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Ornamental nursery crops are an important component of the US horticultural activity, with annual sales estimated in excess of 5200 million dollars. These crops are produced under two systems; field and container. Field nurseries are subclassified by the digging and processing methods, they may be either bare-root or soil-balled. Field production is generally reserved for large plants like shade and flowering trees, some conifers and deciduous shrubs. Factors important to the success of a field nursery operation are an efficient field design and crop rotation schedule, soil management, fertility, irrigation, pruning and harvesting. Although of more recent development, container production has evolved into a highly effective and efficient system. This system allows for uniform growing conditions, produces more plants per unit area and extends marketing season. Container production is however; highly intensive, requiring constant management of irrigation, fertilization, media, and winter protection.

Productivity of out roses can be improved by better starting material. New propagation techniques, control of factors influencing the propagation procedure and selection of invigourating rootstocks are promising tools. Stenting (simultaneously rooting and grafting) and root grafting are techniques which can be applied all around the year. Because the rootstocks are propagated vegetatively the plants will be less heterogeneous than when grafted on seedlings. Moreover these techniques enable clonal selection for a new generation of vigourous rootstocks. Some investigated aspects are presented here. Basal application of IBA to promote root formation of stentlings delayed the formation of a xylem vessel connection, while the normal increase of starch in the stem parts of scion and rootstock was delayed too. Alternation of humidity resulting in 9 % water loss per stenting daily, as well as a high temperature of 32 °C during the first day after stenting, proved to be promotive for development of xylem connection of the graft union. Prerooting treatment of the rootstock before stenting will decrease the vulnerable period between grafting and hardening off up to two weeks. Stented rootstocks can influence the early development of rose bushes. The invigourating effect simulated the diameter of root collar and bottom-breaks as well as the number of bottom-breaks and flowers.

Factors effecting adventitious root formation were studied in stem explants of flowering rose (Rosa hybrid cv. ‘Motrea’).   Rooting at the basal ends of the stem segments was genotype dependent and usually occurred optimally in stem explants which were placed upside down on the culture medium.   Continuous darkness was important for rooting, although light during the first days of the culture period promoted rooting in comparison to continuous darkness. In the range 21-23-25 °C only a small effect of temperature was observed. Good root formation occurred only when both sugar and macrosalts were present in the medium. Adventitious root formation was much better on a culture medium with glucose than with sucrose. The agar brand played a very important role during rooting. Auxin was an absolute requirement for rooting and was only necessary during the first 24 hours of in vitro culture.

A sampling of umbels of plants growing in full sun and under partial shade was conducted. The objective was to obtain data on the number of fruits formed per flower, fruit, camera (1/6 of capsule), or other part related to seed production in this species.   Observation of pollinators shows that the main pollinator is the hummingbird (Cyananthus leantirostris). The number of ruits per umbel varies from 30 to 120. Only a few fruits produced 30 seeds, the highest number found, which represents 0.37 % of the total of 273 observations. One umbel may produce from 30 to 3 600 seeds. The most frequent number of seeds per fruit was from 6 to 10. Plants in full sun produced more fruits than those in the shade. The seed set per fruit was not influenced by the light conditions. Thousand seed mass varies from 6.9 to 7.3 g and the seed number per kg from 137 000 to 144 000.

Fruit sampling of Agave potatorum Zucc. Done in the area of Valsequillo, Puebla, was aimed at determining the number and percentage of seeds suitable for generative reproduction. It was found that seed number per fruit ranged from 11 to 99 with the percentage of viable seeds from 7.48 to 50.00. The use of these species is suggested in the landscaping of open areas as well as a potted ornamental plant for its beauty and low environmental requirements.

Leaving flower stalks of Echeveria on the mother plant, after the flowering period, the formation of axillary shoots below the flower was observed. These shoots had of 2-3 small green leaves. The shoots once removed and located on a rooting substrate readily formed adventitious roots. Those shoots which formed during frequent rainfalis presented adventitious roots while still attached to the inflorescence. The inflorescence stalks removed from a mother plant, and stored in partial shade, were able to form buds with initial shooting. Stalks attached to the mother plant with its inflorescence removed, gave up to 3 shoots per stalk. It was expected that each flower with its pedicel may serve as a cutting. The basic condition to successful rooting of such cutting is the presence of 2-3 small green leaflets below the flower (axilary shoot). Taking into consideration the high number of flowers per plant average number 1,084 flowers per plant – the high propagation potential of such cuttings is obvious. The formation of axillary shoots upon the inflorescence of this species seem to be the natural way of clonal spreading in its natural habitat.

