Ratoon rice,which refers to a second harvest of rice obtained from the regenerated tillers originating from the stubble of the first harvested crop,plays an important role in both food security and agroecology while r...Ratoon rice,which refers to a second harvest of rice obtained from the regenerated tillers originating from the stubble of the first harvested crop,plays an important role in both food security and agroecology while requiring minimal agricultural inputs.However,accurately identifying ratoon rice crops is challenging due to the similarity of its spectral features with other rice cropping systems(e.g.,double rice).Moreover,images with a high spatiotemporal resolution are essential since ratoon rice is generally cultivated in fragmented croplands within regions that frequently exhibit cloudy and rainy weather.In this study,taking Qichun County in Hubei Province,China as an example,we developed a new phenology-based ratoon rice vegetation index(PRVI)for the purpose of ratoon rice mapping at a 30 m spatial resolution using a robust time series generated from Harmonized Landsat and Sentinel-2(HLS)images.The PRVI that incorporated the red,near-infrared,and shortwave infrared 1 bands was developed based on the analysis of spectro-phenological separability and feature selection.Based on actual field samples,the performance of the PRVI for ratoon rice mapping was carefully evaluated by comparing it to several vegetation indices,including normalized difference vegetation index(NDVI),enhanced vegetation index(EVI)and land surface water index(LSWI).The results suggested that the PRVI could sufficiently capture the specific characteristics of ratoon rice,leading to a favorable separability between ratoon rice and other land cover types.Furthermore,the PRVI showed the best performance for identifying ratoon rice in the phenological phases characterized by grain filling and harvesting to tillering of the ratoon crop(GHS-TS2),indicating that only several images are required to obtain an accurate ratoon rice map.Finally,the PRVI performed better than NDVI,EVI,LSWI and their combination at the GHS-TS2 stages,with producer's accuracy and user's accuracy of 92.22 and 89.30%,respectively.These results demonstrate that the proposed PRVI based on HLS data can effectively identify ratoon rice in fragmented croplands at crucial phenological stages,which is promising for identifying the earliest timing of ratoon rice planting and can provide a fundamental dataset for crop management activities.展开更多
Agronomic measures are the key to promote the sustainable development of ratoon rice by reducing the damage from mechanical crushing to the residual stubble of the main crop, thereby mitigating the impact on axillary ...Agronomic measures are the key to promote the sustainable development of ratoon rice by reducing the damage from mechanical crushing to the residual stubble of the main crop, thereby mitigating the impact on axillary bud sprouting and yield formation in ratoon rice. This study used widely recommended conventional rice Jiafuzhan and hybrid rice Yongyou 2640 as the test materials to conduct a four-factor block design field experiment in a greenhouse of the experimental farm of Fujian Agricultural and Forestry University, China from 2018 to 2019.The treatments included fertilization and no fertilization, alternate wetting and drying irrigation and continuous water flooding irrigation, and plots with and without artificial crushing damage on the rice stubble. At the same time, a 13C stable isotope in-situ detection technology was used to fertilize the pot experiment. The results showed significant interactions among varieties, water management, nitrogen application and stubble status.Relative to the long-term water flooding treatment, the treatment with sequential application of nitrogen fertilizer coupled with moderate field drought for root-vigor and tiller promotion before and after harvesting of the main crop, significantly improved the effective tillers from low position nodes. This in turn increased the effective panicles per plant and grains per panicle by reducing the influence of artificial crushing damage on rice stubble and achieving a high yield of the regenerated rice. Furthermore, the partitioning of 13C assimilates to the residual stubble and its axillary buds were significantly improved at the mature stage of the main crop, while the translocation rate to roots and rhizosphere soil was reduced at the later growth stage of ratooning season rice. This was triggered by the metabolism of hormones and polyamines at the stem base regulated by the interaction of water and fertilizer at this time. We therefore suggest that to achieve a high yield of ratoon rice with low stubble height under mechanized harvesting, the timely application of nitrogen fertilizer is fundamental,coupled with moderate field drying for root-vigor preservation and tiller promotion before and after the mechanical harvesting of the main crop.展开更多
The border effect(BE)is widely observed in crop field experiments,and it has been extensively studied in many crops.However,only limited attention has been paid to the BE of ratoon rice.We conducted field experiments ...The border effect(BE)is widely observed in crop field experiments,and it has been extensively studied in many crops.However,only limited attention has been paid to the BE of ratoon rice.We conducted field experiments on ratoon rice in Qichun County,Hubei Province,Central China in 2018 and 2019 to compare the BE in the main and ratoon crops,and to quantify the contribution of BE in the main crop to that in the ratoon crop.The BE of two hybrid varieties was measured for the outermost,second outermost,and third outermost rows in each plot of both crops.To determine the contribution of BE between the two crops,portions of hills in the outermost and second outermost rows were uprooted during the harvest of the main crop so that the second and third outermost rows then became the outermost rows in the ratoon crop.Overall,the BE on grain yield was greater in the main crop than in the ratoon crop.In the main crop,the BE on grain yield was 98.3%in the outermost row,which was explained by the BE on panicles m^(–2),spikelets/panicle,spikelets m^(–2),and total dry weight.In the ratoon crop,the BE on grain yield was reduced to 60.9 and 27.6%with and without the contribution of the BE in the main crop,respectively.Consequently,55.1%of the BE on grain yield in the ratoon crop was contributed from the main crop.High stubble dry weight and non-structural carbohydrate(NSC)accumulation at the harvest of the main crop were responsible for the contribution of BE in the main crop to that in the ratoon crop.Our results suggest that increases in stubble dry weight and NSC accumulation at the harvest of the main crop could be important strategies for developing high-yielding cropping practices in the rice ratooning system.展开更多
Pre-harvest yield prediction of ratoon rice is critical for guiding crop interventions in precision agriculture.However,the unique agronomic practice(i.e.,varied stubble height treatment)in rice ratooning could lead t...Pre-harvest yield prediction of ratoon rice is critical for guiding crop interventions in precision agriculture.However,the unique agronomic practice(i.e.,varied stubble height treatment)in rice ratooning could lead to inconsistent rice phenology,which had a significant impact on yield prediction of ratoon rice.Multi-temporal unmanned aerial vehicle(UAV)-based remote sensing can likely monitor ratoon rice productivity and reflect maximum yield potential across growing seasons for improving the yield prediction compared with previous methods.Thus,in this study,we explored the performance of combination of agronomic practice information(API)and single-phase,multi-spectral features[vegetation indices(VIs)and texture(Tex)features]in predicting ratoon rice yield,and developed a new UAV-based method to retrieve yield formation process by using multi-temporal features which were effective in improving yield forecasting accuracy of ratoon rice.The results showed that the integrated use of VIs,Tex and API(VIs&Tex+API)improved the accuracy of yield prediction than single-phase UAV imagery-based feature,with the panicle initiation stage being the best period for yield prediction(R^(2) as 0.732,RMSE as 0.406,RRMSE as 0.101).More importantly,compared with previous multi-temporal UAV-based methods,our proposed multi-temporal method(multi-temporal model VIs&Tex:R^(2) as 0.795,RMSE as 0.298,RRMSE as 0.072)can increase R^(2) by 0.020-0.111 and decrease RMSE by 0.020-0.080 in crop yield forecasting.This study provides an effective method for accurate pre-harvest yield prediction of ratoon rice in precision agriculture,which is of great significance to take timely means for ensuring ratoon rice production and food security.展开更多
