With the continuous development of facilities and horticulture, the area of vegetable planting in facilities increased year by year. Watermelon (Citrullus vulgaris Schrad) as the main cultivars within the facility, the continuous cropping problem is very serious, resulting in continuous cropping obstacles become increasingly obvious, the incidence of fusarium wilt increased year by year. Grafted watermelon roots developed to improve the growth of grafted roots of the conditions, resulting in robust plant growth. At the same time, the use of different purposes of the rootstock can make watermelon in different soil conditions under normal growth, such as the use of low temperature, drought, salt tolerance, barren and other characteristics of the rootstock. Secondly, the rootstock of the strong absorption of water absorption capacity, to promote the growth of grafted watermelon plants strong, large watermelon fruit, high yields. In addition, grafted watermelon seedlings grow fast early, for early maturing cultivation and overcome the seedless watermelon early growth slow defects is extremely favorable. So the use of pumpkin as a watermelon grafting rootstock, can effectively improve the effect of watermelon resistance to Fusarium wilts. And provide the theoretical basis and scientific basis for the further study of photosynthetic characteristics, disease resistance breeding and effective control of watermelon. In this experiment, the watermelon varieties with different resistance to fusarium wilt were selected, and the anti-fusarium wilt watermelon was studied systematically. There are changes in physiological characteristics during growth and development. In conclusion, grafting promotes the growth of watermelon and physiological characteristics of the index rose.

KEYWORDS: watermelon; fusarium wilt; growth period; physiological characteristics

The project of returning farmland to forest is a new project of increasing farmers' income, ecological efficiency and

benefiting the country. The key to the success of returning farmland to forest project is to strictly control the key technologies such as regional planning, forest species selection, tree species selection, good seedling, structural configuration, meticulous soil preparation, serious planting, tending and management. According to the actual

situation of Yuanling County, suitable for the tree, choose the market prospects, fast-growing tree species afforestation,

reasonable adjustment of forest structure, ecological benefits and economic benefits simultaneously, take high-

quality high-yield and efficient forestry development. Returning farmland to forest project has played huge ecological benefits, economic and social benefits.

The nylon 66/nano-CaCO3 composites were prepared by melt blending on a twin-screw extruder. Scanning electron microscopy (SEM), polarized light microscopy (PLM), thermal loss (TGA) and differential scanning calorimetry (DSC) The effects of nanometer calcium carbonate on the polycrystalline behavior and thermal properties of nylon 66/nano CaCO3 composites were investigated. The results show that the nanometer calcium carbonate particles are dispersed in the nylon 66 matrix and exist in the form of aggregates. The nanometer calcium carbonate has the effect of heterogeneous nucleation, which can reduce the size of the spherules. The decomposition temperature of the nylon 66 is 400 ℃, the addition of nano-CaCO3 to reduce the decomposition temperature. At the same time, DSC test showed that the β-crystalline form in the material reduced the melting temperature of the material. The addition of nano-CaCO3 in the nylon 66 matrix resulted in the decrease of the crystallization temperature and the increase of the half-height width of the endothermic peak. The lower the crystallization temperature, the wider the crystallization temperature range.

Investment growth in many emerging market and developing economies (EMDEs) has slowed sharply since 2010. Investment growth performance has varied significantly across different regions, however. This paper examines the evolution of investment growth in six EMDE regions, documents remaining investment needs, especially for infrastructure, and presents a set of region-specific policy responses to address these needs. It reports three main findings. First, investment growth has been particularly weak in EMDE regions hosting a large number of commodity exporters. In regions with a substantial number of commodity-importing economies, investment growth has been somewhat resilient but has also declined steadily since 2010. Second, sizable investment needs remain in most EMDE regions to make room for expanding economic activity and rapid urbanization. A large portion of these investment needs is in infrastructure and human capital. Finally, while specific policy priorities vary across regions, several policy options to address remaining investment needs apply universally. These include more, and more efficient, public investment and measures to improve overall growth prospects and the business climate. Improved project selection and monitoring, as well as better governance, may enhance the efficiency and benefits from public investment.

This work investigates epoxy composites reinforced by randomly oriented, short glass fibres and silica microparticles. A full-factorial experiment evaluates the effects of glass fibre mass fraction (15 wt% and 20 wt%) and length (5 mm and 10 mm), and the mass fraction of silica microparticles (5 wt% and 10 wt%) on the apparent density and porosity, as well as the compressive and tensile strength and modulus of the hybrid composites. Hybrid epoxy composites present significantly higher tensile strength (9%) and modulus (57%), as well as compressive strength (up to 15%) relative to pure epoxy.