Dissertation
Dissertation > Agricultural Sciences > Forestry > Silviculture, tree breeding and afforestation techniques > Nursery school (nursery )

Tolerance Test during the Seeds Germination and Nutritive Bowl Seedling Cultivation Technology Research on Two Common Tree Species in Xinjiang

Author JiangCui
Tutor LiHong
School Xinjiang Agricultural University
Course Ornamental Plants and Horticulture
Keywords Xanthoceras sorbifolia Bunge Ulmus pumila L. Seed germination Substrates Nutritive bowl seedlings Growing seedlings cost
CLC S723
Type Master's thesis
Year 2011
Downloads 23
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Taking Xanthoceras sorbifolia Bunge and Ulmus pumila L. seeds as material, the germination test of the direct seeding afforestation and nutritive bowl seedlings cultivation technology were studied. By monitoring the germination of the two species’seeds under the conditions of different water and salt, the drought and salt resistance level of germination will be revealed. It can provide the theory basis for finding the soil water and salt qualification fitting X. sorbifolia and U. pumila direct seeding. The ground substance compounding and the nutritive bowl seedlings combination have influence on the nutritive bowl seedlings growth. In order to grope the growth characteristic of the two species’ nutritive bowl seedlings, the two factors were analyzed. Considering the cost of raising seedling, by aggregate analyzing and evaluating, the optimum set of nutritive bowl seedlings used to afforeste will be picked out. The main results are as follows:(1) The average rate of the contribution of the soil total salt content to X. sorbifolia seed germination was slightly lower than that of the soil moisture content. The condition was opposite in U. pumila. But the influence of the salinity and the moisture content on the two seed germination was correspondent, and the difference of their contribution rates was not very remarkable. Statistics analysis indicated that the two factor interactions are remarkable. The seed germination was restricted by salinity and water stress synergicly.(2) To develop the direct seeding of X. sorbifolia and U. pumila is feasible in arid non-salinified area of Xinjiang. The seed’s germination percentage and the germination index of the two species’seeds assumed the extremely remarkable relevance with the soil salt content and water content. The adaptation scope of U. pumila seeds was smaller than the X. sorbifolia’s. When the soil moisture content<15% or salt content> 0.4% of X. sorbifolia, and the soil moisture content<17% or salt content>0.3% of U. pumila, the seed germination cannot be completed finely, and the germination percentage is low. But between the above-mentioned range, the seed germination percentage may reach above 50%.(3) In the different process conditions, the X. sorbifolia appearanced the upper limit phenomenon at the time of 60 days (B1=8×8cm),70 days (B2=10×10cm) and 80 days (B3=12×13cm) respectively. However, the U. pumila had not placed an upper limit until the last stage of the experiments. So the ground substance and the nutritive bowl seedlings are not the main factors deciding the upper limit phenomenon. Taking 20cm the standard height for U. pumila leaving the garden to afforeste, the time meeting the afforestation requirements were 95 days (B1)and 85days(B2) after seedling emergence. The B1 process had not met the garden height requirements. The two seedlings had formed the good root system and the close root group in the above situation. They can be used to foreste. The nutritive bowl seedlings afforestations were feasible for the two species. But their nutritive bowl seedling’s growth characteristic was different.(4) The base materials which are suitable for the growth of young seedlings of X. sorbifolia and U. pumila are different. X. sorbifolia grows well in the environment such as good air permeability and well-drained soil, low alkalinity, EC<2.28ms/cm, and the pH is close to neutral. High soil moisture can lead to seed and root rotten which will eventually cause the plants to die; compared with X. sorbifolia, U. pumila is more saline-alkali tolerant and prefers humid and rich light loam environment. (5) Considering the overall biological benefit(including growth quantity, physiological index, biomass and growth characteristic, afforestation demand)and economic efficiency(growing seedlings cost, transportation cost, afforestation result) of the nursery stocks, the result showed that A1B and A2B2 are the best combination of nutritive bowl seedlings which are used for afforestation under the entire light cultivating condition for X. sorbifolia and U. pumila respectively.

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