Yield loss(Y_(Loss)) in the ratoon crop due to crushing damage to left stubble from mechanical harvesting of the main crop is a constraint for wide adoption of mechanized rice ratooning technology.Soil drying before t...Yield loss(Y_(Loss)) in the ratoon crop due to crushing damage to left stubble from mechanical harvesting of the main crop is a constraint for wide adoption of mechanized rice ratooning technology.Soil drying before the harvest of the main crop has been proposed to overcome this problem.The objective of this study was to determine the effect of soil drying during the mid-to-late grain filling stage of the main crop on grain yield of the ratoon crop in a mechanized rice ratooning system.Field experiments were conducted to compare Y_(Loss) between light(LD) and heavy(HD) soil drying treatments in Hubei province,central China in 2017 and 2018.Y_(Loss) was calculated as the percentage of yield reduction in the ratoon crop with the main crop harvested mechanically,relative to the grain yield of the ratoon crop with the main crop harvested manually.In comparison with LD,soil hardness was increased by 42.8%-84.7% in HD at the 5-20 cm soil depth at maturity of the main crop.Soil hardness at 5 and 10 cm depths reached respectively 4.05 and 7.07 kg cm^(-2) in HD.Soil drying treatment did not significantly affect the grain yield of the main crop.Under mechanical harvesting of the main crop,HD increased the grain yield of the ratoon crop by 9.4% relative to LD.Consequently,Y_(Loss) was only 3.4% in HD,in contrast to 16.3% in LD.The differences in grain yield and Y_(Loos) between the two soil drying treatments were explained mainly by panicles m^(-2),which was increased significantly by HD in the track zone of the ratoon crop compared with LD.These results suggest that heavy soil drying practice during the mid-to-late grain filling stage of the main crop is effective for reducing Y_(Loss) of the ratoon crop in a mechanized rice ratooning system.展开更多
Ratoon rice cropping is an important component of the rice cropping system in Texas and south Louisiana,USA,and expanded to Asian countries in 1970.Two field studies were conducted with widely planted rice(Oryza sativ...Ratoon rice cropping is an important component of the rice cropping system in Texas and south Louisiana,USA,and expanded to Asian countries in 1970.Two field studies were conducted with widely planted rice(Oryza sativa L.)cultivars at Eagle Lake,Texas,USA to determine the effects of nitrogen(N)management in main(first)crop(MC)and ratoon(second)crop(RC)on RC yield.In 2012 and 2013,one cultivar(Presidio)was adopted to determine the effects of RC N management on ratoon yield and head rice yield.In 2016 and 2017,CL153,CL163 and CL272 in addition to Presidio were adopted to examine the effect of MC N management on ratoon yield and head rice yield.N applied at preflood after MC harvest considerably improved RC yield.Application of 99 kg N ha^(–1)at preflood after MC harvest was practically adequate for RC regrowth,development and approaching the yield potential for Presidio.RC could produce quite high average grain yields of 5.90 to 6.53 t ha–1 in 2012 and 2013,respectively.Main crop N rate only significantly affected MC yield;however,given N applied of 99 kg ha^(–1)at preflood after MC harvest,ratoon yield was not significantly affected by MC N rate.Neither the main nor ratoon crop N management had a significant effect on RC head rice yield.Considerable RC head rice yields(55–65%)were observed in all of the four cultivars and 4 years except for CL272 in 2016.These results indicat that without very high N fertilizer application,rice ratoon crop could produce a considerable grain yield and an expectative head rice yield.Rice ratooning could be a practical way to increase rice yields with the minimal input in south Texas and regions with a similar climate.展开更多
This study attempted to clarify the carrying-over effect of different nitrogen treatments applied to the main crop on the crop population growth and yield formation of ratoon rice under mechanized cultivation in South...This study attempted to clarify the carrying-over effect of different nitrogen treatments applied to the main crop on the crop population growth and yield formation of ratoon rice under mechanized cultivation in Southeast China.Based on the constant total nitrogen application amounts(225.00 kg ha;)in the main crop,an experiment with different ratios of basal and topdressing nitrogen fertilizer(the ratio of basal fertilizer:primary tillering fertilizer:secondary tillering fertilizer:booting fertilizer at 3:1:2:4(N1),3:2:1:4(N2),3:3:0:4(N3),and 4:3:0:3(N4),respectively,and a control without nitrogen treatment(N0))was set up across two consecutive years in field using hybrid rice variety Yongyou 1540 as the test materials.The results showed that the total tiller number and effective tillering percentage increased in the main crop under the N1 treatment,more nitrogen fertilizer applied in late growth stage of the main crop,and its effective tillering percentage of the main crop was the highest at up to 70.18%,which was 9.15%higher than that of conventional fertilization treatment(N4),more nitrogen fertilizer applied in early growth stage of the main crop.The same tendency was observed in leaf area index(LAI)value of the main crop and its subsequent ratoon rice,which were 16.52 and 29.87%higher,respectively,in the N1 treatment than that in the N4 treatment at the full heading stage.The same was true in the case of the transport rates of stem and sheath dry mater and the canopy light interception rates in both the main and its ratoon crops.The transport rate of stem and sheath in main crop rice under N1 treatment increased by 50.57%compared with N4 treatment.The canopy light interception rate of N1 treatment increased by 5.07%compared with N4 treatment at the full heading stage of the ratoon crop.Therefore,the total actual yield was the highest in the main and its ratoon crops under N1 treatment,averaging 17351.23 kg ha;in two-year trials,which was 23.00%higher than that in the conventional fertilization treatment(N4).The results showed that appropriate nitrogen treatment was able to produce a good crop stand in the main crop,which was essential for producing a good ratoon crop population and high yield especially under mechanized cultivation with low stubble height of the main crop.The study suggested that shifting the proper nitrogen application amounts to the late growth stage of the main crop,such as N1 treatment,not only had a higher productive effect on ensuring the yield of the main crop,but also had a positive effect on the axillary bud sprouts from the stubbles for ratoon rice,resulting in an increased percentage of productive panicles and achieving the goal of one planting with two good harvests under the conditions of our study.展开更多
In order to determine the optimal sowing date of ratoon rice in South Henan's rice-growing areas,this paper performs a comparative analysis of rice growth process,seedling quality and yield of first season rice an...In order to determine the optimal sowing date of ratoon rice in South Henan's rice-growing areas,this paper performs a comparative analysis of rice growth process,seedling quality and yield of first season rice and ratoon rice under different sowing date treatments. The results show that under climatic conditions( 2014),by using dry seedling cultivation in a small plastic shed,the growth of seedling sown on February21 was affected,while the sowing treatments from March 1 to April 11 can breed normal seedlings,and in this period,the maturity period of first season rice was delayed with prolonged sowing date,and ratoon rice yield declined with prolonged sowing date( total production of rice sown on 11 March reaching a peak). Thus,it is considered that the optimal sowing date of ratoon rice in South Henan's rice-growing areas is mid-March.展开更多
The ratoon crop occupies approximately 40% of the total area of sugarcane crop in tropical India. The main reason for the lower average cane productivity is the yield decline in ratoon crops (40 - 50 t/ha) despite the...The ratoon crop occupies approximately 40% of the total area of sugarcane crop in tropical India. The main reason for the lower average cane productivity is the yield decline in ratoon crops (40 - 50 t/ha) despite the release of the high yielding varieties and advanced cane production technology. The physiological factors associated with ratooning performance and the variation in growth and yield were studied in 11 sugarcane varieties in two cycles of one plant and two ratoon crops each. The first ratoon and second ratoon crop showed 17.0% and 28.1% reduction in tiller production and 15.5% and 15.7% reduction in NMC, respectively, over plant crop. The differences in growth parameters between the plant and ratoon crops at the formative phase were lesser than that of grand growth and maturity phases. Varieties Co 86032, Co 97008, Co 95020 Co 99004 and Co 2000-10 showed better physiological efficiency in terms of plant height, shoot population, leaf size, TDMP, partitioning efficiency, chlorophyll content and nitrate reductase activity and significantly higher yield components such as NMC, SCW, cane length, internodal length as well as cane yield compared to other varieties. The higher reduction in ratoon yield in Co 99008, Co 94012, Co 8021 and Co 97009 (>35.00% reduction) was due to higher reduction in tiller production associated with stunted plant growth and root system, reducetion in individual leaf size and LAI, TDMP, total chlorophyll content, NMC, internodal length and SCW. The results obtained indicated that the plant height, TDMP, stem partitioning, leaf size, total chlorophyll content, SCW, cane length and cane girth were highly associated with yield of first and second ratoon crops than that of plant crop. Therefore the difference in the association between physiological parameters with yield of plant and ratoon crops therefore decides the ratooning potential of the crop.展开更多
