Effects of Ratio of Row Spacing to Intrarow Spacing on Yield and Top Three Leaves of Super High-yielding Early and Late Rice

Using a split plot design, super high-yielding early rice ＆quot;Zhongjiazao 17＆quot;and ＆quot;Ganxin 203＆quot; and super high-yielding late rice ＆quot;Ganxin 688＆quot; and ＆quot;Wufengy-ouT025＆quot; were taken as materials with planting density the same at 312 000 hil s/hm2, to explore the effects of RS/IS （Ratio of row spacing to intrarow row spacing） on yield, top three leaves morphological features and its relationship of them in 2011 and 2012. The results showed that, whether early or late rice, biomass, accumula-tion and apparent utilizing rate of nitrogen were lower in RS/IS5.0 （40.0 cm ＆#215;8.0 cm） treatment, but yield of rice was higher in RS/IS2.0 （25.0 cm ＆#215;12.8 cm） treatment;grain numbers per spike of rice was more in RS/IS2.8 （30.0 cm＆#215;10.7 cm） treatment, and thousand-grain weight of rice was higher in RS/IS1.3 （20.0 cm＆#215;16.0 cm） treat-ment. For 4 varieties of early or late rice aforementioned, basal angle, opening an-gle and leaf area of 2nd leaf from top were larger in RS/IS5.0 treatment, and basal angle and opening angle were smal er in RS/IS2.0 treatment and leaf area smal er in RS/IS1.3 treatment.

Effects of Soil Acidification on Yield of Late Rice and Differences in Acid Resistance among Varieties

Effect of soil acidification on yield of late rice was studied and acid resistance of late rice varieties were compared with 23 late rice varieties as materials in Changsha County, Hunan Province. The results indicated that the difference in yield among varieties was obvious, yield in common field was among 5 226.6-9 202.1kg/hm^2, and yield in acidified field was among 3 643.2-7 714. 8 kg/hm^2. Compared with common field, yield of Yueyou 6135, Huayou 18, Jinyou 284 and Ⅱyou 46 increased by 3.24%-26.33% in acidified field, while yield of other varieties decreased by 2.04%-56.79% in acidified field. According to acidification sensitivity, Wufengyou T025, Jinchuyou No.148, Yueyou No.6135, Shenyou No.9586, Xiangfengyou No.103,Zhongyou No.288, Nongxiang No.18, Shanyou No.432, Ⅱ you No.6, and Zhong 9A/R10402 were sensitive to soil acidification; Wuyou No.308, Zhunliangyou No.608,Fengyuanyou No.227, Fengyou No.1167, Fengyuanyou No.299, T you No.272, and Zhong 9A/R9963 were moderately sensitive to soil acidification; Yueyou No.9113,Jinyou No.284, Shenyou No.9588, Huayou No.18, Ⅱ you No.46 and Ⅱ you No.3027 were slightly sensitive to soil acidification

Study on Seedling Quality of Double-cropping Late Rice Sowed at Different Dates in Guangdong

[Objective] The aim was to study seedling quality of rice sowed at different dates so as to provide theoretical basis for determining the best seeding time.[Method] By investigating the characters of shoot and root of different varieties sowed at different dates,the best seeding time of double-cropping late rice was determined.[Result] The first leaf sheath height and the second leaf length shared significantly positive correlation,which fit the quadratic equation well.The effects of different sowing dates on shoot and root of three rice varieties appeared significant difference.[Conclusion] The best seeding time of Tianyou428 was in June 25-July 2 and that of Tianyou998 and Yuxiangyouzhan was in July 2-9.

Effect of Different Seedling Age on the Growth and Yield of Double Cropping of Late Rice

The study aims to solve the problems of late transplanting rice with differ- ent seedling ages at the lower reaches of Yangtze River. We selected six varieties of different thermal and photo-response characteristics as the test material to study the effect of different seedling ages on growth and yield of rice. The results showed that growing period of thermal-response rice was delayed by long seedling age, but less affected by the impact of photo-response rice; the yield of later thermal-re- sponse varieties with 25 days and 30 days seedling ages was significantly reduced. In contrast, the yield of early thermal-response varieties and later photo-response varieties were significantly reduced with 30 days seedling age. The optimal trans- planting seedling age was 15 days of thermal-response rice, while photo-response rice was 20 days. The thermal-response rice should be selected as early maturing varieties, while the photo-response rice could be selected as late maturing varieties for high yield.

