Posts filed under ‘Experiment Details’
Our aim is to see if the growth of broad beans is affected by the liquid it’s grown in. In our experiment we will compare the growth of a control bean (grown in water) against a bean grown in a salt solution, a sugar solution and a tea solution.
We predict that the changes in the water solution fed to the bean (i.e. the things we have added to it) will affect the way that the bean grows.
More specifically, we predict that the salt will have an adverse affect on bean growth, and that this bean will either die or become sickly as a result of the changes to the water. I suspect that this may be due to the fact that salt dehydrates.
We predict that the tea and sugar beans will survive, but that the solutions may have some impact on their growth rates, health and colour. We hope to find out whether the effects will be positive or negative through the experiment.
The control bean will grow as normally expected and will provide a good comparative with the other beans.
The group has decided that whilst germination takes place we will water the beans as normal. This means that we will water the seed every other day and we agreed as a group how much water to give the seed. Each group member has a plastic cup with a line marked on the cup, this line represents the amount of water that should be given every other day to the seed.
As a group we planted the seeds in the same way, each group member filled a white plastic cup halfway up with soil. We then placed the bean on the soil and filled the plastic cup up the rest of the way. We also agreed that the bean should be kept on a window sill but not near any heating appliances.
Once the seedling sprouts (is visible to the eye) we will begin the experiment. We decided this because we believe that the seeds will sprout at different times. Each group member will continue to water their plant with either: tea, salt water, sugar water and normal tap water. For the salt and sugar solutions – one teaspoon of either salt or sugar will be added to the agreed water amount. We will water the plant every other day as before.
Each day we will measure the growth of the bean. We will measure the bean from the top of the soil using a mm ruler. The group has decided that we will do this for eight days, day one will be when the plant is visible. We will record our results on a table. Once all group members have their results we shall compare findings.
Four Primary PGCE students in Group D (Jenny, Emma L, Charlene and Chloe) track the progress of broad beans’ growth as part of a science project. Currently, we’re waiting for the seeds to germinate…
These pictures show the beans before they were planted. They were all healthy normal beans before the start of the experiment. We each had our own plastic cup were we planted the beans.
As this graph shows, growth of the bean shoot was steady until Day 6, where a growth spurt occured, the bean increasing in length from 35mm to 68mm. This rapid growth occured until Day 8 where at 110mm, the bean slowed its growth.
By Day 14, having reached 130mm, the shoot was beginning to turn brown, its leaves undernorished and the steam to become limp. It is possible that the crystalised sugar was preventing the nutrients in the soil from being absorbed by the roots.
A reason for the beans growing tall and healthy initially with the sugar solution might be because the plant gained an increase of glucose which is needed for photosynthesis. However by the 8th day, there was perhaps an excess of sugar which prevented the plant from gaining sufficient water.
In conclusion, the best solution to use when growing a bean is water. The other solutions all ultimately had a negative effect on the bean’s rate of growth and heath.This could be for the following reasons:
– Salt dehydrated, and therefore takes away the water from the plant cells where it is needed.
– Tea contains caffeine which is a toxin, and collects in the plant cells. Furthermore tea is acidic, and for many plants this will damage growth and health.
– Sugar may have had an initial benefit for the young plant’s growth, but the mature plant can make sugar through photosynthesis and so too much sugar saturates the plant and stops it from being able to absorb water through the roots.