Maximum Root Diameter Research Articles

Effect of Organic and Inorganic Fertilizers on Growth, Yield and Quality of Radish (Raphanus sativus L.) cv. Pusa Himani

In this report, we compared the integrated effect of FYM, vermicompost, poultry manure with inorganic fertilizers incorporated with PSB for yield in radish cv. Pusa Himani in response of morphological, yield as well as quality attributes. As per data analysis T6 [NPK (75%) + vermicompost (25% of N) + PSB] significantly enhanced the highest plant height, leaf length, number of leaves per plant, fresh weight of shoot and dry weight of shoot at 20 DAS, 40 DAS and at harvest, respectively. Similarly, at harvest maximum root length, maximum root diameter, maximum average weight of root, maximum yield per hectare, minimum days to harvest and quality parameters i.e. T.S.S., ascorbic acid, chlorophyll content of leaves, net return and B-C ratio in comparison to all concentration with all integrated nutrient combination. So, we may conclude that [NPK (75%) + vermicompost (25% of N) + PSB] increase yield by stimulating source activity as well improves utilization of PGR (plant growth regulators).

Effect of Harvest Time on Growth and Bioactive Compounds in Salvia miltiorrhiza.

Danshen (Salvia miltiorrhiza) is a perennial medicinal plant belonging to the Lamiaceae family. It is adapted to a wide range of soil pH with the potential to serve as an alternative crop in the United States. To enhance its cultivation and economic viability, it is crucial to develop production practices that maximize bioactive compound yields for danshen. The objective of this study was to investigate the effects of different harvest times on plant growth and subsequent yields of bioactive components of danshen. Three harvest times were selected (60, 120, or 180 days after transplanting [DAT]). In general, plants harvested at 180 DAT had higher plant growth index (PGI), shoot number, shoot weight, root number, maximum root length, maximum root diameter, and root weight compared to plants harvested at 60 or 120 DAT. However, plants harvested at 60 or 120 DAT had higher SPAD (Soil Plant Analysis Development) values. Plants harvested at 120 or 180 DAT had a higher content of tanshinone I, tanshinone IIA, cryptotanshinone, and salvianolic acid B compared to those harvested at 60 DAT. This study provides insights for optimizing the time of harvest of danshen to maximize plant growth and bioactive compound production.

Effect of Plant Density on Growth and Bioactive Compounds in Salvia miltiorrhiza

Danshen (Salvia miltiorrhiza) is an herbaceous plant widely used in the pharmaceutical industry. However, the majority of medicinal plants utilized in the US are imported, posing challenges such as fluctuations in bioactive compound concentrations and insufficient supply to meet demand. Determining the optimal plant density is a key management decision for danshen production. This study aimed to investigate the effects of different plant densities on the growth and bioactive compound content of danshen cultivated in Mississippi. A field experiment was conducted to investigate the effects of different plant densities on individual plant growth, photosynthesis, and the content of bioactive components in danshen in 2020 and 2021. Six plant densities were designed: 30 × 20 cm (between row spacing × within row spacing), 30 × 30 cm, 30 × 40 cm, 45 × 20 cm, 45 × 30 cm, or 45 × 40 cm. A plant density of 45 × 40 cm resulted in danshen plants exhibiting the highest Plant Growth Index (PGI), SPAD, root number, shoot number, shoot fresh and dry weight, maximum root diameter, maximum root length, net photosynthesis, intracellular CO2 concentration, tanshinone I, and cryptotanshinone, regardless of year. Plants spaced at 45 × 30 cm had similar root fresh weight, root dry weight, and tanshinone IIA and salvianolic acid B levels compared with plants grown at the 45 × 40 cm spacing, and both were significantly higher than other densities.

Influence of Organic Manures and Inorganic Fertilizers on Growth, Yield and Quality of Turnip (Brassica rapa L.)

An experiment entitled the Influence of organic manures and Inorganic fertilizers on growth, yield and quality of turnip (Brassica rapa L.) cv. Purple Top white globe was conducted at Department of Horticulture, Naini Agriculture Institute, SHUATS, Prayagraj during, Rabi season of 2022. The experiment was laid out in Randomized Block Design with fifteen treatments combination and three replications in which Farmyard manure (FYM), Poultry manure, Vermicompost were used. Among all the treatments, T11 (80% Nitrogen + 10% FYM + 10% Vermicompost) showed significant result in terms of plant height (29.13cm), maximum number of leaves/plant (13.81), higher Shoot weight (166.81g), maximum Root diameter (7.40 cm), average root length (9.04 cm), average fresh weight/ plant (162.59 g), average root yield (55.77 q/ha), ascorbic acid (36.19 mg), TSS (6.08o Brix).