Rice ratooning,or the production of a second rice crop from stubble after the harvest of the main crop,is considered to be a green and resource-efficient rice production system.The present study was conducted to exami...Rice ratooning,or the production of a second rice crop from stubble after the harvest of the main crop,is considered to be a green and resource-efficient rice production system.The present study was conducted to examine variance in amylose content(AC),grain morphology,crystal structure,and thermal properties of starch between main-and ratoon-season rice of seven varieties.Ratoon-season rice grains had higher ACs and significantly lower transition gelatinization temperatures(To,Tp,and Tc)than did main-season rice grains.The relative crystallinity and lamellar peak intensity of ratoon-season rice starch were 7.89%and 20.38%lower,respectively,than those of main-season rice starch.In addition,smaller granules with smoother surfaces and lower thermal parameters were observed in the starch of ratoon-season rice.The relative crystallinity and lamellar peak intensity of starch correlated negatively with the AC and positively with transition gelatinization temperatures.These results suggest that the superior cooking quality of ratoon-season rice is attributable to the moderate increase of grain AC,which reduces the relative crystallinity,weakens the crystal structure,and lead to a decrease in the gelatinization temperature.展开更多
The experiment was conducted with the traditional manual harvesting and mechanical harvesting of sugarcane,to compare the effects of different harvesting method on the sugarcane stubble quality and the growth of ratoo...The experiment was conducted with the traditional manual harvesting and mechanical harvesting of sugarcane,to compare the effects of different harvesting method on the sugarcane stubble quality and the growth of ratoon.The experimental results are as follows.(i) The stubble height and breaking stubble rate of mechanical harvesting was significantly higher than manual harvesting,the stubble height of lodging species and difficult defoliation species increased in mechanical harvesting condition.Varieties with higher levels of fiber had lower rate of broken stubble.(ii) The effects of mechanical harvesting on germination of next year ratoon were quite different due to different varieties,indicating that the better perennial species have less impact than the poor perennial species.(iii) Compared with manual harvesting,mechanical harvesting had slightly higher plant height and single-stem weight and less effective stems number,the difference of cane yield was not significant,but sucrose content increased 0.53%.(iv) Mechanical harvesting combining with leaves crushing could reduce the impact on the germination of ratoon,improve the single-stem weight and increase the effective number of stems.展开更多
[Objectives] This study was conducted to explore the effect of machine harvesting on ratooning ability of Guitang 47, and to provide basis for mechanized production of Guitang 47. [Methods] On the basis of mechanized ...[Objectives] This study was conducted to explore the effect of machine harvesting on ratooning ability of Guitang 47, and to provide basis for mechanized production of Guitang 47. [Methods] On the basis of mechanized planting and management of newly planted sugarcane Guitang 47, a comparative test of machine harvesting and manual harvesting was conducted, during which the plant generation rate, sugarcane yield, sucrose content and related agronomic traits of ratoon cane were continuously investigated in two years after machine harvesting of the newly planted sugarcane. [Results] There were no significant differences in the plant generation rate, plant height, stalk diameter, millable cane, sugarcane yield and sucrose content from manual harvesting of Guitang 47 in the first and second years after machine harvesting. In the second year after machine harvesting, the yields of ratoon cane and the sugar content reached 101.70 and 15.32 t/hm^2, respectively, which were equivalent to those of manual harvesting. [Conclusions] Guitang 47 has strong ratooning ability and lodging resistance and strong resistance to rolling and crushing, and is adaptive to full mechanized production. It should be promoted and accelerated in sugarcane areas lacking labor to reduce costs and increase benefits.展开更多
[Objective]The paper was to clarify the occurrence of sugarcane ratoon stunting disease(RSD)in Hainan sugarcane-growing areas.[Method]In 2019,270 samples of sugarcane leaves were collected from six main sugarcane-grow...[Objective]The paper was to clarify the occurrence of sugarcane ratoon stunting disease(RSD)in Hainan sugarcane-growing areas.[Method]In 2019,270 samples of sugarcane leaves were collected from six main sugarcane-growing areas in Hainan Province,and RSD was detected by PCR assay with specific primers.[Result]RSD was detected out in 41 out of 270 sugarcane samples,with an average detection rate of15.19%.The detection rates of RSD were different in six sugarcane-growing areas;the detection rate of RSD in Danzhou sugarcane-growing area was the highest of 22.00%;the detection rate of RSD in Lingao sugarcane-growing area was the lowest of 9.26%.RSD was detected out in 8 out of10 main sugarcane cultivars,among which Xintaitang 22 suffered the heaviest damage,with the positive detection rate of 45.83%;RSD had not been detected out in Zhongtang 1 and Zhongtang 2,while the positive detection rates of RSD in the remaining seven sugarcane cultivars were10.00%-31.25%.[Conclusion]RSD commonly occurs in Hainan sugarcane-growing areas.The research results provide a basis for scientific prevention and control of RSD and promotion and application of healthy virus-free sugarcane seedlings.展开更多
[Objectives]To study the effect of mechanical harvesting of main crop on soil rolling and yield of ratooned rice.[Methods]In this study,the harvesting method was optimized and improved through field research and theor...[Objectives]To study the effect of mechanical harvesting of main crop on soil rolling and yield of ratooned rice.[Methods]In this study,the harvesting method was optimized and improved through field research and theoretical research.[Results]Compared with farmers'habits,the mechanical harvesting method could significantly increase the working area per unit time and reduce the rolling area in the field,but it would increase the rolling rate of the land or transfer area.At the same time,the optimization method could reduce the soil bulk density in the primary rolling area,but it had no significant impact on soil compactness.[Conclusions]Compared with the farmer's customary method,the optimization method could reduce the crushing and damage of rice piles in the field,increase the seedling rate and panicle extraction rate,thus increasing the yield of rice in the ratooning season.展开更多
The effect of slow-release fertilizer application on reducing the fertilization times of ratooning rice was explored by carrying out plot experiments using different slow-release fertilizer formulas.The results showed...The effect of slow-release fertilizer application on reducing the fertilization times of ratooning rice was explored by carrying out plot experiments using different slow-release fertilizer formulas.The results showed that compared with conventional fertilization of farmers(TCK),there were no significant differences in plant heights of the first rice crop and ratoon rice crop and the number of tillers was slightly increased,by applying different ratios and types of slow-release fertilizers,indicating that reducing fertilization times did not affect rice growth.Compared with the TCK,the yields of treatments T1,T2,T3 and T4 of slow-release fertilizers increased to a certain extent.The yield of the first rice crop increased by 14.7%,16.7%,23.5% and 17.5%,respectively,the yields of the ratoon rice crop increased by 6.3%,5.8%,7.4% and 8.1%,respectively,and the yields of the two rice crops increased between 10.8% and 16.1%,indicating that reasonable combined application of slow-release nitrogen and fast-acting nitrogen fertilizer could meet the nutrient requirements of ratooning rice at different growth stages,and the application of slow-release fertilizers could reduce the fertilization times of ratooning rice.Based on the combination of rice yield and slow-release fertilizer cost in the first rice crop and ratoon rice crop,the T 3 formula was preferred,that is,urea-formaldehyde slow-release nitrogen fertilizer was used as the base and tillering fertilizer,and polyurethane-coated slow-release nitrogen fertilizer was used as the panicle-sprouting fertilizer.展开更多
