表7-3在生长季节喷钙对Cox苹果储存过程中钙含 量和损耗百分数的影响( Sharples and Johnson, 1977) 损耗(%) 未喷 钙含量(mg/100g鲜重) 3.35 3.90 储存失调现象 坏死斑点凹陷 104 衰老破坏 10 内部苦豆病 30.0 3.4 Gloesporiun腐烂 9.2 1.7
表7-3 在生长季节喷钙对Cox苹果储存过程中钙含 量和损耗百分数的影响（Shavples and Jsohnson， 1977） 损耗（%） 未喷 喷 钙含量（mg/100g鲜重） 3.35 3.90 储存失调现象 坏死斑点凹陷 10.4 0 衰老破坏 10.9 0 内部苦豆病 30.0 3.4 Gloesporium腐烂 9.2 1.7
Contributors to Ca deficiency Overfertilization, esp. N K+& Mg compete for uptake B deficiency reduces Ca uptake Excessive pruning Large fruit(genetics or undercropping Drought
Pollination Ca Seeds/fruit Fruit dia Fruit Ca (mm) (ppm) 67 174 2-3 70 208 71 215 5 223
Calcium K, Mg, or NHa may compete for uptake Ca moves very slowl May take 2-4 years to move from soil to shoot tip or fruit Veg Rep organs compete for Ca Moves in transpiration stream Leaves use more water than fruit
Diagnosing Ca deficiency What is the history of the block? Are ca related disorders common Weather? Wet, dry, hot, cool, humid Irrigation Tissue testing not reliable. No correlation between leaf and fruit ca levels