Abstract:In this article the pork market (including live pigs and frozen pork)in Hong Kong is analysed thoroughly from three aspects,viz. 1. the demand and supply of pork in Hong Kong;2. the source of live pigs and frozen pork imported 13. prices of pork. Preliminary study showed that the demand for pork was continuously rising ,and the local production of live pigs could only supply less than twenty percent. Live pigs and frozen pork from inland China shared the major portion of the Hong Kong market. The prices of live pigs and frozen pork did not change much in recent years. However,both the prices of live pigs and frozen pork from inland China were comparatively low.The problems of exportation of live pigs and frozen pork from inland China were analysed. In conclusion,suggestions were made to improve the export of these agricultural products.

Abstract:At several stages before and after infection by rust fungus ( Puccoda arachidcs ) .analysis was made of the activities of several enzymes, including phenylalanine ammonia lyase ( PAL). peroxida.se (PO) and polyphenodoxidase ( PPO), in five cultivars of peanut ( Arachis hypogaea Linn. ) with different levels of resistance, and their relationships to resistance. PAL was an induced enzyme, whose activity could only be observed after infection ,and was found to be positively related to resistance. The level of PO activity in infected plants was higher than that in healthy ones in most cultivars at 12,24,and 48 horus after infection, the more susceptible the cultivar.ihe more its change in infected plants. PPO activity in healthy plants was significantly related to resistance of the cultivars,but no relationship was found bwtween its activity and resistance in infected tissues.

Abstract:Colibacillosis in chicken currently occurs widely in our country, threatening the healthy development of the poultry industry. According to many years personal clinical experiences, research achievements and information from world literature, the author discusses Colibacillosis in chicken in detail, including its etiology, epidemiology, clinical forms, diagnosis, treatment and prevention.

Abstract:用网袋法研究了早稻稻杆,晚稻稻杆,红萍(Azolla imbricata (Roxb)Nakai)及紫云英(Astragalus sinicus L.)在水田耕作层的分解动态,结果表明干物重、含氮量、含磷量和含钾量的残存百分率(y)均可用y=a·t描述,其中t为分解时间,a、b为回归系数,有机物中氮的释放速度慢于磷钾的释放速度,分解残留物的氮含量趋向1％。有机物氮含量(％)与干物重消失50％所需时间之间的相关系数R=-0.997 5。

Abstract:Attempt was made to treat certain confused issues of plant physiology with the system approach. As a result, we introduced certain new concepts concerning the bioenergetic system in heterotrophic cells, carbon assimilation system in autotrophic cells and effect-signal system in target cells.

Abstract:Five systems of Ulmaceae are analysed and compared from the aspects of morphology, anatomy, botanical chemistry and pollen morphology in this paper. The shortcomings of these systems are pointed out. Dividing Ulmaceae into 3 subfamilies is considered reasonable.

Abstract:The citrus bud gall midge(Dasixeura ctiriyanmina)is a new citrus pest found in South China. Four to five generations each year in Guangdong Province were observed. The larvae led on young buds, which became galls after injury. The larval stage was about 4 - 25 days,but the diapause larvae lived 210-250 days. The pupal period varied from 6 to 28 days. The life - span of the adults was 2 - 7 days. The adults were phototropic and active at daytime. About 20 - 60 eggs were laid in a mass by each female on the young buds. The egg stage lasted 1 - 6 days. There were three larval instars; the larvae lived inside the galls all the time; the matured larvae dropped down into the soil to pupate. In late spring when the matured larvae fell to the soil ,they entered diapause within thin elliptical cocoons, remained there until late November, and then resumed their activity gradually moving to the surface of the soil to pupate. The pupal stage lasted 10 - 20 days and the adults appeared in early December. At the emergence ol 1st generation adults, spraying contact insectcides on the surface of soil and trees could kill the pest with satisfactory result.

Abstract:The genetic differences between sugarcane parents were estimated by ten genetic divergence criteria, and principal component analysis was performed on these ten divergence indices of 28 combinations. The first three eigenvalues and corresponding eigenvectors of the principal components which accounted for more than 88 % of the total variation of all the indices were selected. The first three principal component values of each cross were caculated, and the relationship between the first three principal components of the crosses and major economic characters of the hybrids were investigated. The research methods described were discussed.