Effect of Transplanting Density on Rice Yield,Nitrogen Uptake and ^(15)N-fertilizer Fate

[Objective] The aim of this study was investigated the rice yield, nitrogen uptake and ^15-fertilizer fate at different transplanting density to provide scientific ba- sis for improving the yield of rice and applying reasonably fertilizer. [Method] A field experiment was carried out to study the effect of different transplanting density on rice yield, nitrogen （N） absorption, sources of N uptake by rice and the N balance in the plant-soil systems by using ^15-labelled urea. [Result] There were no significant differences in rice yields and total N uptakes by rice between treatments 30 cm × 30 cm and 40 cm × 40 cm, but the yield of rice and total N absorption in the two treatments were remarkably higher than those in 50 cm × 50 cm treatment. The amounts of total N uptake by rice were in the range of 112.3-162.7 kg/hm2 in the three transplanting densities. The result showed that about 1/3 of the total N uptake by rice was supplied by application fertilizer and the other 2/3 was obtained from the soil N pool. The ^15N-labelled urea absorbed by rice, residual in soil and lost accounted for 16.3%-26.1%, 17.0%-20.9% and 53.0%-66.7% of the total fertilizer, respectively. A great deal of ^15N-labelled urea was lost during the rice growing season. [Conclusion] Considering the rice yield and environmental protection, the transplanting density of 30 cm×30 cm was recommended in the hilly area of Sichuan basin in the southwest China.

山地城市公园坡地对林地植物景观的影响研究

为探讨坡地对林地植物景观的影响,提出针对山地城市林地植物景观营造的意见,对重庆市主城区五大森林公园进行基础调查,采用层次分析法(APH)对其进行景观评价。结果表明,调查样方内共有维管植物49科80属88种,随坡度的增加,物种数逐渐减少,整体栽培度降低;坡度为0～15°条件下最佳栽培度为76°～100°,坡度为16°～30°条件下最佳栽培度为51°～75°,坡度为31°～45°条件下最佳栽培度为26°～50°。提出针对不同的坡度段选择不同的栽培度,既能保持良好的生态特性,又能提高植物景观的观赏性。并针对不同坡度段给出适宜的植物配置模式和植物种类建议。

Effects of Transplanting Density on Yield Formation Characteristics of Purple Rice

Liangtianzi 1 was used as a material to study the effects of transplanting density on the yield formation characteristics of purple rice. The results showed that the whole growth period of Liangtianzi 1 was 146 d. Its biomass yield was above 10 t/hm^2, while its economic yield was only about 3 t/hm^2. Transplanting density had a large impact on the number of effective panicles, number of grains par panicle, seed setting rate and yield of purple rice variety. In this study, the planting spacing of 20.0 cm × 20.0 cm gained the highest yield, 3.63 t/hm^2. Key techniques for high-yielding cultivation of Liangtianzi 1 remain to further research.

Response of Over-summer Hydroponic Lettuce to Nutrient Solution Temperature Control

Temperature, as an important feature of hydroponic nutrient solution, is closely related to dissolved oxygen content of nutrient solution and growth status of plant roots. How to precisely adjust the temperature of nutrient solution is the key to obtain high quality and high yield of hydroponic vegetables over summer. With Lactuca sativa vat. crispa ＇Luosheng No.3＇ as the test material, the effect of chiller cooling technology on the temperature of nutrient solution, as well as on the yield and quality of Luosheng No.3, in over-summer hydroponic cultivation was studied. The results showed that the chiller cooling technology controlled the nutrient solution temperature in a reasonable range （（20 ± 1）℃） and promoted the growth and dry matter accumulation of Luosheng No.3, instead of affecting the quality. In short, the chiller cooling technology is applicable to the temperature regulation of nutrient solu- tion in hydroponics over summer.