Nitrogen Fertilization Improves Growth and Bioactive Compound Content for Salvia miltiorrhiza Bunge

Salvia miltiorrhiza B., an herb used in traditional Chinese medicine, has been widely used to prevent and treat cardiovascular and other diseases. Currently, the majority of medicinal plants used in the US are imported from foreign countries, which involves transportation, quality control, and other issues. The objective of this study was to investigate the effect of nitrogen fertilization on growth and content of tanshinone I, tanshinone IIA, cryptotanshinone, and salvianolic acid B for Salvia miltiorrhiza B. in Mississippi. Plants were fertilized with one of five nitrogen (N) rates (0, 2, 4, 6, or 8 g N/plant from NH4NO3). Plants were harvested in November 2020 and 2021. Plants treated with 8 g N had higher plant growth index, leaf SPAD value, shoot and root number, shoot and root weight, maximum root length and diameter, shoot: root ratio, N concentration in root, and content of bioactive components compared to plants treated with 0, 2, 4 g N. Plants receiving 6 g N had similar shoot number, maximum root length, maximum root diameter, root weight and content of bioactive components compared to plants receiving 8 g N. However, plants receiving 6 g N had higher photosynthetic activity compared to plants receiving the higher N rate. Higher N rates increased plant growth and content of tested bioactive compounds.

Supporting evidences for vegetation-enhanced stormwater infiltration in bioretention systems: a comprehensive review.

Stormwater mitigation efficiency of bioretention systems relies for a large part on their capacity to infiltrate rapidly received runoff. Within this context, the primary aim of this literature review was to clarify the vegetation influences on bioretention media hydraulic conductivity, with the ultimate goal of improving guidance on plant choice for system durability. A thorough synthesis of studies dealing with the comparison of plant species, functional types, or traits on infiltration-related processes in biofilters was achieved. Overall, results converged to a positive impact of plants on water infiltration and percolation, either under greenhouse or field conditions. In most cases, vegetation selection had a determining role in maintaining initial media infiltration rates, with in terms of improvement: turfgrass < prairie grass < shrubs < trees. Wind-induced movements of rigid foliage or stems are believed to avoid complete surface clogging. Species with thick, rhizomatous or fleshy (with maximum root diameter near the centimeter range), and tap or deep root systems could be preferred to maximize infiltration rates in permeable bioretention media. In fine-textured soils, higher specific root length, root length density, or mass density could also enhance infiltration. Root mass densities (0.1-2.2kg.m3) were positively linked with infiltration rates in unlined systems while roots around 1mm diameter would favor macropore-related preferential flows and increased hydraulic conductivity. Finally, implementation of high-diversity plant communities would ensure the presence of a more functionally rich vegetation community with species possessing adequate physiological adaptations (including root system architecture) to local environmental conditions for perennial cover and proper bioretention hydrological functioning.

Tree root distribution modelling in different environmental conditions

The ability to predict the spatial distribution of tree root system variables (e.g., the Root system Area (RA), the maximum root diameter, the number of roots in diameter classes, the density of fine roots, etc.) under different environmental conditions is relevant to several scientific disciplines and to engineering practice. In this work, three well known analytical models from the literature are assembled into a unique framework called the Root Distribution Model (RDM). RDM models the expected vertical and horizontal distribution of coarse and fine root system variables for mature plants growing in different environmental conditions ranging from moderately humid to arid climates. All soil and moisture dynamic parameters are physically based, which make the model straightforward to calibrate via a single tuning parameter. At this investigative stage, it is shown that the model has the flexibility to represent a broad range of situations where soil moisture may result from precipitation inputs or from water level fluctuations due to either the presence of a water coarse or of deep aquifers or both. Accordingly, the distribution of the sectional RA may be either positively or negatively skewed, as well as show a peculiar bi-modal structure. The model can be used to study the impact of changing scenarios affecting precipitation, aquifer and channel hydrology.

