Plant tropisms--their directional movement in response to stimuli--are a fundamental concept in plant science and excite students because they are the observable signs of life in plants. Unfortunately, the precollege teaching literature is full of tropism misconceptions. An inexpensive clock clinostat is invaluable for student gravitropism and…

Author provides details about Helmont's experiment that was a milestone in the history of plant biology since it marked the start of experimental plant physiology. Concludes that Jean Baptista van Helmont's supposedly simple experiment becomes complex when trying to determine the methods he used, evaluate his sources of experimental error, and…

Describes an activity demonstrating the importance of photoperiod on plant development. Uses the plant devil's backbone for the experiment and studies the details of photoperiodic requirement for plantlet formation. (Contains 12 references.) (YDS)

Discusses Knob's solution, which was considered the ideal plant growth solution in 1865, and recommends eliminating Knob's solution from active teaching. Describes solution culture basics including nutrient solutions, containers and aeration, and plants and light. (Contains 12 references.) (YDS)

Introduces the plant Amaryllis, which is the common name for the Hippeastrum species. Describes how to grow and bloom Amaryllis in soil using hydroponics. Introduces experiments investigating the anatomy of the bulb, growing and elongation rates, the flower, and foliage. (Contains 21 references.) (YDS)

Describes historical accounts dating back to as early as 604-562 BC of the various uses of hydroponics. Throughout the article, diagrams and simple instructions are provided to aid in classroom use of hydroponics. (ZWH)

Discusses the idea that hands-on science education should give credit to the scientists who originally conducted the experiments now repeated in classrooms. Plant experiments originally done by Stephen Hales are described and given as examples. (KR)

Describes an experiment to induce carbon dioxide deficiency to demonstrate its effects on plant growth. Suggests further studies to examine respiration by soil microbes and the effects of relative humidity, other gases, and air pollution on plant growth. (MDH)

A student laboratory exercise on the development of nutrient deficiency and toxicity symptoms was linked to analytical techniques and ion chemistry by having the students determine which ions in the nutrient solutions were missing or present in excess. (Contains 15 references.) (Author/MDH)

Describes how lectures, laboratories, and role playing can be used to introduce students to the importance of water quality of water used for plant growth. (PR)

Discusses traditional school demonstrations and experiments in hydrotropism. Explains that these experiments seem to "prove" hydrotropism, but yet most botanists reject hydrotropism. Teachers continue to teach the concept because it is logical and the experiments are simple. (PR)