Effects Of Spraying A Combined Plant Growth Regulator On The Tillering,Cold-resistance,Yield And Grain Quality Of Different Wheat Varieties

The application of plant growth regulators has not only become the development and supplement of traditional agronomy technology but also one of the important measures to achieve high yield,stable production and commercialization in agriculture with its advantages of high efficiency,low cost and labor saving.In China,some chemical technology has become the conventional technology during the production of cotton,rice and rape,which is also an important coordinated technology for high-yielding technology.However,the exploitation and application of growth regulators on the main grain crops such as wheat and maize are not ideal and can not be widely used in the field.Given this,a formula of combined growth regulator was developed according to the characteristics of the growth and development of wheat seedlings before winter and the technical requirements for the cultivation and management,which can promote the tillering of Xinong 389 before winter and not affect its cold physiological performance.At present,the combined plant growth regulator has got a national invention patents.As the effect of growth regulators is often varied with plant species and varieties,the application of the growth regulator to other wheat varieties and the effect on yield needs a further discussion.Thus effects of spraying a combined plant growth regulator on the tillering,cold-resistance,yield and grain quality of different winter wheat varieties(Xinong 979,Xinong 889,Zhengzhou 831 and Xiaoyan 22)were compared in field experiments.The aim is to provide more theoretical basis for the application and promotion of the regulator.The results showed that:(1)Spraying the combined plant growth regulator can not only significantly improved the tillering in the winter and increased above-ground biomass of Xinong 979,Xinong 889 and Zhengzhou 831,but also promoted the root growth of Xinong 979.The root biomass of Xinong 889 and Zhengzhou 831 was also increased slightly.While the application of the combined plant growth regulator did not affect Xiaoyan 22's tillering number,above-ground biomass and root growth scarcely.(2)After spraying the combined plant growth regulator,the physiological and biochemical parameters relating to the cold-resistance were not impacted in leaves and roots of all varieties at the winter solstice.Wherease the contents of chlorophyll and carotenoid in leaves of Xinong 979 increased significantly at the great cold with the temperature decreased to lowest naturally.Meanwhile,the contents of soluble sugar,starch,soluble protein and free proline and the activity of SOD and POD in the leaves and roots of Xinong 979 were increased obviously after spraying the plant growth regulator,whereas the content of MDA was significantly lower than the control's.Hence,the cold-resistance of Xinong 979 was enhanced at the time.For the other two varieties,Zhengzhou 831 and Xiaoyan 22,the acativity of SOD in roots was enhanced apparently,while there was no significant change in the contents of chlorophyll and carotenoid in leaves.At the same time,the contents of osmotic regulation,malondialdehyde,glutathione and ascorbic acid in the leaves and roots were not affected by the growth regulator obviously,the variation trend of POD and CAT activity was also the same.The starch contents in roots of Xinong 889 was only improved.(3)Regarding the most important growth indexes at different stage the next spring,results showed that at the green stage,the application of the plant growth regulator remarkably improved the contents of soluble sugar and starch in the aboveground and underground parts of Xinong 979,The contents of Xinong 889 and Xiaoyan 22 in the aboveground were enhanced too.Otherwise,the carbon metabolism of Zhengzhou 831 was not affected during the period.On the other hand,the contents of soluble protein and free amino acid of all varieties in roots was promoted evidently at this time.The plant height and leaf area were not affected from jointing stage to grain-filling stage respectively.Otherwise,the heading time of all cultivars was brought forward four to eight days.(4)In the case of yield trains after the wheat is rippen,the spike number per plant of Xinong 979,Xinong 889 and Zhengzhou 831 were increased by 19%,17.8% and 5.3%,while the yield per unit area was increased by 16.9%,16.2% and 5.9%,respectively,by the application of the plant growth regulator and the changes of grain and grain number per spike is not obvious.Contrarily,Xiaoyan22's spike number per plant decreaded 4?and the spike grain number increased by 2.4 kernel per plant,resulting in the yield per unit area decreased by 0.4?.Finally,Testing the effect of the regulator on wheat grain quality,It was found that there were not significant changes in grain milling quality,processing quality and nutritional quality.In summary,the application of the combined plant growth regulator can effectively improve the tillering number of winter wheat and promote its growth,enhance the cold resistance of some varieties(Xinong 979)under the natural low temperature condition.At the same time,the plant growth regulator is beneficial to regulate the metabolic process of carbon and nitrogen at green stage.The change of tillering number resulting in the increasing of single plant panicles during the yield formation.All the results showed that spraying the plant growth regulator have a potential of increaseing yield of winter wheat,while the characteritices of the grain qualities were not affected.Emphasizely,all the applications of the growth regulator are effective on Xinong 979,Xinong 889 and Zhengzhou 831,but not on Xiaoyan 22.