Evaluation of radish genotypes with special study on sowing geometry at agricultural research institute, Tarnab, Peshawar

The research was carried out on the “Evaluation of Radish genotypes with special study on sowing geometry at Agricultural Research Institute, Tarnab Peshawar”. The experiment was laid out in randomized complete block design having three replications. The experiment comprised with two factors, one was sowing dates(19th Oct., 4th., Nov., and 19th Nov) and the other was different genotypes (Mino, Local Red and Local White). The data were recorded on Days to germination, Germination (%), Days to edible maturity, Number of leaves plant-1, Leaf length plant-1 (cm), Root length plant-1 (cm), Root diameter plant-1 (cm), root fresh weight (g), Plot weight (kg) and yield (t ha-1). Sowing dates significantly affected all yield parameters. Sowing of radish on 19th October has more number of Leaves (17.44 leaves) plant-1, Leaf length plant(22.611 cm), root length plant-1(24.058 cm), root diameter plant-1(3.12 cm) fresh root weight (503.95g), the maximum plot weight (50.90 kg plot-1) and higher yield (62.36t ha-1) was observed whereas the crop sown on 19th November showed the minimum days to germination (8.88 days), germination percentage (96.88%) and minimum days to maturity (53 days). Among genotypes Mino take minimum days to germinate(8.22 days), maximum germination percentage (99.22), minimum days to maturity (52.778), maximum number of leaves (19.44 leaves), leaf length (23.422 cm), greater root length (24.588 cm), maximum root diameter (3.53 cm), higher root fresh weight (536.62g), higher weight per plot (52.22 kg) and maximum yield (63.54t ha-1). The results emphasized that the suitable time of sowing for Mino genotype is 19th October for Peshawar.

Effects of harvest period, storage, and genotype on postharvest physiological deterioration responses in cassava

Abstract. Rahmawati RK, Khumaida N, Ardie SW, Sukma D, Sudarso. 2021. Effects of harvest period, storage, and genotype on postharvest physiological deterioration responses in cassava. Biodiversitas 23: 100-109. Postharvest physiological deterioration (PPD) is the major constraint in cassava root production. The breeding program to develop PPD tolerant cassava varieties requires a long period to complete. Although it is the first step in breeding for PPD tolerance, evaluating cassava germplasm responses for the PPD remains a major problem because it is a laborious process, and the evaluation often contains a high experimental error. This study aims to develop methods for evaluating PPD response, i.e., evaluating the effects of two harvest periods and storage on PPD responses of nine cassava genotypes. The developed scoring system based on cassava root discoloration could group the evaluated cassava genotypes into either PPD tolerant, medium tolerant, or sensitive. The tolerant varieties showed less than 10% root discoloration areas, while the medium tolerant was between 11-20%, and the sensitive was larger than 20%, respectively. ADR-24 and GJ-11 were identified as PPD tolerant, while ML-19 was sensitive using the developed scoring system. This study showed that PPD is a complex phenomenon associated with genetics and environmental factors. Root dry matter content and maximum root diameter traits may play an important role in PPD development in cassava. We have developed procedures for identifying genotype responses to PPD and showed that cassava roots harvested as early as eight months after planting and stored as late as five days under the control relative humidity were good conditions for studying PPD. Evaluating the percentages of root discoloration was a good measure for PPD response prediction. Moreover, we showed that less than 10%, 20%, and more than 20% of root discoloration might be used to group cassava into PPD tolerant, medium tolerant, and sensitive for Indonesian accessions. Therefore, the methods developed in this study may support the Indonesian cassava breeding program and provide biochemical and molecular analysis materials to elaborate the mechanisms of PPD in cassava roots.

Effect of different doses of vermicompost on growth, yield and quality of radish (Raphanus sativus L. cv. Mino Early)

A field experiment was conducted at Horticulture farm of Nepal Polytechnic Institute (NPI) Bharatpur-11, Chitwan to study the effects of different doses of vermicompost on growth, yield and quality of radish (Raphanus sativus L. cv. Mino Early) from January 2020 to March 2020. Five different doses (0 ton, 5 ton, 10 ton, 15 ton, and 20 ton per hectare) of vermicompost were taken as treatments and the experiment was replicated four times. The experiment was set up in Randomized Complete Block Design (RCBD). The result of the study showed that there was a significant effect of different doses of vermicompost on plant height, the number of leaves per plant, spreading of the plant, root length, root weight per plant, root diameter, and root yield at harvesting. The maximum plant height, the maximum number of leaves per plant and maximum plant spreading in radish plant on vermicompost application was recorded every 30, 45 and 60 days after sowing (DAS). The maximum root length (29.60 cm), maximum root diameter (36.27 mm), maximum root weight (191.8 g), maximum biomass weight (241.6 g/plant), maximum root yield (47.9 ton/ha), were recorded on applying 15 ton/ha vermicompost at 60 DAS. The control treatment showed the minimum vegetative growth and yield. Among the different doses of vermicompost, the overall performance of radish was found better in 15 ton/ha of vermicompost. Statistical analysis showed no differences among (5 ton, 10 ton, 15 ton, 20 ton per hectare of vermicompost) applications. Hence, 5 ton per hectare of vermicompost application will be best for radish production in Chitwan.