Ratooning is common practice done in sugarcane with purpose of reducing the total cost of cultivation and early cane maturity.More than 35%of sugarcane productivity is lost due to improper attention of the farmers tow...Ratooning is common practice done in sugarcane with purpose of reducing the total cost of cultivation and early cane maturity.More than 35%of sugarcane productivity is lost due to improper attention of the farmers towards ratoons.Majority of farmers reported that the ratoonability wasn’t good when harvested in December-January.This experiment was carried out to find the appropriate ratoon shaving time with response to different varieties in sugarcane ratoon crop in the year 2018/19 at national sugarcane research project,Jitpur,Bara.The experiment was conducted in split plot design with four levels of cane genotypes as Co–0238,CoLk–94184,Co–0233 and CoS–07250 as the main plot factor while four harvesting dates as sub plot factor with three replications.Observations of a number of millable canes,single cane weight,plant height and single cane diameter were recorded,tabulated and analyzed in R-studio.Ratoon stubble shaving in the month of November had the highest number of millable canes(88079/ha)which wasn’t significantly different from the stubble shaving in the month of December,January.Likewise,highest cane yield(60.04 mt/ha),single cane weight(0.757 kg),cane diameter(2.11 cm),plant height(1.82 m)were found in early stubble shaving dates.Cane Yield and various yield parameter shows better performance in early ratoon shaving periods i.e.from November to January than late ratoon shaving dates.展开更多
This study was to develop the real-time fluorescence quantitative PCR technique for detecting the ratoon stunting disease (RSD) in virus-free seedcane seedlings. Healthy tissue culture seedlings were obtained from six...This study was to develop the real-time fluorescence quantitative PCR technique for detecting the ratoon stunting disease (RSD) in virus-free seedcane seedlings. Healthy tissue culture seedlings were obtained from six plants of sugarcane ROC22, which had been confirmed RSD-positive by detecting the sugarcane juice, by employing the sugarcane seedlings production protocol. Real-time fluorescence quantitative PCR was used to detect RSD pathogens in tissue culture samples. The results showed that target fragment of RSD pathogens was not found in all 10 samples in real-time fluorescence quantitative PCR, with the Ct values of 37-39. The healthy tissue culture sugarcane seedlings do not carry RSD pathogens, indicating that adopting healthy seedcane seedlings production technique could thoroughly get rid of RSD pathogens.展开更多
Rice ratooning refers to the production of second crop from the stubble after the harvest of main crop. Main and ratoon rice growth and development are affected by different factors. These factors include varieties se...Rice ratooning refers to the production of second crop from the stubble after the harvest of main crop. Main and ratoon rice growth and development are affected by different factors. These factors include varieties selection, water management,fertilizer management, stubble height, plant protection practices and external environmental factors such as temperature and light.In this review, we discussed the different factors affecting the yield and yield components of main and ratoon rice. Among these factors the most important and first one is varietal selection. Varieties should be selected according to the requirement of specific area and prefer varieties resistant to insects/pests and diseases. Sufficient amount of water and fertilizer should be supplied.Stubble height of 10-20 cm will resulted in high production of ratoon rice. Too low or too high temperature and light would reduce the grain yield and quality of rice. Optimal temperature is useful for higher yield. It was concluded that by keeping the management practices more efficiently, the yield of main rice as well as ratoon rice could be increased. There is a need of more studies focusing on improvement of the quality of ratoon rice.展开更多
Rice ratooning,the fast outgrowth of dormant buds on stubble,is an important cropping practice in rice production.However,the low ratooning ability(RA)of most rice varieties restricts the application of this cost-effi...Rice ratooning,the fast outgrowth of dormant buds on stubble,is an important cropping practice in rice production.However,the low ratooning ability(RA)of most rice varieties restricts the application of this cost-efficient system,and the genetic basis of RA remains unknown.In this study,we dissected the genetic architecture of RA by a genome-wide association study in a natural rice population.Rice ratooning ability 3(RRA3),encoding a hitherto not characterized nucleoredoxin involved in reduction of disulfide bonds,was identified as the causal gene of a major locus controlling RA.Overexpression of RRA3 in rice significantly accelerated leaf senescence and reduced RA,whereas knockout of RRA3 significantly delayed leaf senescence and increased RA and ratoon yield.We demonstrated that RRA3 interacts with Oryza sativa histidine kinase 4(OHK4),a cytokinin receptor,and inhibits the dimerization of OHK4 through disulfide bond reduction.This inhibition ultimately led to decreased cytokinin signaling and reduced RA.In addition,variations in the RRA3 promoter were identified to be associated with RA.Introgression of a superior haplotype with weak expression of RRA3 into the elite rice variety Guichao 2 significantly increased RA and ratoon yield by 23.8%.Collectively,this study not only uncovers an undocumented regulatory mechanism of cytokinin signaling through de-dimerization of a histidine kinase receptor-but also provides an eximious gene with promising value for ratoon rice breeding.展开更多
基金supported by the National Natural Science Foundation of China(42271360 and 42271399)the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(CAST)(2020QNRC001)the Fundamental Research Funds for the Central Universities,China(2662021JC013,CCNU22QN018)。
文摘Ratoon rice,which refers to a second harvest of rice obtained from the regenerated tillers originating from the stubble of the first harvested crop,plays an important role in both food security and agroecology while requiring minimal agricultural inputs.However,accurately identifying ratoon rice crops is challenging due to the similarity of its spectral features with other rice cropping systems(e.g.,double rice).Moreover,images with a high spatiotemporal resolution are essential since ratoon rice is generally cultivated in fragmented croplands within regions that frequently exhibit cloudy and rainy weather.In this study,taking Qichun County in Hubei Province,China as an example,we developed a new phenology-based ratoon rice vegetation index(PRVI)for the purpose of ratoon rice mapping at a 30 m spatial resolution using a robust time series generated from Harmonized Landsat and Sentinel-2(HLS)images.The PRVI that incorporated the red,near-infrared,and shortwave infrared 1 bands was developed based on the analysis of spectro-phenological separability and feature selection.Based on actual field samples,the performance of the PRVI for ratoon rice mapping was carefully evaluated by comparing it to several vegetation indices,including normalized difference vegetation index(NDVI),enhanced vegetation index(EVI)and land surface water index(LSWI).The results suggested that the PRVI could sufficiently capture the specific characteristics of ratoon rice,leading to a favorable separability between ratoon rice and other land cover types.Furthermore,the PRVI showed the best performance for identifying ratoon rice in the phenological phases characterized by grain filling and harvesting to tillering of the ratoon crop(GHS-TS2),indicating that only several images are required to obtain an accurate ratoon rice map.Finally,the PRVI performed better than NDVI,EVI,LSWI and their combination at the GHS-TS2 stages,with producer's accuracy and user's accuracy of 92.22 and 89.30%,respectively.These results demonstrate that the proposed PRVI based on HLS data can effectively identify ratoon rice in fragmented croplands at crucial phenological stages,which is promising for identifying the earliest timing of ratoon rice planting and can provide a fundamental dataset for crop management activities.
