Responses Of Soybean(GLYCINE MAX MERR.) And Citrus(CITRUS RETICULATA BLANCO) Yield And Quality To Application Of ZN And AMF

Arbuscular mycorrhizal fungi(AMF)are integral components of the ecosystem because they can obtain nutrients from the soil and show interest in plant nutritional status.When plants experience biotic and abiotic stresses such as drought,extreme temperatures,heavy metals,salt,disease and metal pollution,AMF takes action to improve soil moisture status and nutrient uptake.About 80% of terrestrial plant species have this type of symbiotic relationship between their roots and fungal hyphae.Fungal hyphae obtain nutrients by consuming sugars and fats in the roots of host plants,which benefit from the interaction of AMF to increase water and nutrient uptake from the soil surface.In soil,zinc(Zn)appears to have this dual role with AMF.AMF help plant to absorb Zn at lower cocentration of soil solution;in contrary to this AMF avoid uptake at higher concentration of Zn.Therefore we investigated the effects of applying AMF and Zn on the yield and quality of citrus and soybean under different scenarios,and the interaction mechanism between AMF and Zn was investigated.1)Through field experiments on soybean,it was found that the root colonization rate,protein content,carotene,lycopene and phenolic content of soybean plants increased with the increase of AMF concentration and the increase of foliar application of Zn.There were no significant differences in flavonoids,leaf number,plant height,normalized difference vegetation index(NDVI),and soil plant analysis and development(SPAD).The root colonization rate of AMF varied from 5% to 85%,and the protein content of soybean varied from 40% to 51%.There was also an overall decrease in soil nitrogen content,an increase in organic matter(OM),an increase in phosphorus and potassium content,and a decrease in p H and Zn content.2)Using soybeans from the Agricultural Research Station(ARS),Pakrhribas,Dhankuta,Nepal,as experimental material,a factorial randomized complete block design was used to determine drought(1.25 ETmax and 0.5ETmax),Zn fertilizer(0,0.5 and 1%)and mycorrhizal(M)and non-mycorrhizal(NM)effects.The results showed that drought had deleterious effects on plant biomass,plant height,stem weight,leaf number,leaf weight,pod number,pod weight,root weight,root length and root nodules.However,other factors such as Zn treatment and mycorrhizae were not significantly affected.In addition,mineral nutrients such as nitrogen,phosphorus,potassium and Zn content in roots,stems,leaves and grain bearing pods were not significantly affected.3)In the experiments of Wenzhou mandarin orange and Nanfeng mandarin orange,a completely randomized block design was used,and 3 levels of Zn sulfate(0,0.5,1%)were sprayed on the foliar surface and 3 levels of Zn sulfate(0,40,80g/plant)were applied to the soil.After 6 months of treatment,the N,P and K contents of Wenzhou and Nanfeng mandarin increased respectively.The yield of the Wenzhou citrus variety reached 15-30t/hm~2,and the yield of Nanfeng reached 5-10t/hm~2.And there was no significant effect on chlorophyll a,b,carotenoids,SPAD levels,nitrogen,phosphorus,potassium,Zn,soluble solids,vitamin C and titratable acidity as quality indicators of citrus.