This year, we had the privilege of an exchange student from Mexico, who did the project on his own. He studied the effects of light intensity in combination with calcium nutrition on Easter lilies.
There were two projects studying light quality and organic production, respectively. The third group (referred to as the Leamington connection) tackled the effect of phosphorus on cucumber growth.
All students were third- or fourth-year students, and were working towards a bachelor of science in agriculture (B.Sc. Agr.) degree. The research topics came mostly from suggestions by industry contacts. These studies present the results of a one-shot experiment, which had to be completed within a 10-week period, so there were no replications.
THE EFFECT OF LIGHT QUALITY ON GROWTH AND DEVELOPMENT OF POTTED GERBERA
By Diane Relyea and Patricia Slaght
Abstract: Potted gerbera daisies (Gerbera jamesonii) were used to identify the effect of light quality on growth and development. Plants were exposed to three light qualities – blue, red or white light (control) by using different fluorescent light bulbs (Penatron, TS bulbs). The total amount of light (8 mol/m2/day) was the same in each growth chamber.
|Figure 1. Gerbera plants that were grown for five weeks under three different light spectra in a growth chamber. Total light sums were maintained the same (8 mol/m2/day). The plant groupings are, from left to right: red, white and blue light from fluorescent lamps.
Plants exposed to red light had consistently higher plant mass and a larger number of leaves than plants under blue light (Figure 1). The plants exposed to blue light showed a slightly increased rate of development in the flower buds compared to plants under red light. Plants exposed to white light were intermediate in terms of plant mass.
GROWTH COMPARISONS OF THREE INORGANIC AND ORGANIC FERTILIZERS ON GREENHOUSE-GROWN SALAD MIX
By Rebecca Hodges
Abstract: The objective of this study was to compare three organic fertilizers with inorganic fertilizers and the growth of four leafy vegetables. All the plants were given 100 ppm of total nitrogen while the three organic fertilizers contained different amounts of phosphorus and potassium (4-2-3; 3-3-3; and 16-0-0).
The inorganic fertilizers contained the same amounts of nitrogen, and relatively equal amounts of (P2O5) and (K2O) as the organic. The source of nutrients in the organic fertilizers was blood meal, bone meal, seaweed extracts and fish meal.
|Figure 2. Lettuce plants grown with organic fertilizer compared to inorganic fertilizer. From left to right, pots alternate organic and inorganic starting with 4-2-3 fertilizer (left), 16-0-0 fertilizer (middle), and 3-3-3 organic fertilizer (right).
EFFECTS OF LIGHT INTENSITIES AND CALCIUM NUTRITION ON THE HEIGHT OF EASTER LILIES (LILIUM LONGIFLORUM)
By Oscar Atilano Ruvalcaba
Abstract: Easter lilies (Lilium longiflorum ‘Nellie White’) were grown under three different levels of shade inside a greenhouse (0, 25 and 50 per cent shade) using neutral shade materials. Within each shade regime, plants were irrigated at every watering with three concentrations of calcium (0, 2.5, and 5 mM [millimole/L]) using otherwise complete nutrient solutions.
|Figure 3. Easter lily grown at the Bovey Greenhouses, University of Guelph.
EFFECT OF DIFFERENT PHOSPHORUS CONCENTRATIONS ON OVERALL PLANT GROWTH OF GREENHOUSE CUCUMBERS
By Steve Stasko and Tyler Sabelli
Abstract: A cucumber crop was studied to investigate the effect of different phosphorus concentrations on overall plant growth. The cucumber plants were irrigated with three different phosphorus concentrations: 0.25 mmol P/L, 1.0 mmol P/L and 4.0 mmol P/L (Figure 4).
|Figure 4. Set-up of cucumber experiment using three rates of phosphorus in the nutrient solution.