Manifestations in Yield and Agronomic Traits of Sorghum 'Jia141' in Jiamusi Area

The suitable plant density was favorable for sorghum yield increase. In order to clarify the suitable plant density of dwarf-stem, early-maturing sorghum variety ＇Jiza141 ＇, in the open field condition,150 000, 200 000, 250 000, 300 000 and 350 000 plants/hm^2 tests were set to study the effect of different densities on yield and yield traits. The results showed that with the increase of planting density, LAI increased, chlorophyll content decreased, plant length had no significant difference, era length and era diameter tended to decrease, while biomass increased with the increase of density. The 1000-grain weight and single panicle weight had the maximum effects on yield, and both of them showed a significantly positive correlation with the yield. In Jiamusi growing areas, the optimal plant density of sorghum ＇Jiza141＇ was 200 000 plants/hm^2, and the yield could reach 9 183.00 kg/hm^2. The study provides a theo- retical basis and technical support for the ＇Jiza141＇ variety in the Jiamusi ecological region.

Effect of planting density on plant growth and camptothecin content of Camptotheca acuminata seedlings

C. acuminata seedlings cultivated in greenhouse were transplanted into the fields with 5 designed planting densities (11, 16, 25,44 and 100 plants·m^-2) in May of 2004 and were harvested in the middle of September of 2004. The seedling growth indexes including plant height and crown width, biomass allocation, camptothecin (CPT) content and CPT yield of different organs (young leaf, old leaf, stem,and root) were studied. For the 5 selected planting densities, the plant biomass, height, crown width, and total leaf area of C. acuminata seedlings all showed highest values at the planting density of 25 plants ·m^-2. CPT content in young leaves was higher than that in other organs of seedlings and presented an obvious change with the variation of planting densities and with the highest value at density of 100plants·m-2, while for other organs no significant variation in CPT content was found with change of planting density. The accumulation of CPT was enhanced significantly at the planting density of 25 plants·m^-2. It is concluded that for the purpose to get raw materials with more CPT from C. acuminata, the optimal planting density of C. acuminata seedlings should be designed as 25 plants·m^-2.

Influence of ginseng cultivation under larch plantations on plant diversity and soil properties in Liaoning Province,Northeast China

Currently, transforming the mode of forest management and developing multiple forest management practices are actively encouraged in China. As one forest management type, ginseng cultivation under larch plantations has been developed significantly in the east of Liaoning Province. However, research on the influence of the ecological environment for this mode of production is still deficient. Based on this, our study compares the plant diversity and soil properties in the ginseng cultivation under larch plantations(LG) with larch plantations(LP) and natural secondary forests(SF). First, we randomly selected three plots for each of the three stand types which have similar stand characteristics; then, we carried out a plant diversity survey and soil sampling in each of the nine plots. The results show that no significant difference was found in plant diversity between LG and LP, but theevenness of herbs was significantly lower in LG than LP. No obvious changes in soil physical properties were found in LG, but a significant decrease in most of the soil nutrient content was presented in LG. Furthermore, we found a correlation between plant diversity(H') and soil properties in the three kinds of stand types, especially between herbaceous plant diversity and soil properties. We conclude that ginseng cultivation under larch plantations has no obvious effect on plant diversity, except the herbaceous evenness. Soil fertility can be depleted significantly in LG, but physical structures are not affected. Moreover, maintaining the diversity of herbaceous plants and controlling the density of ginseng cultivation in LG by farmers are important for the ecological environment. Based on this study and its good comprehensive benefits and with the support of policy, we think this forest management type should be promoted moderately in the region.

Effect of Potash Application Patterns on Crop Yields Under Different Cultivation Systems

Three patterns of potash application were used in the corn-wheat and rice-wheat rotation experiments,which were conducted in the upland and wetland of Siyang County, northern Jiangsu Province, and the wetland of Liyang City, southern Jiangsu Province. The results of 5 cropping seasons (2 seasons/year)showed that the direct response of corn to K was larger than that of wheat, but no difference was found between rice and wheat in Siyang when the total annual amount of K was applied only in one cropping season. However, the response of wheat was much greater than that of rice in Liyang. If potash was applied in the preceding season, the residual effect of K on wheat was larger than that on rice both in Siyang and Liyang, but less than that on corn. The total effect (direct and residual effects) of K applied to corn or rice was greater than that to wheat in Siyang, but that to wheat was greater in Liyang. The direct and total effects of K application in the upland were larger than those in the wetland of Siyang; but for the wetland,the effects were larger in Liyang than in Siyang, especially in the wheat season. The results demonstrated that the most profitable practice to be recommended to the local farmers was to apply a limited amount of potash to only rice or corn but not to wheat. Equally applying half of the total annual amount of K to each of the crops may be advisable in order to lessen possible fertilization risks.

