| Summary: | 碩士 === 臺灣大學 === 植物病理與微生物學研究所 === 95 === English Summary
As the concept of using less pesticide arouses, consumers tend to buy agricultural products without chemicals, which leads the producers to change their traditional pest control measures using a lot of pesticides. Instead of chemical pesticides they use safe and efficient materials in replacement, which are referred as non-pesticide materials. To understand whether these materials cause damage or not to the plants applied, this experiment chose some popular materials to try on plants.
In the first part of this experiment we diluted PAOS, SALATT, Tween20 and baking powder (NaHCO3) 50 and 100 times and spread them on lettuce (Lactuca indica L. form. indivisa (Maxim.) Hara), cabbage (Brassica oleracea var. capitata), leaf mustard (Brassica juncea), Chinese kale (Brassica oleracea), and broccoli (Brassica oleracea var. italica). Results show that necrosis appears to be the major symptom of every reagent. The surfactants also cause distortion other than necrosis and baking soda doesn’t, but the necrosis lesion of baking soda will eventually fall off and cause shothole. Of all the reagents PAOS and SALATT cause necrosis more serious than others, and Tween20 causes less phytotoxicity.
In the former experiment some new grown leaves were found with symptoms of distortion; this was thought as damage to the genes and their expression. Because of this, several kinds of plants were added to the second part of this experiment to test the severity of phytotoxicity and their chronic symptoms. The plants used in this part were strawberry (Fragaria ananasa), Chinese kale (Brassica oleracea L. var. Acephale Group), ching chiang pai-tsai (Brassica rapa L. Chinesis Group), water convolvulus (Impomoea aquatica) and cucmber (Cucumis sativus L.). The reagents used were PAOS, SALATT and HEAD& SHOULDERS. After strawberries were treated with the reagents above, leaf distortion appears on new grown leaves but necrosis barely occurs. The other plants treated with PAOS, SALATT and HEAD&SHOULDERS showed that ching chiang pai-tsai is the only plant that expressed leaf curl, distortion, epinasty and color adding on new grown leaves, whereas the acute symptom is mostly the necrosis. However, PAOS and SALATT also cause bronzing and silvering lesions on both Chinese kale and ching chiang pai-tsai. The number of dilutions which is the threshold to inducing phytotoxicity necrosis of Chinese kale is about 100-200 times, ching chiang pai-tsai about 500-1000 times, and cucumber ranges from 100-2000 times for these detergents.
The third part of the experiment is a test on the phytotoxicity of household insecticides on plants. Three oil-based insecticides Pen Shiaw, Puff Dino, Keh Chon and two water-based insecticides Pen Shiaw and Black Cat were sprayed on tomato (Lycopersicon esculentum Mill) and lettuce (Lactuca sativa L.). Every insecticide caused severe necrosis on the next day, but Puff Dino is the most severe. Lettuce treated with two water-based insecticides appear with symptoms of albino a week later, and lettuce treated with Keh Chon appears with symptoms of leaf curl a week later. As all of the insecticides contained the CFC as propellant aerosol, to find out whether the propellant in these cans is phytotoxic or not, three aerosol sprays including Rexona deordorant, Sifone hair spray and Spa aroma spray, were used in the same test. Results show that these three aerosol sprays have no effect on the plants.
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