Effects Of Si, Ca On The Growth And Development And Quality Of Watermelon

Take the’Zao jia(8424)’watermelon as raw materials, the effects of different Ca2+and Si concentrations on the growth and development, yields and qualities, crack and accumulation and absorption of other mineral elements were studied in order to provide the theory basis for applying calcium and silicon fertilizer reasonablely in the watermelon production. The main conclusions are following:1. The influence on the growth of seedling stage (from2-3leaves to6-7leaves)The results showed that in0-220mg/L of Ca2+, the growth of watermelon seedlings was slow in Omg/L-50mg/L of Ca2+, but POD and SOD activity was significantly higher than that in other treatments. The growth rate and plant height was the best at220mg/L of Ca2+. In the treatment of190mg/L of Ca2+, growth and photosynthesis index were significantly higher than that in other treatments, In0-84mg/L of Si, transpiration reduced and chlorophyll content (SPAD) improved with the increase of silicon concentration. In the treatment of56mg/L of Si, growth and other photosynthesis index of plant were significantly higher than that in other treatments. POD and SOD activity increased with the increase of silicon concentration, and reached peak at84mg/L of Si.2. Effects on vegetative growth of plant (from7-8leaves to bloom):The results showed that within70-250mg/L of Ca2+, the growth rate, plant height and root dry weight were the best at220mg/L of Ca2+, then the growth rate declined over220mg/L of Ca2+. In the treatment of190mg/L of Ca2+, growth and photosynthesis index were higher than that in other treatments, within0-84mg/L of Si, transpiration reduced with the increase of silicon concentration. In the treatment of56mg/L of Si, growth and other photosynthesis index of plant were significantly higher than that in other treatments.3. Effects on the growth and qulity of watermelon fruit:It could result in crack if Ca2+concentration was less than160mg/L or higher than220mg/L in nutrient solution. Adding silicon into nutrient solution could prevent crack. In the treatment of190mg/L of Ca2+and56mg/L of Si, the fruit node was lower and days from pollination to mature were longer that in other treatments. The fruit weight, content of soluble solid state material, Vitamin C and soluble protein were significantly higher than that in other treatments. The quality of watermelon fruit was the best in the two treatments.4. The effect on absorption and accumulation of nutrient elements in different organs of watermelon:Effects of Ca2+concentration in nutrient solution on the absorption and accumulation of Ca, Mg, Fe, Mn elements in plants and skin of watermelon changed greatly. Conten of Ca and Mn elements in four organs fell after increased first along with the raise of Ca2+concentration in nutrient solution, but conten of Mg and Fe elements changed inconsistently.Silicon in nutrient solution can restrain the absorption and accumulation of Ca, Mg, Fe, Mn elements in plants and skin of watermelon.