The Campus Tabasco – Postgraduate College has created a germoplasm bank of orchids for developing diferents researchs about various topics with the aim to obtain at short and long time a productive technique that permit the conservation of this kind of plants and also new financial sources for farmers from Southest of México.   The research done in experimental field, greenhouse, laboratory and the natural place where the orchid are collected have permited to know with accuracy the stages of development of these species, as well the differents requeriments for commercial production, such as the suitable media, climatic conditions, fertilizers for growing of orchids, and also techniques for micropropagation of species with the high ornamental value.

With the objective of giving an overall view of the pteridophytes of El Bajío and their possibilities as ornamental plants, the article includes information on important aspects of their cultivation and propagation. Also included is a list of 80 wild species of pteridophytes which grow in the region, as part of the inventory of flora of El Bajío and adjacent regions.

The genus Pinguicula (Lentibulariaceae) has gone practically unnoticed among Mexican horticulturists; however, in Europe it has been cultivated for more than a century. These are herbaceous plants which, because of their small size, showy flowers, and their adaptation to shade, are very attractive as indoor plants. The genus consists of 70 species widely distributed in temperate zonas of the northern hemisphere. In México, there are 33 species, reason for which it is considered the main center of diversification and evolution. Some species of Pinguicula are easy to grow, since they require little soil and can be grown in shallow pots. These include P. moranensis, P. esseriana, P. ehlersae, P. gypsicola and P. reticulata. However, other species cannot stand the cultivated conditions and die easily. Among these are P. crenatiloba, P. gracilis and P. oblongiloba.

The genus Begonia is important due to the great number of species described, over the world and torit great value as ornamental plants. Up to now 86 native species and 7 exotic have been registered in a data base (D BASE III). Species from which cultivars have been obtained are mentioned. Propagation and cultivation data are mentioned.

Exploratory samplings of the under ground part of Sprekelia formosissima Hebert (Amaryllidaceae) were conducted in order to obtain basic data about various components of bulb and root size and about aspects of their morphology. The samplings were made in two sites. The first two were conducted in the home garden, based on the material obtaine from seeds. The third one, in natural habitat. The data permitted the definition of the bulb’s maximum dimensions (fresh weight, longitude, diameter), maximum horizontal, vertical, contractile and normal root dimensions.With these data, a regression range was obtained. Contractile roots presented high hydratation degree. This, with the high contribution in the total weight of the subterraneus parts and especially regarding the bulb’s weight, suggests that this root system functions as the storage of water.

This contribution has the objective of discussing the importance of the Cactaceae family as ornamental plants as well as the present state of its conservation in Mexico. Also the knowledge acquired by some Mesoamerican peoples of this important group of plants is highlighted.   In recent decades, a selective and intense demand of Mexican cactuses on the international market has presented itself, demand which has not been entirely satisfied by the mayor producers. It is for this reason that programs of propagation of cactuses with a potential as ornamentals is encouraged in Mexico. The authors consider that an alternative for their use may contribute to the conservation of the cactuses which are having problems of survival.

The investigation was done at the Universidad Autónoma Chapingo, with the purpose to find a treatment (mixtures of sand and borax) that permit an effective dried in rose, gerbera and carnation flowers, as well as, to determine the best time of drying in each one of the thern, to preserve the features of color, shape, texture and appearance. The evaluated variables were: % of loss of dampness, % of spotty, abscission, appearance, texture and shape. It was found that the desiccate mixtures have different effect on each specie, because of the own characteristics of their desiccate mixture, plant material and the environmental conditions. The results indicate that in rose and carnation, the river sand and high borax proportions in the desiccate mixture with 15 and 20 days from drying had favorable effects. On the other hand, gerbera with sea sand and low borax proportions in combination whit 10 and 15 days from drying were favorable for the dehydration, however not the results were completely satisfactory.

The areas of postharvest physiology and technology of ornamental plants are of recent development, compared to the information available for fruits and vegetables. In a few countries like the Netherlands and recently Colombia many postharvest technologies have been developed for different ornamental plants. In México, there is a lot of potential for the production and commercialization of ornamentals so there is a need to develop an appropriate postharvest technology. Some important areas to consider in the near future are: production of ornamentals of high quality, development of new cultivars and species, domestication of wild plants, more research on the physiology of many species for the generation of particular postharvest management, finally a widest diffusion of works done in these areas is needed.

