Week 10

The outside experiments did better than those inside like I had expected, but the bulbs in the greenhouse and cold treatment surprised me in some ways. The experiments outside were more successful than those inside. Both the light and the etiolation treatments had greater dry and wet weights, length of shoots, and diameter of bulbs than the groups inside. The bulbs in the greenhouse surprised me in their success insofar as they had strong root systems and good growth. Many of the bulbs did rot away, which I believe was due to the heat. The cold treatment did better than I expected, but many of the bulbs did not have strong root systems and some did rot. Not surprisingly, all of the bulbs in the heat treatment rotted. There was no significant growth and no root development at all in those experiments.

The height of the tulips in the etiolation experiments was significantly longer than those of their counterparts because they were stretching out in search of light. The bulbs of the etiolation treatments generally weighed more than their counterparts because there was not enough time for the tulips that were exposed to light to really get photosynthesizing. In the twelfth week, all of the light experiment shoots were just barely poking out of the sand. Given time, I believe that the etiolation experiments growth in weight would have plateaued while their counterparts would have continued to climb.

The average diameter of the bulbs in the twelfth week was about the same and in some cases slightly less than the diameter recorded in the sixth and seventh weeks. I believe this was because of the fungicide treatment that was applied in the ninth week killed the mold that had been feeding on the outer scales of the bulbs. When I was rinsing the bulbs for the last wet weight, as soon as many bulbs touched the water many of their previously moldy scales fell into the water.

If I could do anything different with this experiment, for one thing I would have started sooner. When I planted the bulbs February 14th, part of me did not believe that the tulips would even grow because they had been planted so late. Another thing I would do differently is I would continue the experiment until all of the tulips had flowered and the foliage had died. I believe that would have been a more accurate way of doing the experiment, but my time was limited. I would have set the cold growth chamber about ten or twenty degrees Fahrenheit cooler, and the warm growth chamber about ten degrees cooler as well. For the experiments in the growth chambers and the greenhouse, the soil temperature was that of the air temperature because they had not been heeled in. Although I recorded the air temperature for the treatments outside, I wish that I had also recorded the soil temperature. I also would have gotten another group of bulbs in the beginning of the experiment and taken their dry weight as a control.





Outside treatment exposed to light.

Outside treatment removed from light.

Greenhouse treatment exposed to light.

Greenhouse treatment removed from light.

Cold treatment exposed to light.

Cold treatment removed from light.

The tulips were dried in order to obtain their dry weight.

The tulips after being dried.