Author Archives: Erik Runkle

About Erik Runkle

Erik Runkle is associate professor at Michigan State University. You can eMail him at runkleer@msu.edu.

Energy-Efficient Annuals: Petunias

Escalating fuel costs have made it important for greenhouse growers to improve production efficiency and schedule crops more efficiently. At Michigan State University (MSU), we have performed experiments with many seed-propagated annuals to quantify how temperature and daily light integral (DLI) influence flowering time and plant quality. In the sixth article of this series, we

Energy-Efficient Annuals: Ageratum & Cosmos

Scheduling annual bedding plants in flower for specific market dates is of increasing importance to many greenhouse growers. During the past several years at Michigan State University (MSU), we have performed experiments with many seed propagated annuals to quantify how temperature and daily light integral (DLI) influence flowering time and plant quality. In the fifth

Energy-Efficient Annuals: Dianthus & Snapdragon

Energy-efficient greenhouse production requires information on how crops respond to average daily temperature and daily light integral (DLI) so they can be more precisely scheduled. At Michigan State University (MSU), we have performed experiments with many seed-propagated annuals to quantify the effects of temperature and DLI on flowering and the impacts of different cropping strategies

Energy-Efficient Annuals: Timing Marigolds

In the first article of this scheduling annuals series, we introduced the concepts of temperature and daily light integral (DLI) and how these factors influence crop timing and plant quality. In the second article, Virtual Grower software was presented as a tool to predict energy costs for greenhouse heating. In this article, we present crop

Energy-Efficient Annuals: Scheduling Bedding Plants

Examples of software interface panels of Virtual Grower. This program can be downloaded free at VirtualGrower.net and can be used to estimate greenhouse energy costs throughout the United States. Desirable scheduling of garden plants includes producing a marketable crop for a specific date with the least amount of inputs as possible. A large contribution to

Coming Together by Erik Runkle

The floriculture industry in the United States has changed dramatically over the last 25 years, and it will continue to change at an increasing pace. In the early 1980s, the industry was transitioning out of cut flower production and into flats of bedding plants. In 1981, the average wholesale price received for a flat of

Getting Results With A Liner Dip

Controlling plant height is a key factor in producing a quality crop and maximizing the number of plants that can be shipped per rack. Growers often use both chemical and non-chemical height control techniques to suppress stem elongation. Plant growth regulators (PGRs) are commonly applied as foliar sprays, media drenches or sprenches (high-volume spray with

Comparing PGRs

Figure 1. Celosia (Celosia plumosa ‘Fresh Look Red’) was sprayed with either Dazide (daminozide, Fine Americas), B-Nine (daminozide, OHP), Citadel (chlormequat chloride, Fine Americas) or Cycocel (chlormequat chloride, OHP) seven days after plugs were transplanted into 4½-inch pots and grown at 68°F. Controlling plant height is an essential aspect of producing greenhouse crops. Plant growth

Cold-Chain Management

Temperature management is the predominant factor that impacts the post-harvest performance of horticultural crops. Over the past several years, we have been working with cutting suppliers to improve the reliability of delivering unrooted cuttings that perform well in propagation. Inevitably, all roads lead back to temperature management. Cutting performance relies on strong cold-chain management. The strength