Individual Leaf Area Research Articles

Improved methods for predicting leaf area for (L. Vicia faba)

Plant Leaf area parameter is an important measure in ecological and physiological studies for its importance in the reception of light and photosynthesis up to plant production. The study was conducted in order to find mathematical model allows individual leaf area estimation of broad bean without destruction and be easy, accurate and inexpensive by measuring the leaf dimensions as length, width and producing combinations, (500) leaf with different dimensions were collected for two varieties of broad bean (local and sahar) cultivated under conditions of rain-fed in fields of Koya/Erbil. simple, multiple and exponential regression analysis were used by adoption of leaf dimensions as independent variables to choose the most accurate models (the highest coefficient of determination r2 and the less MSE). The results showed that the best with more accurate models were the mathematical model of the Linear regression LA = 0.04 + 0.45 (LW) that depend leaf length width Multiple as independent variable , mathematical model (LA = - 0.57 + 0.26 L2 + 0.19 W2) that depend on leaf square length and square width as independent variables, and the mathematical model of the exponential model (LA = 6.12e0.10 (L + W)) that depend sum of leaf length and width as independent variable, so using these mathematical models enable the researcher to estimate the leaf area for ​​large numbers of broad bean leaves with high accuracy and without leaf destruction or use of expensive equipment.

Legacy Effects in Buds and Leaves of European Beech Saplings (Fagus sylvatica) after Severe Drought.

Against the background of climate change, we studied the effects of a severe summer drought on buds of European beech (Fagus sylvatica L.) saplings and on leaves formed during the subsequent spring in trees attributed to different drought-damage classes. For the first time, we combined assessments of the vitality (assessed through histochemical staining), mass and stable carbon isotope ratios (δ13C) of buds from drought-stressed woody plants with morphological and physiological variables of leaves that have emerged from the same plants and crown parts. The number, individual mass and vitality of the buds decreased and δ13C increased with increasing drought-induced damage. Bud mass, vitality and δ13C were significantly intercorrelated. The δ13C of the buds was imprinted on the leaves formed in the subsequent spring, but individual leaf mass, leaf size and specific leaf area were not significantly different among damage classes. Vitality and δ13C of the buds are suitable indicators of the extent of preceding drought impact. Bud vitality may be used as a simple means of screening saplings for the flushing capability in the subsequent spring. European beech saplings are susceptible, but-due to interindividual differences-are resilient, to a certain extent, to a singular severe drought stress.

Allometric models to estimate the individual leaf area of arabica coffee: an approach from frequentist and Bayesian statistics

Allometric models to estimate the individual leaf area of arabica coffee: an approach from frequentist and Bayesian statistics

Rapid online plant leaf area change detection with high-throughput plant image data

High-throughput plant phenotyping (HTPP) has become an emerging technique to study plant traits due to its fast, labor-saving, accurate and non-destructive nature. It has wide applications in plant breeding and crop management. However, the resulting massive image data has raised a challenge associated with efficient plant traits prediction and anomaly detection. In this paper, we propose a two-step image-based online detection framework for monitoring and quick change detection of the individual plant leaf area via real-time imaging data. Our proposed method is able to achieve a smaller detection delay compared with some baseline methods under some predefined false alarm rate constraint. Moreover, it does not need to store all past image information and can be implemented in real time. The efficiency of the proposed framework is validated by a real data analysis.

Growth, Biomass Partitioning, and Photosynthetic Performance of Chrysanthemum Cuttings in Response to Different Light Spectra

