Leaf Blade Width Research Articles

Comportamento Per se de híbridos de capim-elefante para fins energéticos

The aim of this study was to evaluate the Per se performance of elephant grass hybrids obtained by partial diallel crossing and also their parents for energy purposes through agronomic traits during rainy and dry seasons. The experiment was conducted at Pesagro experimental station, Campos dos Goytacazes, RJ, Brazil, in randomized blocks, with three repetitions. The crosses were made between contrasting parents in a partial diallel scheme with 5 female parents x 5 male parents. The treatments consisted of ten parents, twenty-five hybrid combinations and the control. Three cuts were realized for evaluations (April and October 2013 and April 2014). The characteristics evaluated were: plant height (ALT), in m; stem diameter (SD), in cm; leaf blade width (LB), in cm; number of tillers per linear meter (NP); dry matter percentage (%DM) and dry matter production (DMP), in t.ha-1. Variance analysis were performed and the means were grouped according to Scott-Knott test (P <0.05). It was oberved that the hybrid H4 (Cuban Pinda x Taiwan A-144), H7 (Cameroon - Piracicaba x Três Rios), H8 (Cameroon - Piracicaba x Mercker 86-Mexico), H10 (Cameroon - Piracicaba x Roxo), H13 (P241-86-Piracicaba x Mercker 86-Mexico), H17 (IAC Campinas x Três Rios) and H18 (IAC-86-Campinas x Mercker 86-Mexico) presented high biomass production.

Estimates of heterosisparameters in elephant grass (Pennisetumpurpureum Schumach.) for bioenergy production

With a high growth rate and a DM yield of up to 80 t ha-1 yr1, elephant grass (Pennisetum purpureum Schumach.) has been utilized as an alternative source of energy. However, genotypes adapted to and productive in the different regions of Brazil need to be developed. Thus, the objectives of the present study were to estimate and evaluate heterotic effects in elephant-grass hybrids obtained in a partial diallel cross (5 x 5), with the aim of assisting the superior hybrids selection for bioenergy production. The experiment was conducted in Campos dos Goytacazes, Rio de Janeiro, Brazil. The following traits were evaluated: plant height (HGT), stem diameter (SD), leaf blade width (LBW), number of tillers per linear meter (NT), percentage of DM (%DM), and DM yield (DMY). The experiment was conducted in a randomized block design, with 35 treatments (five female parents, five male parents, and 25 hybrid combinations) and three replicates. The adopted statistical model was that of Miranda Filho and Geraldi, in an adaptation of Gardner and Eberhart. Significant heterosis was observed for most traits in the rainy and dry seasons. Hybrid combinations H1 ('Cubano Pinda' x 'Mercker'), H7 ('Cameroon-Piracicaba' x 'Tres Rios'), H8 ('Cameroon-Piracicaba' x 'Mercker 86-Mexico'), H17 ('IAC-Campinas' x 'Tres Rios'), H18 ('IAC-Campinas' x 'Mercker 86-Mexico'), and H25 ('Guacu/IZ.2' x 'Roxo') showed potential for use in breeding programs that aiming at develop clones with a energy biomass production capacity high.

Genetic divergence evaluation of apple germplasm by D2 multivariate analysis

Genetic divergence was worked out in the new germplasm of apple (Malus × domestica Borkh.) including 42 genotypes. Mahalanobis's D2 statistics was applied for identifying the potential parents to be involved in the hybridization programme for trait specific improvement or selecting better segregants. On the basis of performance for various traits, genotypes were grouped into three clusters and maximum numbers of genotypes i.e. 28 were accommodated in cluster I , while 10 and 4 genotypes were arranged in cluster II and III respectively. The average intra cluster distance was maximum in cluster II (2.214) and minimum in cluster III (1.212). Inter cluster distance was maximum between cluster II and III (5.077) indicating that hybridization between genotypes from cluster II and III can be utilized for getting the superior recombinants in segregating generations. On the basis of cluster means for various characters , cluster II was found superior for shoot thickness (0.34cm), inter - nodal length (2.38cm), number of lenticels (62.10) and leaf blade length (8.79cm) whereas cluster III was found superior for leaf blade width (5.10cm), petiole length (2.64cm) and leaf blade ratio (3.62). Hence, hybridization between parents from cluster II and cluster III for these characters can produce better recombinants in segregating generations.

