论文部分内容阅读
唐山市位于河北省的东北部,年平均气温10.6℃,无霜期180～190d,年降雨量600～700mm。1999年由山东省砧化县、河北省沧州市引进冬枣.总株数58.1万株,栽植冬枣园466.7hm~2。栽植株行距为2×3、2×4m;土壤为沙壤土、壤土、粘土、黑土、重盐碱粘土,80%的冬枣园有水源条件。为保证建园质量,市林业局制定了冬枣栽培技术要点,新建冬枣园成活率较高,树体生长健壮,生长正常。有的冬枣园2001年已有产量,但2003年早春发生了严重冻害,幼树死亡率高。乐亭县、唐海县、滦南县、丰南区最高死亡率达54.5%,低的也在22%。死树症状主要表现在树干基部地表以上部位有一圈皮层变成褐色,树干上老皮纵裂,新梢至干部抽条死亡。
Tangshan City is located in the northeast of Hebei Province, the annual average temperature of 10.6 ℃, frost-free period 180 ~ 190d, the annual rainfall of 600 ~ 700mm. The jujube was introduced from Anhua County in Shandong Province and Cangzhou City in Hebei Province in 1999. The total number of plants was 581,000 and the planting area was 466.7hm ~ 2. Planting row spacing of 2 × 3, 2 × 4m; soil sandy loam, loam, clay, black soil, heavy saline-alkali clay, 80% of the jujube garden water conditions. In order to ensure the quality of the construction of the park, the Municipal Forestry Administration has formulated the winter jujube cultivation techniques. The new winter jujube orchard has a higher survival rate, and the tree body is robust and grows normally. Some winter jujube garden have been produced in 2001, but severe frost damage occurred in early spring in 2003, and the sapling mortality rate was high. Laoting County, Tanghai County, Luannan County, Fengnan District, the highest mortality rate of 54.5%, the lowest is also 22%. Dead tree symptoms mainly in the trunk above the surface of the ground has a circle around the cortex turns brown, the old skin on the trunk longitudinal crack, shoot from the shoot to cadre death.