The best nutritional situations for duckweed growth are in waters with decaying organic material, providing it with a steady supply of nutrients. Early growth should be exponential, or in other words it should occur at an increasing rate. h�22W0P���w�/�+Q0���L)�66 Check all that apply. This experiment investigates the growth of duckweed in response to sunlight exposure. Gently raise the strainer and allow … The free-floating, freshwater plant consists of a green elliptical frond with one root and is found in still waters, from temperate to tropical zones. In treatment-1 ponds were supplied with duckweed as supplementary fish feed and in treatment-2 ponds were kept as control (without supply of duckweed). endstream endobj 176 0 obj <>stream One of the many environmental factors that affect duckweed growth is the wavelength of the light that strikes the fronds. We will use the tiny aquatic plant Duckweed (Lemna minor) in this investigation because it undergoes continuous growth. This is particularly true for wildlife and fisheries biologists and plant and animal ecologists interested in protecting endangered species (plants and … An experiment on duckweed (Lemna minor) as supplementary feed in monoculture of nile tilapia (Oreochromis niloticus) was conducted for a period of 90 days. Also, if one spot fails, you have several others producing. Spirodela polyrhiza (greater duckweed) grown on filtered wastewater from Princeton Meadows Wastewater Treatment Plant. In Part A the growth of lab populations of Lemna minor and Sprirodela polyrhiza grown alone and in mixed cultures are monitored. changed from counting the number of duckweed at day 0 and day 14 to counting them every day changed from testing duckweed growth in beakers to testing duckweed growth in large outdoor tanks changed from testing the effect of pH on duckweed growth to testing the effect of light levels on duckweed … Duckweed are useful plants for students to use to develop investigations. Different wavelengths of visible light appear as different colors. Ponds were stocked at a … It is predicted that a lower light intensity will lower the rate of growth in duckweed. www.saps.org.uk 1. %PDF-1.5 %���� �9;�B�S�;%e3 �"�`LQ� It was predicted that the duckweed exposed to more sunlight will have a higher population. It is hypothesized that altering the amount of light received by duckweed will alter its photosynthetic rate. On average, fronds live for four to five … Duckweed prefers slow moving water however, you will notice fastest growth with areas of agitation. We also learned that duckweed needs nutrients to survive, not only sunlight and water. �K�6y��c��ǚ:L0y�\r��y�R�9G �X�q��o�4����ۥϕ�Va�J�@�����'E3R�`O Aquatic habitats have, in general, degenerated throughout the world because of pollution by both industry and other activities. Conclusion Literature In conclusion, the results of the experiment were pretty close to what was hypothesized: If duckweed is exposed to various levels of pH, its growth will be closely correlated with how close the pH level is to 6 Although the duckweed living in the petri dish 1), The duckweed was placed in stagnant water which contributes to the growth of the duckweed as this is a more favourable condition for duckweed growth (John W. Cross, 1998-2002). A dense cover of duckweed inhibits competing submerged aquatic plants, which require solar energy for growth and they can also often exclude algae from bodies of water. In this lab we will be testing how it grows in different environments. ��9��m���P�Dɒc;�|�I�e8�>�$�D)b,Q�0H�.$Q�Ɖ�V #F[�9a�)��9�%�\I���F� W� 4T�n-%�A�%����aD�1�SI��qF�� �Aav$E��S+��'@�(��e�*���Xc��8��N��V���✀Ζ0*��uPP0��X a���� y(H�X��_~�Np%����Z���";'2�X]mrCg�K9,��Q����"���e�pWe��ş�_{j�ٌC33Xx&܌�\�,��vQcL�`ᬛIzb Duckweed is a small aquatic plant that is able to grow rapidly, making it the ideal specimen for our experiment. Experiment # Lemna minor(Duckweed) Population Growth Introduction– Students will grow duckweed (Lemna minor) over a two to three week period to observe what happens to a population of organisms when allowed to grow without predation or competition. 