Abstract:In this paper, suitable sowing date for several main forage grass species imported is determined by "5-day-sliding-average" approach, using historical daily mean temperature data in Guangdong Province.

Abstract:1. At high temperature, (34f33 after mounting) the male accessory glands showed adnormal shapes, shorter length and lighter dry weight. 2. High temperature caused changes in the histological structure, such as damaged nuclear system, nonhomogenous nucleoplasm, broken rough endoplasmic reticulum, damaged mitochondria. 3. The DNA and RNA contents decreased. 4. The compositions of protein and amlno acid in the secretion were changed and (heir contents decreased. 5. The activity of motile sperms varied with the duratJon of the high temperature treatment, the longer the time, the weaker the activity and hegher the percentage of unfertilized eggs.

Abstract:The study of six crops in three successive years showed that under the same conditions of soil productivity, fertilizer supply and water irrigation, the no-tillage method increased the yield of grain and reduced the production cost by 1. 4%-6. 5% and 23%-44% respectively as compared with the conventional tillage method. The reason for the higher yield lies in that the no-tillage method gave rise to better economic characters of rice than the conventional method. Yet, this advantage is associated with the improvement of the basic physical characters of the soil by the no-tillage method and the consequent improvement of the growth capacity and physiological activities of the root system and the above-ground part.

Abstract:In order to find out the relationship between root system of rice and its yield, a field plot research of different levels of fertilizer applications was conducted.Result showd that there was significant different existed between treatments, but there was no significant different existed between replications. Multiple rank test showed that the yield of plot with N, P, K was the highest and the yield of plot without fertilizer was the lowest.Research showed that plot yield was directly affected by the development of rice root system, besides fertilizer, the number of short root, long rooth had the greatest influence on yield and the amount of bleeding had the least influence through regression analysis.Reseacrch also showed that one of the key measure to get hight yield of rice is to promote root system development though fertilizer application control.

Abstract:鸡骨草主要分布于年最冷月平均温度大于10℃的部分南亚热带和热带地区,呈星散分布。主成分分析表明,温度为影响鸡骨草分布的主导气候因子.分布区内主要植物群落类型为马尾松—桃金娘—芒萁群落.主要土壤类型为赤红壤.鸡骨草茎、叶的生长动态为双峰型。影响其生长的主要外界因子是显度和光照。最后,对如何发展生长提出了一些建议。

Abstract:This paper reports the morphological character and classifcation of main achenes of composite family weeds from Guangzhou, and a new variety is described.

Abstract:Sphoerophoria flavianusana is described as a new species from Guangxi Autonomous Region in this present paper. Type specimens are deposited in Insect Collection of South China Agricultural University.

Abstract:Three basic communities resistant to scab(Gibberella Zeae(schw) Petch) were separately established with eight varieties (Lines) in recurrent selection program. It was found that the mean mumber of diseased spikelets and the resistance of community were improved obviously after a recurrent selection circle. Nine wheat lines resistcnce to scab were selected through several recurrent selection circles and their resistance to scab was ranged from mid-resistance to resistance by natural and artificial inoculating identification in Plant Protection Institutes of Jiang Su,. Zhe Jiang, Jian Yang region of Fu Jian etc. , while agronomic characters were also improved simultaneously in. there resistant lines.The resistance stability of parent, techniques of inoculation and selection are also discussed here.

Abstract:This paper deals with the resistance of rice varietal grains to the rice weevil. Of the 42 rice varieties tested, 15 exhibited resistant and 16 moderately resistant. A significantly positive correlation was found between the percentage of gaping glumes and susceptibility index. No correlation between resistance and protein, starch, amyiopectin, amylose content, or gelatinization temperature was demonstrated.

Abstract:The experiment was carried out in the pine plantation of Pinus massonis and Pinus .elliottii in which the Massonis Pine Caterpillar (Dendrolintus punctotus Walker) has four generations per year. By simulating the damage caused by the Massonis Pine Caterpillar by articial defoliation of the pine tree and using the design of stochastic group, we got the following; 1) There is no great difference in the amount of needles eaten by each larva in four generations. 2) The model was constructed to estimate the amount of pine needles and percentage of wood volume losses by using the easy measurement. 3) Economic threshold of controlling the Massonis Pine Caterpillar were constructed.

