Dependent and independent variables in corn borer yield experiments

¶ … European Corn Borer affect the yield of corn?

Experiment 1-140 days

Chamber 1 -- BT 123 Corn, no infestation

Plate 1 -- 160.1 g

Plate 2 -- 164.8 g

Plate 3 -- 164.2 g

Chamber 2 -- BT 123 Corn, low infestation

Plate 1 -- 164.0 g

Plate 2 -- 162.6 g

Plate 3 -- 168.3 g

Experiment 2 -- 140 days

Chamber 1 -- BT 123 Corn, no infestation

Plate 1 -- 160.1 g

Plate 2 -- 164.8 g

Plate 3 -- 164.2 g

Chamber 2 -- BT 123 Corn, high infestation

Plate 1 -- 155.1 g

Plate 2 -- 163.0 g

Plate 3 -- 163.9 g

Experiment 3 -- 140 days

Chamber 1 -- Golden crop (non-BT crop), no infestation

Plate 1 -- 181.6 g

Plate 2 -- 182.8 g

Plate 3 -- 189.8 g

Chamber 2 -- Golden crop (non-BT crop), high infestation

Plate 1 -- 135.4 g

Plate 2 -- 139.6 g

Plate 3 -- 138.3 g

Table 1 -- Data from experiments none low high

Golden Crop

none

Golden Crop

high

Describe the effects of the ECB infestations you used. Were all corn varieties equally effective at controlling the ECB? How do you know?

ECB infestations were conducted in two different crops: BT 123 and Golden crop (non-BT). Both types of crops were subjected to no infestations and high infestations. Both types of crop yielded different results. The BT crop was named for the fact that the soil it was planted on would have the bacteria Bacillus thuringiensis (Bt), while the golden crops did not have BT. Of those denominations, the corn crop was further broken down to BT 123 and BT 456, as well as the golden and super-harvest crops. Of the set of experiments performed, those of the BT corn variation fared better in both doses of high and low concentrations of ECB infection. Conversely, the non-BT crops were significantly affected after high doses of ECB infection, yielding an average of about 75% of its normal yield. The bacteria found in the BT crops aid in ECB defense.

2. If there was no ECB infestation in a certain year, would a farmer gain or lose financially by planting Bt corn? Explain why.

Without ECB, the golden and super-harvest crops would flourish much more effectively than the BT crops. Because of the bacteria found in the BT plants, the growth is limited, with a difference of at least 20 grams in mass. On average (without ECB), a BT 123 plant would yield 163 grams per ear of corn; whereas on average (without ECB), a non-BT Golden crop would yield 184.7 grams per ear of corn. The difference is about 12%, and thus the farmer would financially lose 12% of profits by planting BT crops as opposed to non-BT crops.

3. What might happen if Bt corn affects non-target organisms such as beneficial insects or harmless insects?

The downside of Bt, should it target beneficial insects and other harmless insects, would not be beneficial in the growth of crops. For one, beneficial insects aid in the pollination of plants and crops, enabling a more natural cause for growth. Should the Bt crop target the other insects along with ECB, then most likely the crop growth will stagnate and be stunted. The yield would be lower, and in-so-doing, become less profitable.

4. What might happen if ECB became resistant to Bt?

Should a resistance in Bt occur, ECB infestation will most likely lower the amount of growth in Bt crops. Because of the resistance gained, the ECB will not be stopped and will infect the plants similar to the way it infects non-Bt plants. Like the golden crops -- which have no Bt -- the yield will most likely be around 75%. It then becomes more advantageous just to use the non-BT plants, which at least yield to a higher original average in the first place.

5. Discuss possible benefits and drawbacks of a transgenic organism such as Bt corn?

Because of various infestations on plants, transgenic organisms such as Bt corn are beneficial to constant growth factors. It is an insurance during years when infestation runs rampant; the losses experienced become minimal at best. A non-transgenic organism will lose much of its worth should there be an infestation during that year, resulting also in a loss of profit for farmers and growers. Unfortunately, because of the nature of the bacteria found in Bt corn, the growth is also not at its highest potential, and thus for a maximized amount of growth and profit, the use of non-transgenic organisms might be more beneficial -- for both the farmer and the organisms in the crop environment. Still, there would be risks involved either way.