Morphological parameters leaves woody plants in an urban environment (on Gomel example)

At present much attention is paid to the investigation of the indicative features of organisms on the whole and vegetative objects in particular. However, it should be noted that sources of toxic elements distributed unevenly on the territories and having various character and intensity in the form of the enterprises and constructions create rather motley picture of environmental pollution both by structure of pollutants, and by their concentration. Therefore an important scientific problem is the examination not only of changes in conditions of technogenic influence in general, but the research of dependence of intensity of morphological plants parameters change on structure and concentration of chemical pollutants in the environment, and also the assessment of possible consequences of pollutants accumulation in vegetative objects. This was the aim of this work. To perform the work used landscape-geochemical analysis include, extending the definition of the emission factor load, characteristic technogene sources of pollution in the form of industrial plants, evaluation of storage medium (vegetation). Vegetation condition was assessed by determining morphological parameters - the length and width of the leaf blade. The article presents a comparative assessment of the anthropogenic impact level of the largest industrial enterprises on the air state in the city of Gomel. Enterprises of western and southern industrial zone have proved to make the greatest contribution to the urban air pollution. The value of the standard deviation was used to assess the degree of anthropogenic impact of industrial enterprises on morphological parameters of woody plants. This index increased in the western and southern industrial zones in the direction from the enterprises with the large volume of pollutant emissions to the enterprises with the small volume of emissions. This trend is caused by stabilizing selection action due to the environmental stress in the form of emissions of the industrial enterprises in these zones. It is also revealed that in western and southern industrial zones the formation of the leaf blade length and width depends more on the level of anthropogenic impact of the chemical plant, combined heat and power plant, JSC «Centrolit» and JSC «Gomeldrev» compared with other companies, that should be considered when further improvement of environmental activities. The results are generally characterized by scientific novelty of the research and can be used for the purpose of indexing the level of anthropogenic impact on urban areas and further improve the methods of monitoring the state of the urban environment. Next it is planned to evaluate the morphological parameters of the leaf blade of woody plants growing in the area of two large industrial enterprises of the Gomel region – JSC «Mozyr Oil Refinery» (Mozyr), JSC «Belarusian Metallurgical Plant» (Zhlobin) and in city parklands. Then the further testing of the heavy metals content will be carried out in the samples of woody plants, grasses and soil from the territory of the industrial enterprises and parklands of the city of Gomel, Mozyr, and Zhlobin.

Estimativa da divergência entre ecótipos de braquiária baseada em descritores quantitativos e qualitativos

O presente trabalho objetivou estimar a divergência genética entre ecótipos de Urochloa brizantha com base na análise de descritores quantitativos, qualitativos e sua análise conjunta a fim de selecionar os promissores para liberação como cultivares desta espécie. Oito ecótipos (B1, B2, B3, B4, B5, B6, B8) e a cultivar 'Marandu' de U. brizantha foram implantados em piquetes, com 1000m2 cada, em duas repetições. Foram avaliados cinco descritores quantitativos e dez qualitativos no período seco e das águas. Os descritores quantitativos foram: área foliar, comprimento e largura das lâminas foliares, massa seca (MS) e proporção de lâmina foliar na MS. Os descritores qualitativos mensurados foram: resistência ao cisalhamento, volume de gás acumulado na fração rápida e lenta, proteína bruta, fibra em detergente neutro, fibra em detergente ácido, celulose, lignina em ácido sulfúrico, sílica e digestibilidade in vitro da matéria orgânica. Houve divergência genética entre os ecótipos de U. brizantha, especialmente em relação aos descritores quantitativos. Com base nos agrupamentos dos descritores quantitativos, qualitativos e sua análise conjunta, o agrupamento contendo de B1, B3 e B5 com 'Marandu' podem resultar em ecótipos promissores de U. brizantha

