“Application of microwave energy allowed to control successfully seed phytopathogenic infection, improved sowing qualities of the processed seeds (the germination increased by 16-17 %), promoting an intensification of growth processes” (Article information)
Variables:
Independent variable:
Time spent under the microwave radiation
Dependent:
- Length of seed sprout
- Number of leaves
- Number of seeds that germinated
Controlled:
- same microwave
-
same volume of water (10cm3 every other day)
- same size of petri dish
- same amount of cottons
- same surrounding temperature
- same surrounding atmosphere
- all seeds were put in the dark
Materials:
- Lentil seeds
- Microwave
- Petri dish
- Paper towel
- Water
- Ruler
- Graduated Cylinder
- Plastic plate (to fit the seeds when they grow)
Method:
- Divide seeds into two groups (15 seeds each group); experimental and control.
- Put each group in separate petri dishes.
- Put the control group aside and label the containers control.
- Take the experimental groups and label them according to how much time they will get radiated.
- Put the experimental groups in the microwave for the time indicated (10 sec, 20 sec, 40 sec and 60 sec).
- Observe both experimental and control groups of seeds in their petri dishes
-
Water seeds 10cm3 with a graduated cylinder every 48 hours
- Record data: measure the length of the stem and the number of leaves
Results:
Stem height:
x = final height from initial
n = number of data (15 seeds)
Sum of size () = 221.1
Mean () = / n = 221.1 / 15 = 14.74
Deviation from mean:
(Deviation from mean) 2 (x-) 2:
Sum of squares (2) = 719.72
Standard deviation () = 6.93
Variance (S2) = () = 51.41
x = final height from initial
n = number of data (15 seeds)
Sum of size () = 280.2
Mean () = / n = 280.2/ 15 = 18.68
Deviation from mean:
(Deviation from mean) 2 (x-) 2:
Sum of squares (2) = 1012.97
Standard deviation () = 8.22
Variance (S2) = () = 72.36
Stem height (± 0.05 cm) of lentil plants put under radiation for 20 seconds
Lentil seeds did not exhibit any growth.
Stem height (± 0.05 cm) of lentil plants put under radiation for 40 seconds
Lentil seeds did not exhibit any growth.
Stem height (± 0.05 cm) of lentil plants put under radiation for 60 seconds
Lentil seeds did not exhibit any growth.
Number of leaves:
x = number of leaves from initial
n = number of data (15 seeds)
Sum of leaves () = 53
Mean () = / n = 53 / 15 = 3.5
Deviation from mean:
(Deviation from mean) 2 (x-) 2:
Sum of squares (2) = 37.74
Standard deviation () = 1.59
Variance (S2) = () = 2.7
x = number of leaves from initial
n = number of data (15 seeds)
Sum of leaves () = 60
Mean () = / n = 60 / 15 = 4
Deviation from mean:
(Deviation from mean) 2 (x-) 2:
Sum of squares (2) = 70
Standard deviation () = 2.16
Variance (S2) = () = 5
Number of leaves for lentil plants put under radiation for 20 seconds
Lentil seeds did not exhibit any growth.
Number of leaves for lentil plants put under radiation for 40 seconds
Lentil seeds did not exhibit any growth.
Number of leaves for lentil plants put under radiation for 60 seconds
Lentil seeds did not exhibit any growth.
T Calculated values:
Degrees of Freedom = 28
T critical value = 2.048
T test =
H0 is accepted or rejected with 95% Confidence
H0 is accepted or rejected with 95% Confidence
Observations
Fungus grew alongside the plants on the 3rd day.
Conclusion
Plants use energy from the sun to grow and make food through the process of photosynthesis in their leaves. Some of the sun's energy is in the form of ultraviolet radiation, a kind of electromagnetic radiation. Electromagnetic radiation is also produced in microwaves. Electromagnetic energy can often cause heat; therefore the seeds will be exposed to certain intensities of heat in the microwave. As the heat increases to the optimum temperature enzyme stimulation will occur; this is needed for a faster growing rate.
The results above show us several things that need to be taken into consideration. The groups of lentil seeds exposed to different intensities of light produced by electromagnetic radiation from the microwave grew at different speeds and to different extents. Some grew a lot and some didn't grow at all. The results show us that the group of lentil seeds exposed to microwave radiation for ten seconds grew at the fastest rate. Also, the mean of height and number of leaves is the highest for this group than any other. The group of lentil seeds which represented the control also grew and sprouted leaves proving that my experiment is feasible. However, the groups of lentil seeds which were exposed to 20, 40 or 60 seconds of microwave radiation did not grow at all. After processing my data and producing a t test, it is clear that all my H0 has been accepted which means the data is credible.
The results are not surprising at all. The type of radiation the seeds were exposed to, as previously mentioned, has proved to reduce pathogenic infections in the seed therefore making it better quality and able to grow with a faster rate. This explains why the lentil seeds that were exposed to 10 seconds of electromagnetic radiation grew at a much faster rate than the control or, expectedly, any of the other groups. The fact that the seeds that have been microwaved for 20, 40 and 60 seconds did not grow at all is also not surprising seeing as, which was also mentioned in my hypothesis that they might have been under too much heat which resulted in them being cooked in the microwave.
The mean of growth of stem height (± 0.05 cm) of lentil plants put under radiation for 10 seconds is 18.68cm whereas the mean of growth of stem height (± 0.05 cm) of lentil plants for control is 14.74cm which is not a great difference but nevertheless a clear one which is further credited by the accepted H0. The same can be said for the number of leaves where the number of leaves for lentil plants for control have a mean of 2.7 where the mean is 4 for lentil plants put under radiation for 10 seconds. Once again this shows a rather realistic difference which is further proved by the accepted H0. The graphs both show how at first the mean height and mean number of leaves increased as microwave radiation increased but then dropped when the seed was put under too much radiation. These results are all calculated by taking the plants within these groups which did not show any growth for other reasons into consideration.
Therefore it is safe to say that the results are perfectly consistent with what was expected and apply to the hypothesis and there is no need to suggest any different or new hypothesis. Microwave radiation does help the growth of lentil seeds and in fact speeds it up. However too much of the heat will result in cooking the seeds and therefore they will not grow as they are damaged.
Sources of error and improvements
Sources of error:
- Some seeds in the control and 10 second groups did not grow even though their likes did. There are many explanations to that which are not related to microwave radiation. Two of these seeds were found in the control group. As for the 10 second group only one did not grow at all and another only germinated to 0.8cm and then stopped. Although a minor difference, this nevertheless may have affected the results one way or another
- Most of the test groups did not grow which means that it was a mistake using this variation seeing as not much can be said from only the control and one successful attempt
- The stems are curved, therefore some of the measurements may not be completely accurate
- Transporting seeds from agar plate to plastic plate and when watering the seeds may have affected the growth.
Improvements:
- Check that there are no faults in the seeds chosen for the experiment and that can be done by checking growth after the third day; if no germination occurred when the rest of the seeds have then clearly there is a problem and the seed should be changed
- Change the variation; instead of 10, 20, 40 and 60 seconds, used 5, 10, 15 and 20.
- Take measurement of stem height several times and calculate average to assure more accuracy