Fruit protected cultivation in China

Protected fruit cultivation in China has developed very quickly from the early 1990s, and now it is an important branch in fruit cultivation. A brief review including fruit species, developing history, growing area, output, and distribution in the whole country is made in the paper. Characteristics of the dominant kinds of greenhouse, environmental control methods, and standards of temperature, humidity, light and CO2 for different fruit species are presented. Information on varieties, growing benefits, special management practices and other aspects of the main fruit species used for protected cultivation are also presented.

Potential for Safflower Cultivation under Temperate Conditions

Safflower is a Mediterranean-subtropical oil crop, with temperate climate. To assess the suitability of safflower may have certain production potential in organic farming in regions cultivation under temperate climate in low input organic farming, ten cultivars were grown in two years experiment in Lindhoft-Kiel in Northern Germany in clay/sand soil. Pearson correlations reveal that oil yield exhibited tight positive correlations with plant height, plant dry matter, capitula plant-1, achenes capitulum-1 and thousand achene mass （TAM）, but was not correlated with days to full flowering or oil concentration. Yield component analysis reveals that achenes capitulum1 had the major influence on the variation of oil yield of all studied cultivars, followed by capitula plant1 and TAM, while the oil concentration had slightly negative influence, and the plant density was negatively associated with oil yield. Although two years field experiment is not enough to analyse the performance of safflower adaptability to certain region, it can be concluded that the most adaptive cultivars are PI-209286 originated from Romania, and cultivar CART-19/89 originated from Poland, while the less adaptive cultivars were DO-13/03 and DO-15/03 with German origin in addition to the Canadian cultivar PI-572475/Saffire. The most striking yield component that contributes to the high yield is achene capitulumt, which can be used as a base for selecting cultivars adaptive to humid cold conditions. The growth period between full flowering and harvest influencing this yield component must be given attention to avoid low temperature and rainfall by tuning sowing date to improve yield at these conditions.

The Biodiversity of Cyprus Island

The aspects considered in this paper refer to remains of food plants found in the archaeological area of Pyrgos （Early Bronze Age, 2000 B.C.） near Limassol in Cyprus, related to the history of agriculture and cultivated plant processing technologies. For the purposes of an initial comparison of the archaeobotanical data, the authors updated a map of rainfall distribution on Cyprus with rainfall and temperature data for the period from 1973 to 2007, to produce an updated view of possible microclimates on the island. Cyprus was one of the Mediterranean islands whose particular orographic features encouraged the phylogenetic evolution of many species, and today it is especially rich in endemic species. Cyprus located at the southeastern boundary among the Mediterranean region, the Pontic region （the Irano-Turanic element） and the Near East （the Syriac and Nubo-Sindic elements） it doesn＇t seem to have effectively influenced the most important endemic species, they were probably preserved by the island＇s microclimates and particular edaphic conditions.

Fruit development rule of two Chinensis Actinidia cultivars ‘Fengyue’and ‘Cuiyu’

The fruit development rules of two Chinensis Actinidia cultivars were studied in this paper. ‘Fengyue’has the same fruit development cycle as‘Cuiyu’. According to soluble solids content, there are four stages during fruit development phase named comparatively stable period, slow increase period, rapid increase period and stagnating increase period. Fruit firmness change exhibits two periods, i.e. slowly declining period and rapidly declining period. There is an obvious corresponding relation between the changes of fruit firmness and the soluble solids content, i.e. the rapidly declining time of fruit firmness corresponds with the rapidly increasing time of soluble solids content. According to the experiment, the best picking periods of ‘Fengyue’and ‘Cuiyu’are mid September to mid October and early October to early November, respectively.

