Rice Yield Estimation by Integrating Remote Sensing with Rice Growth Simulation Model

Since remote sensing can provide information on the actual status of an agricultural crop, the integration between remote sensing data and crop growth simulation models has become an important trend for yield estimation and prediction.The main objective of this research was to combine a rice growth simulation model with remote sensing data to estimate rice grain yield for different growing seasons leading to an assessment of rice yield at regional levels. Integration between NOAA (National Oceanic and Atmospheric Administration) AVHRR (Advanced Very High Resolution Radiometer) data and the rice growth simulation model ORYZA1 to develop a new software, which was named as Rice-SRS Model, resulted in accurate estimates for rice yield in Shaoxing, China, with an estimation error reduced to 1.03% and 0.79% over-estimation and 0.79% under-estimation for early, single and late season rice, respectively. Selecting suitable dates for remote sensing images was an important factor which could influence estimation accuracy. Thus, given the different growing periods for each rice season, four images were needed for early and late rice, while five images were preferable for single season rice.Estimating rice yield using two or three images was possible, however, if images were obtained during the panicle initiation and heading stages.

Effects of Temperature,Humidity and Different Rice Growth Stages on Vertical Migration of Aphelenchoides besseyi

The vertical migration of Aphelenchoides besseyi under different temperatures and humidities and at different rice growth stages was investigated. It was found that the optimum temperature for the development and reproduction of A. besseyiwas 25-30℃. At the same temperature, the rate of vertical migration increased with rising relative humidity. Artificial inoculation tests showed that at the elongation stage, nematodes survived mainly on the upper and middle parts of rice culms and the number of nematodes decreased by 50% at 20 days after inoculation compared with that at 5 days after inoculation. Whereas at the booting stage, nematodes accumulated in young panicles and reproduced quickly,, and the average number of nematodes at 20 days after inoculation increased to 164.5, three times of that at 5 days after inoculation.

A Rice Growth Models (RGM) System by Object-Oriented Programming with Visual C++

Object-oriented programming divides the crop production into subsystems and simulates their behaviors. Many classes were designed to simulate the behaviors of different parts or different physiological processes in crop production system. At the same time, many classes have to be employed for bettering user's interface. But how to manage these classes on a higher level to cooperate them into a perfect system is another problem to study. The Rice Growth Models (RGM) system represents an effort to define and implement a framework to manage these classes. In RGM system, the classes were organized into the model-document-view architecture to separate the domain models, data management and user interface. A single document with multiple views interface frame window was adopted in RGM. In the architectures, the simulation models only exchange data with documents while documents act as intermediacies between simulation models and interfaces. Views get data from documents and show the results to users. The classes for the different functions can be grouped into different architectures. Different architectures communicate with each other through documents. The classes for the different functions can be grouped into different architectures. By using the architecture, communication between classes is more efficient. Modeler can add classes in architectures or other architectures to extend the system without having to change system structure, which is useful for construction and maintenance of agricultural system models.

Functions of Phytochrome in Rice Growth and Development

Phytochrome family mainly senses red and far-red light to regulate a range of developmental processes throughout the life cycle of plants. Rice phytochrome gene family is composed of three members known as PHYA, PHYB and PHYC. It has been elucidated that individual phytochromes display both unique and overlapping roles in rice photomorphogenesis by characterization of all rice phytochrome mutants including single mutants, all combinations of double mutants as well as triple mutants. Based on the published data and authors’ ongoing studies, current knowledge of rice phytochrome functions in regulating seedling de-etiolation, root gravitropic response and elongation, plant architecture, flowering time and fertility is summarized. Additionally, the important issues in the field of rice phytochromes are proposed.

Effects of Rice Husk and Rice Husk Charcoal on Soil Physicochemical Properties, Rice Growth and Yield

