| In this study,Ukraine Daliqiao was used as the test material.The two-year test was carried out in autumn 2018 and spring 2019,respectively,and the verification test was carried out in spring 2019.This test was designed by two factor random area group test.silicon fertilizer（containing 25%≧Si O2）was the main area factor and phosphorus fertilizer（containing 15%P2O5≧Si O2）was the secondary area factor.Silicon fertilizer set 4 levels,0（A1）,120 kg·hm-2（A2）,240 kg·hm-2（A3）and 360 kg·hm-2（A4）;Phosphorus fertilizer set 4 levels,0（B1）,200 kg·hm-2（B2）,400 kg·hm-2（B3）and 600 kg·hm-2（P6）.The fertilizer ratio was 16 treatments and repeated 3 times.The changes of lodging habits,mechanical characteristics,morphological characteristics,biochemical characteristics and root morphological characteristics of stems during flowering,filling and maturity periods were studied by combining the application of silicon and phosphorus fertilizer,the effects of each treatment on photosynthetic characteristics of sweet buckwheat during filling period.The internal mechanism,root system,photosynthesis and lodging of sweet buckwheat were analyzed.The optimum amount of silicon and phosphate fertilizer combined with base fertilizer was selected to provide reference for improving lodging resistance and yield of sweet buckwheat.The main findings are as follows:1.Effect of silicon and phosphorus application on lodging of Ukraine Daliqiao.suitable amount of silicon and phosphorus fertilizer application delayed lodging period of Ukraine Daliqiao,reduced lodging level and lodging rate.As the amount of phosphorus applied increased,the lodging period was delayed and then advanced;the lodging level first decreased and then increased;the lodging first decreased and then increased;the lodging index decreased first and then increased in all three periods,preferably in A3B3(240 kg·hm-2,400 kg·hm-2).Under the A2(120 kg·hm-2),A3(240kg·hm-2)and A4(360 kg·hm-2)levels,with the increase of phosphorus application,the lodging period was delayed and then advanced;the lodging level first decreased and then increased;the lodging first decreased and then increased;the lodging finger increased.The number decreased first and then increased in all three periods,compared with A4(360 kg·hm-2),A2(120 kg·hm-2)and A3(240 kg·hm-2)had more significant changes,and the A3B3 treatment performed best.2.Effect of silicon and phosphorus application on yield and yield composition of Ukraine Daliqiao.Silicon and phosphorus application on the yield,grain number,grain weight and thousand-grain weight were significantly increased,and with the increase of silicon-phosphorus application,the trend was first increased and then decreased,and reached the maximum in A3B3(240 kg·hm-2,400 kg·hm-2)treatment.The amount of silicon and phosphorus combination significantly increased the yield of sweet buckwheat,the number of grains per plant and the weight of 1000 grains,but the excess of silicon and phosphorus combination was not conducive to increasing the yield.3.Effect of silicon and phosphorus application on folding resistance of stal in Ukraine Daliqiao.From the flowering stage to the mature stage,the bending resistance of the stem increased continuously,and the treatment of silicon-phosphorus increased the bending resistance of the stem of Ukraine’s large-grain buckwheat,and with the increase of the amount of silicon-phosphorus showed that it increased first and then decreased,and reached the maximum value in the A3B3(240 kg·hm-2,400 kg·hm-2)treatment.4.Effects of silicon and phosphorus application on morphological characteristics of buckwheat stalk in different periods.From the flowering stage to the mature stage,the plant height,the height of stem center of gravity,the fresh weight of stem,the length and thickness of the second node and the fresh weight of the second node increased continuously,and the fresh weight and the fullness of the second node increased first and then decreased.During the same growth period,with the increase of the amount of silicon phosphorus,the change trend of length,fresh weight,plant height and height of center of gravity was V.5.Effect of silicon and phosphorus application on root morphological index of buckwheat.From flowering stage to mature stage,the root length and root tip number increased first and then decreased.With the increase of silicon and phosphorus application on the total root length and root tip number increased first and then decreased,and the root surface area,root diameter and root volume increased the growth period.With the increase of silicon phosphorus application,root surface area,root diameter and root volume increased first and then decreased,and then decreased in A3B3(240 kg·hm-2,400 kg·hm-2)treatment.6.Effect of silicon and phosphorus application on physicochemical characteristics of buckwheat.With the increase of the amount of silicon and phosphorus,lignin,CAD and POD all showed a single peak curve change trend,reaching the maximum value in A3B3(240 kg·hm-2,400 kg·hm-2).With the growth period,the lignin content gradually increased,and the CAD and POD activities decreased continuously;4 CL and PAL activities increased first and then decreased,and the activity was the highest in the grouting period.7.Effects of silicon and phosphorus application on nitrogen,phosphorus and potassium silicon in stem of buckwheat during different period.The content of nitrogen,phosphorus and potassium decreased from flowering stage to mature stage.At the same growth period,the content of nitrogen,phosphorus and potassium increased first and then decreased with the increase of silicon-phosphorus application.8.Effect of silicon and phosphorus application on photosynthetic effect of Ukraine Daliqiao during grouting period in 2019.The effect of silicon and phosphorus application on net light and rate,stomatal conductance,transpiration rate and intercellular carbon dioxide was significant.As the amount of silicon-phosphorus application increased,the net photosynthetic rate,intercellular carbon dioxide concentration and stomatal conductance all showed the trend of first increasing and then decreasing,with the maximum value at A3B3(240 kg·hm-2,400 kg·hm-2),while the evaporation rate decreased first and then increased.To sum up,the combination of silicon and phosphorus has a significant effect on common buckwheat lodging,yield and its constituent factors,stem morphological characteristics,root morphological indicators,second internode morphological indicators at the base of stem,lignin and its synthetic related enzyme activities,photosynthesis,nitrogen,silicon and potassium.Appropriate amount of silicon and phosphorus can increase the lodging resistance,decrease the lodging rate and increase the yield.The optimum amount of silicon and phosphate was 240 kg·hm-2,phosphate fertilizer 400 kg·hm-2. |
