提高杉木种子园种子产量及品质技术措施的研究

对湖南省东安县杉木无性系种子园施肥试验的结果表明：３、６、８月中旬每次每株各施尿素０．４ｋｇ、过磷酸钙０．３ｋｇ、氯化钾０．２ｋｇ为球花产量最高的施肥方案；施肥对当年的种子播种品质有影响，但不大；种子园大片母树不挂果的原因是土壤和树体中锰含量过高而树体中的硼元素缺乏，对此提出对土壤施石灰和对母树针叶喷Ｂ肥的改良措施；３—８月是杉木种子园施Ｎ、Ｐ．Ｋ肥最适宜时期；确定８月是杉木种子园母树营养诊断进行针叶分析的最佳采样时期，并制定出杉木种子园母树的针叶中全Ｎ含量为０．８％、全Ｐ含量为０．１２％、全Ｋ含量为０．７％是其临界值；针叶全Ｎ含量０．８—１．２％、全Ｋ含量０．７－０．９％是其最适浓度范围；中耕松土对种子园种子产量影响不明显。

STUDIES ON INPROVEMENT ON SEED QUANTITY AND QUALITY OF CLONAL SEED ORCHARD OF CHINESE FIR

This paper reports the research results of fertilization of the grated seed orchard of Chinese fir (Cunninghamia lanceolata Hook.) in Dongan, Hunan province. The results revealed that it was the best plan for fertilization to improve the production of conelets that each tree was spreaded 0.2kg ofpotassium chloride, 0.4kg of urea and 0.3kg of superphosphate in every middle 10 days of March, June and August. The seed quality by fertilization was not obviously effected. Analyses of nutrient elements in needles and soil showed the reason why the seed production was so low in the orchard was that Mn content was too high and B content was deficient. It was suggested that lime should be added to the soil and B be spraied on the foliage, and the mostsuitable period for spreading N, P, K fertilizers was from March to August in a year. The desirable period of collecting leaf samples for nurtientdiagnosis was August. It was found that the critical values of different nutrient elements in the needles were N 0.8%, P 0.2%,K 0.7% with the suitable ranges N 0.8-1.2%, K 0.7-0.9%. Ploughing and weeding could not significantly improve seed production of the orchard.