To investigate the effect of the application of rice husk (RH) and rice husk charcoal (RHC) on soil properties and rice production, pot experiment comprising of five treatments was conducted. Soil was mixed at the rate of 0 (control), 2% and 4% (w/w) with RH and RHC, respectively with randomized complete block design (RCBD). RHC incorporation had a potential to reduce the acidity of the soil, whereas, RH incorporation had almost no effect on the pH of the soil. RH and RHC amendment both increased the saturated hydraulic conductivity, saturated water content, plant available water and field capacity but decreased the bulk density of soil. Crop growth components at harvest revealed that the highest plant height was recorded in RH4%. However, for the panicle length, panicle weight and number of tillers, the highest value was found in RHC2%, 14.2 cm, 4.0 g and 28.8 cm, respectively. Furthermore, number of panicle, 1000-grains weight and grain yield were also found highest in RHC2%, 22.4 g and 4.41 t/ha, respectively. However, for the number of grain per panicle and percentage of filled grain, the highest value was found in RH4%, 79.0 and 88.5, respectively. The grain yield increased by 38%, 28%, 18% and 22% and the biological yield increased by 27%, 18%, 14%, and 16% for RHC2%, RHC4%, RH2%, and RH4%, respectively, compared to that of the control;however, the significant difference was found only for RHC2% for both. The harvest index increased under all application rates of RH and RHC compared to that of control.

Effect of Silicon Application on Rice Growth and Production Structure

This paper studies the effect of silicon on the growth and production structure of rice( Oryza sativa L.),and proposes the appropriate applying amount of silicon. The results show that the application of silicon fertilizer to rice can increase specific leaf weight and leaf area index,and improve rice yield by increasing grain number,kernel number and thousand kernel weight. The growth rate of rice yield is 3. 45%-15. 69% by applying silicon. In the Jianghan Plain,the applying amount of silicon fertilizer for rice( SiO_2) is recommended at 15-30 kg/ha.

Integrated sensor system for monitoring rice growth conditions based on unmanned ground vehicle system

Ground-based platform systems provide a good tool for monitoring and managing crop conditions in precision agriculture applications and have been widely used for monitoring crop conditions.To develop an unmanned ground vehicle system(UGVS)based multi-sensors and test the feasibility of this system for monitoring rice conditions,an UGVS was developed to collect real-time rice condition information including NDVI values,reflectance measurements and crop canopy temperature in this study.Major components of the integrated system are GreenSeeker R100 system,hyper-spectroradiometer and infrared temperature sensor.The leaf area index(LAI)was measured by the CGMD302 Spectrometer.The Independent Samples T-Test method and the one way ANOVA method were used to determine the best spectral indices and analyze the relationship between the vegetation indices and rice LAI.It was found that the two best spectral indices for estimating LAI were NDVI(860 nm and 750 nm)with the correlation coefficient(R^(2))at 0.745 and RVI(853 nm and 751 nm)with the R^(2)at 0.724.The results show the UGVS can support multi-source information acquisition and is useful for crop management and precision agriculture applications.

SDG721 and SDG705 are required for rice growth

Summary H3K4me3 plays important roles in development, transcription, and environmental responses. Here, we report that SDG721 （SET-domain group protein 721） and SDG705 are involved in regulating rice development. SDG721 and SDG705 encode TRITHORAX-Iike proteins, which appear to modulate H3K4 methylation levels. Loss of SDG721 and SDG705 function resulted in GA-deficient phenotypes, including semi-dwarfism, reduced cell length, and reduced panicle branching.

Effect of K and Al on Growth and Nutrient Uptake of Rice

The effects of K and Al in K-deficient and complete nutrient solutions on the growth and nutrient uptake of rice were studied in the work. The effect of Al on the growth of roots and above-ground part of rice was associated with the concentration of Al in solution. A low level (0.1 mmol L-1) of Al promoted but a high level (1 mmol L-1) of Al inhibited the growth of both the root and the aerial part of rice, and the magnitude of K concentration in the nutrient solution also had an appreciable impact on this. Thus, in the low-Al solution, the plant treated with K2 (80 mg K L-1) produced much longer roots, showing the presence of interaction between Al and K; in the high-Al solution the K-treated plant had more and longer roots and a considerably greater dry weight of the above-ground pat compared with the plant deficient in K, showing the alleviating effect of K+ on Al toxicity.The mechanism of the Al-K interaction affecting the rice aerial part growth is not yet known, but part of the reason might be that the excessive amount of Al inhibited the uptake of some nutrients such as Ca and Mg and reduced their transfer to the plant aerial organs, whereas K showed its compensating effect on this; therefore, K could relieve Al toxicity at a high level of Al and promoted rice growth at a lOw level of Al.