The relationship of the main root-shoot morphological characteristics and biomass allocation of Saussurea salsa under different habitat conditions in Sugan lake wetland on the northern margin of the Qinghai-Tibet Plateau

The response analysis of plant morphological characteristics and biomass allocation in salt marsh wetland to heterogeneous habitats is helpful to explore the internal correlation between plant morphological plasticity mechanism and biomass allocation, which is of great significance for the in-depth understanding of habitat stress tolerance strategies of salt marsh plants. However, the relationship between the main root-shoot morphological indexes and biomass allocation of inland alpine arid area salt marsh plant is still unclear. According to the difference of the habitat conditions of Saussurea salsa, 3 test sample were set up, plot I (the Inland salt marsh area, 200–500 m from the lakeshore), plot II (the Oasis Wetland area, 500–1000 m from the lakeshore), plot III (the Seasonal river wetland area, 1000–1500 m from the lakeshore). The relationship between the main root-shoot morphological characteristics and biomass allocation of Saussurea salsa in the Sugan Lake salt marsh was studied in response to heterogeneous habitats. The results showed that Saussurea salsa tended to form the large and thick leaf pattern, the root morphological construction pattern with moderate root diameter (RD) and specific root length (SRL), and the root-shoot ratio (RSR) with minimum biomass allocation strategy in plot I. In plot II, the thin-leaf pattern with the largest specific leaf area (SLA) and the smallest thickness (LT) was formed. Meanwhile, the slender root morphology pattern with the smallest RD, the largest SRL and the moderate RSR was preferred. In plot III, a lobular pattern with minimum leaf area (LA) and SLA, and moderate thickness was formed. At the same time, a thick root pattern with maximum RD and minimum root length, and a maximum RSR were formed. Moreover, there was a highly significant negative correlation (p < 0.01) between SLA and RD at three plots. Besides, there appeared a less significant positive correlation (p < 0.05) between LA and LT, shoot biomass at three plots. Through the synergistic changes of morphological characteristics of aboveground and underground organs and biomass allocation strategies, the inland salt marsh plant population can maintain normal survival, growth and reproduction under harsh environment, which reflects its morphological plasticity and stress resistance mechanism under heterogeneous environment.

Growth Characteristics of Adenophora triphylla var. japonica Hara Seedlings as Affected by Growing Medium.

Adenophora triphylla var. japonica Hara is a highly valued medicinal plant that is used to treat or prevent bronchitis, cough, cancer, and obesity. However, there has been no study on the production of Adenophora triphylla var. japonica Hara seedlings in a closed-type plant production system (CPPS). This study was conducted to examine the growth characteristics of Adenophora triphylla var. japonica Hara seedlings as affected by different growing media. The seeds were sown on a 128-cell plug tray filled with urethane sponges (US), LC grow foam (LC), rockwool (RW), or terra-plugs (TP). The seedlings were cultured for a duration of 54 days under temperature 25 ± 1°C, a photoperiod of 12/12 h (light/dark), and light intensity of 180 µmol·m−2·s−1 photosynthetic photon flux density provided by RB LEDs (red:blue = 8:2) in a closed-type plant production system (CPPS). The germination rate of Adenophora triphylla var. japonica Hara was significantly highest in the TP. Also, seedling shoot growth indicators of plant height, leaf length, leaf width, number of leaves, fresh weight (FW), and dry weight (DW) of the shoot, and leaf area were markedly the greatest in the TP and the lowest in the US. The SPAD (soil-plant analysis development) value was higher in the TP and US than in the LC or RW. In addition, the seedling root growth characteristics of total root length, root surface area, root volume, and number of root tips were significantly greatest in the TP. Moreover, the maximum root diameter, FW and DW of roots were the greatest in the TP. In conclusion, the results suggest that TP are viable for the growth development of Adenophora triphylla var. japonica Hara seedlings.

