costus has rather straight and upright stems. Conical red inflorescences, which resemble the head of a snake, emerge from the base of the plants. The flowers are light yellow and emerge between the red scales on the rather long-lasting, attractive inflorescences. This study was carried out to evaluate the possibility of using these species as a garden plant, cut flower and cut stem. Thus, the characterization was made based on 28 characters of the plant, the leaves, the flower stem, the flowers, as well as season blooming characteristics and flower postharvest longevity.

In vitro propagation of Glandularia peruviana (L.) Small, an ornamental native plant from South America

The flower market is characterized by being both eager for novelties and highly competitive. The exploration of native species with ornamental potential represents a remarkable area of research, since it entails the introduction and development of novel promising ornamental crops. The genus Glandularia, widely distributed in Argentina, holds an enormous ornamental potential, due to the variety of colors of its inflorescences (red, violet, white, rose and lily), and extended flowering period. There is little information on tissue culture of Glandularia, thus highlighting the relevance of this research. In this work, the conditions for in vitro multiplication of G. peruviana were optimized. It was concluded that WPM supplemented with TDZ, in concentrations ranging from 1.1 to 9.0 μM, was the most adequate treatment, rendering a multiplication rate of approximately 10 de novo shoots per explant. This paper presents a protocol for the in vitro propagation of this species and introduces interesting prospects in the application of biotechnological tools to breed Glandularia.

Feeding and oviposition preferences of the diamondback moth Plutella xylostella (Lepidoptera: Plutellidae) on six Brassicaceae host plant species

Plutella xylostella (diamondback moth, DBM) is a globally distributed Lepidopteran that feeds and oviposits almost exclusively on plants in the Brassicaceae family. DBM disperses from the southern United States and Mexico into Canada in the spring and summer. Establishment of DBM in Ontario is partially dependent upon the quantity and quality of host plants available and the preference of DBM for different hosts. Host plants include many crops such as broccoli, canola and cabbage, as well as landscape ornamentals and wild plants. It has previously been established that DBM are attracted to host plants by chemicals, specifically glucosinolates. I examined the preference of DBM among crop, wild and ornamental host plant species and how preference varies with insect life stage (3rd and 4th instar larvae and adults). Experiments included exposing DBM larvae from five populations coming from different locations in Canada to six Brassicaceae species and evaluating the preferences and weight gain over one hour. Then adult females were exposed to these same plant species and their oviposition preferences were examined. Populations from Alberta, Saskatchewan and Ontario were compared to assess differences in preference associated with geographic region or species of host plant. The ultimate goal of my study was to understand the potential of various Brassicaceae species to act as reservoirs to sustain and promote population growth of DBM, as well as sinks that may decrease DBM abundance. Results showed that garden cress (Lepidium sativum) was highly preferred over other species (wintercress, black mustard, aubretia, broccoli and ornamental kale) for both food and oviposition sources. Previous studies report that garden cress contains saponins, chemicals shown to be toxic to developing DBM larvae, however no studies have yet shown a preference for garden cress. These results provide information on a novel host plant with the potential to control DBM population growth. No difference in preferences was found among populations of DBM from various sources in Canada.

Regulation of plant growth in container-grown ornamentals through the use of controlled irrigation

The aim of this research was to determine whether shoot growth could be regulated and plant quality improved through two controlled irrigation techniques: Regulated Deficit Irrigation (RDI) or Partial Root Drying (PRD). An additional benefit of such techniques is that they would also improve the efficiency of irrigation application and reduce the volume of water used on commercial nurseries. Results from two ornamental woody plant species (Cotinus and Forsythia) demonstrated that plant quality could be significantly improved when RDI was applied at ≤ 60% of potential evapo-transpiration (ETp). Stomatal closure and reduced leaf and internode growth rates were associated with both the RDI and PRD techniques, but reduced leaf water potential was only recorded in the RDI system. Changes in xylem sap pH and ABA concentrations were correlated with changes in shoot physiology, and thought to be generated by those roots exposed to drying soil. By adopting such controlled irrigation systems on commercial holdings it is estimated that water consumption could be reduced by 50 to 90%.