Effects of elevated ozone on growth and yield of field-grown rice in Yangtze River Delta,China

With rapid industrialization and urbanization in the Yangtze Delta, China, the tropospheric ozone concentration has increased to levels that induce crop yield loss. Rice, a widely grown crop in China, was investigated in field-established, open-top chambers. Four treatments were used： charcoal-filtered air （CF）, non-charcoal-filtered air （NF）, and charcoal-filtered air with two levels of additional ozone （O3-1 and O3-2）. The AOT40s （accumulated hourly mean ozone concentration above 40 ppbv） were 0, 0.91, 23.24, and 39.28 ppmv.h for treatment of CE NF, O3-1, and O3-2, respectively. The rice height and biomass were reduced in the elevated ozone concentration. Less organic matter partitioning to roots under the elevated ozone significantly decreased rice root activity. The yield loss was 14.3% and 20.2% under O3-1 and O3-2 exposure, respectively. This was largely caused by a reduction in grain weight per panicle.

Effect of Rice Straw Biochar on Soil Quality and the Early Growth and Biomass Yield of Two Rice Varieties

Sustainable rice production in Sierra Leone faces serious constraints due to soil acidity, low cation exchange capacity, low nutrient contents accelerated mineralization of soil organic matter and soil loss by erosion (particularly on the uplands). One possible approach to addressing the soil constraints to rice production both on uplands and lowlands of Sierra Leone is the recycling of rice residues through biochar production and application to soils. A pot experiment was conducted to investigate the effects of application of biochar from rice residues on (i) soil physicochemical properties and (ii) the early growth characteristics of two rice varieties, NERICA L19 and ROK3. The experiment was arranged in a completely randomized design (CRD) with two biochar levels (0 and 15 g/kg soil) and two rice varieties in three replications. For the biochar treated soils (+biochar), 75 g rice straw biochar was applied to 5 kg air-dry soil (15 kg biochar/kg soil), mixed thoroughly and placed into perforated black polythene bags. Seeds of two rice varieties, NERICA L19 and ROK3 were planted on the treated and untreated soils for eight weeks. Application of biochar improved available phosphorus, exchangeable cations and cation exchange capacity in biochar treated soils compared to the control soil without biochar. Plant height, tiller number, and dry biomass weight of both rice varieties grown in soils amended with rice straw biochar were significantly higher than those on untreated soils. The most remarkable increase in plant growth characteristics as a result of biochar addition to soil was reflected in the biomass yield and tiller numbers. Dry shoot biomass for ROK3 rice variety varied significantly from a mean of 3.5 g (control) to 26.2 g (+biochar) while tiller numbers significantly varied from 10 (control) to 29.6 (+biochar). Similarly, for NERICA L19 rice variety, dry shoot biomass increased significantly from 4.5 g (control) to 22.7 g (+biochar) while tiller numbers increased significantly from a mean of 12.3 (control) to 30 (+biochar). Thus converting rice residues to biochar and applying to soil holds promise for improving rice production in Sierra Leone.

Rice plant growth and yield: foliar application of plasma activated water

Plasma activated water(PAW)was prepared for 10 min to be applied one tofive times as a foliar spray to rice plants,to investigate plant growth,yield and the concentrations of total soluble protein and sugar in the rice grains produced.The results reveal that(1)the plant height,stem diameter,dry weight,chlorophyll and total carotene concentrations were improved by∼15%,∼25%,∼24%,∼47%and∼45%,respectively,with respect to control,(2)defense mechanisms of the plants treated with PAW were improved,(3)concentrations of total soluble protein and sugar were enhanced in the rice grains of PAW treated plants and(4)yield was increased by∼14%.

Effects of Four Pesticides on Grain Growth Parameters of Rice

Effect of four commonly used pesticides, triadlmefon, jingganmycin, triazoplos andimidacloprid, on grain growth parameters was examined using a growth equation in thepresent paper. Two hundreds of spikes, not damaged by pests were simultaneously markedper plot during the heading stage of rice. Rice plants were sprayed at 1 d after marking.Thereafter, 20 spikes were sampled at 4 d intervals and dried in an oven. Then, 10superior and inferior grains were picked from each spike, and brown rice was weighedafter shelling, respectively. First, second and third order derivates were deduced fromthe following grain growth formula:bt-aKwe1+=, where W was the weight of 100 grains brownrice at time t; K was maximum of grain growth; a and b were parameters of the formula. Theparameters were calculated as following:Where R0, △t, GT and Vmax were initial growth power, active growth stage, accumulativeweight of dried content during △t and maximum growth rate, respectively. The resultshowed that GT and K of superior grain following 22.5 and 45 ga.i.ha-1 of imidaclopridsprays were significantly reduced, and △t was significantly decreased for 112.5 and 225ga.i.ha-1 jingganmycin treatments. In addition, the high dose of imidacloprid signifi-cantly reduced the weight of 1000 rice grains by 9.77%. However, there was no significantdifference for the weight of 1000 grains between the high dose of jingganmycin and thecontrol, indicating that effective duration of jingganmycin on grain filling was shorterthan that of imidacloprid.