Field Efficacy Trial and Optimum Control Period of Rice False Smut(Ustilaginoidea virens) in Single Cropping Middle-late Rice

[Objective]The paper was to study optimum chemical agents and control periods against rice false smut( Ustilaginoidea virens) in single cropping middle-late rice. [Method]Taking chemical agents( triadimefon,armure,Jinggangmycin) as main treatments and spraying periods( within 7 d before initial heading stage,within 7 d before initial heading stage + initial heading stage,initial heading stage) as assisted treatments,the field efficacy trial and optimum control period of U. virens in single cropping middle-late rice were studied using Huanghuazhan and Jinnongsimiao as experimental materials in 2013. [Result] Three chemical agents,triadimefon,armure,Jinggangmycin,extremely reduced diseased panicle rate and disease index of U. virens,but there was no significant difference among three chemical agents. Spraying period did not have significant impact on diseased panicle rate and disease index of U. virens,whereas spraying within7 d before initial heading stage and during initial heading stage had relatively good control effect. Yield increased significantly after application of three chemical agents,and armure led to greater increase. The reason for yield increase was that seed setting rate was significantly increased,and the number of filled grains per panicle was significantly increased. Although spraying period influenced yield,the difference was not significant. [Conclusion] Triadimefon,armure and Jinggangmycin had good control effects against U. virens in single cropping middle-late rice,of which armure had better control effects. Spraying chemical agents increased seed setting rate,and further increased the number of filled grains per panicle and yield. Spraying within 7 d before initial heading stage and during initial heading stage had relatively better control effect against U. virens.

Performance and Matching Cultivation Techniques of New Late Rice Variety Xiangyou196 with Early Maturity and High Yield

In this paper, the characteristics and yield performance of new variety Xi-angyou196 were introduced, and its high-yielding cuItivation techniques were summa-rized, finally, the corresponding matching cuItivation techniques through experiment and demonstration were put forward.

Breeding of High-Quality Late Rice Combination Taoxiuyouhuazhan

Taoxiuyouhuazhan is a high-quality fragrant late rice combination which was bred by the cooperation between Hu Nan Tao Hua Yuan Agricultural Technologies Co.,LTD.and Changde Institute of Agriculture and Forestry Science.With good yield,wide adaptability,resistance to rice blast,and the quality reaching third level of the national agricultural standard of Quality of Edible Rice Varieties.It has been authorized by the National Crop Variety Committee of the Ministry of Agriculture and Rural Affairs in February 2019.

Chemical Weeding in Dry Direct Seeding Fields of Single Cropping Middlelate Rice

Chemical weeding in dry direct seeding fields of single cropping middle-late rice was studied in Huida vegetable farm of Huizhou City in 2012. The main treatment was herbicide（ pretilachlor ＋ bensulfuron-methyl,Yangguo and butachlor）,and the sub-treatment was application method（ soil treatments,seedling treatment and integrated treatment）. The results showed that 80 g pretilachlor ＋ bensulfuron-methyl（ 36% pretilachlor ＋ 4% bensulfuron-methyl） diluted with 50 kg water could be sprayed or 200 g Yangguo（ 23. 9% butachlor ＋ 1. 1% bensulfuron-methyl） mixed with 15 kg sandy soil could be broadcasted per 667 m2 on the sowing day or the second day under moist condition of soil,which could effectively control weeds in dry direct seeding fields of single cropping middle-late rice.

The impacts of timing and insecticides at early stage of late rice on the population development of brown plant hopper(BPH)

Field experiments were carried out in northern Zhejiang Province. Three insecticides (methamidophos,Shachongshuang and triazophos) were used to control the rice leaffolder Cnaphalocrocis medinalis and rice striped stemborer Chilo suppressalis in rice fields during 18—27 days after transplantating. The impacts of timing and insecticides on the population development of brown planthopper Nilaparavata lugens was surveyed by direct counting on the plants or by tapping method.

