บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Effects of pre- and post-harvest foliar spray of urea on the leaf composition and cold resistance in satsuma mandarin (Citrus unshiu Marc.).

Kim YoungYong; Ko KwangChool;

Journal of the Korean Society for Horticultural Science Year: 1996 Vol: 37 Issue: 1 Pages: 70-76 Ref: 28 ref.

1996

บทคัดย่อ

Effects of pre- and post-harvest foliar spray of urea on the leaf composition and cold resistance in satsuma mandarin (Citrus unshiu Marc.).

The effects of foliar-applied urea (0.5-3%) and harvest time (early or late) on cold tolerance and the N, P and K contents of leaves of satsumas (cultivars Miyagawa Wase and Hayashi Unshiu) were investigated in trees with heavy or light crop loads. Trees were sprayed 1, 2 or 3 times pre- and/or post-harvest. Higher concentrations and frequencies of urea application increased N content, decreased P content and tended to increase K content of leaves. Higher chlorophyll and N contents in leaves were observed following early harvesting; the lower contents observed in trees harvested late were increased by urea treatment. High leaf proline contents and good cold resistance were observed following urea sprays 1 week before harvest + 1 week after harvest or 3 postharvest sprays at intervals of 1 week. Early harvesting promoted leaf proline content and cold resistance and decreased defoliation ratio. Similar results were observed for soil-applied urea, but its effects were not as great as those for foli

ar-applied urea.