Comparison of Effect of Brassinosteroid and Gibberellin Biosynthesis Inhibitors on Growth of Rice Seedlings

Brassinosteroid（BR） and gibberellin（GA） are two predominant plant hormones that regulate plant cell elongation. Mutants disrupt the biosynthesis of these hormones and display different degrees of dwarf phenotypes in rice. Although the role of each plant hormone in promoting the longitudinal growth of plants has been extensively studied using genetic methods, their relationship is still poorly understood. In this study, we used two specific inhibitors targeting BR and GA biosynthesis to investigate the roles of BR and GA in growth of rice seedlings. Yucaizol, a specific inhibitor of BR biosynthesis, and Trinexapac-ethyl, a commercially available inhibitor of GA biosynthesis, were used. The effect of Yucaizol on rice seedlings indicated that Yucaizol significantly retarded stem elongation. The IC_（50） value was found to be approximately 0.8 μmol/L. Yucaizol also induced small leaf angle phenocopy in rice seedlings, similarly to BR-deficient rice, while Trinexapac-ethyl did not. When Yucaizol combined with Trinexapac-ethyl was applied to the rice plants, the mixture of these two inhibitors retarded stem elongation of rice at lower doses. Our results suggest that the use of a BR biosynthesis inhibitor combined with a GA biosynthesis inhibitor may be useful in the development of new technologies for controlling rice plant height.

Characteristics of Growth and Yield Formation of Rice in Rice-Fish Farming System

By using single rice cultivation as a control, the effect of rice-fish culture on growth dynamic, plant type and yield formation of rice was studied. The results showed as follows： rice-fish culture improved the physical-chemical properties of arable layer soil of paddy field, extended growth period of rice, increased dry matter and LAI of different growth stages, improved three top leaves area, deterred the degeneration of leaves function, increased the diameter of stem, promoted the growth of roots and the formation of roots in the extended stem. At the same time, rice-fish culture extended the length of basal internodes, increased the number of internodes, uplifted the gravity of plant, and depressed the root vigor. For the grain yield and yield structure office, rice-fish culture decreased ear/tillering ratio, spikelet/panicle and seed set percentage, increased grain weight. If variety choice and cultivation technology were controlled appropriately, rice-fish culture could increase the effective panicles and improve grain yield of rice.

Simulation and Validation of Rice Potential Growth Process in Zhejiang Province of China by Utilizing WOFOST Model

A crop growth model of WOFOST was calibrated and validated through rice field experiments from 2001 to 2004 in Jinhua and Hangzhou, Zhejiang Province. For late rice variety Xiushui 11 and hybrid Xieyou 46, the model was calibrated to obtain parameter values using the experimental data of years 2001 and 2002, then the parameters were validated by the data obtained during 2003. For single hybrid rice Liangyoupeijiu, the data recorded in 2004 and 2003 were used for calibration and validation, respectively. The main focus of the study was as follows： the WOFOST model is good in simulating rice potential growth in Zhejiang and can be used to analyze the process of rice growth and yield potential. The potential yield obtained from the WOFOST model was about 8100 kg/ha for late rice and 9300 kg/ha for single rice. The current average yield in Jinhua is only about 78% （late rice） and 70% （single rice） of their potential yield. The results of the simulation also showed that the currant practice of management at the middle and late growth stages of rice should be reexamined and improved to reach optimal rice growth.

Mining Applicable Elite Alleles of Growth Duration, Plant Height and Panicle Number per Plant by Conditional QTL Mapping in Japonica Rice

Unconditional and conditional QTL mapping were conducted for growth duration (GD), plant height (PH) and effective panicle number per plant (PN) using a recombinant inbred line (RIL) population derived from a cross between two japonica rice varieties Xiushui 79 and C Bao. The RIL population consisted of 254 lines was planted in two environments, Nanjing and Sihong, Jiangsu Province, China. Results showed that additive effects were major in all of QTLs for GD, PH and PN detected by the two methods, and the epistatic effects explained a small proportion of phenotypic variation. No interactions were detected between additive QTL and environment, and between epistatic QTL pairs and environment. After growth duration was adjusted to an identical level, RM80-160bp was detected as an applicable elite allele for PN, with an additive effect of 0.71. When effective panicle number per plant was adjusted to an identical level, RM448-240bp was detected as an applicable elite allele for GD, with an additive effect of 4.64. After plant height was adjusted to an identical level, RM80-160bp was detected as an applicable elite allele for PN, with an additive effect of 0.62, and RM448-240bp was detected as an applicable elite allele for GD, with an additive effect of 3.89. These applicable elite alleles could be used to improve target traits without influencing the other two traits.

