Plant Growth Variables Research Articles

Isolation and identification of plant growth promoting rhizobacteria from maize (Zea mays L.) rhizosphere and their plant growth promoting effect on rice (Oryza sativa L.)

AbstractThe use of plant growth promoting rhizobacteria is increasing in agriculture and gives an appealing manner to replace chemical fertilizers, pesticides, and dietary supplements. The objective of our research was to access the plant growth promotion traits ofPseudomonas aeruginosa,P. fluorescensandBacillus subtilisisolated from the maize (Zea maysL.) rhizosphere.In vitrostudies showed that isolates have the potential to produce indole acetic acid (IAA), hydrogen cyanide, phosphate solubilisation, and siderophore. RNA analysis revealed that two isolates were 97% identical toP. aeruginosastrain DSM 50071 andP. aeruginosastrain NBRC 12689 (AK20 and AK31), while two others were 98% identical toP. fluorescensstrain ATCC 13525,P. fluorescensstrain IAM 12022 (AK18 and AK45) and one other was 99% identical toB. subtilisstrain NCDO 1769 (AK38). Our gnotobiotic study showed significant differences in plant growth variables under control and inoculated conditions. In the present research, it was observed that the isolated strains had good plant growth promoting effects on rice.

Temporal Variability of Source-Specific Solvent-Extractable Organic Compounds in Coastal Aerosols over Xiamen, China

This study describes an analysis of ambient aerosols in a southeastern coastal city of China (Xiamen) in order to assess the temporal variability in the concentrations and sources of organic aerosols (OA). Molecular-level measurements based on a series of solvent extractable lipid compounds reveal inherent heterogeneity in OA, in which the concentration and relative contribution of at least three distinct components (terrestrial plant wax derived, marine/microbial and fossil fuel derived organic matter (OM)) exhibited distinct and systematic temporal variability. Plant wax lipids and associated terrestrial OM are influenced by seasonal variability in plant growth; marine/microbial lipids and associated marine OM are modulated by sea spill and temperature change, whereas fossil fuel derived OM reflects the anthropogenic utilization of fossil fuels originated from petroleum-derived sources and its temporal variation is strongly controlled by meteorological conditions (e.g., the thermal inversion layer), which is analogous to other air organic pollutions. A comparative study among different coastal cities was applied to estimate the supply of different sources of OM to ambient aerosols in different regions, where it was found that biogenic OM in aerosols over Xiamen was much lower than that of other cities; however, petroleum-derived OM exhibited a high level of contribution with a higher concentration of unresolved complex matters (UCM) and higher a ratio between UCM and resolved alkanes (UCM/R).

Nematode resistance to tropical Meloidogyne species in Moringa oleifera

Attempts are underway to cultivate Moringa oleifera Lam. in tropical areas as a developmental crop due to its nutritional, pharmacological and industrial applications. However, the success of developmental-plant-related projects depends on the degree of nematode resistance in the introduced plants to the tropical root-knot (Meloidogyne species) nematodes. The objective of this study was to determine the degree of nematode resistance in M. oleifera seedlings to M. incognita race 2 and M. javanica under greenhouse conditions. Two parallel experiments were conducted, with seedlings in each inoculated with a series of different nematode species. At 56 days after inoculation, the M. incognita race 2 and M. javanica reproductive factor (RF) values ranged from 0–0.34 and 0.01–0.42, respectively. Nematode infection did not have any effect on plant growth variables. In conclusion, M. oleifera was resistant to population densities of tropical Moloidogyne species in South Africa.

