Effect Of Propamidine On Plant Growth Of Tomato

Propamidine is a kind of novel alkyl amidine systemic fungicide developed by Research and Development Center of Biorational Pesticides, Northwest A & F University, and the chemical name is 1, 3-two (4- guanylphenoxy) propane. This product is mainly used to control many plant diseases caused by Botrytis cinerea in economic crops such as vegetables and fruit trees, which owns the dual efficacy of therapy and protection. The application in field found that propamidine can promote the growth of plants such as tomato and cucumber under the recommended dose of 90~180 g/hm2. In order to determine the regulatory effect of propamidine on the growth of tomato better than chemical treatment and the control whether is because the propamidine itself stimulates the crop growth or is because the diseases are controlled effectively, the thesis studied the propamidine on plant morphology, growth physiology, resistant physiology, fruit quality and yield of tomato systematically. The main results are as follows:Under tested dosage (33.33,50.00 & 100.000g/hm2), Propamidine could stimulate the growth of tomato plant. Concrete results are as follows:(1)Propamidine could control the morphogenesis of tomato plant. Under efficiency dosage(100.000g/hm2), compared with the control, Propamidine could lowered the relative growth rate, the space between the first and the second inflorescence, the weight per area leaves and the length-width rate by 4.69%,12.02%,13.95% and 4.85%,respectively.And increased the net increase of stem diameter, the average increment of total number of leaves, number of flowers, thickness of leaves , length of root and volume of roots by 151.95%,17.65%,23.91%,21.88%,28.16% and 28.08%, respectively.(2) Propamidine could enhance the disease-resistance and stress-resistance of tomato plant. Under efficiency dosage (100.00g/hm2),compared with the control, the increase rate of POD activity, the content of pollen free proline, total phenol, flavonoid, Chl a, Chl b,Chl a+b and Car was 85.03%,48.05%,15.79%,18.75%,22.02%,11.27%,15.17% and 13.04%. compared with the control, but the intercellular CO2 concentration(Ci), MDA content and electric conductivity was lowered by 9.58%,40.89 and 30.59%, respectively. However, under efficiency dosage (33.33g/hm2), compared with the control, the increase rate of the net photosynthetic(Pn), stomatal conductance(Gs) , transpiration(Tr) , roots vitality ,SOD and CAT activity were 21.80%,42.31%, 53.72%,11.46%,164.73% and 50.00%, respectively.(3) Propamidine could increase the yield and improve the quality of tomato fruit. Under efficiency dosage (100.00g/hm2), compared with the control, average weight per fruit and the prophase yield increased by 31.02% and 25.07%,with the ratio of horizontal length to vertical length lowered by 31.58%.The tomato fruit grow with oblate.(4) Propamidine could effect the quality and lowered the flavor of tomato fruit. The reduced rate of ascorbic acid content and sugar acid ratio were 19.09% and 29.95%,but the content of nitrate increased by 55.86% which also in the requirement range of hygiene and safety of vegetable, compared with the control under efficiency dosage (100.00g/hm2).The results shows that, under the recommended dose, Propamidine has obvious regulatory effect on the plant growth of tomato.It said that Propamidine has certain value of popularization and application.