Variasi Morfologi Bambu Tali [Gigantochloa apus (Schult.F.) Kurz.] pada berbagai ketinggian tempat di Sub Daerah Aliran Sungai Pelus

A study on the morphological variation of tali bamboo [Gigantochloa apus (Schult.f.) Kurz] has been conducted at various altitudes of Sub Watershed Pelus Banyumas, Central Java. This study was aimed at determining the morphological variations in relation to altitudes above sea levels. The method used was survey with stratified sampling. The variables measured included culm diameter, culm internode length, culm sheath length and width, ovate-triangular blade length and width, leaf blade length and width, stem color and hairs, and altitude. The results of this study indicated that the altitudinal difference effect some morphological characteristics of tali bamboos such as: 1) green young seedling with black hairs found at 200-299 m and 300-399 m asl. 2) morphological variations are effected by altitude. Tali bamboo grows optimally at the altitude of 400 to 499 m asl. The results of regression analysis showed that the altitude has a relatively close correlation with somes of morphological character of tali bamboo.

Charakterystyka anatomiczno-morfologiczna blaszek liściowych odmian Lolium multiflorum [Anatomical-morphological characteristics of Lolium multiflorum leaf blades

Results are reported of morphological-anatomical investigations on cultivated varieties of <i>Lolium multiflorum</i>. These varieties exhibit wide differences as regards the width, thickness and length of leaf blades and thicknes of the dermal layer, mesophyll and diameter of vascular bundles. For a more precise characteristic of varieties the ratio of the derma layer thickness to the vascular bundles diameter and mesophyll thickness is important. In the characterization of varieties the correlations between morphological and anatomical traits of leaves can be utilized.

Identification of Three Distinct Eggplant Subgroups within the Solanum aethiopicum Gilo Group from Côte d’Ivoire by Morpho-Agronomic Characterization

The Solanum aethiopicum Gilo group, described as homogeneous, shows a high diversity, at least at the morphological level. In Côte d’Ivoire, farmers distinguish three subgroups, named “N’Drowa”, “Klogbo” and “Gnangnan”, within this group. Data were obtained from 10 quantitative and 14 qualitative morpho-agronomic traits measured in 326 accessions of Gilo eggplants, at flowering and fruiting stages. Univariate and multivariate analyses allowed clearly clustering the studied accessions into the three subgroups. Fruit taste, leaf blade width, fruit diameter, leaf blade length, fruit weight, fruit color at commercial ripeness, petiole length, germination time, plant breadth, fruit position on the plant, fruit length and flowering time were, in decreasing order, the twelve most discriminating traits. Compared to the “Gnangnan” subgroup, the “N’Drowa” subgroup has smaller plant breadth and larger leaves. The fruits of this subgroup were mainly white at commercial ripeness, larger and sweeter. Most of the traits of the “Klogbo” subgroup were intermediate between those of the “N’Drowa” and “Gnangnan” subgroups. Our results could contribute to a better understanding of S. aethiopicum diversity and to the development of a core collection for African eggplant breeding.

Correlações e análise de trilha em capim-elefante para fins energéticos

The elephant grass for its high dry matter production has been used as a source of renewable energy. The selection for the improvement of traits could influence the production of dry matter and therefore it is necessary to study the correlation between these traits. The objectives of this study were to evaluate the correlation coefficients and display genotype correlations into direct and indirect effects of variables such as plant height, stem diameter, number of tillers and leaf blade width in dry matter production in clones of elephant grass. The experiment was conducted in Campos dos Goytacazes-RJ, using forty genotypes of elephant grass. The design was a randomized block with two replications. Evaluated in two cuts, plant height, stem diameter and width of the leaf blade showed positive and significant genotypic correlation with dry matter production. Plant height was the most directly and positively influenced the dry matter production during the second cut. In the third section, it occurred to the characteristics stem diameter and number of tillers.