PEMANFAATAN SALVINIA MOLESTA D.S. MITCHELL, AKUMULATOR MERKURI DI SAWAH TERCEMAR LIMBAH PENAMBANGAN EMAS

Mercury is one of important contaminants in mine lands. One approach to remediaterisks from this metal pollutant is phytoextraction using hyperaccumulator plants. Theseremarkable plant species accumulate appreciable high concentrations of metals thando normal plants when the normal plants suffer yield reduction from metal phytotoxicity.Some plant species growing in gold mine contaminated areas indicated high toleranceand potentially effective in accumulating mercury in their roots and above groundportions. Salvinia molesta is one of them. This plant could be utilized as hyperaccumulatorfor cleaning up mercury contaminated sites. This research aim to study phytoextractionof mercury by Salvinia molesta and the effectiveness of mercury degradator bacteria onplant tolerance and mercury phytoextraction. In this study Salvinia molesta was grown inmercury contaminated liquid gold mine waste, added with Mercury (II) Chloride (HgCl2)0 ppm Hg, 10 ppm Hg, 30 ppm Hg and 50 ppm Hg. Mercury degradator bacteria wasapplied in the media. The results showed that Salvinia molesta was able to survive evenin media with high level of mercury concentration (50 ppm), although the number ofplant survival tend to decrease with the increase of mercury concentration. Variables ofsurface coverage and live plants decreased with the increase of mercury concentrationin the media. There was a close correlation between plant growth variables and mercuryconcentration in the media. The effects of mercury toxicity on plants seems to decreasein bacteria treated plants. It was indicated by the higher percentage of surface coverageand plant survival in bacteria treated plants than that of untreated plants up to 30 ppm Hg.Recovery from toxicity was shown in bacteria treated plants up to 30 ppm Hg. Mercuryaccumulation in plants tent to increase with the increase of mercury concentration inmedia. It can be concluded that plant performance was better and mercury concentrationdecreased in bacteria treated plants.

Response of an invasive plant, Flaveria bidentis, to nitrogen addition: a test of form-preference uptake

Plants differ in their capacity to use various forms of nitrogen (N). Although previous studies have suggested invasive plants alter N availability, few distinguish their responses to various forms and different concentrations of inorganic N. In order to understand how plant preference for N affects invasions, we tested the growth and physiological response of Flaveria bidentis, an invasive plant across north China, to different forms and concentrations of inorganic N. Seedlings of F. bidentis were cultivated in a mothproof screen house to determine if this invader benefits from increased or altered forms of N. 15N-labeled NH4 + and NO3 − were applied to the soil to gain insight into N partitioning in communities invaded by this species. We determined that plant growth and biomass variables, chlorophyll content, and photosynthesis parameters all varied depending on the form of available N. Specifically, N addition altered the biomass allocation pattern of plants, with F. bidentis tending to maximize its reproductive output under increased N availability. Also, F. bidentis had higher 15N–NH4 + recovery across biomass components than both co-occurring native plants, Amaranthus retroflexus and Eclipta prostrata. F. bidentis demonstrated a strong preference for ammonium (NH4 +) over nitrate (NO3 −) and captured at least twice the 15N–NH4 + as the native plants. By comparison, the two native species showed no preferences for the form of N. The greater above-ground biomass of F. bidentis contributed to its higher 15N recovery. We suggest that the ability of F. bidentis to respond rapidly to changes in the N pool, especially in ammonium, may confer a competitive advantage to this species over native species. Our results provide insight into how species-specific N preferences influence the ability of this species to invade a native community.

Antifungal activity of pomegranate peel extract against fusarium wilt of tomato

Pomegranate (Punica granatum) is an important source of bioactive compounds and has been used in folk medicine for many centuries. This paper describes the in vitro antifungal activity of pomegranate peel aqueous extract (pae) on the development of Fusarium wilt of tomato caused by Fusarium oxysporum, f. sp. lycopersici. HPLC-DAD-ESI/MS analysis was performed to identify punicalagins and ellagic acid, which are the main antifungal compounds. In vivo tests established the efficacy of pae treatments in controlling Fusarium wilt by evaluating improvements in growth variables of tomato plants. At high concentrations, pae showed allelopathic activity in tomato plants. The germination and the radicle growth of tomato seeds were significantly affected by pae. Increasing the extract concentration led to a progressive decrease in germination and in the length of the radicle. The reduction of the Fusarium population in soil and the increase in number of healthy plants obtained as a result of pae treatments indicate that this plant extract could have an important role in biologically-based management strategies for the control of Fusarium wilt in tomato crops.

