Effects Of Processed Product From Medicinal Plant Castor On The Seedling Growth Of Soybean And Maize

The derivatives from medicinal plant castor are widely used in medicine,chemical industry,aviation,and national defense.Among which,the by-product castor cake takes up a large part of percentage and is enriched in crude protein,amino acid and mineral elements,which is wildly used as organic fertilizer and animal feeds(after detoxification).In the present study,to explore the influence on seed germination and seedling growth of soybean(Glycine max L.)and maize(Zea mays L.),0.5%,2.5%,5% and 10%(w/v,g/ml)concentrations of castor cake extracts were prepared.We mainly investigated the selected indicants,such as percentage of germinated seeds,length of hypocotyls,activity of root system,root and shoot length,and dry/fresh weight,to assess the different effects of castor cake extracts between monocotyledons and dicotyledonous and to figure out the most suitable concentration used for cultivation,providing the scientific basis and reference for the utilization of medicinal plant resources and excavation of the potential value to create a higher economic benefit in agricultural industry.The main results were obtained as following:Compared with the control,the selected concentrations(0~10% w/v)of the castor cake extracts had no influence on the germination rate in soybean,but could inhibit the germination rate in maize,especially the lethal effect in concentration of 10%.The allelopathic effects of castor cake extracts showed significantly different between soybean and maize during the seed germination.The results revealed that castor cake extracts promoted the elongation of hypocotyls in soybean at a lower concentration of 0.5%(w/v)while inhibited the elongation of hypocotyls at higher concentrations of 2.5% to 10%.And0.5% of castor cake extracts also promoted the elongation of primary roots of maize.Our results suggested that the most suitable concentrations used for soaking were 0.5% solution for 2 h in soybean and 0.5% solution for 2~4 h in maize.The castor cake extracts could enhance the activity of root in soybean,with significantly increase at the concentrations of 2.5% to 10%.While the the activity of root in maize showed firstly decrease and then increase and decrease again,with the lowest activity at the concentration of 2.5% and the highest at 5%.The allelopathic effects of castor cake extracts showed opposite pattern between soybeanand maize during the seedling growth.The castor cake extracts inhibited the growth of the above-ground portion in soybean at the concentrations of 5% to 10% and improved the Root/Shoot Ratio at 0.5% as well as the elongation of root and stem at 2.5%.While in maize,the allelopathic effect was promoted in lower concentration and inhibited in higher concentration,as shown by the changed pattern of the elongation of root and stem and the fresh weight of the above-ground portion.Our results suggested the most suitable concentrations used for irrigation soybean and maize seedlings were 0.5% to 2.5% and2.5%~5%,respectively.