The Influence Of Different Factors On The Apple Seedling Branching And Growth Characters

Most of domestic apple seedlings are fast-growing seedlings, single trunk with single branch, small root system, low survival rate, slow growing, late bearing, meanwhile, seedlings carried the virus disease frequently. The main reason which caused low quality apple seedling is the high breeding density, the breeding seedling trunk is very thin and have few branches and few plump buds, small root system, moreover, the whole apple seedling quality is very low. Therefore, this experiment is mainly discussing the influence to apple seedling from suitable breeding density and suitable Promalin concentration, besides, studying planting effects of different seedling age, which will provide reference for improving apple seedling quality . the results as follow:1.The different Promalin concentration had no obvious difference to leaves DW/FW and leaves thickness , while leaves area increased with the increasing concentration(except 0 mg/kg). with Promalin concentration increasing, leaves Chl. content increased first then decreased (except 1 600 mg/kg). High Promalin concentration could inhibit the tree height growth and promote stem diameter growth. Promalin concentration 1 000 mg/kg does not only have effectual branching, but also could increase the Chl. Content, meanwhile improve Photo.2.Different planting density had no obvious difference to the growth of apple seedling tree height, stem diameter and Chl. Content. And Photo and total branches No. increased with the rising of density, while Ci increased with the decreasing of density, when the planting density reach 60×20,those indexes would not change with the the increasing density; different row space influenced the Cond. Obviously, and the DW, FW and DW/FW of 60 cm row pitch were better. The result showed the planting density of row pitch 60 cm and row space more than 15 cm were the suitable density. And the high density of mass breeding, lead to the low Photo, which was difficult to breed the seedling with branches.3.Choosing 2-year-old and 3-year-old apple seedling as the material, separately with blank treatment, heading-back treatment and Promalin treatment. In continuous 3 months' growth period, (1) 2-year-old apple seedlings' total branches No. and effectual branches No. were obviously higher than 3-year-old seedlings, therefore, 2-year-old apple seedlings were forming branches relatively easily. (2) 3-year-old apple seedlings'tree height, leaves thickness, DW, FW were obviously higher than 2-year-old seedlings; while, there were no obvious difference on stem thickness and Chls' content between 3-year-old and 2-year-old seedlings. so in 3-year-old apple seedling, nutrition of tree was rich, quality of leaves were higher. Therefore, 3-year-old apple seedling with some branches should be planted in orchard.