Cu Nanoparticles absorbed on chitosan hydrogels positively alter morphological, production, and quality characteristics of tomato

Use of nanoparticles as nano copper (nCu) may be useful in agriculture. The objective of the present study was to evaluate responses in plant growth and antioxidants in tomato fruits upon application of nCu absorbed on chitosan hydrogels. The study was performed in two stages. The first stage, with tomato seedlings, was done to determine the most appropriate nCu concentration. nCu was absorbed on a chitosan hydrogel at 100 mg nCu kg-1 of hydrogel, and five different treatments of hydrogel were applied to the substrate prior to transplantation: 0.3, 0.15, 0.06, 0.03 and 0.015 g L-1, plus a control. The second stage evaluated the best treatment results from the previous stage, a chitosan treatment without nCu and a control. Effects of the treatments on antioxidants in the leaves and fruit were evaluated, along with fruit quality. The results from the first stage demonstrated that 0.06 g L-1 nCu-chitosan hydrogel treatments had better results. Outcomes from the second stage demonstrated that treatment with nCu had the best results for most of the plant growth variables, with differences in catalase activity in the leaves and lycopene concentration in the fruit. Application of chitosan hydrogels with nCu was favorable to tomato growth and quality.

First establishment of the planthopper,Megamelus scutellarisBerg, 1883 (Hemiptera: Delphacidae), released for biological control of water hyacinth in California

Water hyacinth (Eichhornia crassipes (Martius) Solms-Laubach) is a non-native, invasive floating aquatic weed in the Sacramento San Joaquin Delta and associated river watersheds of northern California. Prior releases of biological control agents have not led to sustained control. The South American planthopper, Megamelus scutellaris Berg, 1883, permitted and released first in the southeastern U.S., was released at three sites in this region from 2011 to 2013, leading to establishment at one site in a pond off Willow Creek in Folsom in the American River watershed. Planthopper populations consisting of nymphs (two-thirds or more of total counts) peaked in late summer each year between 2013 and 2015, reaching densities of six to nine planthoppers per plant by 2015. Megamelus scutellaris dispersed 50 m per year from the point of release between 2013 and 2015 and, based on degree-day estimation, were capable of producing four generations per year at the Folsom site. Proportion live leaves per plant declined by 27% in the Folsom pond between 2012 and 2015. In 2015, plants in the release pond had 40% less live above-water biomass than plants 200 meters away in a canal, into which planthoppers had dispersed in 2014–2015. This early impact of the planthopper could, however, be obscured by inter-annual and within-site variability in plant growth. This study documents the first establishment of M. scutellaris on water hyacinth in the western U.S.

Ácido abscísico y sacarosa afectan la formación in vitro de túberos en plantas de ñame (Dioscorea rotundata Poir.)

El túbero de ñame (Dioscorea rotundata Poir.) es una de las principales fuentes alimenticias de los pobladores de la Costa Atlántica Colombiana y la cuenca del Caribe, y su demanda ha aumentado en el mercado internacional en los últimos años; sin embargo, las técnicas convencionales de cultivo afectan la cantidad y calidad de la producción. Con el fin de ofrecer mecanismos de producción de material de siembra de ñame de buena calidad, se evaluó el efecto de tres concentraciones de sacarosa y cuatro niveles de ácido abscísico en la producción in vitro de microtúberos a partir de explantes nodales. Los tratamientos se distribuyeron con un diseño completamente al azar con ocho repeticiones por tratamiento. El análisis de varianza y la prueba de media de Duncan indicaron que tanto las variables del crecimiento de las plantas como el número de microtúberos mostraron diferencias significativas (Pr<0,05) como resultado de los niveles de ABA/sacarosa, una dosis de 60 g L-1 de sacarosa combinada con 3,0 mg L-1 de ABA indujo el mayor número de microtúberos, mientras que las plantas cultivadas en presencia de 90 g L-1 de sacarosa formaron mayor número de tallos, hojas y raíces.

