| In recent years, the planting area of chestnut is expanded in the mountain area and in the foothills in South of Henan Province. However, there is a conflict in the course of chestnut growing between nutrition and reproduce. To make the seedling produce fruit early and more, the author adopts compound chemical regulator by applying plant growing elements, including paclorbutrazol (code PP333), uniconazole (code S3307), brassinolide (BR), etc. As for the experiments, the species called Castanea mollissima Blume I little red oil chestnut is taken as a sample. The experimental garden is ten-year born chestnut plantation with a sunny slope and the color of the soil is yellow and brown.The organism in soil is 9.62g/kg-10.59g/kg, pH5.9-6.3, plant in the location of equal height from east to west; spacing in the rows is 3m×4m. The methods used the plant growing elements are as follows: PP333 is applied in the ditch in ring rows in the growing season in November of the previous year; S3307 is applied at the germinative growing leaves stage; BR, at the early blooming stage, is sprayed on the surface of trunk and leewes, 1000ml/tree. In 2002, three experiments were carried out separately in different small areas of different density of plant growing elements for contrast. And according to these experiments, suitable density for the single factor experiment was selected. In 2003, experiments of suitable density and suitable density of different groups consisted of PP333+BR and S3307+BR were performed for contrasts. With these basis, the one that made the production increase mostly was selected to deal with the compound chemical regulative experiment in small areas carried out in 2004. The results show (that): the 3-year experiments performed during 2002-2004 iunstrate that PP333 and S3307 of single factor experiment can obviously restrain the growing of new tips of branches and control the growing height of the crowns. Apply PP333 1g/tree before winter coming, the rate of growth is 10.43%-11.06%; Spray S3307 100mg/L during the germinative and leaf-spreading period, the rate is up to 14.03%-15.28%, Spray only BR 0.01mg/L during the early blooming stage, the increasing rate is 10.27%. But when we use PP333+BR and S3307+BR together, the increasing rate rises to 16.49%-18.88%. And if the plant growing elements are stopped using the next year, trees will grow with nutrition like past time when there were no plant growing elements applied to them, and in this way, the production will be at about the same level with that of contrast. If the plant growing elements are applied continuously, the increasing effect will be alike the last year. compound chemical regulator can very obviously increase, chlorophyll in leaves, dissoluble sugar and starch content, and water potential in leaves' tissue decreases sharply, therefor enhance the photosynthesis of trees. It is very favorable for water absorption and subustance accumulation. Compound chemical regulator can shorten trees. The best shortening effect is only to apply PP333 and S3307. Compared with the contrast, the height of trees reduced by 1.28% and 0.66% respectively. The best effect of thickening trunk is to use PP333 + BR and S3307 + BR, Compared with the contrast, the thickness of trunk increases by 0.22% and 0.21%: In addition, all the treatments of compound chemical regulator can make chestnut trees grow short, thick, and leaves grow smaller, increase the thickness of leaves, the net weight of leaves, the weight of trunk; And all the treatments of compound chemical regulator can increase the bearing rate of chestnut, weight of fruit, the number of average seeds as wea as seeds rate. There is a sharper improvment than that of the contrast. The best effect of increasing production is to apply PP333 + BR and S3307 + BR, with the increasing rate as high as 16.73% and 18.88% respectively. In 2005 spray the trets with PP333 1g/tree in the soil before winter coming, spray BR 0.01mg/L at the early blooming stage and spray with S3307 100mg/L when the trees germinate and grow their leaves spray BR 0.01 mg/L when the flowers begin to come out. The are the 2 tenrques. The technology hasn been spreaded through demonstration in many different areas. The former is spreaded as much as 19hm~2, the increasing rate is 14.56% in total.; the later is spreaded 10hm~2 in total, the increasing rate is 16.72%. Harvest chestnut 31106kg in total, train farmer technician 165, and obtain distingtive social economic profits as well. It is an effective measure to increase production compound regulator to 8-12-year born Chestnut seedlings and it is worth spreading and applying.
|
PDF Full Text Request