Chrysanthemum (Chrysanthemum morifolium) is among the most popular ornamental plants, propagated mainly through stem cuttings. There is a lack of information regarding the impact of the lighting environment on the successful production of cuttings and underlying mechanisms. The light spectrum affects plant morphology, growth, and photosynthesis. In the present study, chrysanthemum, cv. 'Katinka' cuttings, were exposed to five lighting spectra, including monochromatic red (R), blue (B) lights, and multichromatic lights, including a combination of R and B (R:B), a combination of R, B, and far red (R:B:FR) and white (W), for 30 days. B light enhanced areal growth, as indicated by a higher shoot mass ratio, while R light directed the biomass towards the underground parts of the cuttings. Monochromatic R and B lights promoted the emergence of new leaves. In contrast, individual leaf area was largest under multichromatic lights. Exposing the cuttings to R light led to the accumulation of carbohydrates in the leaves. Cuttings exposed to multichromatic lights showed higher chlorophyll content than monochromatic R- and B-exposed cuttings. Conversely, carotenoid and anthocyanin contents were the highest in monochromatic R- and B-exposed plants. B-exposed cuttings showed higher photosynthetic performance, exhibited by the highest performance index on the basis of light absorption, and maximal quantum yield of PSII efficiency. Although R light increased biomass toward roots, B light improved above-ground growth, photosynthetic functionality, and the visual performance of Chrysanthemum cuttings.

Determination of Cassava Leaf Area for Breeding Programs

The evaluation of leaf area provides valuable information for decision-making for the cassava yield trail. The objectives of this study were (1) to determine the relationship between the leaf area and yield of the segregating populations and (2) to investigate the suitable mathematical model for calculating cassava leaf area. The single-row trial for 60 segregating progenies of Kasetsart 50 × CMR38–125–77 was conducted from 2021 to 2022. The trial for eighteen progenies and the Kasetsart 50 and CMR38–125–77 was carried out in 2022. The sampled leaves for each genotype were collected to measure the leaf area. The length (L) and width of the central lobe (W), number of lobes (N), the product of the length and width (L × W; K), and the product of the length and number of lobes (L × N; J) were recorded for developing the mathematical models. The result showed that there were statistically significant correlations between the maximum individual leaf area and the total crop fresh weight and storage root fresh weight. The mathematical model LA = −3.39L + 2.04K + 1.01J − 15.10 is appropriate to estimate the maximum individual leaf area and leaf area index (LAI). This mathematical model also provided the estimated individual maximum leaf area that had the highest correlation with actual biomass at the final harvest as compared to the other three functions. The results showed statistical significance for the estimated LAI and biomass correlation.

Air-Pruning Containers Modify Root and Scion Growth and Alter Resource Allocation of Bench-Grafted Apple Plants

The profitability of modern apple orchard plantings depends largely on how rapidly the costs of planting are returned. Tree establishment and growth in the formative years are often can be limited by transplant shock associated with bare-root trees. In this experiment, we examined the effect of two planting systems, air-pruning containers, and field-grown liners, on above- and below-ground growth and development during the first year in the nursery. M9 ‘Nic 29’ bench grafts for three apple cultivars of different vigor classes, ‘Fuji’ (high vigor), ‘Gala’ (moderate vigor), and ‘Honeycrisp’ (low vigor). We hypothesized that air root-pruning containers would alter rooting distribution compared to field-grown liners by increasing fine root production, and this, in turn, would result in improved resource allocation and greater biomass partitioned to above-ground organs. Bench grafts were divided evenly between a field-grown liner bed (for bare root production) and an air-pruning container system. Air-pruning containers produced trees with significantly more root tips and greater total root length per tree than field-grown liners. Importantly, air-pruning containers resulted in a marked and significant increase in roots < 0.4 mm in diameter; however, field-grown liners produced trees had significantly more roots with diameters > 1.5 mm and, thus, significantly greater root dry matter content (DMC). Above-ground parameters (scion length, DMC of wood and leaves, and individual leaf area and DMC) were significantly increased for plants in air-pruning containers. Generally, the growth benefits from air-pruning containers were less pronounced in ‘Gala’ compared to ‘Honeycrisp’ or ‘Fuji’. The percentage of total DMC partitioned to the canopies of air-pruning containerized trees was significantly greater than field-grown liners.

