Study On The Cultivation Technology Of Seedlings Of Alnus Formosana

This paper based on the field test about one year through a series of studies including germination tests under different treatments, and the test of influences of different cultivating technology on seed's germination rate and seedlings' quality. The study on the bio-ecological characteristic of Alnus formosana semination seedlings were conducted from thee aspects, the individual growth process, accumulated biomass and adaptability of Alnus formosana seedlings, finally, summing up the optimum cultivating technology. The results showed:1. Germination test of Alnus formosana seeds.(1) The viability of Alnus formosana seeds stored at 3°Cr for one year reduced from 27.35% to 22.67%. At room temperature, could maintain their viability at 21.37% for the first thee months, but decudecd dramatically till the sixth months.(2) There were significant differences among the five culture medium composed of various materials(vermiculite, genuine pearl rock, thin sands,soft sands and turf). The germination rate of Treatment E(50%gravel+50%peat moss) and treatment A(50%gravel+50% vermiculite) are highest, respectively is 35.0% and 30%, maintaining the productive potential.(3) Effect of temperature treatments on Taiwan alder seeds germination. Compared with the treatment of room temperature, stratification(1℃for 30 days, then disposed at room temperature) and daily alternation of temperature(0℃8h, 25℃16h for a week) can increase the germination about 60%～70%.2. Seedling test of different cultivating technology.(1) Significant influence of the seeds date on the germination.At beginning of Feb. and Mar, the minimal temperature of germination is under 10℃; the minimal temperature of the high germination period is 16℃. Mid-March is the optimum seedtime; the germination ratio could be 52.8%～57.0%.(2) Depth of soil influenced the seeds' germination rate and seedlings' quality significantly.The ideal thickness of earth is 0 to 0.5 centimeter, the seedlings growed quickly, and germination ratio is high, which followed by depth of 0.5～1.0cm and 1.0～1.5cm.(3) Cover depth influenced the germination ratio significantly, A and D treatment were the best modes.Germination time were 5～10d, 30～36d at other time. Meanwhile,The rate of germination was 90%～96%, 30% higher than other treatments.E as the control was at the longest germination time with germination rate at 15 % cultivation failed.(4) Planting quantity have influence directly on stock production and quality.①There are thee treatments of planting quantity, treatment A(30kg.hm^-2), treatment B(50kg.hm^-2), and treatment C(70kg.hm^-2), height growth of young seedlings deduced by seeds number,. ANOVA showed significant differences represented between A treatment and B treatment and A and C.②The growth of diameter deduced with the increment of planting quantity. The multiple comparison result indicated that, significant differences represented between A treatment and B but differences between B and C are not remarkable.③The turn of T/R was followed as A(1.44), B(1.15), C(1.01), and T/R reduced with the increment of seedling quantity. The optimum quantity was 30kg.hm^-2.(5) The Taiwan alder cultivating was divided into two parts. The density of transplanting seedlings was the key factor influencing the seedling quality.①The densities have the positive relationships with the height, the diameter, the average length of lateral branch, the length of main root, biomass and so on.②With the premise of the height of 80cm and diameter at 0.8cm fittest density of one square is 70, the seedling production/ha was 455,000(the percentage of land-use was 65%).3. Study seedling classificationEstablishing the classification standard by seedlings' height and diameter as the following: The grading standard for the seedlings of gradeⅠ,ⅡandⅢwere height≥104.20 cm, basal diameter≥0.97 cm; 104.20 cm>height≥64.40 cm, 0.97 cm>basal diameter≥0.58 cm; height<64.40 cm, basal diameter<0.58 cm respectively.4 Study on the bio-ecological characteristic of nursery stock.(1) Study on the growth process of nursery stock.There were two stages of original bed, one is emergence stage(25th-March—16th-April), and young growth stage(16th-April—27th-May);Taking the height net growth increment of A. formosana seedlings as samples, the height growth process is divided into 3 stages in order by the sequential sample cluster analysis: postpone stage(27th-May—29th-July), rapid growth stage(1st-June—15th-Ste.), and later stage(15th-Ste.—29th-Oct.).(2) The accumulated biomass of Taiwan alder.Material production of mean stock have two periods of accumulated rapidly, one is from ninety five days to one hundred fifty days, the other is the growth later stage.(3) The research result of six months old nursery stock under the artificial climate.High growth of the nursery stock is in turn:25℃/20℃(the daytime/night)>30℃/25℃>20℃/15℃; the seedling diameter is in turn: 25℃/20℃>20℃/15℃＞30℃/25℃, but there were not remarkable difference; Accumulated biomass of the root, the stem and the leaf is in turn: 25℃/20℃>30℃/25℃＞20℃/15℃, the rate of T/R is in turn 25℃/20℃>30℃/25℃>20℃/15℃, there were remarkable difference of them. This shows, the optimum growth temperature of the nursery stock is 25℃/20℃.