Critical limits of the degree of compactness and soil penetration resistance for the soybean crop in N Brazil

AbstractIn agricultural fields soil compaction is a major cause of physical degradation. Degree of compactness (DC) is a useful parameter for characterizing compaction and the response of crops for different soils. The objectives of this study were: (1) to identify the critical DC and PR values for soybean [Glycine max (L.) Merrill] using plant growth variables and (2) to verify the relationship between DC and PR, and assess which parameter is recommended for the evaluation of soil compaction. The study was conducted in a greenhouse in a completely randomized factorial design of 4 textures × 5 compaction levels for sandy loam and sandy clay loam soils, and 3 compaction levels for the clayey and very clayey soils. Soil samples were collected from the surface of a Xantic Kandiudox from the NE region of the State of Pará, Brazil. The DC was calculated from the maximum bulk density obtained by the Proctor test, and the PR curve was determined in undisturbed samples equilibrated in different matric potentials. The growth and development of the soybean was favored in the DC range of 80 to 85%, regardless of soil texture. The critical degree of compactness for the growth of soybean was around 98% regardless of soil texture, while the critical values for penetration resistance at field capacity varied according to soil texture and bulk density and were 28.2, 5.6, 3.5, and 5.2 MPa for the sandy loam, sand clay loam, clayey and very clayey soils, respectively. The root length was the plant growth variable most susceptible to soil compaction. Change in soil penetration resistance was poorly related with change in degree of compactness showing that one parameter cannot be replaced by the other. Because PR is quickly determined in field and have a direct relationship with plant growth, for the soils evaluated in this study we recommend the use of soil PR to assess the state of soil compaction.

Coupling and testing a new soil water module in DSSAT CERES-Maize model for maize production under semi-arid condition

Process-oriented crop simulation models are valuable tools for representing our understanding of the current and future states of a cropping system. The main objective of this research was to couple the Cropping System Model-(CSM)-Crop-Environment Resource Synthesis (CERES)-Maize (CSM-CERES-Maize) with the Soil, Water, Atmosphere, and Plant (SWAP) model in order to benefit from the advantages of both models. A new model was developed by replacing a simplified version of the SWAP with WatBal and SPAM modules of the Decision Support System for Agrotechnology Transfer (DSSAT) version 4.0. In this hybrid model, the CERES-Maize supplied the SWAP model with plant growth variables. Meanwhile, the SWAP model provided the CERES-Maize model with daily evapotranspiration, soil water content, and root water uptake. The model was then validated with a dataset including four irrigation levels (two deficit levels along with one full and one over-irrigation level), and three nitrogen levels (0, 150, and 200kg/ha nitrogen) obtained from a field experiment in 2003 and 2004. The root mean square errors (RMSE) across all treatments in the simulation of final biomass were, respectively, 1175 and 2148kg/ha in the first year and 1274 and 1514kg/ha in the second year for the hybrid and original version of CERES-Maize model. Average RMSE for two non-water stress treatments was 1.29 and 1.35cm in the simulation of soil water content for hybrid and original models, respectively. In general, our findings indicated that the new hybrid model was fairly successful in biomass simulation, which was due to better soil water simulations of all four irrigation levels except severe deficit irrigation.