基金supported by the National Nature Science Foundation of China,the National Key Research and Development Program of China(302001109,2016YFD0300508,2017YFD0301602,2018YFD0301105)the Fujian and Taiwan Cultivation Resources Development and Green Cultivation Coordination Innovation Center,China(Fujian 2011 Project,2015-75)the Natural Science Foundation of Fujian Province,China(2022J01142)。
文摘Agronomic measures are the key to promote the sustainable development of ratoon rice by reducing the damage from mechanical crushing to the residual stubble of the main crop, thereby mitigating the impact on axillary bud sprouting and yield formation in ratoon rice. This study used widely recommended conventional rice Jiafuzhan and hybrid rice Yongyou 2640 as the test materials to conduct a four-factor block design field experiment in a greenhouse of the experimental farm of Fujian Agricultural and Forestry University, China from 2018 to 2019.The treatments included fertilization and no fertilization, alternate wetting and drying irrigation and continuous water flooding irrigation, and plots with and without artificial crushing damage on the rice stubble. At the same time, a 13C stable isotope in-situ detection technology was used to fertilize the pot experiment. The results showed significant interactions among varieties, water management, nitrogen application and stubble status.Relative to the long-term water flooding treatment, the treatment with sequential application of nitrogen fertilizer coupled with moderate field drought for root-vigor and tiller promotion before and after harvesting of the main crop, significantly improved the effective tillers from low position nodes. This in turn increased the effective panicles per plant and grains per panicle by reducing the influence of artificial crushing damage on rice stubble and achieving a high yield of the regenerated rice. Furthermore, the partitioning of 13C assimilates to the residual stubble and its axillary buds were significantly improved at the mature stage of the main crop, while the translocation rate to roots and rhizosphere soil was reduced at the later growth stage of ratooning season rice. This was triggered by the metabolism of hormones and polyamines at the stem base regulated by the interaction of water and fertilizer at this time. We therefore suggest that to achieve a high yield of ratoon rice with low stubble height under mechanized harvesting, the timely application of nitrogen fertilizer is fundamental,coupled with moderate field drying for root-vigor preservation and tiller promotion before and after the mechanical harvesting of the main crop.
基金supported by the Major International(Regional)Joint Research Project of National Natural Science Foundation of China(32061143038)the earmarked fund for China Agriculture Research System(CARS-01-20)+1 种基金the National High Technology Research and Development Program of China(the 863 Project,2014AA10A605)the Fundamental Research Funds for the Central Universities,China(2662020ZKPY015).
文摘The border effect(BE)is widely observed in crop field experiments,and it has been extensively studied in many crops.However,only limited attention has been paid to the BE of ratoon rice.We conducted field experiments on ratoon rice in Qichun County,Hubei Province,Central China in 2018 and 2019 to compare the BE in the main and ratoon crops,and to quantify the contribution of BE in the main crop to that in the ratoon crop.The BE of two hybrid varieties was measured for the outermost,second outermost,and third outermost rows in each plot of both crops.To determine the contribution of BE between the two crops,portions of hills in the outermost and second outermost rows were uprooted during the harvest of the main crop so that the second and third outermost rows then became the outermost rows in the ratoon crop.Overall,the BE on grain yield was greater in the main crop than in the ratoon crop.In the main crop,the BE on grain yield was 98.3%in the outermost row,which was explained by the BE on panicles m^(–2),spikelets/panicle,spikelets m^(–2),and total dry weight.In the ratoon crop,the BE on grain yield was reduced to 60.9 and 27.6%with and without the contribution of the BE in the main crop,respectively.Consequently,55.1%of the BE on grain yield in the ratoon crop was contributed from the main crop.High stubble dry weight and non-structural carbohydrate(NSC)accumulation at the harvest of the main crop were responsible for the contribution of BE in the main crop to that in the ratoon crop.Our results suggest that increases in stubble dry weight and NSC accumulation at the harvest of the main crop could be important strategies for developing high-yielding cropping practices in the rice ratooning system.
基金supported by the Key Research and Development Program of Heilongjiang,China(Grant No.2022ZX01A25)Cooperative Funding between Huazhong Agricultural University and Shenzhen Institute of Agricultural Genomics(Grant No.SZYJY2022014)+2 种基金Fundamental Research Funds for the Central Universities,Beijing,China(Grant Nos.2662022JC006 and 2662022ZHYJ002)National Natural Science Foundation of China(Grant No.32101819)Huazhong Agriculture University Research Startup Fund,China(Grant Nos.11041810340 and 11041810341).
