Screening Of High-quality And Efficient Cultivation Substrates For Potted Chrysanthemum

Chrysanthemum morifolium has extremely high ornamental and economic value,and the market demand is increasing year by year.However,traditional cultivation techniques have certain limitations in modern industrial production and are not suitable for large-scale production.Substrate cultivation techniques are widely used in production for their advantages of high quality and high efficiency,improving land utilization rate and avoiding continuous cropping obstacles.Therefore,substrate cultivation is the inevitable requirement of the development trend of modern flower industrialization.Substrate is the most important factor to determine the growth environment of plant roots.Peat,which is widely used at present,is a non-renewable resource,and its massive exploitation has greatly damaged the ecological environment.At the same time,there are still some problems in the traditional chrysanthemum cultivation process,such as easy root system damage when transplanting and high disease incidence,which leads to low production efficiency and low quality.Therefore,in this study,three chrysanthemum cultivars,Chrysanthemum morifolium‘Huihuang’,C.morifolium‘Boerduohong’and C.morifolium‘Huangfurong’were used as plant materials,and pot experiments were carried out with different substrates to solve the above problems,in order to screen out new high-quality and efficient cultivation substrate formulas suitable for the growth of potted chrysanthemum.The main results were as follows:1.The physical and chemical properties of 20 commonly used substrates were analyzed and clustered.It was found that agricultural and forestry wastes had the characteristics of low bulk density,high totalporosity,high EC value and high nutrient content of nitrogen,phosphorus and potassium,among which leaf mould and rice husk had the lowest bulk density,which was suitable for the subsequent study of light and renewable substrates.2.Leaf mould and rice husk could be used as cultivation substrates instead of peat.The addition of leaf mould and rice husk significantly increased the available N content,available P content and available K content in the substrate,which made potted chrysanthemum grow more vigorously and have better flowering effect.In Q1 treatment(peat: perlite: leaf mould:rice husk=6:2:1:1),Q2 treatment(peat: perlite: leaf mould: rice husk=2:1:1:1)and Q3treatment(peat: perlite: leaf mould: rice husk=2:2:3:3),the stem diameter,crown width,inflorescence number,leaf area and Pn of three potted chrysanthemums were generally better than Q0 treatment(peat: perlite =4:1,volume ratio,the same below)and the comprehensive evaluation index obtained by principal component analysis and membership function method is higher than Q0,so they were ideal cultivation substrates,and the comprehensive evaluation coefficient of Q2 treatment was the highest.Moreover,the addition of leaf mould and rice husk instead of peat significantly reduced the bulk density of each formula,the bulk density of Q2 treatment was 47.5% lower than that of Q0 treatment,which could be used as a light and renewable cultivation substrate for potted chrysanthemum,and also provided a basis for the resource utilization of agricultural and forestry wastes.3.The light and renewable substrate screened in the previous chapter was used as a nutrient layer and combined with different rooting layers.The results showed that,the rooting and survival rate of potted chrysanthemum cuttings were high in Z1 treatment(river sand +nutrient layer),Z2 treatment(perlite + nutrient layer),Z3 treatment(vermiculite + nutrient layer)and Z4 treatment(peat + nutrient layer),all of which were 100%,but low in Z5treatment(coconut bran + nutrient layer)and Z12 treatment(rice husk: perlite=4:1 + nutrient layer).Among them,the root system was short and stout in Z1 and T2 treatment,but long and thin in Z3 and Z4 treatment.The plant height,stem diameter,crown width,flowering period and Pn of potted chrysanthemum were excellent in Z1-Z3 treatment.Z2 treatment has the highest comprehensive evaluation coefficient,which could be used as the best one-step substrate,followed by Z1 and Z3 treatment.4.In order to study the influence of cow dung compost on the growth and fungal inhibitory effect of potted chrysanthemum,1/2,1/4 and 1/6 cow dung compost were added to the substrate respectively,and the available N content,available P content and available K content in the substrate increased significantly,which provided a good root growth environment for potted chrysanthemum.The survival rate of potted chrysanthemum was 100%in each treatment,among which ‘Huihuang’ grew best in Y1 treatment(common substrate: cow dung compost =1:1),the plant height increased by 36.8% compared with Y0 treatment,‘Boerduohong’ and ‘Huangfurong’ grew best in Y3 treatment(common substrate: cow dung compost =5:1),and the plant height was 34.6% and 18.8% higher than Y0 treatment respectively,and the comprehensive evaluation coefficient was highest.The disease index of‘Huihuang’ was the lowest in Y1 and Y2 treatments(common substrate: cow dung compost=3:1),while that of ‘Boerduohong’ and ‘Huangfurong’ was the lowest in Y3 treatment.Adding appropriate amount of cow dung compost to different cultivars could significantly reduce the disease index of potted chrysanthemum infected with black spot.