Effect of Different Calcium Levels on Growth,Yield and Fruit Quality of Tomatoes in Substrate Culture

Tomato seedlings were grown in substrate culture with pots. The formulation of Holland Greenhouse Horticulture Research Institute was used(as CK) and the effects of different Ca concentrations(LCa, CK and HCa)on growth, yield, and fruit quality(protein, Vitamin C, nitrates, organic acid and soluble sugar) of tomato were studied keeping concentrations of other nutrients unchanged in the nutrient solution. The results showed that parameters related to the growth of tomato(plant height and Stem diameter), changes of tomato yield per plant and quality of tomato fruits were the highest when the plants were grown at 20% Ca treatments. In the second study, increased EC concentrations of nutrient solution resulted in stronger plants with improved yields and quality. Four different concentration gradients of nutrient solution treatment were designed based on the results of the first research stage(EC=1.5, 2.5, 3.5, 4.5 m S/cm, respectively). The single tomato plant had the highest production which is 2 268.994 g/plant, when the nutrient solution strength was at EC=1.5 m S cm, whereas they have the best fruit quality when the solution strength at EC 4.5 m S/cm. This suggests the need for wide popularization of the nutrient solution formula in large areas to improve the tomato production.

Above-Optimum Temperature-Induced Differential Photosynthetic and Roots Morphometric Responses in Two Contrasting Rice Genotypes

Temperature thresholds during the rice （Oryza sativa L.） cycle development have been reported to affect plant metabolism Therefore, this study aimed to evaluate the effects of the above-optimal temperature on photosynthetic and morphometric parameters in two contrasting irrigated rice genotypes （BRS Quer^ncia--sensitive and Nagina 22 （N22）~tolerant）. Plants of both genotypes were grown in rhizotrons and always maintained under two temperature conditions： Out--under environmental temperature conditions, and In--rhizotrons inside a plastic structure, which increased the temperature about 3 ~C to 5 ~C above the external one. In the genotype N22, there was an increase （twofold higher） in CO2 assimilation in plants cultivated under elevated temperature （In）. In BRS Quer^ncia, the stomatal conductance （gs） and transpiration rate （E） decreased upon high temperature. The rise in the temperature also negatively impacted in the modulated fluorescence parameters in both genotypes. Increases in root dry weight （RDW） and shoot dry weight （SDW） were also observed in the genotype N22 when compared to BRS Quer^ncia upon temperature rise. In general, the N22 genotype showed greater response to the above-optimal temperature due to its intrinsic thermotolerance traits over BRS Quer^ncia. Thus, N22 appeared as a potential donor of heat tolerance genes aiming to obtain new cultivar to face current global wanning.

Assessment of Variabilities in Wheat Genotypes to Yellow and or Strip Rust, Puccinia striiformis in Glass House Conditions

Yellow/stripe rust caused by Puccinia striiformis is a major problem in the Middle East specially Iran. Virulence survey of cereal rust fungi have traditionally used differential host genotype and virulent physiologic race 134 E 134 AT was received to evaluate the segregating lines. A set of 35 segregating lines and three additional susceptible cultivars were added, making a total of 38 eultivars-lines. Spreader plants served as a source of inoculums. The plants were evaluated after two months based on infection percentage and the disease scoring scales. The results indicated that, there are significant changes in susceptibility assessments of the segregating lines in contrast to cultivated varieties to the yellow rust P. striiformis as far as the disease incidence and rust development is concerned in these experiments. The selected differential genotypes associated with various levels of resistance. The infection percentages were varied on the lines and the varieties, whereas the severity percentages were entirely different. The lowest severity is of line 38 with 34.70% and the highest in line 1 with 93.49% indicating 2.7 folds reduction in severity. For discrimination among the lines, the results on scoring scales gave distinctions of five classes of resistance, in which, the highest score is 29.93 and the lowest one 11.46. The cluster analysis showed almost similar results and confirmed, the analysis by Duncan＇s Multiple-lest rang as the above five distinctive groups.

