Studies On Anti-lodging Effect And Its Physiological Property Of Decapitation And Inhibiting Sucker At Growth Later Stage In Flax

By studying on different topping time,topping number,topping extent and the type,concentration,spraying volume of inhibiting bud agent at growth later stage in flax under field experiment,the anti-lodging cultivation technology of topping and inhibiting sucker at growth later stage in flax was established using lodging rate,lodging index,the original stem yield,fiber quality appraisal as the main indicators.This paper ascertained preliminary physiological characteristics of high-yield(original stem yield),high-quality,highly efficient of anti-lodging cultivation of topping and inhibiting sucker at growth later stage in flax through comparatively study of lodging resistances mechanical characteristics changes,morphological structure characteristics,group photosynthetic characteristics and inorganic nutrition characte-ristics.The main results were as follows:1.The topping time at growth later stage in flax is ranged from squaring period to the beginning of flowering and the best topping time is early flowering period.It need at least twice topping and the second topping time should be completed in 7 d after the first topping;It's better to retain the length of main strains(ie strains base to its first branch).The maleic agent such as 30.2%yawei EC,25%yake grams water,25%yiyamin EC,and 33%chuyatong EC,etc all have some inhibition sucker effect,but 25%yiyamin EC is the best;The best concentration of yiyamin EC is 300 to 400-fold dilution and the best dosage is 650～750 kg/hm~2.2.Topping,inhibition sucker,topping + inhibition sucker would have some anti-lodging effect,but topping + yiyamin had the best anti-lodging effect.Its field lodging rate was only 5.8%,reduced 85.4%comparing with the control.Its raw stem yield was slightly lower than the control,but process output was significantly(23.68%) higher than control.Fiber strength was 17.06%higher than the control and fiber splitting was corresponded to that of control.3.Topping+yiyamin obviously reduced center of gravity height(33.14%) and lodging index(51.06%) and enhanced breaking resistance of stem,the maximum weight carrying capacity of flax(46.05%and11.12%).Flax canopy weight was significantly positively and negatively correlated with center of gravity height and breaking resistance of stem respectively. It was negative correlated with the maximum carrying capacity of flax,which showed topping + yiyamin can effectively reduce canopy weight and improve stem capacity of lodging resistance.4.The plant height decreased significantly(25.17%) and stem diameter increased 12.24%. The number of branches,branch length and fresh weight of branches reduced 67.50%,52.80%, 94.55%respectively after topping +yiyamin.The thickness of epidermis cortex,phloem and xylem increased significantly,but the diameter of medullary cavity was not obviously incremental.Stem breaking resistance was significantly negative correlated with plant height and branch fresh weight and was significantly positive correlated with stem diameter.It was also significantly positive correlated with the thickness of epidermis cortex and phloem and was positive correlated with xylem thickness and cavity size.5.The leaf area reduced slightly at initial stage and increased significantly at mid-and latter-of topping+yiyamin treatment,which was 2.95,6.06 times than the control at mature stage respectively.Stem,flowers and fruits of the proportion of the total dry matter were significantly increased,reduced respectively and the change of leaf percentage of total dry matter was not obvious after topping+yiyamin.Stem fracture resistance was positively correlated with indicators of group photosynthetic characteristics and was significantly positively correlated with stem dry matter.It was negatively correlated with branch dry matter.These showed that the improvement of photosynthetic characteristics and reduction of branch weight after topping+yiyamin treatment at growth later stage can increase the capacity of lodging resistance.6.The change in active absorption area(%)and specific surface area of roots was not obvious,but the root dry weight per plant,root volume,total absorption area and root oxidation power increased significtively after topping+yiyamin.The nitrogen accumulation per plant was slightly reduced,but phosphorus and potassium accumulation per plant increased.The nitrogen, phosphorus and potassium distribution ratio of leaf and stem increased obviously,and proportion of capsule fruit in the distribution decreased significantly.Stem fracture resistance was positively correlated with indicators of root characteristics and was positive and negative correlated with per plant nitrogen and phosphorus,potassium accumulation respectively.It was significtively positive correlated with nitrogen and phosphorus, potassium accumulation of stem.All these indicated the improvement of root characteristics and increase of nitrogen,phosphorus and potassium accumulation of stem can increase lodging resistance in flax.