Untangling leaf expansion triggers: A new experimental study with Epipremnum aureum (Araceae)

Allomorphic aroid vines exhibit a distinct morphology compared to the typical “sun and shade” leaf pattern. Their leaves exposed to high light irradiance at canopies are up to 30 times larger in area compared to leaves in the forest understory. Growth axis direction, contact with the host, and canopy light are morphogenesis-inducing factors for these aroids. While the first two factors are directly related to growth, the light obtained at canopies is associated with foraging and reproduction. In previous studies, the stimulus of light or the simultaneous application of contact and growth axis direction was not able to induce intense changes in leaf, petiole, and stem dimensions, as seen in nature. In this study, we tested the simultaneous interaction of light intensity, growth axis direction, and contact as inducing factors of morphological shoot development in the allomorphic aroid vine, Epipremnum aureum. An experiment with 60 cuttings was established, which included three growth conditions (horizontal, hanging, and climbing) and two light conditions (low light and high light). After 10 months, the leaf, petiole, and internode dimensions and dry mass allocation were compared. In both the horizontal and hanging treatments, the presence of high light doubled the individual leaf area to approximately 60 cm2. However, when high light was combined with vertical growth and contact stimuli in the climbing treatment, this increase was 20-fold, producing leaves up to 1,000 cm². Dry mass allocation followed the same pattern. This result shows that the enormous leaf area expansion of E. aureum is a synergistic effect of the simultaneous application of light, growth axis direction, and contact. The increase in light interception by wider leaves is an advantage to the maintenance of allomorphic aroid vines in a variable light environment such as in canopies.

Varied multi-season response of Aconitum heterophyllum Wall. to increased CO2 in the Indian Himalaya

Plant responses to increasing atmospheric CO2 vary among species. The present study investigates the effects of elevated CO2 on an Indian alpine rhizomatous herb Aconitum heterophyllum using four open-top chambers. Thirty seedlings per chamber were observed for three growing seasons. Atmospheric CO2 was elevated to 650 ppm in two chambers during June to October when above-ground shoot systems were present. Shoot morphometric data were assessed at day 45, 90 and 120 of each season, while biomass and nutrient composition were assessed at completion. Flowering time, flower morphometric data and seed biomass were recorded, and seed germination tests conducted. Elevated CO2 resulted in greater plant height, individual leaf area, stem and leaf thickness during seasons 1 and 2, but in season 3 these shoot morphometric data were either lower or not significantly different. Shoot biomass production in the third season was lower but root biomass was not affected, resulting in a higher root mass fraction. Tissue nitrogen decreased and potassium increased. The soil pH and available nitrogen in 650 ppm CO2 decreased, while other soil nutrients increased. Plants in 650 ppm CO2 flowered 14 days earlier and produced smaller pods with smaller and lighter seeds. Vigor index and seedling biomass were lower, reducing seedling survival, though germination percentage was not affected. Reduced biomass accumulation in the third season could be due to reduced available nitrogen, or the first expression of a longer-term trend. More multi-season studies are required to predict the implications of climate change to this species.

Yield and Quality of Three Cultivars of Dark Fire-Cured (Kentucky) Tobacco (Nicotiana tabacum L.) Subjected to Organic (Compost) and Mineral Nitrogen Fertilization

A biennial experiment (2009 and 2010) was conducted at Calvi (Benevento, Southern Italy) to evaluate the effect of compost by organic fraction municipal solid waste (OFMSW), in combination with mineral nitrogen (N) fertilization, on yield and quality of three Dark Fire-cured (Kentucky) tobacco cultivars commonly cultivated at Benevento province (Campania region, Southern Italy). Six N fertilization treatments (N0 = soil N reserves available for plant growth; MIN = 135 kg ha−1 of N applied as mineral fertilizer; C10 = 10 Mg d.w. ha−1 compost; C10N = 10 Mg d.w. ha−1 compost + 50% MIN; C20 = 20 Mg d.w. ha−1 compost; C20N = 20 Mg d.w. ha−1 compost + 50% MIN) were combined with the following cultivars: (i) Foiano, medium early maturing; (ii) Riccio Beneventano (local ecotype), medium maturing; (iii) SKL, medium maturing. Yield of cured leaves (Mg ha−1) and growth components (number of leaves per plant, mean individual leaf area, leaf area per plant, specific leaf weight, stem diameter and height) and color parameters (L*, a*/b*) were measured. Leaf quality traits (nitrates, total N and alkaloids contents, score) and N use efficiency were also determined. The best growth and yield performance was reached in 2010 when plants were taller, developed both stems that were more robust and leaves having greater individual leaf area, and showed a higher leaf area per plant than in the first year. Regardless of the form of applied N (compost, mineral fertilizer, or a combination of both), tobacco plants appeared to be directly and positively influenced by increasing quota of readily available N received by each treatment, which was determined at the beginning of field growth by N soil balance and taking into account the percentage of N supplied by organic (compost) and mineral fertilizers. Results obtained with compost treatments, particularly when combined with mineral fertilizer (at C10N more than C20N), appeared comparable or sometimes better than those of full mineral fertilization although N fertilization by synthetic products was applied at very low doses.