Evaluation of Cold Dew Wind Monitoring Precision for Late Rice Based on CLDAS Data in Guangxi

The low temperature process of cold dew wind( from September 19 to 27 in 2011) for late rice production was dynamically monitored by using CLDAS temperature,combined with the background information of rice cultivation from multi-source satellite database together with an reference to the monitoring indexes of cold dew wind disaster to verify the precision of CLDAS data,so as to provide a reference for monitoring chilling damage caused by cold dew wind in late rice production in Guangxi. The results showed that the cold wind dew caused heavy damage to an area of 3 159. 76 km^2,moderate damage to an area of 559. 77 km^2 and light damage to an area of 2 452. 14 km^2. The correlation coefficients between CLDAS inversion temperature and actual temperature of 12 verification meteorological stations were all larger than 0. 93,and the difference in daily average temperature was 0. 3 ℃. The time difference between maximum and minimum temperature provided by CLDAS and corresponding actual temperature from 12 meteorological stations was less than 1 h. The temperature data provided by CLDAS was in accordance with actual temperature data. With an advantage of rapidly,minutely and accurately monitoring the grade distribution of local cold dew wind disaster for late rice,CLDAS can be used in monitoring cold dew wind in late rice production in Guangxi.

Effects of different machine transplanting methods on the physiological and yield characteristics of late rice in China

To address problems caused by rice machine transplanting such as injury to the seedlings and recovery period that extend growth period,this study explored the effects of different machine transplanting methods on the physiological and yield characteristics of late rice in China,and determine the appropriate machine transplanting method for late rice,which was expected to provide a basis for high-yield and high-efficient cultivation of machine-transplanted late rice.Hybrid indica rice Taiyou 398 and conventional indica rice Jing Gangruanzhan were selected as the research objects,and large-pot carpet seedling machine transplanting(M1),conventional pot carpet seedling machine transplanting(M2)and ordinary carpet seedling machine transplanting(M3)were adopted respectively to analyze their effects on seedling quality,population physiological characteristics,yield and its components and economic benefits of late rice.The results showed that compared with M2 and M3,M1 achieved higher seedling quality,showing significant advantages in the early stage despite average root entwining force that met the requirement of machine transplanting.The seedlings transplanted using M1 had shorter recovery period after mechanical transplanting,with earlier tillering,earlier peak seedling,and slower declining of stems and tillers in the late stage;the peak seedling number was not high,but the effective tiller number and earbearing tiller percentage were significantly higher than those achieved by the other two machine transplanting methods.Also,M1 achieved stronger photosynthetic capacity of flag leaves before HS,with more photosynthetic products in stems and leaves transported to panicles and more efficiently after HS.Compared with seedlings transplanted using M2 and M3,the recovery period of those transplanted using M1 was shortened by 3 and 5 d,the heading stage(HS),and maturity stage(MS)were advanced,which effectively reduced the risk and impact of“cold dew wind”on machine-transplanted late rice.M1 had significant yield increase advantage and economic benefit,with better grain maturity,and“larger panicles,more panicles,more and fuller grains”.M1 achieved an average yield increase of 10.31%-11.10%,20.67%-25.10%in 2 years,and an average income increase of 18.65%-131.06%and 62.85%-323.78%,respectively.Therefore,vigorously developing M1 is the key to the high-yield and high-efficient cultivation of machine-transplanted late rice in China.

Yield and Quality Performance of Japonica Rice Varieties Grown in the Late Season in a Double Rice Cropping System of China

Meeting the demand for high-quality japonica rice is a major challenge facing China's grain security. In the present study, a two-year field experiment was conducted to investigate the yield, quality, and profitability of japonica rice varieties(including hybrids and inbreds) grown in the late season as compared with local elite indica hybrids in a double rice cropping system of China where indicas are traditionally planted. Indica hybrids had significantly longer vegetative(from sowing to heading) and total(from sowing to maturity) growth durations than japonicas in both2011 and 2012, while reproductive growth duration(from heading to maturity) was longer for indica hybrids than for japonicas in 2011 but not in 2012. Indica hybrids produced higher grain yield than japonicas in 2011, but with no significant differences in 2012. Japonicas had higher brown rice, milled rice, and head rice percentages than indicas, but had lower gelatinization temperature and amylose content,while with no significant differences in gel consistency and protein content. Indica hybrids tended to have lower chalky grain percentage and chalkiness degree than japonicas, though the differences were not statistically significant due to large genotypic variations. The net returns were 16.1% and 9.9% greater for indica hybrids than for japonica hybrids and japonica inbreds in 2011, with only 3.8% and 1.3% in2012, respectively. Thus, our results suggest that replacing indicas with japonica varieties as late rice may not be feasible at the present site unless locally adapted japonica varieties are developed.

