Transpiration

Discussion and Evaluation

I believe that this investigation went well. Even though I did come into problems. When I was setting up my experiments, I found that the water-tube that I had was not long enough so I had to improvise. I added an extra piece of 5 cm tubing to each plastic tube. I believe that this made no difference what so ever to my end results. I also had a bit of trouble finding suitable sized cuttings around the school (I was carrying out my experiments at school during the term one holidays) some cuttings didn't have enough leaves, while some had to many. These cuttings would not have given me accurate results. It took me a fair while just to find suitable cuttings, but these cuttings were all cut at the same time so no bias was created in my experiments. The parafilm gave me problems too. You had to be careful when poking the cuttings into parafilm, or else the parafilm would slip down into the water tube on the tip of the a cutting. This was easily solved, I held onto the parafilm while poking the cutting in. The parafilm then stuck easily to the water-tube creating an airtight environment. This is vital; as if any air got into the water tube it would up-set the pressure causing the results to have a bias.

The windy environment created by the use of the fan produced the highest transpiration rates, of an average of 0.8 ml water lose. If the cutting was to carry on in this situation it would've surely wilted and died. This would be because the fan is creating an area of low concentration of water molecules in that area; the plant would have to 'pull' up more water from the water tube...