Study On Growth Characteristics,Disease Occurrence And Control Of Ailanthus Altissima ’Liaohong’

Ailanthus altissima’Liaohong’is a variety of Ailanthus altissima with wide applicability and good ornamental after years of cultivation by the research group of Liaocheng University.It obtained the certificate of new plant variety right on December 31,2019.Because of its unique ornamental characteristics of brilliant Samara and the excellent characteristics of Ailanthus altissima economic value,ecological value,medicinal value and biological control function,Ailanthus altissima’Liaohong’has unique popularization value.Taking Ailanthus altissima’Liaohong’as the test material,this thesis studied the types of leaf diseases,the control of leaf spot disease,the ecological adaptability of Ailanthus altissima’Liaohong’seedlings and efficient cultivation techniques.The main achievements are as follows:1.By measuring the germination rate,germination potential,germination index and average germination speed of Ailanthus altissima’Liaohong’seeds under different temperatures,storage conditions and soaking time,it is clear that the most suitable germination temperature of Ailanthus altissimais’Liaohong’25℃.With the extension of time,the seed germination rate decreases,and the germination rate is the highest when soaking time is 24 hours.2.Under different water supply conditions,the simulated precipitation of 400 mm is the most conducive to the growth of Ailanthus altissima’Liaohong’seedlings.N:P:K ratio of 2:1:2 is the best fertilization formula,and N:P:K ratio of 1:2:1 is inferior to the best group,but the dosage is relatively economical.3.Through the treatment of Ailanthus altissima’Liaohong’under drought stress,salt stress and high temperature stress,the tolerance of Ailanthus altissima’Liaohong’in harsh environment is tested.The experimental results show that Ailanthus altissima’Liaohong’has good drought resistance,Salt tolerance 0.4%and high temperature tolerance of 40℃,which provides technical support for the popularization and application of the new variety Ailanthus altissima’Liaohong’.4.Through field investigation,many leaf diseases of Ailanthus altissima’Liaohong’were found,and four pathogenic fungi were isolated.The pathogen of Ailanthus altissima’Liaohong’leaf disease was identified by combining morphology,molecular biology and Koch’s rule.The results showed that the pathogen of anthracnose was Colletrichum siamense,the pathogen of black spot was Alternaria alternata and Nigrospora oryzae,and the pathogen of leaf spot was Exserohilum rostratum.5.The indoor virulence of three fungicides,difenoconazole,prochloraz and chlorothalonil,against the pathogen of Ailanthus altissima’Liaohong’leaf spot,exserohilum rostratum,was determined by growth rate method.Among the three agents tested,difenoconazole had the strongest toxicity and the best bacteriostatic effect,with EC₅₀of 0.5886μg/ml,followed by prochloraz,with EC₅₀of 1.116μg/ml,and chlorothalonil had the worst effect,with EC₅₀of 114.2μg/ml.