Suitable growing zone and yield potential for late-maturity type of Yongyou japonica/indica hybrid rice in the lower reaches of Yangtze River, China

Late-maturity type of Yongyou japonica/indica hybrids series （LMYS） have shown great yield potential, and are being widely planted in the lower reaches of Yangtze River, China. Knowledge about suitable growing zone and evaluation of yield advantage is of practicall importance for LMYS in this region. Fifteen LMYS, two high-yielding inbred japonica check varieties （CK-J） and two high-yielding hybrid indica check varieties （CK-I） were grown at Xinghua （119.57°E, 33.05°N） of Lixiahe region, Yangzhou （119.25°E, 32.30°N）of Yanjiang region, Changshu （120.46°E, 31.41°N）of Taihu Lake region, and Ningbo （121.31°E, 29.45°N） of Ningshao Plain in 2013 and 2014. The results showed that maturity dates of the 15 were later than the secure maturity date at Xinghua and 6, 14 and 15 LMYS were mature before the secure maturity date at Yangzhou, Changshu and Ningbo, respectively. One variety was identified as high-yielding variety among LMYS （HYYS） at Yangzhou, 8 HYYS in 201：3 and 9 HYYS in 2014 at Changshu, 9 HYYS at Ningbo. HYYS here referred to the variety among LMYS that was mature before the secure maturity date and had at least 8% higher grain yield than both CK-J and CK-I at each experimental site. Grain yield of HYYS at each experimental site was about 12.0 t ha-1 or higher, and was significantly higher than CK varieties. High yield of HYYS was mainly attributed to larger sink size due to more spikelets per panicle. Plant height of HYYS was about 140 cm, and was significantly higher than check varieties. Significant positive correlations were recorded between duration from heading to maturity stage and grain yield, and also between whole growth periods and grain yield. HYYS had obvious advantage over check varieties in biomass accumulation and leaf area duration from heading to maturity stage. Comprehensive consideration about safe matudty and yield performance of LMYS at each experimental site, Taihu Lake region （representative site Changshu） and Ningshao Plain （representative site Ningbo） were thought suitable growing zones for LMYS in the lower reaches of Yangtze River. The main factors underlying high yield ofHYYS were larger sink size, higher plant height, longer duration from heading to maturity stage and whole growth periods, and higher biomass accumulation and leaf area duration during grain filling stage.

Resistance Evaluation of Some Hybrid Rice, Conventional Early Indica and Late Japonica Rice to Magnaporthe grisea

Thirty isolates of Magnaporthe grisea collected from 18 provinces/cities representing 21 pathotypes and 9 different lineages were inoculated to rice varieties with known resistance genes and some hybrid rices, conventional early indica and late japonica varieties cultivated recently in China. Virulence spectrum of the 30 isolates was very different, showing that they recognize numerous different resistance genes. Varieties also revealed very different resistance patterns showing that they carry different resistance genes or combinations of resistance genes. On the basis of comparisons with international differential varieties with known resistance genes, resistance genes in certain Chinese varieties could be speculated. The results indicated that some of them were resistant to most of the isolates tested and that they could be of interest as resistance sources for hybrid parents or to be planted in the field directly.

Comparative Test of New Late Indica Hybrid Rice Combinations with Good Quality

[Objectives]This study was conducted to screen rice varieties suitable for planting in Nanchang City with high quality,high yield,good yield,and strong disease and stress resistance.[Methods]Seven new late indica hybrid rice combinations with good quality bred in Jiangxi Province in recent years and seven new late indica hybrid rice combinations with good quality bred by Nanchang Academy of Agricultural Sciences were introduced,and compared with Tianyouhuazhan as a control.[Results]The rice quality and taste of the tested combinations were better than those of the control.Among the tested combinations,Yuliangyoufuxiangzhan,Xintaiyousizhan,Yuxiangliangyou No.8 and Guangheyou 33 had good stress resistance,high yield and good rice quality.[Conclusions]This study provides a theoretical basis for the selection and breeding of new rice varieties in Nanchang City.