Density of Standing of Plants at Cultivation of Cauliflower Seeds in Uzbekistan

The results of researches aimed to establish the optimum growing space and density of standing of plants at cultivation of cauliflower seeds in Uzbekistan are stated in the article. Researches were spent in the suburb of Tashkent with a mid-early grade ＂Domestic＂. In experiences were compared 5 densities of standing （31746, 35714, 40806, 47620 and 57142 pieces/hectare） received at planting of sprouts with row-spacing of 70 sm and distance between plants in a row 25, 30, 35, 40 and 45 sm. Experiences were pawned in quadruple frequency with the area of an allotment 10 M2. 60-65 day sprouts were planted under film tunnel shelters on February 11-12. Film shelters were kept over plants till the end of March. Seed plants were grown up without formation. Experiences were accompanied by phonological control, calculation of leaves quantity, an establishment of average weight of a head, definition of quantity of the plants, which have given seeds, the account of a crop of seeds from a bush and of a unit of area. It has been defined that reception of seeds of a cauliflower at cultivation under film tunnels is quite possible in Uzbekistan. It is established that with representation of the big growing space the plants form more leaves, earlier and larger form the heads, develop the testicles acceleration and increase their seed efficiency. It has been revealed that the more plants thickness is, the bigger share of them does not give seeds. In this connection the greatest crop of seeds has been received at growing space 70x45 sm at which 31.7 thousand Pl/ha had been planted. It is proved that in the conditions of Uzbekistan it is possible to cultivate high-grade seeds of cauliflower with productivity of 127-147 kg/ha.

Substrate Type Affects Growth, Yield and Mineral Composition of Cucumber and Zucchini Squash

The expansion of hydroponics in many countries of the world in the last few decades may be ascribed to the ability of soilless growing systems to avoid various problems arising from the use of the soil. Cucumber （Cucurnis sativus L.） and zucchini （Cucurbita pepo L.） plants were grown in closed-soilless culture under unheated-greenhouse conditions at the experimental farm of University of Tuscia, Central Italy to evaluate the effects of four substrates （rockwool, pumice, perlite, and cocofiber） on growth, yield and plant mineral composition. For both cultures, plants grown in cocofiber, perlite and pumice yielded more than those grown in rockwool. The better temperature regime in cocofiber, perlite and pumice was due to the greater thermal inertia compared to rockwool slabs. Thc concentration of N in zucchini and cucumber leaves was significantly higher in cocofiber, perlite and pumice in comparison to the rockwool treatment. The concentration of K was significantly affected by the substrate only for the zucchini squash with the highest value recorded on the organic substrate （cocofiber）, whereas the Ca concentration was significantly influenced by the growing media only for cucumber with the highest value observed on pumice. Finally, the lowest Mg concentration in leaf tissue was observed on plants grown with the rockwool substrate for both zucchini squash and cucumber. We can conclude that cocofiber, perlite and pumice are suitable for zucchini and cucumber production in closed soilless system, whereas the use of rockwool is more suitable for crops grown under heated greenhouse conditions.

Effects of Land Management Practices on Labile Organic Carbon Fractions in Rice Cultivation

A research trial with four land management practices, i.e., traditional tillage-fallow (TTF), traditional tillage-wheat (TTW), conservation tillage-fallow (CTF) and conservation tillage-wheat (CTW), was sampled in the 15th year after its establishment to assess the effects of different management practices on labile organic carbon fractions (LOCFs), such as easily oxidizable organic carbon (EOC), dissolved organic carbon (DOC), particulate organic carbon (POC) and microbial biomass carbon (MBC) in a typical paddy soil, Chongqing, Southwest China. The results indicated that LOCFs were significantly influenced by the combination of no-tillage, ridge culture and crop rotation. And, different combination patterns showed different effectiveness on soil LOCFs. The effects of no-tillage, ridge culture and wheat cultivation on EOC, DOC, POC and MBC mainly happened at 0-10cm. At this depth, soil under CTW had higher EOC, DOC, POC and MBC contents, compared to TTF, TTW and CTF, respectively. Moreover, the contents of LOCFs for different practices generally decreased when the soil depth increased. Our findings suggest that the paddy soil in Southwest China could be managed to concentrate greater quantities of EOC, DOC, POC and MBC.