The afterlife of herbaceous plant species: A litter decomposition experiment in a temperate oak-hornbeam forest

Understanding the mechanisms of singular species and their traits impacts on ecosystem functions, is crucial in the era of unprecedented anthropogenic changes of the environment, e.g. to predict changes in carbon and nutrient cycling connected with species shifts. It may allow us to take protective measurements and mitigate the negative effects of global changes. Litter decomposition is a crucial process shaping nutrient cycling in ecosystems. Studies on decomposition in forest ecosystems are mainly limited to foliar litter. In contrast to woody plant species, our knowledge of decomposition of herbaceous plants is scarce. Thus, unanswered questions remain about the model that best describes the decomposition process of herbaceous plants. The relationship of decomposition rate to functional traits is unknown for this species pool. We used the litter bag method to determine the decomposition rate of 13 herbaceous plant species and four overstory tree species growing in a temperate oak-hornbeam forest. We showed that the litter decomposition rate and C and N release were higher in spring ephemerals than summer green herbaceous species, as the plants with small total individual aboveground biomass (TAB) and small total leaf area (TLA) decomposed the fastest. Our results demonstrate that in this generally acquisitive group of plants, size traits have a stronger impact on decomposition than economic traits. For almost all species, the two-phase exponential decay model explains the course of herbaceous species litter decomposition only slightly better than the single exponential model.

Status of Spray Penetration and Deposition in Dense Field Crop Canopies

HighlightsCrop production practices, spray drift control, and sprayer productivity affect spray penetration into dense crop canopies.Question is raised whether airflows near foliar surfaces or within the canopy can assist spray penetration under windy conditions.Current structural descriptions of canopies do not accommodate droplet trajectories to improve spray application.New nozzle tip designs, sensors, and air-assisted spraying need tuning to improve spray penetration and deposition.Abstract. The objective of this study was to review representative publications for improved knowledge of spraying dense field crop canopies to augment the current understanding of the interaction between target foliage characteristics, spray practices, and the environment. Emphasis was placed on measured deep-canopy spray deposits made by full-scale sprayers and studies of airflow within and around crop canopies. Airflow could act as a spray droplet carrier and/or indicator of the internal canopy structure that restricts droplet penetration. High variation in natural airflows was noted in several studies. Crop canopy descriptions for spray studies were generally limited to overall canopy/row dimensions, descriptions of individual plant structures, leaf shapes, and leaf area index. Few studies evaluated the internal canopy “openness” with characteristic shape and size of internal volumes that would accommodate spray droplet trajectories. There have been significant increases in available spray tip designs with multiple orifices, discharge configurations, and droplet sizes that offered the applicator many choices. Advanced sprayer technologies ranging from nozzle control to sensor navigation are available, provided that suitable algorithms can be developed in a timely manner that pertain to a wide variety of spray and crop conditions. The air-assist technique provides a dynamic alternative to traditional over-the-top sprays for increasing spray penetration and deposit, advocating that the specifics of air discharge, spray droplet sizes, and canopy structure can be integrated. The complexity of the spraying process needs an extensive collaborative effort of many stakeholders to develop solutions for sprays to penetrate foliage that is subject to diseases and pests. Keywords: Air-assisted sprayer, Airflow, Boom sprayer, Canopy openness, Droplet trajectory, Foliar canopy, Foliar density, Row crops, Spray blockage, Spray coverage, Spray deposit, Spray nozzles.

