Effect of Combined Application of Organic Fertilizer and Chemical Fertilizer in Different Ratios on Growth,Yield and Quality of Fluecured Tobacco

The effect of different ratio of organic and inorganic fertilizers on the growth and the yield and quality of flue-cured tobacco was studied.Using randomized blocks design,the data of the test materials K326 were analyzed by using variance analysis,significance test and other methods.The release efficiency of organic fertilizer in the soil was slower,and the effect of organic fertilizer on the growth of tobacco plants was worse than that of chemical fertilizers,and under 25% organic fertilizer + 75% chemical fertilizer treatment,the quality of the fluecured tobacco was good.Under the treatment of 50% organic fertilizer + 50% chemical fertilizer,the production of flue-cured tobacco was high and the ratio of first-class tobacco was high.It is suggested that the organic fertilizer application ratio should be 25%-50% in the agricultural production.

Application of ferrous sulfate alleviates negative impact of cadmium in rice(Oryza sativa L.)

Soil contamination with toxic heavy metals[such as cadmium(Cd)]is becoming a serious global problem due to rapid development of social economy.Iron(Fe),being an important element,has been found effective in enhancing plant tolerance against biotic and abiotic stresses.The present study investigated the extent to which different levels of Ferrous sulphate(FeSO_(4))modulated the Cd tolerance of rice(Oryza sativa L.),when maintained in artificially Cd spiked regimes.A pot experiment was conducted under controlled conditions for 146 days,by using natural soil,mixed with different levels of CdCl_(2)[0(no Cd),0.5 and 1 mg/kg]together with the exogenous application of FeSO_(4) at[0(no Fe),1.5 and 3 mg/kg]levels to monitor different growth,gaseous exchange characteristics,oxidative stress,antioxidative responses,minerals accumulation,organic acid exudation patterns of O.sativa.Our results depicted that addition of Cd to the soil significantly(P<0.05)decreased plant growth and biomass,gaseous exchange parameters,mineral uptake by the plants,sugars(soluble,reducing,and non-reducing sugar)and altered the ultrastructure of chloroplasts,plastoglobuli,mitochondria,and many other cellular organelles in Cd-stressed O.sativa compared to those plants which were grown without the addition of Cd in the soil.However,Cd toxicity boosted the production of reactive oxygen species(ROS)by increasing the contents of malondialdehyde(MDA),which is the indication of oxidative stress in O.sativa and was also manifested by hydrogen peroxide(H_(2)O_(2))contents and electrolyte leakage to the membrane bounded organelles.Although,activities of various antioxidative enzymes like superoxidase dismutase(SOD),peroxidase(POD),catalase(CAT)and ascorbate peroxidase(APX)and non-enzymatic antioxidants like phenolics,flavonoid,ascorbic acid,anthocyanin and proline contents increased up to a Cd level of 0.5 mg/kg in the soil but were significantly diminished at the highest Cd level of 1 mg/kg in the soil compared to those plants which were grown without the addition of Cd in the soil.The negative impacts of Cd injury were reduced by the application of FeSO_(4) which increased plant growth and biomass,improved photosynthetic apparatus,antioxidant enzymes,minerals uptake together with diminished exudation of organic acids as well as oxidative stress indicators in roots and shoots of O.sativa by decreasing Cd retention in different plant parts.These results shed light on the effectiveness of FeSO_(4) in improving the growth and upregulation of antioxidant enzyme activities of O.sativa in response to Cd stress.However,further studies at field levels are required to explore the mechanisms of FeSO_(4)-mediated reduction of the toxicity of not only Cd,but possibly also other heavy metals in plants.

Effect of Different Boron Fertilizer Supply Patterns and Levels on Growth,Development and Quality of Flue-Cured Tobacco

Boron,one of the essential trace elements for normal growth and development of tobacco,has a great impact on the yield and quality of flue-cured tobacco. The objective of this study is to explore the best pattern and level of boron fertilizer supply of red soil in the Honghe tobacco area. In this study,the randomized block design was used to study different boron fertilizer supply methods and levels. The results showed that during transplanting,it was good to apply 1. 50 kg/ha Fertibor boron with pure boron content≥15%; at the resettling stage,it was good to spray 225 kg solution composed of 75 m L/ha Compo liquid boron with pure boron content≥130 g/L mixed with water onto leaves when night fell in a sunny day. The two fertilization methods had better effect than the basal application of boron fertilizer,and the resistance to pests and diseases or economic character of tobacco plants was better than under spraying treatment.

Relationship between Ponkan Mandarin Fruit Quality and Nutrient Concentrations

Five age groups of trees were carried out in order to study relationships between the deterioration of Ponkan mandarin fruit quality and changes in tissues nutrient concentrations with tree age.Fruit quality and nutrient concentrations in fruits and leaves were measured.Comprehensive fruit quality decreased in the order:5-year-old > 13-year-old > 38-year-old > 8-year-old >18-year-old.In 18-year-old trees,calcium(Ca) concentrations of fruit and leaf were lower,while potassium(K) and boron(B) concentrations of fruit and magnesium(Mg) and manganese(Mn) concentrations of leaf were higher.Negative relationships were observed between fruit total soluble solids and leaf B,while positive relationships were observed between fruit total soluble solids and leaf and fruit Ca concentrations,and between titratable acidity and leaf Mn.Fruit quality decreasing with tree age most likely resulted from an imbalance of high K,Mg and B but lower Ca concentrations in leaves and fruits.