文摘Pre-harvest yield prediction of ratoon rice is critical for guiding crop interventions in precision agriculture.However,the unique agronomic practice(i.e.,varied stubble height treatment)in rice ratooning could lead to inconsistent rice phenology,which had a significant impact on yield prediction of ratoon rice.Multi-temporal unmanned aerial vehicle(UAV)-based remote sensing can likely monitor ratoon rice productivity and reflect maximum yield potential across growing seasons for improving the yield prediction compared with previous methods.Thus,in this study,we explored the performance of combination of agronomic practice information(API)and single-phase,multi-spectral features[vegetation indices(VIs)and texture(Tex)features]in predicting ratoon rice yield,and developed a new UAV-based method to retrieve yield formation process by using multi-temporal features which were effective in improving yield forecasting accuracy of ratoon rice.The results showed that the integrated use of VIs,Tex and API(VIs&Tex+API)improved the accuracy of yield prediction than single-phase UAV imagery-based feature,with the panicle initiation stage being the best period for yield prediction(R^(2) as 0.732,RMSE as 0.406,RRMSE as 0.101).More importantly,compared with previous multi-temporal UAV-based methods,our proposed multi-temporal method(multi-temporal model VIs&Tex:R^(2) as 0.795,RMSE as 0.298,RRMSE as 0.072)can increase R^(2) by 0.020-0.111 and decrease RMSE by 0.020-0.080 in crop yield forecasting.This study provides an effective method for accurate pre-harvest yield prediction of ratoon rice in precision agriculture,which is of great significance to take timely means for ensuring ratoon rice production and food security.
基金supported by the Major International (Regional)Joint Research Project of National Natural Science Foundation of China (32061143038)the China Agriculture Research System(CARS-01-20)the Fundamental Research Funds for the Central Universities (2662020ZKPY015)。
文摘Yield loss(Y_(Loss)) in the ratoon crop due to crushing damage to left stubble from mechanical harvesting of the main crop is a constraint for wide adoption of mechanized rice ratooning technology.Soil drying before the harvest of the main crop has been proposed to overcome this problem.The objective of this study was to determine the effect of soil drying during the mid-to-late grain filling stage of the main crop on grain yield of the ratoon crop in a mechanized rice ratooning system.Field experiments were conducted to compare Y_(Loss) between light(LD) and heavy(HD) soil drying treatments in Hubei province,central China in 2017 and 2018.Y_(Loss) was calculated as the percentage of yield reduction in the ratoon crop with the main crop harvested mechanically,relative to the grain yield of the ratoon crop with the main crop harvested manually.In comparison with LD,soil hardness was increased by 42.8%-84.7% in HD at the 5-20 cm soil depth at maturity of the main crop.Soil hardness at 5 and 10 cm depths reached respectively 4.05 and 7.07 kg cm^(-2) in HD.Soil drying treatment did not significantly affect the grain yield of the main crop.Under mechanical harvesting of the main crop,HD increased the grain yield of the ratoon crop by 9.4% relative to LD.Consequently,Y_(Loss) was only 3.4% in HD,in contrast to 16.3% in LD.The differences in grain yield and Y_(Loos) between the two soil drying treatments were explained mainly by panicles m^(-2),which was increased significantly by HD in the track zone of the ratoon crop compared with LD.These results suggest that heavy soil drying practice during the mid-to-late grain filling stage of the main crop is effective for reducing Y_(Loss) of the ratoon crop in a mechanized rice ratooning system.
文摘Ratoon rice cropping is an important component of the rice cropping system in Texas and south Louisiana,USA,and expanded to Asian countries in 1970.Two field studies were conducted with widely planted rice(Oryza sativa L.)cultivars at Eagle Lake,Texas,USA to determine the effects of nitrogen(N)management in main(first)crop(MC)and ratoon(second)crop(RC)on RC yield.In 2012 and 2013,one cultivar(Presidio)was adopted to determine the effects of RC N management on ratoon yield and head rice yield.In 2016 and 2017,CL153,CL163 and CL272 in addition to Presidio were adopted to examine the effect of MC N management on ratoon yield and head rice yield.N applied at preflood after MC harvest considerably improved RC yield.Application of 99 kg N ha^(–1)at preflood after MC harvest was practically adequate for RC regrowth,development and approaching the yield potential for Presidio.RC could produce quite high average grain yields of 5.90 to 6.53 t ha–1 in 2012 and 2013,respectively.Main crop N rate only significantly affected MC yield;however,given N applied of 99 kg ha^(–1)at preflood after MC harvest,ratoon yield was not significantly affected by MC N rate.Neither the main nor ratoon crop N management had a significant effect on RC head rice yield.Considerable RC head rice yields(55–65%)were observed in all of the four cultivars and 4 years except for CL272 in 2016.These results indicat that without very high N fertilizer application,rice ratoon crop could produce a considerable grain yield and an expectative head rice yield.Rice ratooning could be a practical way to increase rice yields with the minimal input in south Texas and regions with a similar climate.
基金funded by the National Key Research and Development Program of China(2016YFD0300508,2017YFD0301602 and 2018YFD0301105)the FujianTaiwan Joint Innovative Centre for Germplasm Resources and Cultivation of Crop,China(Fujian 2011 Program+1 种基金2015-75)the Science and Technology Development Fund of Fujian Agriculture and Forestry University,China(KF2015043)。
文摘This study attempted to clarify the carrying-over effect of different nitrogen treatments applied to the main crop on the crop population growth and yield formation of ratoon rice under mechanized cultivation in Southeast China.Based on the constant total nitrogen application amounts(225.00 kg ha;)in the main crop,an experiment with different ratios of basal and topdressing nitrogen fertilizer(the ratio of basal fertilizer:primary tillering fertilizer:secondary tillering fertilizer:booting fertilizer at 3:1:2:4(N1),3:2:1:4(N2),3:3:0:4(N3),and 4:3:0:3(N4),respectively,and a control without nitrogen treatment(N0))was set up across two consecutive years in field using hybrid rice variety Yongyou 1540 as the test materials.The results showed that the total tiller number and effective tillering percentage increased in the main crop under the N1 treatment,more nitrogen fertilizer applied in late growth stage of the main crop,and its effective tillering percentage of the main crop was the highest at up to 70.18%,which was 9.15%higher than that of conventional fertilization treatment(N4),more nitrogen fertilizer applied in early growth stage of the main crop.The same tendency was observed in leaf area index(LAI)value of the main crop and its subsequent ratoon rice,which were 16.52 and 29.87%higher,respectively,in the N1 treatment than that in the N4 treatment at the full heading stage.The same was true in the case of the transport rates of stem and sheath dry mater and the canopy light interception rates in both the main and its ratoon crops.The transport rate of stem and sheath in main crop rice under N1 treatment increased by 50.57%compared with N4 treatment.The canopy light interception rate of N1 treatment increased by 5.07%compared with N4 treatment at the full heading stage of the ratoon crop.Therefore,the total actual yield was the highest in the main and its ratoon crops under N1 treatment,averaging 17351.23 kg ha;in two-year trials,which was 23.00%higher than that in the conventional fertilization treatment(N4).The results showed that appropriate nitrogen treatment was able to produce a good crop stand in the main crop,which was essential for producing a good ratoon crop population and high yield especially under mechanized cultivation with low stubble height of the main crop.The study suggested that shifting the proper nitrogen application amounts to the late growth stage of the main crop,such as N1 treatment,not only had a higher productive effect on ensuring the yield of the main crop,but also had a positive effect on the axillary bud sprouts from the stubbles for ratoon rice,resulting in an increased percentage of productive panicles and achieving the goal of one planting with two good harvests under the conditions of our study.