P3373Predictors of dilatation of ascending aorta in patients with bicuspid aortic valve, a longitudinal multicenter study

Abstract Introduction The bicuspid aortic valve (BAV) is frequently associated to dilation of the ascending aorta. Some cross-sectional studies have related the aortic dilation with morphotype and valvular dysfunction. The aim of this longitudinal multicenter study was to analyze the progression of the aortic dilation and to identify its predictors. Methods We included 459 patients (mean age 52±17; 325 men 70.8%) with BAV, without aortic coarctation. The BAV morphotype, significant valvular dysfunction and dilation of the aortic root and ascending aorta were established by echocardiography. The patients were followed annually, with an average of 7.5±3.2 years. Results 77% of the patients had BAV with a fusion between left and right cusps, 21% between right and non coronary cusps and 2% between left and non coronary cusps, with a raphe in 77% of these patients. Risk factors included: 35% hypertension, 20% smoking, 5% diabetes and 18% dyslipidemia. The baseline study showed a maximum root diameter of 36±6.2 mm and ascending aorta of 39±8.1 mm. In 7% the aortic root was&gt;45 mm, while in 32% the ascending aorta&gt;45 mm. There was no valvular dysfunction in 17% of patients, while the 8% had significant aortic stenosis and 35% significant aortic regurgitation. The annual growth of the aortic root was 0.33±0.2 mm and for the ascending aorta was 0.38±0.3 mm. At the end of follow-up, 16% of the patients had a root&gt;45 mm and 41% an ascending aorta&gt;45 mm. The annual progression of aortic diameters was not related to valvular morphotype, valvular dysfunction or cardiovascular risk factors. The univariate analysis showed a significant relationship between the annual growth of the aortic root and arterial hypertension (p=0.028) and the annual growth of the ascending aorta with the male sex (p=0.019), smoking (p=0.046) and significant (moderate or severe) aortic stenosis (p=0.013). Diabetes mellitus and the presence of raphe were found to be slightly protective (p=0.049 and p=0.031, respectively). In the multivariate analysis, only the male sex and significant aortic stenosis were independent predictors of dilation of the ascending aorta. Conclusions In patients with bicuspid aortic valve, the progression of the dilation of the aortic root is related to hypertension and the growth of the ascending aorta with the male sex and the presence of significant aortic stenosis. Both bicuspid valve morphotype, basal aortic diameter or age were not related to the progression of aortic dilation.

Root life history of non-dehiscent sesame (Sesamum indicum L.) cultivars and the relationship with canopy development

This study described sesame’s rooting behavior and the relationship between above- and belowground biomass in architecture and senescence dynamics. Six non-dehiscent sesame cultivars, branched and non-branched, were grown for two years in North Central Florida’s sandy soils in 2013 and 2014. The root systems were imaged in situ with a minirhizotron camera 5 times in 2013 and 7 times in 2014. Total root length, surface area and diameter were measured for each image, and roots were separated between alive, dying and dead. Leaf area index was recorded 5 times both years. Results showed that averaged maximum root diameter for all cultivars was <2 mm. Most roots were present between 20 to 50 cm deep, and a multivariate approach, namely a canonical discriminant analysis, showed that some cultivars tended to have more roots in the soil mid-depth ranges than others. However, these observations were not stable throughout the season. Leaf area index showed differences between cultivars, but these did not translate into contrasting yields. Results also highlighted a lag between leaf area index and total root length senescence, the former declining about 2 weeks before the latter. This study is among the first to describe sesame rooting characteristics in details.

Vegetative Propagation of Punica granatum by Stem Cuttings Using Non-Mist Propagator