2 mg/L was considered as the threshold toxicity in Lemna … Student Project: Investigations with Lemna Minor. Our group has selected to look at how light affects the growth. Also, the effect of plant growth on the removal efficiencies of cer- tain pollutants was investigated. Growth rates were four-fold higher for Tilapia supplemented with duckweed compared with Taro leaves or no supplement; and were 22% higher in ponds fertilized with biodigester effluent compared with no fertilizer . The control group did not have any drops of nitrate solution, so it stopped growing after the seventh day. These plants are very useful for investigations on population growth. Duckweed is a small aquatic plant that is able to grow rapidly, making it the ideal specimen for our experiment. All cups placed in the environment began with 25 fronds. In order to verify duckweed tolerance to Cu, photosynthesis was measured at the maximal concentration which caused no effect on the plant growth. Wait while the duckweed floats back over the strainer. To be able to model this growth at these temperatures, an experiment is conducted with as goal; determining the death rate of duckweed at temperatures above 35°C. Discover everything Scribd has to offer, including books and audiobooks from major publishers. Duckweed can tolerate a wide range of pH (3.0–10.0), but displays optimum growth in a medium of 5.0–7.0. Duckweed (Lemna minor) as a Model Plant System for the Study of Human Microbial Pathogenesis Background Plant infection models provide certain advantages over animal models in the study of pathogenesis. 2 mg/L, the growth index was optimal. 175 0 obj <>stream The purpose of this research was to investigate the ef- fect of wastewater dissolved salt content on the growth of duckweeds (Spirodela) when a duckweed system is em- ployed for municipal wastewater treatment. Finally, we placed two, high light cups were placed under a high light, the, a window, and the low light cups were placed. 2�K�O�;�:����䕭uk,iB^��Q��`&�l��Ohi�i�Ҏ�)�9�R(O�p�"�r ^������m�U��U��jS_����}U"���v ^�:�[��f=�xs��"��K��a�� c�yx g�M�ެ^�\/�T/�����-.�E DOCX, PDF, TXT or read online from Scribd, 0% found this document useful, Mark this document as useful, 0% found this document not useful, Mark this document as not useful, Duckweed is an aquatic plant used often in removing some nitrates, left in natural light for a week will yield, natural light which was near the window, high light on a, * There could be a confounding variable with the s, counted out twenty-five duckweed frons and put that amount in each, natural light, low light). Population Growth 1 Lab 2. The Effect of Fertilizer on Duckweed Growth by: Bri Benardin and Darien Ellis Discussion The control group steadily grew until it leveled out at and average of 65 fronds in the three cups. It is predicted that a lower light intensity will lower the rate of growth in duckweed. 5 mg/L, duckweed growth was inhibited by 70% (indicated on the figure by the broken line) representing the minimal growth index attained under our experimental conditions. For Lab 7, the duckweed lab, the purpose is to test what factors might affect the growth of duckweed. Yes, duckweed makes good fertilizer as it absorbs the nutrients from the pond water. Duckweed growth is optimum at temperatures between 20 and 30 °C, but serious effects will occur at temperatures between 35 and 40 °C. In other … 2. Do not grow in the same area as you are … However, current plant models face some limitations, e.g., plant and pathogen cannot co-culture in a contained environment. It will disturb the duckweed. As the weeks went by a significant difference between the duckweed samples without phosphate and the samples with phosphate was noticeable, … POPULATION GROWTH IN Lemna (Duckweed) A. Slight agitation, such as where an outlet flows, seems to increase the asexual reproductive process. Lemna minor has variable growth rates under varying climatic conditions. It is hypothesized that altering the amount of light received by duckweed will alter its photosynthetic rate. The hypothesis that was tested was that sunlight is a limiting factor for duckweed growth. Below 17 °C some duckweeds show a decreasing rate of growth. Materials Duckweed fronds, 16 Dissecting needle or forceps Fertilizer, liquid Graduated cylinder, 25-mL Potting soil Marker or wax … The relationship between duckweed growth and the total nitrogen concentration in the mediium follows the Mitscherlich Function and is similar to that of other plants.
2020 duckweed growth experiment