基金Supported by Modern Agricultural Industry Technology System in Henan Province(S2015-04-04)Key Scientific and Technological Project in Henan Province(132102110023)
文摘In order to determine the optimal sowing date of ratoon rice in South Henan's rice-growing areas,this paper performs a comparative analysis of rice growth process,seedling quality and yield of first season rice and ratoon rice under different sowing date treatments. The results show that under climatic conditions( 2014),by using dry seedling cultivation in a small plastic shed,the growth of seedling sown on February21 was affected,while the sowing treatments from March 1 to April 11 can breed normal seedlings,and in this period,the maturity period of first season rice was delayed with prolonged sowing date,and ratoon rice yield declined with prolonged sowing date( total production of rice sown on 11 March reaching a peak). Thus,it is considered that the optimal sowing date of ratoon rice in South Henan's rice-growing areas is mid-March.
文摘The ratoon crop occupies approximately 40% of the total area of sugarcane crop in tropical India. The main reason for the lower average cane productivity is the yield decline in ratoon crops (40 - 50 t/ha) despite the release of the high yielding varieties and advanced cane production technology. The physiological factors associated with ratooning performance and the variation in growth and yield were studied in 11 sugarcane varieties in two cycles of one plant and two ratoon crops each. The first ratoon and second ratoon crop showed 17.0% and 28.1% reduction in tiller production and 15.5% and 15.7% reduction in NMC, respectively, over plant crop. The differences in growth parameters between the plant and ratoon crops at the formative phase were lesser than that of grand growth and maturity phases. Varieties Co 86032, Co 97008, Co 95020 Co 99004 and Co 2000-10 showed better physiological efficiency in terms of plant height, shoot population, leaf size, TDMP, partitioning efficiency, chlorophyll content and nitrate reductase activity and significantly higher yield components such as NMC, SCW, cane length, internodal length as well as cane yield compared to other varieties. The higher reduction in ratoon yield in Co 99008, Co 94012, Co 8021 and Co 97009 (>35.00% reduction) was due to higher reduction in tiller production associated with stunted plant growth and root system, reducetion in individual leaf size and LAI, TDMP, total chlorophyll content, NMC, internodal length and SCW. The results obtained indicated that the plant height, TDMP, stem partitioning, leaf size, total chlorophyll content, SCW, cane length and cane girth were highly associated with yield of first and second ratoon crops than that of plant crop. Therefore the difference in the association between physiological parameters with yield of plant and ratoon crops therefore decides the ratooning potential of the crop.
基金supported by the National Key R&D Program of China(No.2018YFD0301002)the Earmarked Fund for China Agriculture Research System(No.CARS-01-26).
文摘Rice ratooning,or the production of a second rice crop from stubble after the harvest of the main crop,is considered to be a green and resource-efficient rice production system.The present study was conducted to examine variance in amylose content(AC),grain morphology,crystal structure,and thermal properties of starch between main-and ratoon-season rice of seven varieties.Ratoon-season rice grains had higher ACs and significantly lower transition gelatinization temperatures(To,Tp,and Tc)than did main-season rice grains.The relative crystallinity and lamellar peak intensity of ratoon-season rice starch were 7.89%and 20.38%lower,respectively,than those of main-season rice starch.In addition,smaller granules with smoother surfaces and lower thermal parameters were observed in the starch of ratoon-season rice.The relative crystallinity and lamellar peak intensity of starch correlated negatively with the AC and positively with transition gelatinization temperatures.These results suggest that the superior cooking quality of ratoon-season rice is attributable to the moderate increase of grain AC,which reduces the relative crystallinity,weakens the crystal structure,and lead to a decrease in the gelatinization temperature.
基金Special Fund of Sugarcane Industry Technical System of National Modern Agriculture (CARS-20-3-2)Nanning Key Scientific and Technological Project (201102027B)+1 种基金Special Fund of Agriculture Mechanization Administration of Nanning (2010)Project of Guangxi Graduate Education Innovation (2010)
文摘The experiment was conducted with the traditional manual harvesting and mechanical harvesting of sugarcane,to compare the effects of different harvesting method on the sugarcane stubble quality and the growth of ratoon.The experimental results are as follows.(i) The stubble height and breaking stubble rate of mechanical harvesting was significantly higher than manual harvesting,the stubble height of lodging species and difficult defoliation species increased in mechanical harvesting condition.Varieties with higher levels of fiber had lower rate of broken stubble.(ii) The effects of mechanical harvesting on germination of next year ratoon were quite different due to different varieties,indicating that the better perennial species have less impact than the poor perennial species.(iii) Compared with manual harvesting,mechanical harvesting had slightly higher plant height and single-stem weight and less effective stems number,the difference of cane yield was not significant,but sucrose content increased 0.53%.(iv) Mechanical harvesting combining with leaves crushing could reduce the impact on the germination of ratoon,improve the single-stem weight and increase the effective number of stems.
基金Supported by Guangxi Scientific Research and Technology Development Program(GK AB 16380177)Project of Province and Ministry Co-sponsored Collaborative Innovation Center of Sugarcane IndustryGuangxi Special Finance Project
文摘[Objectives] This study was conducted to explore the effect of machine harvesting on ratooning ability of Guitang 47, and to provide basis for mechanized production of Guitang 47. [Methods] On the basis of mechanized planting and management of newly planted sugarcane Guitang 47, a comparative test of machine harvesting and manual harvesting was conducted, during which the plant generation rate, sugarcane yield, sucrose content and related agronomic traits of ratoon cane were continuously investigated in two years after machine harvesting of the newly planted sugarcane. [Results] There were no significant differences in the plant generation rate, plant height, stalk diameter, millable cane, sugarcane yield and sucrose content from manual harvesting of Guitang 47 in the first and second years after machine harvesting. In the second year after machine harvesting, the yields of ratoon cane and the sugar content reached 101.70 and 15.32 t/hm^2, respectively, which were equivalent to those of manual harvesting. [Conclusions] Guitang 47 has strong ratooning ability and lodging resistance and strong resistance to rolling and crushing, and is adaptive to full mechanized production. It should be promoted and accelerated in sugarcane areas lacking labor to reduce costs and increase benefits.
基金Supported by National Natural Science Foundation of China(31771865)National Sugar Industry Technology System"Scientists for Prevention and Control of Sugarcane Virus Diseases"(CARS-170301)。
文摘[Objective]The paper was to clarify the occurrence of sugarcane ratoon stunting disease(RSD)in Hainan sugarcane-growing areas.[Method]In 2019,270 samples of sugarcane leaves were collected from six main sugarcane-growing areas in Hainan Province,and RSD was detected by PCR assay with specific primers.[Result]RSD was detected out in 41 out of 270 sugarcane samples,with an average detection rate of15.19%.The detection rates of RSD were different in six sugarcane-growing areas;the detection rate of RSD in Danzhou sugarcane-growing area was the highest of 22.00%;the detection rate of RSD in Lingao sugarcane-growing area was the lowest of 9.26%.RSD was detected out in 8 out of10 main sugarcane cultivars,among which Xintaitang 22 suffered the heaviest damage,with the positive detection rate of 45.83%;RSD had not been detected out in Zhongtang 1 and Zhongtang 2,while the positive detection rates of RSD in the remaining seven sugarcane cultivars were10.00%-31.25%.[Conclusion]RSD commonly occurs in Hainan sugarcane-growing areas.The research results provide a basis for scientific prevention and control of RSD and promotion and application of healthy virus-free sugarcane seedlings.