Minimizing ammonia volatilization from urea, improving lowland rice (cv. MR219) seed germination, plant growth variables, nutrient uptake, and nutrient recovery using clinoptilolite zeolite

The anionic nature and high cation exchange capacity (CEC) of clinoptilolite zeolite can be exploited to reduce ammonia (NH3) loss from urea and to improve soil chemical properties to increase nutrient utilization efficiency in lowland rice cultivation. A closed-dynamic airflow system was used to determine NH3 loss from treatments (20, 40, and 60 g clinoptilolite zeolite pot−1). Seed germination study was conducted to evaluate the effects of clinoptilolite zeolite on rice seed germination. A pot study was conducted to determine the effects of clinoptilolite zeolite on rice plant growth variables, nutrient uptake, nutrient recovery, and soil chemical properties. Standard procedures were used to determine NH3 loss, rice plant height, number of leaves, number of tillers, dry matter production, nutrient uptake, nutrient recovery, and soil chemical properties. Application of clinoptilolite zeolite (15%) increased shoot elongation of seedlings and significantly reduced NH3 loss (up to 26% with 60 g zeolite pot−1), and increased number of leaves, total dry matter, nutrient uptake, nutrient recovery, soil pH, CEC, and exchangeable Na+. Amending acid soils with clinoptilolite zeolite can significantly minimize NH3 loss and improve rice plant growth variables, nutrient uptake, nutrient recovery, and soil chemical properties. These findings are being validated in our ongoing field trials.

Dynamic role of organic matter and bioagent for the management ofMeloidogyne incognita–Rhizoctonia solanidisease complex on tomato in relation to some growth attributes

AbstractA disease complex involving Meloidogyne incognita–Rhizoctonia solani was studied on tomato (Lycopersicon esculentum var. Pusa Ruby) under glasshouse conditions to determine their concomitant effect on plant growth variables. Biofertilizers Nerium indicum and Trichoderma harzianum were tested against both pathogens individually as well as concomitantly and found its role in minimizing disease severity. Inoculation of M. incognita and R. solani resulted a significant reduction in plant growth variables over control. The plant growth variables reduction was more pronounced by M. incognita as compared to R. solani. However, T. harzianum exhibited their potential against the disease complex but was less effective than N. indicum. A manifold improvement in plant growth parameters was observed when plants were treated with biofertilizers, N. indicum and T. harzianum simultaneously. The present work has revealed that the combined application of N. indicum and T. harzianum may be a better option for the ma...

Estimation of genetic components for plant growth and physiological traits of wheat (Triticum aestivum L) under normal and stress conditions

This study was conducted to investigate the genetic variability of plant growth and physiological characters in thirty wheat genotypes under normal and drought stress conditions. Selection of important plant growth and physiological traits are essential component for wheat yield improvement. For this purpose, an experiment was conducted in the glasshouse during 2012-13 to estimate the extent of genetic components viz., genetic variance, coefficient of variability and broad sense heritability for plant growth and physiological traits under normal and drought stress conditions. Higher genetic variance was observed between the genotypes for the cell membrane stability, excised leaf water loss, relative water content, proline, sugar and glycine betain under both conditions. This suggested that these indices can be used as direct selection criteria for wheat improvement. While excised leaf water loss and fresh root weight revealed the least variability for GCV and PCV correspond to high heritability under stress condition. Hence, these traits can be used as indirect selection criteria under stress condition.SAARC J. Agri., 13(1): 90-98 (2015)

Responses of macropropagated <i>Musa</i> plantlets to transient moisture stress in six nursery substrates