Genetic diversity analysis for high temperature stress tolerance in pearl millet [Pennisetum glaucum (L.) R. Br

The present study was conducted to evaluate the genetic divergence among thirty-eight elite pearl millet genotypes using Mahalanobis D2 statistics for thirteen different agronomic, morphological and thermotolerance traits, under rain-fed condition. Analysis of variance indicated considerable diversity among genotypes showing significant variability for all the characters including thermo-tolerance. D2-clustering grouped the genotypes into 3 clusters, in which leaf sheath length (11.95 %), leaf blade length (11.61 %), leaf blade width (9.48 %) and MSI (9.33 %) contributed significantly for the genetic divergence observed among genotypes. Cluster II was characterised with genotypes having higher values of MSI and other leaf characters which got associated with higher yield and yield contributing characters. Screening genotype for seedling thermo-tolerance suggested, 841B as most tolerant (MSI = 71.2 %) and PPMI 69 as most susceptible genotype (MSI = 52.5 %). Maximum inter cluster distance was observed between clusters II and III (4.132), while maximum intra cluster distance was observed in group III (3.079). The pattern of distribution of genotypes belonging to same eco-geographical areas was random, which indicated that there was no association between genetic diversity and eco-geographical distribution of genotypes. The clustering of genotypes will help to identify divergent genetic material for obtaining highly heterotic pearl millet hybrid with thermo tolerance through hybridisation.

English

Elephant grass has the potential to be used as a source for energy production. Besides dry matter yield, other characteristics related to biomass quality are important. The canonic correlation analysis is a multivariate statistical procedure that allows for discovering characteristic associations among groups. The objective of this study was to evaluate the canonic correlation existing between the groups of agronomic traits and biomass traits in elephant-grass genotypes aiming to identify possible associations between the groups of variables in order to use this information in breeding programs of elephant grass for energy. The experiment was conducted at Colégio Estadual Agrícola Antônio Sarlo, located in Campos dos Goytacazes, RJ, Brazil. The evaluation cuts were made in June 2009 and February 2011; the first and third evaluation cuts, respectively. In the first cut, the following morpho-agronomic traits were evaluated: dry matter yield, percentage of dry matter, number of tillers, plant height, stem diameter, percentages of ash, cellulose, lignin, acid detergent fiber and crude protein and calorific value. In the third cut, in addition to the morpho-agronomic traits assessed in the first cut, the leaf-blade width and percentages of ash, cellulose, lignin, acid detergent fiber and neutral detergent fiber were also evaluated. The experimental design was of randomized blocks with 40 genotypes. Variance analysis and canonic correlation were performed between the morpho-agronomic and biomass-quality traits for the cuts isolated. A positive correlation was found between the percentage of dry matter and the fiber content and the plant height and number of tillers and the percentage of crude protein.   Key words: Bioenergy, multivariate, Pennisetum purpureum.

English

The objective of this study was to evaluate the morpho-agronomic traits of eighty five accessions of elephant grass (Pennisetum purpureum Schum.) from the germplasm bank located at the Experimental Field of the State Center for Research on Bioenergy and Waste Recovery (Centro Estadual de Pesquisa em Agroenergia e Aproveitamento de Residuos). The experimental design was a randomized block with two replicates, in an annual-harvest system. The evaluated traits were: percentage of dry matter (%DM), dry matter yield (DMY), number of tillers per linear meter (NT), plant height (HGT), stem diameter (SD), leaf blade width (LW) and leaf blade length (LL). Each cut and variable underwent variance analysis and the Scott-Knott test (P<0.05). Tocher’s optimization method, Mahalanobis distance and canonic variables were used for the multi-traits, and importance of the characters in the canonic variables. The following elite genotypes were identified by the Scott-Knott test at 5%: Rico 534-B, Taiwan A-144, Napier S.E.A., Mole de Volta Grande, Teresopolis, Taiwan A-46, Duro de Volta Grande, Turrialba, Taiwan A-146, Cameroon Piracicaba, Taiwan A-121, P241 Piracicaba, Elefante Cachoeira Itapemirim, Guaco/I.Z.2, Cameroon, IJ 7126 cv EMPASC 310, IJ 7139, Australiano, 10 AD IRI, and Pasto Panama. By the analysis of the canonic variables, the first two accumulated 64.6457% of variance. Regarding the relative importance of the evaluated traits, the leaf blade length at cut two was the most important. By Tocher’s optimization method, the eighty five accessions were divided into twenty five groups, indicating a high variability in the germplasm bank. Key words: Pennisetum purpureum, Tocher’s optimization, Mahalanobis distance, elephant grass.

