Effects of Plant Nutrient Deficiency
This experiment aimed to determine the effects of nutrient deficiency on plants. This was done by examining tomato plants grown in a medium that contained all the nutrients needed to survive and comparing those results to plants that were grown in nutrient deficient mediums. The biomass and standard chlorophyll content were the focus of the experiment. The biomass was measured by taking the mass of the plant. The standard chlorophyll content was measured by taking the absorbance of the leaf acetone solution. The results were significant for biomass but were only significant for the distilled water treatment. Nutrient deficiency has an effect on the biomass of plants, but we fail to reject the hypothesis that the standard chlorophyll content of the nitrogen, iron, and phosphorus deficient plants is no different than the SCC of the plants placed in a medium that contained all the nutrients needed to survive healthily.
The purpose of this laboratory was to examine how deficiencies in nitrogen, phosphorous and iron affect tomato plant growth. Distilled water was also used as a medium to grow the tomato plants in. There are many minerals and organic molecules that are obtained through the soil that plants need to survive. These are transported through the roots of the plant when water is absorbed (Helms et al. 1998). Plant nutrient deficiencies can have many effects such as stunted overall growth of the plant, or chlorosis and necrosis of certain plant parts, such as the leaves. One of the features that plants possess is the ability to take nutrients from older tissue and move it to newer tissue. This notion can be visualized. Kosinski states that if there is an inadequate amount of a mobile element, older plant tissue will show symptoms of the deficiency first. Old leaves may become yellow and appear dead (Kosinski 2012). Nitrogen and phosphorus in this lab were considered to be mobile elements. However, if the element in inadequate amounts is immobile, the symptoms will appear first in new foliage. Iron in this experiment was considered an immobile element.
Tomato plants were used in this experiment because they can be easily grown inside the lab and display obvious symptoms of nutrient deficiency (Kosinski). The plants harvested in the lab were currently in the vegetative growth stage and did not have any flowers or fruit growing. Therefore, increase in mass during this stage is due solely to the growth of the foliage (Kosinski). The biomass and the SCC values were calculated based upon the leaves of the plants in the following treatments. The first treatments were the tomato plants grown in the complete medium, containing all macronutrients and micronutrients. These treatments acted as the control for the experiment. The independent variables are the deficiencies. There were plants grown in nitrogen deficient medium, phosphorus deficient medium, iron deficient medium, and in distilled water. The dependent variables for this experiment are biomass and standard chlorophyll content.
Nitrogen is most commonly deficient in plant soils even though it is the most abundant gas in the atmosphere. This occurs because plants can only used fixed nitrogen. Nitrogen, a macronutrient, is very significant in plant growth. It has many roles in proteins and nucleic acids, as well as other macromolecules. It also makes up 1-5% of plant dry weight (Kosinski). Nitrogen deficient plants therefore are usually smaller. This is due to hormonal effects of nitrogen deficiency. Cytokinin synthesis is retarted and abscisic acid is accelerated (Kosinski). These hormonal changes age the plant and reduce the tomato plant’s lifespan. Tomatoes grown in a nitrogen deficient environment are usually rigidly upright, with thin stems and small leaves and branching is reduced (Kosinski, Berry). The leaves first change to a pale green color and then become yellow under extreme...
Cited: Helms, D. R., C. W. Helms, R. J. Kosinski and J. R. Cummings. 1998. Biology in the
Laboratory, 3rd Ed
Kosinski, R. 2012. A literature review on The Nutrient Deficiencies in Tomatoes.
Web site at http://biology.clemson.edu/bpc/bp/Lab/111/nutrient.htm
Kosinski, R. 2012. Procedures for Harvesting Tomatoes OMP. Biology 111 class
handout, Clemson University.
Please join StudyMode to read the full document