Study On The Effect Of Plant Growth Retardants On Different Crops And Its Mechanism

Effective plant growth retardants were screened from13kinds of substances which can make plants grow shorter and stronger, wheat and corn as test materials, combined the method of soil culture and hydroponics in the experiment. In order to determine the plant growth retardants application way and find the best content, the experiment adopted foliar spraying and soil application of two kinds of processing way. Studied the effects of plant growth retardants on corn quality and nutrients absorption, explored the biological effect of plant growth retardants on the crops. Studied the effects of plant growth retardants on corn leaf antioxidant enzyme activity, root morphology and physiology, stem cells, in order to explore the mechanisms of controling fast growing. The results provided a scientific basis for the future a large area using of plant growth retardants and provided technical support for application and popularization of agricultural production. The main results of this paper were as follows:Synthesizing biomass and growth index of wheat seedling, the experiment screened six kinds of plant growth retardants from13kinds of substances which can make plants grow shorter, lodging resistance, slowing growth rate and strong tillering. They are paclobutrazol, diniconazole, mixed application of paclobutrazol and brassins, mixed application of paclobutrazol and DA-6, diniconazole respectively mixed with brassins, DA-6.Synthesizing biomass and growth index of corn, we determined the best applying method of all treatments was spraying on the leaves compared with soil treatment, the best applying content of paclobutrazol was200mg/L, mixed application of paclobutrazol and brassins was200mg/L+0.05mg/L, mixed application of paclobutrazol and DA-6was200mg/L+10mg/L, diniconazole was200mg/L, mixed application of diniconazole and brassins was200mg/L+0.1mg/L, mixed application of diniconazole and DA-6was200mg/L+20mg/L.In this experiment concentration range, plant growth retardants to some extent improved the corn soluble sugar content, soluble protein content and chlorophyll content, improved photosynthetic performance and nutrient content of corn leaves, promoted the NPK absorption of aboveground corn. Root morphological and physiological characteristics of every treatments were significantly improved. Plant growth retardants significantly inhibited cells elongation and shorten the cells, thus shorten internode, but cells transverse width was no significant difference. But soluble sugar content, root morphological and physiological characteristics and nutrient content of mixed application of paclobutrazol and DA-6less than paclobutrazol and DA-6treatment, so the paclobutrazol and DA-6mixed application was not recommended.In a word, plant growth retardants can improve photosynthetic performance and nutrient uptake. By improving root morphology and physiology activity to promote the absorption of nutrients and moisture as well as resistance to external damage, by inhibiting stem cells length to shorten and strong plants, so reduce plant height that achieve the purpose of lodging resistance.