Resposta de cultivares de Brachiaria brizantha a doses de biofertilizantes de aves

Cada vez mais fertilizantes são importados, fato que faz com que o uso de dejetos tratados seja alternativa econômica e sustentável para a produção de forragens. O objetivo do trabalho foi avaliar o efeito da aplicação de diferentes doses de biofertilizante de aves sobre a produção de forragem de cultivares de Brachiaria brizantha (Hochst.) Stapf. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repetições, em esquema fatorial. O primeiro fator consistiu nos cultivares Marandu e Piatã de B. brizantha, enquanto o segundo fator correspondeu às doses de biofertilizante de aves (0, 50, 100 e 150 m3 ha-1). Foram avaliados os seguintes caracteres morfométricos: altura de planta (AP), comprimento da lâmina foliar (CLF), largura da lâmina foliar (LLF) aos 15, 30, 45 e 60 dias após a emergência (DAE), e massa de matéria verde e seca (MV e MS, respectivamente) das folhas, colmo e raízes aos 60 DAE. A dose de 50 m3 ha-1de biofertilizante de aves promoveu incrementos nas características morfométricas e produção de forragem dos cultivares Marandu e Piatã, enquanto doses de 100 e 150 m3 ha-1 ocasionaram a morte desses cultivares.

Invasive Populations of Elephantgrass Differ in Morphological and Growth Characteristics from Clones Selected for Biomass Production

Elephantgrass (Pennisetum purpureum Schum.) has demonstrated potential for use as a biomass crop, but in Florida, some naturalized types are invasive weeds in sugarcane (Saccharum sp.) fields, along roadsides, and in natural areas. It is not known whether elephantgrass introductions and breeding lines developed for biomass production (i.e., “selected”clones) differ from naturalized populations sufficiently that risk assessment and regulatory decisions should be made at the level of the clone instead of the species. The objective was to compare morphological and physiological traits of elephantgrass-naturalized populations and selected clones. Ten naturalized populations and six selected clones were evaluated in replicated trials at two field locations during 2 years. Selected clones were 8–14 % taller and had leaf blade length that was 48–87 % longer, and leaf blade width that was 61–89 % wider than naturalized clones. Selected types averaged 5.7 to 7.2 fewer tillers per plant than naturalized types, but tiller mass of selected types was 70 % greater than naturalized types. Leaf N concentration was 43 % greater for selected types and was associated with greater light-saturated leaf photosynthesis, stomatal conductance, leaf transpiration rate, and leaf dark respiration than naturalized types. Photosynthetic parameters indicated a greater maximum photosynthetic rate, leaf dark respiration, and light compensation point for selected versus naturalized clones. Clones selected for use as biomass crops differ widely in morphology and physiological response from naturalized populations, supporting a conclusion that risk assessment of elephantgrass should occur at the level of the clone rather than the species.