Canopy and reproductive development in mungbean (

Context Mungbean (Vigna radiata (L.) Wilczek) is an important grain legume for food, feed, and green manure. Mungbean yield is highly variable due to fluctuating temperature and unpredictable rainfall. Aims To improve yield stability, it is critical to utilise a model that can simulate mungbean phenology, biomass, and yield accurately. Methods A thorough understanding of the physiological determinants of growth and yield is required to advance existing mungbean crop modelling capability. Currently, there is limited understanding of the physiological determinants of canopy and reproductive development and their variation in mungbean germplasm. Two experiments (controlled and field environments) were conducted at Gatton, Queensland, in 2018–19. Six Australian mungbean genotypes and one black gram (Vigna mungo L.) were grown under non-limiting conditions. Plant phenotypic traits (canopy development, time to first, 50% flowering, duration of flowering and podding, flower appearance, pod addition rates) were recorded. Key results Genotypes M10403 and Satin II had significantly higher leaf appearance rate (LAR). Genotypes with a greater LAR had higher number of leaves but lower individual leaf area. Genotypes varied significantly in time to first and 50% flowering, with Onyx-AU (black gram) and Celera II-AU flowering earliest. Flowering and podding rates, and duration of these phenological phases varied among genotypes. Total plant leaf area (TPLA) approached its maximum at mid-podding stage. Implications This study quantified the key phenotypic and physiological relationships associated with canopy and reproductive development, critical for the improvement of mungbean crop modelling required to accurately simulate growth and development and inform possible canopy constraints that are limiting mungbean productivity.

Light Quality Environment and Photomorphological Responses of Young Olive Trees

Tree densities have increased greatly in olive orchards over the last few decades. In many annual crop species, increased density reduces the horizontal red/far-red (R/FR) and blue/green (B/G) ratios during canopy development even before direct shading occurs, and such changes are known to alter plant morphology. This study with olive trees evaluated: (1) whether the leaf area index (LAI) of neighboring trees modifies the light quality environment prior to a tree being directly shaded and (2) the potential morphological responses of three olive cultivars to changes in light quality. Increasing LAI using different spatial arrangements of potted, three-year-old trees reduced the horizontal R/FR ratio more than that of the B/G ratio. Cultivar-specific responses to low R/FR ratio were observed for individual leaf area and aboveground/belowground biomass ratio using laterally positioned FR mirrors or green fences. No statistically significant responses were detected in response to green vegetation fences that reduced both horizontal R/FR and B/G ratios, but a cluster analysis grouped together the overall morphological responses to both FR mirrors and green fences. These results in olive trees suggest that cultivar differences in response to light quality may be relevant for understanding adaptation to dense orchards and identifying cultivars best suited to them.

Blue and Far-Red Light Affect Area and Number of Individual Leaves to Influence Vegetative Growth and Pigment Synthesis in Lettuce.

Published work indicates that high percentage of blue light can enhance pigment levels but decreases growth, while addition of far-red light to growth light can increase quantum efficiency and photosynthesis in leafy greens. Combining high-energy blue light with low-energy far-red light may increase both vegetative growth and pigment levels. However, the effect of high-energy blue and low-energy far-red light on the vegetative growth and pigments synthesis is unclear. This information can be potentially useful for enhancing the levels of pigments with nutritional value (e.g., beta-carotene and anthocyanins) in the produce grown in vertical farms. We grew romaine lettuce (cv. Amadeus) under similar light intensity (approximately 130 μmol⋅m–2⋅s–1) but different proportions of red: blue: far-red including 90:10: 0 (“High-R”), 50: 50: 0 (“High-B”), and 42: 42: 16 (“High-B+FR”) for 31 days. Results indicated that canopy area and leaf photosynthetic rate of lettuce plants was reduced in the High-B, thereby reducing plant growth. We did not observe photosynthesis enhancement in the High-B+FR. Instead, plants clearly showed photomorphogenic effects. The phytochrome photostationary state (PSS) decreased with far-red addition, resulting in reduced leaf number per plant. This was likely to shift the allocation of resources toward elongation growth for shade avoidance. Further, we observed an increase in the area of individual leaves, canopy area, and shoot dry weight in the High-B+FR. However, these appear to be an indirect consequence of decreased leaf number per plant. Our results also indicate that changes in expansion growth at individual leaf scale largely regulated pigment concentration in plants. As individual leaf area became smaller (e.g., High-B) or larger (e.g., High-B+FR), the levels of pigments including chlorophylls and beta-carotene increased or decreased, respectively. Area of individual leaves also positively influenced canopy area (and likely light interception) and shoots dry weight (or vegetative growth). Our study provides additional insights into the effects of high-energy blue and low-energy far-red light on individual leaf number and leaf growth, which appear to control plant growth and pigment levels in lettuce.

