Researchers at a university want to know if higher levels of nitrogen in fertilizer will increase the production of tomatoes per
plant. Twenty plants are given normal levels of nitrogen and twenty other plants are given ten percent higher levels throughout the growing season. The plants receive the same levels of sunlight, water and are planted in the same soil on one farm. At the end of the experiment the average number of tomatoes produced is the same for each group. The scientists repeat the experiment on two additional farms further south that season. The researchers conclude that increasing nitrogen levels by 10% in tomatoes is not beneficial.
The experiment appears correctly set up as all the factors have been controlled except the experimental treatment, which is a variation in nitrogen level. Perhaps adding a third treatment with 20% nitrogen would have reinforced the results. The use of twenty plants provides a good number of repetitions to reduce the error level and further the experiment was repeated on two additonal farms in sunnier places with the same results. (Here the amount of sunlight was not totally controlled). However the conclusion is not correct. The objective of the experiment was not to test whether the extra nitrogen was beneficial or not, but to test if the extra nitrogen would increase the production of tomatoes per plant. Therefore the conclusion should have been that increasing nitrogen levels by 10% in tomatoes does not increase the production of tomatoes per plant. This conclusion, as a matter of fact, is right, as nitrogen does not indeed increase the production of fruit in any crop.
Sexual reproduction makes genetically diverse offspring, while asexual reproduction makes genetic clones of itself, and doesn't require another parent.
It doesn't show the choices but, Biostimulation<span> involves the modification of the environment to stimulate existing bacteria capable of bioremediation. </span>
Trees share water and nutrients through the networks, and also use them to communicate. They send distress signals about drought and disease, for example, or insect attacks, and other trees alter their behavior when they receive these messages.