Phenotypic Diversity of Farmers’ Traditional Rice Varieties in the Philippines

Traditional rice varieties maintained and cultivated by farmers are likely sources of germplasm for breeding new rice varieties. They possess traits potentially adaptable to a wide range of abiotic and biotic stresses. Characterization of these germplasms is essential in rice breeding and provides valued information on developing new rice cultivars. In this study, 307 traditional rice varieties newly conserved at the PhilRice genebank were characterized to assess their phenotypic diversity using 57 morphological traits. Using the standardized Shannon-Weaver diversity index, phenotypic diversity indices averaged at 0.73 and 0.45 for quantitative and qualitative traits, respectively. Correlation analyses among agro-morphological traits showed a high positive correlation in some traits such as culm number and panicle number, flag leaf width and leaf blade width, grain width and caryopsis width. Cluster analysis separated the different varieties into various groups. Principal component analysis (PCA) showed that seven independent principal components accounted for 74.95% of the total variation. Component loadings for each principal component showed morphological characters, such as culm number, panicle number and caryopsis ratio that were among the phenotypic traits contributing positive projections in three principal components that explained 48% of variation. Analyses of results showed high diversity in major traits assessed in farmers’ rice varieties. Based on plant height and maturity, 11 accessions could be potential donor parents in a rice breeding program. Future collection trips and characterization studies would further enrich diversity, in particular traits low in diversity, such as anthocyanin coloration, awn presence, awn color, culm habit, panicle type and panicle branching.

Morphological Characterization of Fingermillet [Eleusine coracana (L.) Gaertn] Germplasm

Genetic variability and correlation coefficients analyses were carried out in 305 fingermillet genotypes between 13 grain yield and yield related traits. Highly significant mean sum of squares due to genotypes and wide range of variability were noticed among the genotypes for all the characters studied. High values for phenotypic and genotypic coefficients were recorded for grain yield per plant and flag leaf blade length, indicating that more variability is present in the germplasm for these characters. All the characters recorded high heritability in the present study indicated that these characters were relatively less influenced by environmental factors and phenotypic selection would be effective for the improvement of these characters. High estimates of variability together with high heritability and high genetic advance were observed for flag leaf sheath width, flag leaf blade width and 1000 grain weight, which indicated that these characters were governed by additive genes and selection would be effective for improvement of such characters. Highly significant positive correlation observed for the characters like days to 50 per cent flowering, productive tillers per plant, plant height, 1000 grain weight, flag leaf sheath length, days to maturity, flag leaf blade length and finger width with grain yield per plant, indicated the possibility of simultaneous improvement of these characters by selection.

Use of elephant grass for energy production in Campos dos Goytacazes-RJ, Brazil.

Elephant grass is a tropical forage plant widely distributed throughout Brazil. It was first exclusively used in the livestock sector as cattle feed. The grass is characterized by its high productivity and photosynthetic capacity and is considered as an alternative source of renewable energy. Here, we estimated the general combining ability of the parents and specific combining ability of the hybrids based on morpho-agronomic biomass-quality traits. The experiment was conducted in a randomized block design with 3 replicates. The diallel was composed of 16 hybrids and 2 groups of genitors. In the diallel analysis of variance, we observed a significant difference among treatments. A significant difference was observed among genitors for dry matter production (DMP). For the general combining ability of group 1, the traits leaf blade width, DMP, height, percentage of neutral detergent fiber, percentage of hemicellulose, percentage of lignin, percentage of acid detergent fiber, and percentage of cellulose were significant. For the estimates of general combining ability of DMP, parents Porto Rico 534-B, Vruckwona, Taiwan A-146, and Mercker S. E. A. were 0.4748, 3.2819, 1.1659, and 0.4317. The parents of Mercker S. E. A. and Porto Rico 534-B produced the highest percentage of detergent fiber and percentage of lignin with values of 0.1482 and 0.0856. Thus, parents Vruckwona, Porto Rico 534-B, and Taiwan A-146 are promising for integration into breeding programs. The best hybrid combinations for DMP were 1 x 5, 1 x 8, 2 x 6, 3 x 7, and 4 x 5.