Moisture stress causes serious devastating effects on crops ranging from retarded growth, tissue desiccation, and severe yield drop to outright death. In this study, the efficacy of six nursery substrates formulated in varying volume ratios of composted plantain fruit/bunch wastes (PFW), sawdust (SD), poultry manure (PM) and topsoil (TS) were evaluated on growth and moisture stress tolerance of macropropagated banana plantlets in the nursery. Un-amended topsoil was evaluated alongside five other substrates including PFW:SD (3:3), PFW:SD:PM (2:2:2), PFW:SD:PM:TS (1½:1½:1½:1½), SD:PM (3:3) and TS:PM (3:3) in a 6×2 factorial in completely randomized design (CRD) of ten replications. Two uniform sets of 10-week-old plants were used in the study. Watering was withdrawn on one set for 2 weeks, while the other set (watered daily throughout the study period) served as the control. The 2-week moisture stress was followed by a 4-week rehydration period, and thereafter, a second cycle water stress was induced for 3 weeks after which the plants were sampled for growth and dry matter accumulation. Results showed significant (p < 0.05) variability in plant growth and dry matter yield (DMY) across the nursery substrates, vis-à-vis the induced moisture stress. Plant growth and DMY were superior in PFW:SD:PM and PFW:SD:PM:TS, and were comparably good in most other media that contained PM and or PFW. The deleterious effects of the induced moisture stress were most severe in plants raised in un-amended topsoil. In addition to poor growth and reduced DMY observed in the stressed plants, these plants allotted a greater proportion of the accumulated dry matter to the underground components. It was evident from the study that inclusion of composted organic materials in nursery substrates supports the efficient utilization of available water by the plants. The use of organic substrates therefore holds promise for moisture stress management in nurseries. Irrigation (interval or volume) could be regulated to save labour, cut cost and optimize crop water use.Keywords: Nursery media, sucker plantlets, water stress, banana.

Plant growth responses to biochar amendment of Mediterranean soils deficient in iron and phosphorus

AbstractThis study evaluated the effect of biochar on plant growth under Fe‐ and P‐deficient soil conditions. Lupin and sorghum (sensitive to soil Fe and P deficiency, respectively) were pot‐grown on one (Fe) or two (P) soils to which either two biochars of contrasting properties (produced from olive‐tree pruning and pine wood) or Fe/P fertilizers or biochars combined with Fe/P fertilizers were added.Without Fe addition, the olive‐tree pruning biochar increased lupin growth with results comparable to those of the sole application of the Fe fertilization, while biochars combined with the Fe fertilization did not significantly affect plant growth variables relative to the Fe treatment alone. Biochar did not correct P deficiency in the tested soils. However, the application of the pine wood biochar together with a P fertilizer to a calcareous soil increased sorghum biomass yield by 42% relative to the sole application of the P fertilizer. Biochar addition did not significantly affect root traits, suggesting its scarce influence on nutrient mobilization and uptake efficiency.Although biochar alone did not alleviate nutrient deficiency in the studied soils due to the low Fe and P contents added in available form with the tested materials, the present results suggest that biochar can provide additional benefits combined with the use of fertilizers under nutrient‐deficient conditions; and open new options to formulate biochar‐based amendments that can play a relevant role in the context of sustainable agriculture.

Limitações químicas ao crescimento inicial de Eucalyptus saligna em solos arenosos do Pampa Gaúcho: estudo de caso

O trabalho objetivou identificar os principais atributos químicos de solo que limitam o crescimento do Eucalyptus saligna em plantios sem calagem na região Sudoeste do Rio Grande do Sul, bem como determinar os valores críticos de cada fator. O estudo foi realizado em povoamentos florestais de dois Latossolos Vermelhos e um Neossolo Quartzarênico da região. Foram realizadas análises químicas do solo e, através de correlações (P<0,05) entre estes e variáveis de crescimento das plantas, verificou-se que os atributos que mais limitaram o crescimento das plantas foram a saturação por Al, a saturação por bases e o teor de Mg trocável, com decréscimo de até 50% nos parâmetros de crescimento. As correlações com os atributos químicos da camada subsuperficial de solo (20-40cm) foram mais significativas do que na camada superficial (0-20cm). Os níveis críticos médios para obtenção de 80% do rendimento relativo no crescimento em diâmetro e em volume de plantas foram de 79% para saturação por Al, 8,3% para saturação por bases e 0,3 cmolc dm-3 para o teor de Mg trocável. Os resultados indicam que a calagem não deve ser suprimida dos plantios de eucalipto em solos ácidos do Pampa gaúcho, mas a quantidade necessária de calagem para esta cultura parece ser menor do que a atualmente recomendada.