Abstract:松材线虫病在广东深圳发生严重。25℃,松材线虫从产卵到二龄幼虫孵化的胚胎发育为30h,在盘多毛孢菌上培养,从二龄幼虫发育到二龄幼虫需要5天,幼虫通过4次脱皮发育到成虫,第1次在卵内.详细描述了胚胎发育和胚后发育各阶段的过程和形态变化.松材线虫各龄期的区分以热杀时虫体形态、体长作为依据,二龄幼虫、三龄幼虫、雄史分别为“L”、“I”、“J”形,四龄幼虫和雌虫为开阔“C”形,但雌虫生殖器官发育成熟。二龄、三龄、四龄、雄虫的体长分界值依次为359.4μm,444.9μm、574.5μm.观察生殖腺位置、结构和发育程度也是重要依据。

Abstract:The structural characters and dynamic analysis of the virgin hardwood and softwood mixed forest for Pinus kwangtungensis and Tsuga longibracteata growing in subtropical mountain in Ruyang area were discussed. The suggestion of protection and development was presented according to the view by examing the forest succession in this paper.

Abstract:Potassium treatment did not obviously increase chlorophyll content per unit leaf area, but increased the net photosynthetic rate, decreased the rate of respiration, the ratio of photorespiratory rate/net photosynthetic rate, light compensation point and CO2 compensation point. The results also showed that the stimulating photosynthetic function of potassium was affected by the applicate levels of nitrogen and phosphorus.Potassium treatment significantly increased potassium content and carbohydrate accumulation in leaves and decreased relative abscission rate of fruits. The contents of both potassium and starch in leaves rapidly declined after full bloom. It was suggested that the first wave of fruit-drop be closely related with lack of potassium of trees after full bloom and a decline of potassium concentration of fruits, while carbohydrate deficency be a main factor in the second wave.

Abstract:催熟温度越高,激发果实产生的乙烯和CO_2量越多,呼吸跃变期越早出现,果皮颜色变化越快。但温度在26℃以上,果皮转黄受到抑制。果实在30℃催熟约3天,果肉已成熟,但果皮仍基本是绿色,仅带微黄,颜色指数在3以下。建议香蕉催熟周期为5～7天,催熟温度17～21℃,乙烯利浓度500～1000ppm。提高温度或增加乙烯利浓度虽可加快成熟速度,但导致果肉迅速变软和货架寿命缩短。乙烯的大量释出比呼吸跃变期早出现。呼吸跃变期随乙烯利浓度增加而提早出现。不同的果实饱满度和采收季节对催熟处理的敏感性有差异。

Abstract:TIM study was conducted with Annana alomoya CV. African Pride during the years of 1988-1991. Shoots of 30 cm long were decapitaed and/or defoliated at the forth and soventh nodes from the base of shoot, were cut back and /or defoliated at the middle of shoot. The results showed that nelther decapitation, defoliation nor cut-back in-dcced axingry bod grouting, only decapitation and cut-back combined with defoliation induced axillary bud sprouting and Its hower setting enectively. Early treatment was better than the late. 91. 8% of nodes defoliated had new shoot and 91. 9% of them had flower-set.

Abstract:Researches on how to increase the recovery rate and exploring new uses of edible maize protein are described. The results showed that lowering the acidity of the maize fluid to pH8, rate of soluble protein could be increased to about 36%. which was twice as much as that obtained by traditional method of production. A treatment of adjusting the acidity of the protein solution to pH3. 5 or adding 0. 4 g/kg gluconolactone to the solution to coagulate protein, high recovery rate of protein, about 37% and 35% respectively, could be acquired. High recovery rates of 42% and 67% of starch sugar and protein respectively were achieved by treating the maize fluid with starch enzyme. Relatively high quality of the beverage and bread produced from the obtained edible maize protein was confirmed with the Fuzzy mathmatics.

Abstract:本研究是采用分光光度法测定土壤硫的一种新方法.紫红色溶液光谱特性在540nm时有最大吸收值.适宜酸度为0.18mol L~(-1)(1/2H_2SO_4),在2h内溶液吸收值基本不变,测定线性范围0～2.0μg SO_4—S/ml,方法的最低检测浓度为0.17μg SO_4—S/ml,精密度好,主要干扰离子为磷酸根,可以加入CaCl_2消除.实际测定样品SO_4—S含量与参比法结果无显著差异.

Abstract:The studies have been did in the Shi Quan, Rice Center. Japan. The technical index such as material quality, energy consumption and drying efficiency erf drying facilities, have been analyzed. The results will be helpful for the development of new mixed drying technologies.

Abstract:The using grid without support film for section collection has the advantage of unfoldedness. decrease of the links in the pollution chain and inctease of resolving power. Meanwhile, the larger section can enlarge the extent of the analysis by electron microscope and provide the research workers with more analytical information.