Effect of Nitrogen and Density Interaction on Yield Formation of Late Japonica Rice Under Different Transplanting Dates

[Objectives]This study was conducted to clarify the appropriate nitrogen fertilizer amount and transplanting density that should be selected for different transplanting dates.[Methods]The effects of nitrogen fertilizer rate and transplanting density on the traits and yield of late japonica rice in the Jianghuai rice-wheat cropping area under different transplanting dates(transplanting at an appropriate time and delayed transplanting)were studied.[Results]The transplanting date significantly affected the heading,maturity and whole growth period of rice,and when the transplanting date of early-maturing late japonica rice was delayed by 15 d,the growth period was shortened by about 10 d.Nitrogen and density interaction obviously affected the dry matter accumulation and effective tillers of rice,and the dry matter production and effective tiller number of rice treated with B_(1)N_(2) were greater than other treatments.Under the timely transplanting date,the best nitrogen and density combination was 225-300 kg/hm^(2) and 250500 holes/hm^(2),and the nitrogen use efficiency was ideal.It suggests that under the condition of transplanting rice in a timely manner,applying nitrogen fertilizer at an appropriate rate while ensuring a reasonable population density is conducive to the coordination of the number of stems and tillers,the number of grains per panicle,etc.,thereby ensuring the best formation of yield factors in the middle and late stages of rice growth.[Conclusions]This study provides technical support and theoretical reference for reasonable nitrogen and density interaction of rice.

EFFECTS OF SEEDING DENSITY AND BASIC MANURE ON THE GROWTH OF DRY NURSERY SEEDLINGS IN LATE DOUBLE CROPPING RICE IN SOUTH CHINA

During the period of dry nursery seedling raising of late double cropping indica rice in South China, both chemical fertilizer and farmyard manure did not show obvious effect on the growth of shoot and root in young seedlings at 4-leaf stage （18-day-old seedling）, but had significant effects on root growth in old seedlings with 6-7 leaves （27-day-old seedling） at suitable seeding densities (65-125g m-2). There were satistically significant differences （at 0.01 or 0.05 levels）between treatments in root number and rooting ability of root-pruned seedlings.

EFFECTS OF SOIL MOISTURE CONTENT ON DRY NURSERY SEEDLING QUALITY OF LATE DOUBLE CROPPING RICE IN SOUTH CHINA

In the present paper, an experiment was conducted to study the effects of soil moisture content on dry nursery seedling quality in Guangzhou in 1995. Through comparing the difference of dry nursery seedlings and wet nursery seedlings, we found a close relationship between soil moisture content and seedling growth. The seedling emergence of dry nursery seedling was more even, tidy and faster, and the survival rate was higher than that of wet nursery seedling. Dry nursery seedlings had small plant stature, slow leaf stretching speed and low individual seedling dry weight, but had high dry/fresh weight ratio. This was abeneficial factor for seedlings to recover from transplanting shock more quickly. As com-pared with the wet nursery seedlings, dry nursery seedlings had poor rooting ability,but had more vigorous white roots and fewer rust roots. It was the possibly important reasonfor dry nursery seedlings to form strong“explosive force”.

华南地区早晚兼用型水稻产量和氮素吸收在早、晚季的差异特征

为明确华南双季稻区早晚兼用型水稻产量和氮素吸收在早、晚季的差异特征,以6个早晚兼用型水稻品种为试验材料,按当地高产栽培条件在早、晚季种植,测定其产量、产量构成、干物质积累和氮素吸收等。结果表明,早晚兼用型水稻在早、晚季种植时产量分别为6.68~7.91 t/hm^(2)和5.72~6.11 t/hm^(2);早季产量显著高于晚季,平均增幅为1.53 t/hm^(2)。相关分析表明,较高的早季产量与其有效穗数和粒重的提高有关。早、晚季干物质积累量和氮素吸收差异显著;相对于晚季,早季成熟期干物质积累量和氮素吸收平均提高25.0%和29.5%。另外,早、晚季产量与其干物质积累量和氮素吸收显著正相关。早晚兼用型水稻在早季种植时具有较高的产量、物质生产和氮素吸收能力。研究结果可为华南地区早晚兼用型水稻的丰产栽培提供理论依据。

早熟晚粳糯稻新品种扬粳糯5号的选育与应用

扬粳糯5号是江苏里下河地区农业科学研究所以高产糯稻品系镇稻622为母本、优质广适糯稻品种镇糯19号为父本进行杂交,结合稻瘟病抗性基因和米香基因的分子标记辅助选择培育成的优质高产抗病早熟晚粳糯稻新品种。扬粳糯5号全生育期153.9d,株高97.6cm,每亩有效穗21.6万,每穗总粒数120-140粒,结实率90%以上,千粒重27~28g。抗稻瘟病,中感白叶枯病,感纹枯病;稻米品质达农业行业《食用稻品种品质》一级标准。2021年通过江苏省农作物品种审定委员会审定,同时通过安徽省和浙江省引种备案,适宜在江苏、安徽、浙江等省沿江及江南地区种植。