Portable device for contactless, non-destructive and in situ outdoor individual leaf area measurement

Plant phenotyping is a research area concerned with the quantitative measurement of a plant’s structural and functional properties. In the case of measuring a leaf’s surface area, it is more often than not laborious as well as stressful to the plant. In this paper, we present the use of the RGB-D sensor, Kinect v2 as part of a portable device for non-destructive measurements of individual leaf areas (cm2/leaf) outdoors in daylight. The Kinect v2 was utilized to capture a single viewpoint 2.5D frame of plant foliage. An unsupervised clustering method, HDBSCAN was used to segment out individual leaves from the captured 2.5D frame of the subject plant. Performance of the leaf segmentation was measured by evaluating the 10 nearest (max) clusters from the sensor for each frame into 3 different categories, individual leaves (non-occluded, occluded), under-segmented and over-segmented. Probability of segmenting individual leaves differs from plant to plant, ranging from a low of 0.7178 to a high of 0.8975. The surface area of all individual non-occluded leaves obtained via the segmentation method was calculated and compared to its ground truth. The calculated individual leaf surface areas R2 was recorded to range from 0.792 to 0.911 with respect to its best fit regression line while the RMSE range from 4.9482 to 14.4941 cm2. The proposed system and method was shown to be capable of segmenting individual leaves from dense foliage and measuring its surface area.

Nighttime transpirational cooling enabled by circadian regulation of stomatal conductance is related to stomatal anatomy and leaf morphology in rice.

Rice genotypes with larger stomata maintain higher nocturnal stomatal conductance, thus having lower nocturnal leaf temperature via transpirational cooling. Incomplete night stomatal closure has been widely observed, but the mechanisms and functions of nocturnal stomatal conductance (gs,n) are not fully understood. Stomatal anatomy, leaf morphology, gs,n and nocturnal leaf temperature (Tleaf,n) were measured in 30 Oryza genotypes. Nocturnal leaf conductance (gn) showed a significant circadian rhythm; it gradually increased by 58% from 20:30 to 04:30. Contrary to cuticular conductance (gcut), gs,n was highly correlated with gn. Moreover, gs,n accounted for 76% of gn. Tleaf,n was significantly lower than the air temperature, and was negatively correlated with both gs,n and nocturnal transpiration rate (En). gs,n was positively correlated with stomatal size, intervein distance between major veins (IVDmajor), leaf thickness (LT), individual leaf area (LA), and leaf width (LW). It was also found negatively correlated with stomatal density. Reversely, Tleaf,n was negatively correlated with stomatal size, IVDmajor, intervein distance between minor veins, LA and LW. Tleaf,n presented a positive correlation with stomatal density. This study highlights the importance of stomatal anatomy and leaf morphology on regulating gs,n and Tleaf,n. The underlying mechanisms to the determinants of gs,n and the physiological and ecological functions of the Tleaf,n regulation on rice growth and production were carefully discussed.