文摘[Objectives]To study the effect of mechanical harvesting of main crop on soil rolling and yield of ratooned rice.[Methods]In this study,the harvesting method was optimized and improved through field research and theoretical research.[Results]Compared with farmers'habits,the mechanical harvesting method could significantly increase the working area per unit time and reduce the rolling area in the field,but it would increase the rolling rate of the land or transfer area.At the same time,the optimization method could reduce the soil bulk density in the primary rolling area,but it had no significant impact on soil compactness.[Conclusions]Compared with the farmer's customary method,the optimization method could reduce the crushing and damage of rice piles in the field,increase the seedling rate and panicle extraction rate,thus increasing the yield of rice in the ratooning season.
基金Supported by National Key Research and Development Project(No.2018YFD0301302).
文摘The effect of slow-release fertilizer application on reducing the fertilization times of ratooning rice was explored by carrying out plot experiments using different slow-release fertilizer formulas.The results showed that compared with conventional fertilization of farmers(TCK),there were no significant differences in plant heights of the first rice crop and ratoon rice crop and the number of tillers was slightly increased,by applying different ratios and types of slow-release fertilizers,indicating that reducing fertilization times did not affect rice growth.Compared with the TCK,the yields of treatments T1,T2,T3 and T4 of slow-release fertilizers increased to a certain extent.The yield of the first rice crop increased by 14.7%,16.7%,23.5% and 17.5%,respectively,the yields of the ratoon rice crop increased by 6.3%,5.8%,7.4% and 8.1%,respectively,and the yields of the two rice crops increased between 10.8% and 16.1%,indicating that reasonable combined application of slow-release nitrogen and fast-acting nitrogen fertilizer could meet the nutrient requirements of ratooning rice at different growth stages,and the application of slow-release fertilizers could reduce the fertilization times of ratooning rice.Based on the combination of rice yield and slow-release fertilizer cost in the first rice crop and ratoon rice crop,the T 3 formula was preferred,that is,urea-formaldehyde slow-release nitrogen fertilizer was used as the base and tillering fertilizer,and polyurethane-coated slow-release nitrogen fertilizer was used as the panicle-sprouting fertilizer.
文摘Ratooning is common practice done in sugarcane with purpose of reducing the total cost of cultivation and early cane maturity.More than 35%of sugarcane productivity is lost due to improper attention of the farmers towards ratoons.Majority of farmers reported that the ratoonability wasn’t good when harvested in December-January.This experiment was carried out to find the appropriate ratoon shaving time with response to different varieties in sugarcane ratoon crop in the year 2018/19 at national sugarcane research project,Jitpur,Bara.The experiment was conducted in split plot design with four levels of cane genotypes as Co–0238,CoLk–94184,Co–0233 and CoS–07250 as the main plot factor while four harvesting dates as sub plot factor with three replications.Observations of a number of millable canes,single cane weight,plant height and single cane diameter were recorded,tabulated and analyzed in R-studio.Ratoon stubble shaving in the month of November had the highest number of millable canes(88079/ha)which wasn’t significantly different from the stubble shaving in the month of December,January.Likewise,highest cane yield(60.04 mt/ha),single cane weight(0.757 kg),cane diameter(2.11 cm),plant height(1.82 m)were found in early stubble shaving dates.Cane Yield and various yield parameter shows better performance in early ratoon shaving periods i.e.from November to January than late ratoon shaving dates.
基金Supported by Special Funds for Basic Scientific Research of Guangxi Sugarcane Research Institute(G2009006,G2010006,G2009015)Sci-tech Research and Development Program of Guangxi Academy of Agricultural Sciences(200805)
文摘This study was to develop the real-time fluorescence quantitative PCR technique for detecting the ratoon stunting disease (RSD) in virus-free seedcane seedlings. Healthy tissue culture seedlings were obtained from six plants of sugarcane ROC22, which had been confirmed RSD-positive by detecting the sugarcane juice, by employing the sugarcane seedlings production protocol. Real-time fluorescence quantitative PCR was used to detect RSD pathogens in tissue culture samples. The results showed that target fragment of RSD pathogens was not found in all 10 samples in real-time fluorescence quantitative PCR, with the Ct values of 37-39. The healthy tissue culture sugarcane seedlings do not carry RSD pathogens, indicating that adopting healthy seedcane seedlings production technique could thoroughly get rid of RSD pathogens.
基金Supported by the National Basic Research Program of China(2016YFD0300208)
文摘Rice ratooning refers to the production of second crop from the stubble after the harvest of main crop. Main and ratoon rice growth and development are affected by different factors. These factors include varieties selection, water management,fertilizer management, stubble height, plant protection practices and external environmental factors such as temperature and light.In this review, we discussed the different factors affecting the yield and yield components of main and ratoon rice. Among these factors the most important and first one is varietal selection. Varieties should be selected according to the requirement of specific area and prefer varieties resistant to insects/pests and diseases. Sufficient amount of water and fertilizer should be supplied.Stubble height of 10-20 cm will resulted in high production of ratoon rice. Too low or too high temperature and light would reduce the grain yield and quality of rice. Optimal temperature is useful for higher yield. It was concluded that by keeping the management practices more efficiently, the yield of main rice as well as ratoon rice could be increased. There is a need of more studies focusing on improvement of the quality of ratoon rice.
基金the National Natural Science Foundation of China(grants 31930080 and 31821005)the Hubei Hongshan Laboratory(grants 2022hszd015).
文摘Rice ratooning,the fast outgrowth of dormant buds on stubble,is an important cropping practice in rice production.However,the low ratooning ability(RA)of most rice varieties restricts the application of this cost-efficient system,and the genetic basis of RA remains unknown.In this study,we dissected the genetic architecture of RA by a genome-wide association study in a natural rice population.Rice ratooning ability 3(RRA3),encoding a hitherto not characterized nucleoredoxin involved in reduction of disulfide bonds,was identified as the causal gene of a major locus controlling RA.Overexpression of RRA3 in rice significantly accelerated leaf senescence and reduced RA,whereas knockout of RRA3 significantly delayed leaf senescence and increased RA and ratoon yield.We demonstrated that RRA3 interacts with Oryza sativa histidine kinase 4(OHK4),a cytokinin receptor,and inhibits the dimerization of OHK4 through disulfide bond reduction.This inhibition ultimately led to decreased cytokinin signaling and reduced RA.In addition,variations in the RRA3 promoter were identified to be associated with RA.Introgression of a superior haplotype with weak expression of RRA3 into the elite rice variety Guichao 2 significantly increased RA and ratoon yield by 23.8%.Collectively,this study not only uncovers an undocumented regulatory mechanism of cytokinin signaling through de-dimerization of a histidine kinase receptor-but also provides an eximious gene with promising value for ratoon rice breeding.