Application of Lime and Adaptable Variety to Increase Tomato Productivity at Potential Acid Sulphate Soil

High soil acidity is the most important problem that causes low tomato (Lycopersicum esculentum) productivityat potential acid sulphate soil. Soil quality improvement by using ameliorant, such as lime, and introducing adaptable variety are options to increase tomato productivity in the soils. Field experiment was conducted to evaluate the effect of lime and varieties of tomatoes to increase its productivity in a potential acid sulphate soil of Belandean, Barito Kuala District, South Kalimantan during dry season of 2011. The research was arranged in a split-plot design with three replicates. The main plots were two tomatoes varieties, i.e. Permata and Ratna, while sub plots were five levels of lime, i.e: 0, 0.5, 1.0, 1.5, and 2.0 t ha-1. The results showed that liming improved soil quality and tomato yield. It significantly increased soil pH and reduced soil Al-saturation, and increased soil exchangeable-Ca and Mg. It was assumed that due to pyrite oxidation, however, soil pH decreased and Al-saturation increased, while soil exchangeable- Ca and Mg decreased significantly at nine weeks after planting. Liming also increased plant growth and yield variables (plant height, size, number and weight of fruit, and fruit yield) for both varieties. The better variables of Permata variety at control treatment than those of Ratna variety indicated that the first variety was more adaptive than the other variety in potential acid sulphate soil.Keywords: Adaptable variety, lime, potential acid sulphate soil, tomato. [How to Cite: Koesrini, E William and D Nursyamsi. 2014. Application of Lime and Adaptable Variety to Increase Tomato Productivity at Potential Acid Sulphate Soil. J Trop Soils 19(2): 69-76. Doi: 10.5400/jts.2014.19.2.69]

Aboveground to root biomass ratios in pea and vetch after treatment with organic fertilizer

ABS TRACT: Some growth parameters of pea (cv. Pleven 4) and vetch (cv. Obrazets 666) after treatment with organic fertilizer were studied in a field trial carried out at the Institute of Forage Crops, Pleven, Bulgaria. Humustim as organic fertilizer was applied through presowing treatment of seeds, treatment during vegetation and combination between both, at different doses. Ratios of aboveground weight to root system weight, aboveground height to root system length, as well as specific root length were determined. It was found that the growth variables of plants were positively influenced by organic fertilizer. The aboveground weight to root system weight ratios of pea ranged from 4.80 to 6.29 and was higher than vetch. Aboveground height to root system length ratio in pea ranged from 6.95 to 7.93, and in vetch from 5.30 to 7.39. The use of organic fertilizer at the dose of 1.2 L/t and treatment during vegetation resulted in better performance of root system and specific root length was 78.6 for pea and 84.3 for vetch.

Determining Canopy Growth Conditions of Paddy Rice via Ground-based Remote Sensing

Abstract : This study aimed to investigate the canopy growth conditions and the accuracy of phenologicalstages of paddy rice using ground-based remote sensing data. Plant growth variables including Leaf Area Index(LAI) and canopy reflectance of paddy rice were measured at the experimental fields of Chonnam NationalUniversity, Gwangju, Republic of Korea during the crop seasons of 2011, 2012, and 2013. LAI values werealso determined based on correlations with Vegetation Indices (VIs) obtained from the canopy reflectance.Three phenological stages (tillering, booting, and grain filling) of paddy rice could be identified using VIs anda spatial index (NIR versus red). We found that exponential relationships could be applied between LAI andthe VIs of interest. This information, as well as the relationships between LAI and VIs obtained in the presentstudy, could be used to estimate and monitor the relative growth and development of rice canopies during thegrowing season. Key Words : canopy growth, paddy rice, phenology, remote sensing, spatial index, vegetation index