Study On Biology Characteristic Of Abutilon Theophrasti Medikus And Its Competitive Relationship With Soybean

Heilongjiang Province is the largest domestic non-GM soybean production area in China.It is of great significance to ensure the soybean yield in Heilongjiang Province for national food security.In addition,with the continuous use of chemical herbicides,the dominant weed population and community structure in soybean fields in Heilongjiang Province have changed greatly.Abutilon theophrasti is widely distributed in Heilongjiang Province,and its damage has been significantly increased in recent years,Abutilon theophrasti has seriously harmed the yield and quality of soybean.Therefore,the control of Abutilon theophrasti has become a key problem in soybean cultivation.In this study,Abutilon theophrasti,a weed in soybean field,was selected as the research object.The characteristics of dormancy,germination,emergence depth,growth and reproduction of the Abutilon theophrasti,as well as the field occurrence dynamics of the Abutilon theophrasti,were studied by means of laboratory test,pot experiment,field investigation and statistical analysis.The competition relationship with soybean and its effect on soybean yield.Therefore,it provides an important theoretical basis for the comprehensive control of Abutilon theophrasti.The research results of this paper are as follows:(1)The average length and average width of Abutilon seeds in different locations in Heilongjiang Province are about 3 mm,the average thickness is about 1.5 mm,the color is brown or dark brown,the 100-seed weight is about 1 g,and the water content is less than 5 %,rich in soluble sugar and soluble protein.(2)More than 90% of Abutilon theophrasti seeds stored for less than 5 years have vitality,while those stored for 7 years still have vitality of more than 75%.(3)Abutilon theophrasti has seed dormancy,warm water soaked seed handling and warm water combined with gibberellin solution treatment can effectively break the Abutilon theophrasti seed dormancy.(4)The seeds of Abutilon theophrasti from different locations in Heilongjiang Province can germinate at 15～35℃,and 20～30℃ is the best temperature range for germination.The seed germination of Abutilon theophrasti is not sensitive to light.The seed germination rate of Abutilon theophrasti is above 70% when the p H is 4～9.The seed germination rate of Abutilon theophrasti was the highest when the water potential was between 0 and-0.2 MPa,and the germination was completely inhibited when the water potential was less than-0.7 MPa.The seeds of Abutilon theophrasti have strong salt tolerance.When Na Cl concentration is 160 mmol/L,the germination rate is more than 40%.The seeds are highly adaptable to the sowing depth,and seedlings can emerge from the soil layer covering no more than 8 cm.(5)During the whole growth period of Abutilon theophrasti,the average seedling emergence of the artificial plucking treatment was higher than the final average number of the Abutilon theophrasti at the sample point without plucking,indicating that the competition between plants inhibited the growth of the Abutilon theophrasti population,and there was self-thinning phenomenon in the Abutilon theophrasti population.(6)From 10 to 20 days after soybean sowing(May 10)in Harbin,the peak of seedling emergence was observed.The rapid growth period was from June 10 to July 16.In late July,the seeds of the Abutilon theophrasti entered the fruiting stage.Abutilon theophrasti per plant biomass and the amount of seed as the emergence of time delay,and the emergence of Abutilon theophrasti not flowering in late July.(7)The curve of plant height and fresh weight of Abutilon theophrasti was S-shaped,which showed the basic rule of "slow,fast and slow".Abutilon theophrasti enters the rapid growth phase one week earlier than soybean.After this,the average plant height of Abutilon theophrasti is higher than soybean.(8)Within the density range set in this study,the biomass per plant and seed yield showed a decreasing trend with the increase of density,but the total biomass and seed yield per unit area showed an increasing trend.Among them,the relationship between biomass per plant,seed yield and density of the Abutilon theophrasti conforms to exponential function,and the relationship between total biomass per unit area,seed yield and density of the Abutilon theophrasti conforms to logarithmic function.(9)In setting Abutilon theophrasti density within the scope of this study,the air of soybean pod rate and yield loss rate with the increase significantly Abutilon theophrasti density increased,the theory of effective pod number per plant and yield declined significantly with Abutilon theophrasti density increased,and the soybean pod empty rate,the number of effective pods per plant and the theory of the relationship between the yield loss rate and the density of abutilon accords with quadratic equations.