Effect of daminozide, paclobutrazol and chlormequat on development and quality of potted 'persian carpet' zinnia

In Brazil zinnias have good prospect for the flowering potted plant market, once consumers demand for new forms of products is stimulated by novelty. 'Persian Carpet' is a highly ornamental plant, with fast growth, minimal labor requirements and low cost seeds. The present study evaluated the effect of growth regulators on development and quality of 'Persian Carpet' grown as a potted plant. Growth regulators are commonly used to control growth and produce short and compact plants. Paclobutrazol (0.5, 0.75 and 1.0 mg a.i./pot) and chlormequat (1.0, 2.0 and 3.0 g. L-1) were applied as a single drench, and daminozide (2.5, 3.75 and 5.0 g. L-1) as a single foliar spray to runoff. Regulators were applied at apical flower bud stage. Daminozide (5.0 g. L-1), paclobutrazol (0.5, 0.75 and 1.0 mg a.i./pot) and chlormequat (1.0 g. L-1) significantly reduced plant height and side branches length compared to the control. Plant height showed a negative linear response to the increasing concentration of daminozide or paclobutrazol. Paclobutrazol (1.0 mg a.i./pot) and chlormequat (1.0 g. L-1) increased foliage and flowers harvest index. Plant spread diameter and canopy shape were improved with paclobutrazol (0.75 mg a.i./pot). Chlormequat (2.0 and 3.0 g. L-1) caused phytotoxicity symptoms, turning plants unsuitable for commercialization. Studied regulators concentrations did not affect flower diameter and production cycle. Although regulators controlled height and side branches growth significantly, plants were not short and compact enough to attend market quality.

Desenvolvimento e produção de Costus productus Maas como planta de vaso em função de doses de nitrogênio

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Maturity, Pulp Removal and Storage Effects on the Germination of Livistona rotundifolia Seeds

The Livistona rotundifolia species is native to Oceania, and has a high potential for landscaping use and as a pot plant. This work aimed to study the effects of the maturation stage, pulp removal and storage on the germination of L. rotundifolia seeds. The experimental design was entirely randomized in a factorial arrangement 5x2x2 (five storage periods: 15, 30, 45, 60 and 75 days; two maturation stages: green and ripe; and the presence or absence of the pulp - exocarp and mesocarp) with four replications of 25 seeds each. After sorting out the fruits by the maturity stage and removing the pulp out of half of the fruits from each plot, the seeds were placed in closed bottles, which were sealed and stored in a cold chamber at 10 degrees C. The seeds were removed from the cold chamber and left to germinate in plastic boxes (gerbox type) with sphagnum. The boxes were kept at 25-35 degrees C and photoperiod of 12 hours. The germination rate was determined when seed germination was steady. The highest germination rate was found when green fruits had their pulp removed. The germination rate gradually decreased with the increase of the storage period regardless the maturation stage and the presence or absence of the pulp.

Florida plant selector; a guide to choice and use of over 100 landscape plants.

Mode of access: Internet.

Ácaros (Arachnida, Acari) de plantas ornamentais na região noroeste do estado de São Paulo, Brasil: inventário e descrição dos sintomas causados pelos fitófagos

No presente trabalho foram estudados os ácaros associados a plantas ornamentais de praças, ruas e jardins residenciais, no município de Ilha Solteira, SP. Foram amostradas folhas de 20 espécies de plantas e alguns representantes das morfoespécies de ácaros encontrados foram montados em lâminas de microscopia com o meio de Hoyer, para posterior identificação sob microscópio óptico com contraste de fases. Foram registradas 23 espécies pertencentes a 15 gêneros de oito famílias. Dessas espécies, 13 são fitófagas, nove predadoras e uma de hábito alimentar não determinado. A família com maior riqueza de ácaros foi Tetranychidae, com nove espécies, sendo uma delas registrada pela primeira vez após a descrição original e outra pela primeira vez no Brasil. Lorryia formosa Cooremann, 1958 (Tydeidae) foi a que ocorreu em maior número de hospedeiros. As plantas com as maiores riquezas de ácaros foram Lagerstroemia indica L., Mussaenda alicia Hort. e Tabebuia sp., com seis espécies registradas em cada uma.

