| (一) VA fungus is one of the most important kinds of edaphon in agriculture biogeocenose ,which appears abroad in the soil. By observed the separated spores sieved from 10 different yield of Longan (Breed: Hanhe) soils samples, 10 species of VA fungus were identified according to the morphological character. Among these 10 species, 6 species belong to Glomus which takes up 66.7% of the identified species. Therefore, Glomus is the dominant species; according to the experiment result of He Guangze, we identified orther 4 species of spores: Gmulticaule, G claroideum, Gigaspora gigantean , Acaulospora scrobiculata.According to the result of the soil experiment, the quality of soil is fertility of the longan growing. The growing age of longan tree, the higher rate of soil spores density and infection of VA fungus. It is more difficulty for the produce of spores and the infection of VA fungus with the growing content of organic matter, nitrogen, available phosphorus these soil samples. The high level of containing water and Ph has effect on the infection of VA fungus, but not on the density of spores. The content of the spores and the infection of VA fungus have enormous positive correlation with the field of longan.(二) Longan is the rare special local fruit in the south of China, not like the past any more, the price of longan fall that ordinary people can buy it so easy. However, for the safe of market, control the yield of longan is necessary. In this paper, by comparing the error of two the Mathematical Forecasting Models (Grey Markov Forecasting Model and the Regression Markov Forecasting Model), the error of Grey Markov Forecasting Model is much lower which is more suitable to use for forecasting longan yield. |