The present study was carried out to explore rooting performance of Punica granatum (Dalim) in Bangladesh through clonal propagation by stem cutting under 3 different doses of rooting hormone IBA (Indole Buetairic Acid) and planted in the perforated plastic tray filled with coarse sand and gravel placed in the non-mist propagator. The experiment was laid out following a Randomized Complete Block Design (RCBD) with 4 treatments and 4 replications (blocks). The treatments were T0= control, T1 = 0.2% IBA, T2 = 0.4% IBA, T3 = 0.8% IBA. The rooting ability of cuttings was significantly influenced by the application of IBA. The results showed that the highest rooting percentage (70%) and longest root length (11.75 cm) of P. granatum stem cuttings were obtained from the cuttings treated with 0.2% IBA followed by 0.4% IBA (47.5% and 7.95 cm respectively) whereas the highest root number (32) and maximum root diameter (2.7 mm) were recorded with 0.4% IBA followed by 0.8% IBA (28 and 2.47 mm respectively). Survival percentage of the cutlings (the rooted cuttings) after 3 months of transferring them into poly bags was also significantly enhanced by exogenous rooting hormone (IBA) application. The highest survival percentage (73.5%) was observed with 0.4% IBA treatment followed by 0.8% IBA (68.5%). Findings of the present study reveal that P. granatum is highly amenable for clonal propagation by stem cuttings using low-cost non-mist propagator and 0.4% IBA treatment may be recommended for mass production of quality planting stocks for the cultivation of the species in homestead agroforestry or in fruit orchards. These outcomes can assist to provide edible fruit to poor rural people of natural disaster vulnerable Bangladesh.

Influence of biocontrol agents and fungicides on vegetative parameters of groundnut (Arachis hypogaea L.) under greenhouse conditions

In the present study the compatibility of various plant growth promoting organisms [Pseudomonas fluorescens (Pf), Trichoderma viride (Tv) and Rhizobium (Rhi)] along with fungicides (mancozeb, tebuconazole and carbendazim + mancozeb) was tested on groundnut crop (cv. K-6) variety under greenhouse conditions. At 45 days after sowing (DAS), maximum (109) number of root nodules was observed in plants treated with combination of biocontrol agents Pf, Tv and Rhi. Maximum (1314.7 mm) root length was observed in Pf and Rhi combination while root area was recorded to be maximum (1341.8 mm2) in Rhi treatment. Root diameter (3.7 mm), root hairs (79.5) and chlorophyll content (51.7) were significant in Pf and Rhi combination. At 90 DAS, boosting effect on root nodules with maximum number (111) was seen in seeds treated with combination of biocontrol agents Pf, Tv and Rhi. Root length was prominent (1775.5 mm) in Tv treated plants whereas root area was maximum (1865.6 mm2) in Pf and Rhi combination. Maximum root diameter (4.8 mm) was found in Pf and Rhi combination whereas Pf, Tv and Rhi combination showed significant (108.5) root hair number. Pf treated plants showed remarkable (60.3) chlorophyll content compared to other treatments. The study showed increase in overall growth parameters in biocontrol agents treated plants followed by fungicides.

Effects of plant-derived smoke water on accumulation of biomass and active substance of Salvia miltiorrhiza f. alba

To study the effect of plant-derived smoke water on the accumulation of biomass and active substance of Salvia miltiorrhiza f. alba, seedlings of S. miltiorrhiza were treated with different concentrations of smoke water (1:500, 1: 1 000, 1: 2 000). The fresh weight and dry weight of underground part, the number of split-root, maximum root diameter, average root diameter, average root length, the content of lipophilic components and water-soluble components were measured. Results showed that fresh weight and dry weight of underground part were respectively improved by 98.01%, 44.32% and 85.71%, 28.57% with significant difference by smoke water treatment with concentration of 1: 500 and 1: 1 000. Maximum root diameter and dry weight of underground part were respectively enhanced by 58.44% and 85.71% by smoke water with concentration of 1:500. The content of tanshinone I and tanshinone II(A) were improved by smoke water treatment, however there were no significantly difference on the content of cryptotanshinone and dihydrotan shinone. This study indicates that smoke water treatment could be used to improve the accumulation of biomass and active substance content of S. miltiorrhiza f. alba, which could provide new ideas for its green cultivating.