Use of leaf morphometric parameters for identification of the most common cultivated intraspecific taxa of Tilia platyphyllos

Abstract Evarte-Bundere G., Evarts-Bunders P., 2013: Use of leaf morphometric parameters for identification of the most common cultivated intraspecific taxa of Tilia platyphyllos [Morfometrinių požymių panaudojimas dažniausiems kultūriniams Tilia platyphyllos vidurūšiniams taksonams apibūdinti]. - Bot. Lith., 19(2): 83-90. To determine variation of the most important morphological parameters of Tilia platyphyllos Scop., we studied four most frequently found in Latvia taxa: T. platyphyllos subsp. platyphyllos, T. platyphyllos subsp. cordifolia (Besser) C.K.Schneid., T. platyphyllos ‘Rubra’, T. platyphyllos ‘Obliqua.’ Morphometric measurements (length of petioles, width and length of leaf blades, pubescence and margin of leaves) were performed for 10 different specimens of every selected taxon measuring five typical leaves from each specimen. The cultivated intraspecific taxa of Tilia platyphyllos differed by the following morphometric parameters - the pubescence of leaves, the margin of leaves and the length of leaf blades. No significant differences were ascertained between taxa in such morphometric parameters as the width of leaf blades and the length of petioles.

Agronomic characters of some traditional rice (Oryza sativa L.) cultivars in Sri Lanka

Grain yield in rice is a complex trait and highly dependent on the other agronomic characters. Agronomic characters and grain yield of twenty traditional rice cultivars were evaluated at Faculty of Agriculture, University of Ruhuna in Maha-2010/2011 and in Yala - 2011. The experiment was conducted according to the randomized complete block design with three replicates. Twenty plants from each cultivar were evaluated for the selected characters, Plant height, Leaf blade length, Leaf blade width, Number of tillers, Number of reproductive tillers, Panicle length, Number of spikelets per panicle, Number of fertile spikelets per panicle, Number of infertile spikelets per panicle, Seed length, Seed width, 100 seed weight and Yield per plant. Recommended modern rice cultivar Bg 379/2 was used as the reference. Deviations of each character in different traditional rice cultivars from those of recommended rice cultivar Bg 379/2 were recorded. The average plant height of the tallest rice cultivar, Podihatatha was 198 cm and that of the shortest rice cultivar, Rathranwee was 68 cm. The longest leafblade and longest culm length were also belonged to (9.6 tillers per plant) and the highest average number of reproductive tillers (9 per plant), were recorded by rice cultivar Mahasudu wee. The highest value of 100 seed weight was recorded by rice cultivar Galpa wee. However, the most important economical character, the highest yield per plant(28.52g/plant) was recorded by Thanthiribalan which was significantly higher than that of in the recommended rice cultivar Bg 379/2 (26.5 g/plant). Significant correlations were found between the yield per plant and the characters such as number of reproductive tillers (r = 0.692), panicle length (r =0.565) and number of spikelets per panicle (r = 0.761). Agronomic data collected in the present study would be important to understand the suitability of an individual rice cultivar for the farmer field. DOI: http://dx.doi.org/10.4038/jur.v1i1.6150 Journal of the University of Ruhuna 2013 1(1): 3-9

DURABILITY OF ANTHURIUM PLOWMANII LEAVES IN DIFFERENT HARVEST STAGES

Anthurium plowmanii is a tropical plant that stands out due the beauty of its foliage and high postharvest durability. Despite being a native species with great aesthetic value, its cultivation is restricted and little is known about its potential of use and optimum harvest stage. The objective of this study was to evaluate the longevity of cut A. plowmanii leaves at three different maturity stages. The experimental design was completely randomized with 10 replicates. Three fully expanded leaves were harvested counting from the apex: first leaf (T1), second leaf (T2) and third leaf, the oldest one (T3). The following parameters were evaluated: leaf blade length and width and petiole diameter, leaf thickness and leaf weight. The leaves were kept in distilled water and their longevity in days after cutting (DAC) was observed weekly according to a score criteria. The T1 leaves had the longest postharvest life (21.2 DAC) until the first symptoms of senescence appeared, followed by T2 (9.6 DAC) and T3 (5.6 DAC), which lost their commercial value quickly. The symptoms of senescence in order of appearance was leaf yellowing at the margins followed by spots along or near the primary vein, internerval leaf yellowing and finally dryness and wrinkling of margins. Positive correlation was observed between T1 leaves longevity and both thickness and length of the limb. Therefore, younger leaves with greater thickness and length of the blade will have the longest postharvest life after cutting.