The growth, aboveground biomass, crown development, and leaf characteristics of three Eucalyptus species at initial stage of planting in Jepara, Indonesia

Abstract. Wirabuana PYAP, Alam S, Matatula J, Harahap MM, Nugroho Y, Idris F, Meinata A, Sekar DA. 2021. The growth, aboveground biomass, crown development, and leaf characteristics of three Eucalyptus species at initial stage of planting in Jepara, Indonesia. Biodiversitas 22: 2859-2869. Industry development, climate change mitigation and renewable energy currently become the most essential challenge in tropical forest management, primarily in Indonesia. The existence of tropical forests is not only managed to maintain the stability of wood supply for commercial industries but also to reduce greenhouse gas emissions in the atmosphere and to generate energy alternatives from tree biomass. To answer this challenge, the development of fast-growing species like eucalyptus can become a good solution. However, the productivity of eucalyptus depends on its adaptability to the site condition. Therefore, understanding site-species interaction becomes the fundamental requirement before planted on a large scale. This study aimed to evaluate the initial performance of eucalyptus species developed in Jepara. An experiment consisted of three different eucalyptus species, i.e., E. alba, E. pellita, and E. urophylla, was established using a randomized complete block design. Sixteen parameters were selected to assess the eucalyptus performance, including survival, height, diameter, biomass accumulation (stem, branches, foliage, and total aboveground), crown length, crown radius, crown projection area, crown ratio, individual leaf area, individual leaf dry weight, specific leaf area, leaf mass area, and leaf area index. The comparison of the mean of tree attributes from each species was examined using ANOVA, followed by HSD Tukey. Results showed that all measured parameters indicated a significant difference among the three species (p<0.05), except for survival, foliage biomass, and crown ratio (p>0.05). The preliminary performance of E. pellita was relatively better than the other two species, mainly related to height (3.00±0.21 m), total aboveground biomass (49.86±3.60 kg ha-1), crown projection area (2.68±0.27 m2 ), and leaf area index (5.76±0.44). Our study concluded the initial performance of E. pellita in Jepara was substantially superior to E. alba and E. urophylla. Nevertheless, continuous evaluation is needed to monitor the consistent performance of those species in the study area.

파종 시기에 따른 잇꽃의 생장 특성과 건물생산성

Background: Safflower (Carthamus tinctorius L.) is a useful medicinal crop in Korea. The optimal sowing time in the central region is mid-March. This study was conducted to determine the growth characteristics according to the sowing period and number of days after sowing. This basic data would be useful in cultivating safflower.<BR>Methods and Results: Starting in mid-March, plants were sown 10 times at 15-day intervals. Thirty plants were harvested from day 30. The dry weight and leaf area were measured. The seed yield was surveyed at the time of the final harvest. Maximum relative growth rate (RGR) and net assimilation rate (NAR) were observed in the early growth phase. Among the growth analysis characteristics, the crop growth rate (CGR) of individual plants and leaf area index (LAI) of canopy were highest during the flowering period. The seed yield was highest in the fourth sowing treatment phase (April-16th). The seed germination rate was high in the first and second sowing treatments phase (March-16th and April-1st) due to seed decay during the rainy season.<BR>Conclusions: Considering the rate of seed decay and germination, it is important to sow as early as possible in the first sowing treatment phase (March-1st) and harvest before the rainy season.

Shade Avoidance and Light Foraging of a Clonal Woody Species, Pachysandra terminalis.

(1) Background: A central subject in clonal plant ecology is to elucidate the mechanism by which clones forage resources in heterogeneous environments. Compared with studies conducted in laboratories or experimental gardens, studies on light foraging of forest woody clonal plants in their natural habitats are limited. (2) Methods: We investigated wild populations of an evergreen clonal understory shrub, Japanese pachysandra (Pachysandra terminalis Siebold & Zucc.), in two cool-temperate forests in Japan. (3) Results: Similar to the results of herbaceous clonal species, this species formed a dense stand in a relatively well-lit place, and a sparse stand in a shaded place. Higher specific rhizome length (i.e., length per unit mass) in shade resulted in lower ramet population density in shade. The individual leaf area, whole-ramet leaf area, or ramet height did not increase with increased light availability. The number of flower buds per flowering ramet increased as the canopy openness or population density increased. (4) Conclusions: Our results provide the first empirical evidence of shade avoidance and light foraging with morphological plasticity for a clonal woody species.