Study On Forage Grass Selection Suitable For Grass Of Punica Granatum Forest Under Allelopathy Effectt

In this paper,simulated rain and fog leaching,indoor petri dish method was used to study the The effects of aqueous extracts from leaves of Punica granatum at different concentrations on four kinds of common forage grass Lolium perenne,Pennisetum alopecuroides and Trifolium Repens and Medicago sativa seed germination and seedling growth;Using half natural potted method this paper discusses the different concentrations of pomegranate leaf extract,four kinds of forage grass extract,four kinds of forage grass-pomegranate leaf mixed water leaching solution,the biennial pomegranate seedlings of photosynthesis,growth,biomass,root indicators of allelopathy,preliminary discussion of pomegranates and the 4 kinds of common forage feasibility of understory plant interactions.The results are as follows:1.In seed germination test,the inhibition degree of water extract from pomegranate leaves on seed germination stage was from strong to weak in the order of Trifolium Repens > Medicago sativa > Lolium perenne > Pennisetum alopecuroides;At seedling growth stage,the inhibition degree of water extract from pomegranate leaves was as follows: Medicago sativa > Lolium perenne > Trifolium Repens >Pennisetum alopecuroides.In general,the inhibition degree of water extract from pomegranate leaves was as follows: Medicago sativa > Trifolium Repens > Lolium perenne > Pennisetum alopecuroides.2.In the pot experiment,all treatments increased the SPAD value and Ci value of pomegranate leaves,among which the Punica granatum-Medicago sativa treatment group irrigated with low concentration of grass extract had the strongest promoting effect on SPAD value,which increased by 53.8%;the Punica granatum-Trifolium Repens treatment group irrigated with high concentration of grass extract had the strongest promoting effect on Ci value,which increased by 38.0%.The Pn,Gs and E values of pomegranate leaves under different treatments showed allelopathic inhibition,but only increased slightly under partial treatments,showing allelopathic promotion effect.The Punica granatum-Trifolium Repens treatment group without watering low concentration extract had the strongest promoting effect on Pn value,which increased by 30.3%;the Punica granatum-Medicago sativa treatment group with watering low concentration mixed extract had the strongest promoting effect on Gs and E value,which increased by 45.2% and 40.1%,respectively.On the whole,Pn value,Gs value and E value showed a positive trend.3.Different treatments had different allelopathic effects on various indexes of pomegranate diameter and height.Under mixed extract treatment,Trifolium Repens group and Medicago sativa group showed obvious allelopathic promoting effect,while Lolium perenne group showed strong inhibition effect on Punica granatum growth.The Punica granatum-Trifolium Repens treatment group irrigated with low concentration pomegranate extract had the strongest promoting effect on the final base diameter of pomegranate,which increased by 19.7%;the Punica granatum-Trifolium Repens treatment group irrigated with low concentration mixed extract had the strongest promoting effect on the final height and height change of pomegranate,which increased by 27.1% and 51.4%.The Punica granatum-Trifolium Repens treatment group irrigated with low concentration of herbage extract had the strongest promoting effect on the change of basal diameter,which increased by 36.8%.4.Different treatments promoted the fresh weight and dry weight of the aboveground part of pomegranate,and inhibited the fresh weight and dry weight of the underground part of pomegranate.It can promote the growth of pomegranate branches and inhibit the growth of underground roots in a certain range.The Punica granatum-Trifolium Repens treatment group irrigated with low concentration mixed extract had the strongest promoting effect on the fresh weight and dry weight of aboveground part of pomegranate,and the fresh weight and dry weight of underground part of pomegranate increased by 54.9%,53.8%,51.7%,47.8%,respectively.5.Allelopathic effects of different treatments on pomegranate root indexes were inhibited and promoted occasionally.The Punica granatum-Medicago sativa treatment group irrigated with low concentration pomegranate extract had the strongest promoting effect,which increased by 32.0%.The Punica granatum-Trifolium Repens treatment group irrigated with low concentration mixed extract had the strongest promoting effect on pomegranate surface area,which increased by 17.5%.The root system of pomegranate seedlings in Lolium perenne group was strongly inhibited by three kinds of extracts.6.A comprehensive comparison of the effects of several forages on the growth of pomegranate indexes showed that Trifolium Repens had the weakest allelopathic inhibition on the overall growth of pomegranate in all treatment groups.Pomegranate leaves have a certain allelopathic effect on Trifolium Repens,but it is not significant at low concentration.Therefore,Trifolium Repens is the most suitable grass species for pomegranate undergrowth cultivation.Its plants are low and resistant to trod,which is convenient for orchard operation and conducive to the management of Punica granatum garden.Medicago sativa followed.