Over the last few years, we have been experimenting with the idea of applying ethylene-releasing plant growth regulators (PGRs) to the rootzone as a substrate drench. This is a rather radical idea for floriculture production overall and flowerbulb forcing in particular. In this newsletter, we’ll review ethylene as a growth regulator, discuss the commercialy available ethylenereleasing PGRs and ...

Production of herbaceous perennials has been one of the most rapidly growing areas of floriculture for the last 8 to 10 years. However, greenhouse and nursery production of herbaceous perennials requires a significant effort to control the growth of some of these very vigorous plants. Until very recently the primary methods of control were scheduling and pruning. If a grower missed the target d...

A simple and reliable high-performance liquid chromatographic method that uses photodiode array detection was developed for the simultaneous determination of 12 native and synthetic plant hormones, i.e., plant growth regulators (PGRs), in fertilizers, such as 1-naphthol, 2,4-dichlorophenoxyacetic acid, 4-(2,4-dichlorophenoxy)butyric acid, 4-chlorophenoxyacetic acid, indole-3-acetic acid, 4-(3-i...

Plant growth regulators (PGRs) are commonly used in commercial farming to control lodging in cereals. PGRs have been shown to alter yield formation and plant stand structure, other than the straw length. To study their potential in Northern growing conditions PGRs and their application time impacts on plant stand structure and yield formation in tall and short statured cultivars of barley, oat,...

Graph-reduction specifications (GRSs) are a powerful new method for specifying classes of pointer data structures (shapes). They cover important shapes, like various forms of balanced trees, that cannot be handled by existing methods. This report formally defines GRSs as graph-reduction systems with a signature restriction and an accepting graph. We are mainly interested in PGRSs, which are pol...

Growing degree day models can successfully predict the performance of gibberellin-inhibiting plant growth regulators (PGRs) applied to cool-season golf putting greens. These models are effective because metabolism or degradation of PGRs was found to be directly related to air temperature. Relative clipping yield of turfgrasses treated with PGRs follow a sinewave model with a period of growth su...

Plant Genetic Resources (PGRs) are one of the most valuable natural resources of anycountry. Biotechnology through genetic engineering of plants and the creation of new plantvarieties can increase the value of these resources. Different technical and legalmechanisms such as ex situ/in situ collection of PGRs, and Intellectual Property Rights(IPRs...