The post-harvest management of flower species is an important aspect in an integral production process. In this study, the effect of five preservative solutions and water on fresh weight and useful life of chrysanthemum (cv. Polaris) stems in a laboratory and under refrigeration were evaluated. There were great differences for the environmental factors and solutions used as variables in the study. Maintaining the flower stems at between 7 and 80 °C, with a relative humidity of 100 % in a stable solution increased vase life and fresh weigth. It was found that 8HQC (200 ppm) + Ac, citric acid (75 ppm) + 5 % sucrose is an efficient preservative for maintenance of chrysanthemum flower stems both at room temperature and under refrigeration.

In recent years, white rust of chrysanthemum (Chrysanthemum morifolium) caused by Puccinia horiana has become a serious threat to the chrysanthemum industry worldwide including Mexico and the United States. Control strategies begin with the avoidance of the importation of infected plant material via quarantines, inspections and prompt eradication of diseased plants. Cuttings must be obtained from a commercial company with a reputation for producing disease-free cuttings. Cultural practices which reduce relative humidity around plants are helpful. In problem areas, the use of resistant cultivars is suggested. Several fungicides are efficacious against the pathogen including myclobutanil, propiconazole, triadimefon, and triforine,. Myclobutanil has been reported as a curative agent for the disease.

The white rust of chrysanthemum caused by Puccinia horiana Hennings is a aggressive disease in many places of the world, including Mexico. Control methods have been animed at obtaining resistant cultivars. In this work the susceptibility to the disease of a set of 16 introduced cultivars and two local cultivars was evaluated. The study was carried out in a rustic greenhouse at the Facultad of Ciencias Agrícolas (UAEM), El Cerillo, México. The experiment was arranged in three randomized blocks. The incidence of the disease was assessed weekly during eight weeks. By level of incidence, the cultivars were classified in four groups as follows: a) Very Susceptible: Spider (SPI) and Super White (SWH); b)Susceptible: White Polaris (WPO), Yellow Polaris (YPO), Artic (ART), Divinity (DIV), Dinara USPPP (DIN), White Marble (WMA) and White Indianapolis (IND); c) Resistant: Sassy Marble (SMA), Blue Marble (BMA), Florida Marble (FMA), Show Cristal (SCR) and Snowdon USPPP (SNO) and d) Inmunes: Yellow Knight (YKN), Fred Shoesmith (FSH), Albatros (ALB) and Yellow Albatros (YAL).

This study forms part of the program “Production and genetic improvement of ‘chilacayote’ (Cucurbita ficifolia Bouché)” which has been underway in the Plant Science Department of the Universidad Autónoma Chapingo, México, since 1993.   Two types of chilacayote were used as plant material: “fancy” and “common”. These were established in a design with paired off plots in which the experimental unit and useful plot were 4 and 1 plants, respectively. The growing cycle was from April 15 to December 23, 1993. The objective was essentially to obtain basic knowledge on the aspects of the plant that are of agronomical interest, focusing on production of the tender fruit, as a type of vegetable. The results showed that the “fancy” type of chilacayote showed better agronomical characteristics than the common type. It produced tender fruits 35 days earlier and 30 days longer (104 days), with an estimated production of 69.0 t more and, logically, a larger number of fruits than the common type. It is important to point out that there wqs no need for the use of agrochemicals.

Mexico is one away from passing a Plant Breeder’s Rights Law (PBR). This PBR is the Mexican govermment’s reaction to the GATT-TRIPS and NAFTA agreements, but it is not a national demand. The passing of this law will not affect ornamental plant producer, who are requesting that the law be put into effect as soon as possible in order to permit them access to new ornamental varieties which are available only on the international markets because foreign companies are afraid to sell them in México without any legal guarantee that their royalties will be protected.

This work describe dry matter accumulation and tuberous root development in dahlia plantlets, from seed germination to the flower bud stage. Groups of ten plantlets were analized each week. The first visible event of tuberous root development occurs after two weeks. Tuberous root formed in the cotyledonar node, they increase in weight and number through week twelve, where flower bud appears. After dry matter from stem and leaves reach a peak, removilization to tissues like tuberous root occur.