Modeling the functional influence of vegetation type on streambank cohesion

ABSTRACTThe important role of vegetation in adding cohesion and stabilizing streambanks has been widely recognized in several aspects of fluvial geomorphology, including stream restoration and studies of long‐term channel change. Changes in planform between braided, meandering, and anabranching forms have been attributed to the impacts of vegetation on hydraulic roughness and bank stability. However, these studies focus either on flume studies where analog vegetation is used, or case studies featuring one species, which is commonly invasive. We present functional differences of bank‐stabilizing root characteristics and added cohesion, with vegetation categorized as woody and non‐woody and by the vegetation groups of trees, shrubs, graminoids, and forbs. We analyzed root morphology and tensile strength of 14 species common to riparian areas in the southern Rocky Mountains, in field sites along streambanks in the montane and subalpine zones of the Colorado Front Range. Using the vegetation root component (RipRoot) of a physically‐based bank stability model (BSTEM), we estimated the added cohesion for various sediment textures with the addition of each of the 14 species. Significant differences exist between woody and non‐woody vegetation and between the four vegetation categories with respect to the coefficient of the root tensile strength curve, lateral root extent, and maximum root diameter. Woody vegetation (trees and shrubs) have higher values of all three parameters than non‐woody species. Tree roots add significantly more cohesion to streambanks than forb roots. Additionally, rhizomes may play an important role in determining the reach‐scale effects of roots on bank stabilization. Differences in root characteristics and added cohesion among vegetation categories have several important implications, including determining the likelihood of planform change, developing guidelines for the use of bank‐stabilizing vegetation, and linking the effect of vegetation to geomorphic structure that can benefit ecosystem functioning. Copyright © 2014 John Wiley &amp; Sons, Ltd.

Diploid‐Tetraploid Comparisons in Rye. III. Temperature Effects on Seedling Development1

The late fall planting season for rye in the southeastern USA is typically characterized by an extreme range of temperature conditions. The potential for selection of diploid and tetraploid rye (Secale cereale L.) populations possessing superior seedling growth characters over a broad range of temperatures was assessed by examining the effect of genetic background on various seeding growth characters at three temperatures (12, 20, 28°C). Diploid populations, and their colchicine‐derived tetraploid counterparts from five genetic backgrounds (‘Elbon’, ‘Explorer’, ‘Florida Black’, ‘Gator’, ‘Wrens Abruzzi’) were compared. The seedling characters included shoot and primary root growth day−1, root cross‐sectional area at the meristematic region, and primary root bluntness ratio (distance from the plane of maximum root diameter at the meristematic region to the root tip divided by the maximum root diameter at the meristematic region). Highly significant ploidy level (PL), genetic background (GB), and temperature (T) main effects were obtained for both shoot and primary root growth day−1. A highly significant T✕GB✕PL interaction was found for shoot growth day−1, but this effect was not significant for root growth day−1. The T ✕ PL interaction was significant for primary root growth day−1 at the 0.05 level. Highly significant ploidy level (PL) and temperature (T) main effects were obtained for root cross‐sectional area. A highly significant ploidy level (PL) main effect was found for the bluntness ratio. The lower ratios obtained for the tetraploid populations indicated that the tetraploid root tips were blunter than those of diploids, which may be a factor in soil penetration and root proliferation. The results indicated that substantial genetic variation for seedling growth characters was present among genetic backgrounds as well as within populations at both ploidy levels over a wide temperature range. It was concluded that selection for diploid as well as tetraploid rye populations possessing superior seedling growth characters over a broad range of temperatures would be successful.

Varietal Differences in Root System and its Relationship with Shoot Development and Tuber Yield

Ten varieties were grown under the field conditions at the two locations, and number, diameter and dry weight of root were measured at the 4th leaf stage, the initial flowering stage and the full leaf expanding stage. The results obtained are summarized as follows: 1. Number, diamcter and dry weight of root attained to the maximum value about the initial flowering stage, and maximum diameter and dry weight of root were greater in late varieties than in early ones. 2. Number of roots per plant indicated a positive correlation with shoot numbcr (r=0.743), but dry weight of root per plant was correlated with dry weight of root per stem (r=0.792), not with shoot number. Moreover, maximum root diameter and dry weight of root correlated positively with stem length, number of leaves on main stem and stem diameter. 3. Root dry weight of each variety reached the maximum value several weeks earlier than shoot dry weight at each location. 4. During the period from the 4th leaf stage to the initial flowering stage, there were distinct differences among varieties in root and tuber growth rates. The growth rates in late varieties were higher in root, but lower in tuber, compared with early ones, and there was a highly negative correlation between them. However, varietal differences in growth rate per plant were very litte except Shimakei No. 161, and not related with the earliness. In addition, growth rates in each organ were correlated with their distribution ratios, not with growth rate per plant. 5. Root dry weight was significantly correlated with tuber yield. However, leaf and stem dry weight were greater in late varieties than in early ones and showed also highly significant correlations with tuber yield. Therefore, it was assumed that the relationship between root system and tuber yield was not due to the direct contribution of root system, but due to the pleiotropic expression of the earliness.