Study On Application Of UV-B Supplement Combined With CO₂ Enrichment In Winter Plastic Greenhouse Tomato Planting

Aiming for the lack of UV-B and CO2 in winter plastic greenhouse, the UV-Bsupplement combined with CO2 enrichment were given to tomato in winter plastic greenhouse.The objective was improving the fruit quality by UV-B supplement, on the other hand,reducing the disadvantage of UV-B radiation through CO2 enrichment. we choosed differentUV-B radiation dose about 0.581 kJ.m-2.d-1, 0.872 kJ.m-2.d-1,1.163 kJ.m-2.d-1,1.454kJ.m-2.d-1,1.744 kJ.m-2.d-1combined with CO2 enrichment at 700μmol.mol-1.The effects ontomato growth, physiological characteristic, yield and fruit quality were supervised.Primarily study results as follows: 1. UV-B radiation inhibited the plant height ,leaf area, DW of tomato seedling, especiallyreduced leaf area about 34.86%.CO2 enrichment could reduce this inhibition. UV-B radiationreduced the leaf wide significantly and less influenced the leaf length under CO2 enrichmentin tomato planting. 2. UV-B radiation changed the transport of dry materials, increased the root/shoot ratioof. tomato seedling. 3. Low dose of UV-B radiation (≤1.163kJ.m-2.d-1)stimulated increasing of leafchlorophyl1 content, activity of antioxidative enzymes , these effects were overlapped withCO2 enrichment effects. High dose of UV-B radiation done harm to leaf chlorophyl1. Thethe reduction of chl a were bigger than chl b. UV-B supplement and CO2 enrichment reducedthe stomatal conductance samely,the effects overlapped at low dose of UV-B radiationcombined with CO2 enrichment. 4. Low dose of UV-B radiation combined with CO2 enrichment promoteded the contentof TSS, sugar ,especially in Vc and lycopene of tomato fruits, enhanced the early yield oftomato.The best treatment that we sift was B3C. 5. CO2 enrichment in winter plastic greenhouse improved the tomato growth, fruitquality and yield. The yield improving of combined treatment mainly contributed to CO2enrichment. 6. In winter plastic greenhouse tomato planting applied low dose of UV-B radiationsupplement (≤1.163kJ.m-2.d-1)combined with CO2 enrichment could improve the fruitquality and increase the yield .The key point was the selection of UV-B radiation supplementdose.