Fontes e doses de corretivos de acidez no solo na nutrição e produção de alface

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Daily photosynthesis, water relations, and ion concentrations of uuonymus irrigated with treated wastewater

Euonymus japonica Thunb. (euonymus) plants were submitted for 9 months to two irrigation treatments using water from different sources: a control (C) water with electrical conductivity (EC) less than 1.2 dS.m(-1) and reclaimed wastewater (RW) with EC approximate to 4 dS.m(-1). At the end of the experiment, no differences in the total dry weight were observed between treatments, whereas the leaf dry mass increased (to the detriment of the root part in RW plants). Throughout the day, the stem water potential (Psi(stem)) of the RW plants was lower than in C, whereas stomatal conductance (g(S)) was slightly reduced in RW from 0800 HR to 1200 HR, but no significant variation in photosynthesis (P-n) or energy conversion efficiency (F'(v)/F'(m)) in photosystem II was detected through the effect of salinity. Gas exchange and fluorescence showed a tendency to increase after midday in plants treated with RW. The photosynthetic behavior and fluorescence of RW plants may have been related to the nitrogen and chlorophyll content of the leaves, confirming the resistance of the photosynthetic mechanism to salinity in this species in these conditions. The toxic effects produced by high concentrations of boron (B), sodium (Na+) and chloride (Cl-) were offset by the effect of other ions like magnesium (Mg2+), potassium (K+), and phosphorus (P) in plants irrigated with RW, thus improving their physiological status without decreasing their ornamental value.

Essays in Greenhouse/Nursery Economics

This dissertation focuses on the greenhouse and nursery industry in the United States. Two major issues are explored: irrigation and plant disease. The first two essays examine wireless soil-moisture sensor networks, an emerging technology that measures soil moisture and optimizes irrigation levels in real time. The first essay describes a study in which a nationwide survey of commercial growers was administered to generate estimates of grower demand and willingness to pay for sensor networks. We find that adoption rates for a base system and demand for expansion components are decreasing in price, as expected. The price elasticity of the probability of adoption suggests that sensor networks are likely to diffuse at a rate somewhat greater than that of drip irrigation. In the second essay, yields, time-to-harvest, and plant quality were analyzed to measure sensor network profitability. Sensor-based irrigation was found to increase revenue by 62% and profit by 65% per year. The third essay investigates greenhouse nursery growers’ response to a quarantine imposed on the west coast of the United States from 2002 to present for the plant pathogen that causes Sudden Oak Death. I investigate whether growers choose to 1) improve their sanitation practices, which reduces the underlying risk of disease without increasing the difficulty of detecting the pathogen, 2) increase fungicide use, which also prevents disease but makes existing infections much harder to detect, or 3) change their crop composition towards more resistant species. First, a theoretical model is derived to formalize hypotheses on grower responses to the quarantine, and then these predictions are empirically tested using several public data sources. I do not find evidence that growers improve their sanitation practices in response to the quarantine. I do, however, find evidence that growers heavily increase their fungicide use in response to a quarantine policy that requires visual (as opposed to laboratory) inspection for the disease before every crop shipment, suggesting that the quarantine may have the adverse effect of making the pathogen harder to identify. I also do find evidence that growers shift away from susceptible crops and towards resistant crops.

Flora ornamental de Cerdanyola del Vallès, idoneïtat respecte les al·lèrgies i mesures pal·liatives

El pol·len de plantes alliberat durant la pol·linització pot produir al·lèrgies a persones sensibles amb tendència ascendent en el temps, provocant malestar i elevades pèrdues econòmiques. La mala planificació en flora ornamental urbana és, en part, responsable; aquest estudi identifica, ajudant-se de plànols de simple interpretació, els principals problemes d’aquesta en relació a les al·lèrgies en Cerdanyola. S’observa una elevada presència de gèneres amb alta al·lerginicitat, molts concentrats en determinades localitzacions, essent especialment perillosos en març i abril, i una sobreplantació d’Acer negundo. Millorar la qualitat de vida dels afectats passa principalment per disminuir el nombre d’espècies altament al·lergògenes prioritàriament en les localitzacions amb més perill, tasca que ha de ser idealment realitzada per un equip d’experts.

Growth retardants on development and ornamental quality of potted 'Lilliput' Zinnia elegans Jacq.

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)