Nutrient Composition and Distance from Point Placement to the Plant Affect Rice Growth

Point placement of urea is an efficient technology to improve urea use efficiency in transplanted rice(Oryza sativa L.), but it is largely unknown how nutrient composition in the point placement and the distance from placement site to the plant influence rice root distribution and growth, nutrient uptake, and rice grain yield. A controlled greenhouse experiment was conducted using both N-and P-deficient soil with point placement of N only or N and P together(N + P) at a distance close to or far from the plant,in comparison to an N-spilt application and a no-N control. Both nutrient composition and distance significantly affected rice root growth. Compared with the N point placement, the N + P point placement led to smaller root length and mass densities, higher specific root length(SRL) around the placement site, smaller root system, higher straw mass and grain yield, and higher N and P uptake. The difference between the N + P and N point placements was greater when close to the plant than when far from the plant. It is suggested that higher SRL around the placement site is essential for improving nutrient uptake and rice grain yield, and simultaneous point placement of N and P has a synergistic effect on rice growth.

Enhancement of Growth and Grain Yield of Rice in Nutrient Deficient Soils by Rice Probiotic Bacteria

Plant associated bacteria are promising alternatives to chemical fertilizers for plant growth and yield improvement in an eco-friendly manner.In this study,rice associated bacteria were isolated and assessed for mineral phosphate solubilization and indole-3-acetic acid(IAA) production activity in vitro.Six promising strains,which were tentatively identified as phylotaxon Pseudochrobactrum sp.(BRRh-1),Burkholderia sp.(BRRh-2),Burkholderia sp.(BRRh-3),Burkholderia sp.(BRRh-4),Pseudomonas aeruginosa(BRRh-5 and BRRh-6) based on their 16 S rRNA gene phylogeny,exhibited significant phosphate solubilizing activity in National Botanical Research Institute phosphate growth medium,and BRRh-4 displayed the highest phosphate solubilizing activity,followed by BRRh-5.The p H of the culture broth declined,resulting in increase of growth rate of bacteria at p H 7,which might be due to organic acid secretion by the strains.In presence of L-tryptophan,five isolates synthesized IAA and the maximum IAA was produced by BRRh-2,followed by BRRh-1.Application of two most efficient phosphate solubilizing isolates BRRh-4 and BRRh-5 by root dipping(colonization) of seedling and spraying at the flowering stage significantly enhanced the growth and grain yield of rice variety BRRI dhan-29.Interestingly,application of both strains with 50% of recommended nitrogen,phosphorus and potassium fertilizers produced equivalent or higher grain yield of rice compared to the control grown with full recommended fertilizer doses,which suggests that these strains may have the potential to be used as bioinoculants for sustainable rice production.

Advanced Backcross QTL Analysis for the Whole Plant Growth Duration Salt Tolerance in Rice(Oryza sativa L.)

Salinity is a major factor limiting rice yield in coastal areas of Asia. To facilitate breeding salt tolerant rice varieties, the wholeplant growth duration salt tolerance（ST） was genetically dissected by phenotyping two sets of BC2F5 introgression lines（ILs） for four yield traits under severe natural salt stress and non-stress filed conditions using SSR markers and the methods of advanced backcross QTL（AB-QTL） analysis and selective introgression. Many QTLs affecting four yield traits under salt stress and nonstress conditions were identified, most（〉90%） of which were clustered in 13 genomic regions of the rice genome and involved in complex epistasis. Most QTLs affecting yield traits were differentially expressed under salt stress and non-stress conditions. Our results suggested that genetics complementarily provides an adequate explanation for the hidden genetic diversity for ST observed in both IL populations. Some promising Huanghuazhan（HHZ） ILs with favorable donor alleles at multiple QTLs and significantly improved yield traits under salt stress and non-stress conditions were identified, providing excellent materials and relevant genetic information for improving rice ST by marker-assisted selection（MAS） or genome selection.