The dual effect of sand-covered biocrusts on annual plants: Increasing cover but reducing individual plant biomass and fecundity

Chemical weed control with acrolein has been shown to be a lower cost method for reducing submerged plant biomass of sago pondweed in the irrigation district of the Lower Valley of Rio Colorado, Argentina (39°10′S–62°05′W). However, no experimental data exist on the effects of the herbicide on plant growth and its survival structures. Field experiments were conducted during 3 yr to evaluate the effect of acrolein on growth and biomass of sago pondweed and on the source of underground propagules (i.e., rhizomes, tubers, and seeds). Plant biomass samples were collected in irrigation channels before and after several herbicide treatments. The underground propagule bank was evaluated at the end of the third year. Within each treatment, plant biomass was significantly reduced by 40 to 60% in all three study years. Rapid new plant growth occurred after each application; however, it was less vigorous after repeated treatments. At the end of the third year at 3,000 m downstream from the application point, plant biomass at both channels ranged from 34 to 3% of control values. Individual plant weight and height were affected by acrolein treatments, flowering was poor, and seeds did not reach maturity. After 3 yr, acrolein did not reduce the number of tubers. However, they were significantly smaller and lighter. Rhizomes fresh weight decreased by 92%, and seed numbers decreased by 79%. After 3 yr of applications, operational functioning of the channels could be maintained with fewer treatments and lower concentrations of acrolein.

Download Full-text

Alteration in plant spacing improves submergence tolerance in Sub1 and non-Sub1 rice (cv. IR64) by better light interception and effective carbohydrate utilisation under stress

Functional Plant Biology ◽

10.1071/fp19364 ◽

2020 ◽

Vol 47 (10) ◽

pp. 891 ◽

Cited By ~ 1

Author(s):

Debarati Bhaduri ◽

Koushik Chakraborty ◽

A. K. Nayak ◽

Mohammad Shahid ◽

Rahul Tripathi ◽

...

Keyword(s):

Leaf Senescence ◽

Plant Biomass ◽

Rice Cultivar ◽

Antioxidant Enzyme Activities ◽

Individual Plant ◽

Submergence Tolerance ◽

Light Penetration ◽

Imaging Data ◽

Seedling Vigour ◽

Plant Plant

Besides genetic improvement for developing stress-tolerant cultivars, agronomic management may also add considerable tolerance against different abiotic stresses in crop plants. In the present study, we evaluated the effect of six different spacing treatments (S1: 10 × 10 cm; S2: 15 × 10 cm; S3:15 × 15 cm; S4:20 × 10 cm; S5: 20 × 15 cm; S6: 20 × 20 cm (row-row × plant-plant)) for improving submergence tolerance in rice. A high yielding submergence intolerant rice cultivar IR64 was tested against its SUB1 QTL introgressed counterpart (IR64-Sub1) for 12 days of complete submergence for different spacing treatments in field tanks. Relatively wider spaced plants showed higher individual plant biomass and early seedling vigour, which was particularly helpful for IR64 in increasing plant survival (by 150% in S6 over S1) under 12 days of submergence, whereas the improvement was less in IR64-Sub1 (13%). Underwater radiation inside the plant canopy, particularly beyond 40 cm water depth, was significantly greater in wider spacing treatments. Leaf senescence pattern captured by SPAD chlorophyll meter reading and chlorophyll fluorescence imaging data (Fm, Fv/Fm) taken at different time intervals after stress imposition suggested that there was lesser light penetration inside the canopy of closer spaced plants, and that it might hasten leaf senescence and damage to the photosynthetic system. The initial content of total non-structural carbohydrate (NSC) was higher in wider spaced plants of IR64, and also the rate of depletion of NSC was lesser compared with closer spaced plants. In contrast, there was not much difference in NSC depletion rate under different spacing in IR64-Sub1. Further, higher antioxidant enzyme activities in wider spaced plants (both IR64 and IR64-Sub1) after de-submergence indicated better stress recovery and improved tolerance. Taken together we found that wider spacing (row-row: 20 cm and plant-plant: 15 cm and more) can significantly improve submergence tolerance ability in rice, particularly in submergence intolerant non-Sub1 cultivar like IR64, perhaps due to better underwater light penetration, delayed leaf senescence and slower depletion of NSC reserve.

Download Full-text

An alternative approach to the analysis of mixed cropping experiments. 2. Marketable yield.

Netherlands Journal of Agricultural Science ◽

10.18174/njas.v31i2.16954 ◽

1983 ◽

Vol 31 (2) ◽

pp. 143-155

Author(s):

C.J.T. Spitters

Keyword(s):

Harvest Index ◽

Plant Biomass ◽

Niche Differentiation ◽

Individual Plant ◽

Mixed Cropping ◽

Resource Exploitation ◽

Marketable Yield ◽

Land Equivalent Ratio ◽

Alternative Approach ◽

Competition Effects

The effects of competition on marketable yield are derived from those on biomass by means of the relation between individual plant biomass and harvest index. A method is presented to estimate competition effects and advantage of mixed cropping directly from the data of marketable yield. The effect of spp. composition and population density on the advantage of mixed cropping, measured by the land equivalent ratio, is partitioned into an effect due to better resource exploitation (niche differentiation), a favourable influence of mixed cropping on harvest index and an effect due to density which can also be achieved by growing monocrops at a higher density. The approach is illustrated with the results of an experiment on mixed cropping of maize and groundnuts. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Download Full-text

Accumulation of trace metals by aquatic macrophytes and their possible use in phytoremediation techniques

Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis ◽

10.11118/actaun200856010097 ◽

2008 ◽

Vol 56 (1) ◽

pp. 97-104

Author(s):

Michaela Hillermannová ◽

Radovan Kopp ◽

Ivo Sukop ◽

Tomáš Vítek

Keyword(s):

Surface Water ◽

Trace Metals ◽

Plant Species ◽

Aquatic Plants ◽

Aquatic Macrophytes ◽

Plant Biomass ◽

Water Current ◽

Ecological Group ◽

Individual Plant ◽

The Individual

The aim of the performed research was to obtain knowledge on the ability of aquatic plants naturally growing at a site to absorb trace metals contained in bottom sediments and surface water. Furthermore, we compared differences in the accumulation of trace metals by the individual groups of aquatic plants (submerged and emergent) and assessed a possible use of the individual plant species in phytoremediation techniques. Representative samples of water, sediments and aquatic macrophytes were taken from three anthropogenically loaded streams in six monitoring cycles in several collection profiles differing in the distance from a source of contamination. The samples were analysed for the total content of selected trace metals (As, Cd, Pb, Al, Hg, Zn, Fe, Mn, Cr, Ni and Cu). For comparison, one profile at an unloaded site was sampled as well. The obtained results were subjected to multivariate statistical analysis of data. Increased contents of Fe, Al, Mn, Cr and Zn were detected in sediments and plant biomass at loaded sites, namely 2–3× higher than at the comparing site. The contents of metals in surface water samples were altogether below the detection limit of the analytical method. When evaluating the individual plant species, we can state that the lowest contents of metals were detected in shore species (reed canary grass Phalaroides arundinacea, wood club-rush Scirpus silvaticus and red dock Rumex aquaticus); plant species growing in the very water current (water star-wort Callitriche sp. and flote-grass Glyceria fluitans) exhibited mean contents of metals. In species forming mats (Fontinalis antipyretica and Cladophora sp.), these contents were several times higher as compared to the previous species. The results of the performed research show that one of important factors, which influence the accumulation of trace metals in plants, is their ecological group (emergent – submerged) affiliation and the species classification within this group. Based on the evaluated data, we can recommend species of moss and algae that form mats eventually species growing in the very water flow for the future use in phytoremediation techniques.

Download Full-text

Some ecological and demographic characteristics of two growth forms of wild soybean (Glycine soja)

Canadian Journal of Botany ◽

10.1139/b94-065 ◽

1994 ◽

Vol 72 (4) ◽

pp. 486-492 ◽

Cited By ~ 16

Author(s):

Masashi Ohara ◽

Yoshiya Shimamoto

Keyword(s):

Growth Form ◽

Plant Biomass ◽

Glycine Soja ◽

Wild Soybean ◽

Morphological Difference ◽

Demographic Characteristics ◽

Environmental Stability ◽

Individual Plant ◽

Growth Forms ◽

Percent Germination

Ecological and demographic characteristics of two morphologically distinct forms of Glycine soja, namely, the twining and branching forms, were investigated in a riverbank habitat. Besides the morphological difference, the ecological distribution and reproductive characteristics for the two forms were also distinctive. The branching form occurred on the open riverside, while the twining form was found in shady, moist inland areas. The branching form had a much larger individual plant biomass and produced more pods and seeds than the twining form. However, the branching form occurred less frequently because of the high mortality it suffered after flooding and the high percent dormancy of seed in the unpredictably disturbed riverside conditions. Despite its lower seed productivity, the twining form was dominant in stable and predictable inland habitats because of its high percent germination and its subsequent high percent survival. The two growth forms of G. soja clearly represent reproductive and ecological differentiation in relation to environmental stability. Key words: disturbance, Glycine, growth form, hard-coatedness, mortality.

Download Full-text

Dominance of individual plant species is more important than diversity in explaining plant biomass in the forest understorey

Journal of Vegetation Science ◽

10.1111/jvs.12624 ◽

2018 ◽

Vol 29 (3) ◽

pp. 521-531 ◽

Cited By ~ 12

Author(s):

Safaa Wasof ◽

Jonathan Lenoir ◽

Tarek Hattab ◽

Aurélien Jamoneau ◽

Emilie Gallet-Moron ◽

...

Keyword(s):

Plant Species ◽

Plant Biomass ◽

Individual Plant ◽

Forest Understorey

Download Full-text

The effect of bottom sediment on biomass production by Italian ryegrass and maize

Polish Journal of Chemical Technology ◽

10.2478/v10026-007-0088-6 ◽

2007 ◽

Vol 9 (4) ◽

pp. 48-51 ◽

Cited By ~ 2

Author(s):

Barbara Wiśniowska-Kielian

Keyword(s):

Bottom Sediment ◽

Biomass Production ◽

Plant Biomass ◽

Lolium Multiflorum ◽

Acid Soil ◽

Italian Ryegrass ◽

Composition Analysis ◽

Individual Plant ◽

Total Biomass ◽

The Individual

The effect of bottom sediment on biomass production by Italian ryegrass and maize A two-year pot experiment (2005 and 2006) was conducted to estimate an effect of dredged bottom sediment from Rożnów Reservoir addition to the light, very acid soil on the plant biomass production. The sediment was applied in the amount from 1 to 20% of the substratum mass. Italian ryegrass (Lolium multiflorum L.) and maize (Zea mays L.) were cultivated as the successive test plants. The lowest amount of plant biomass was obtained on the soil (control) and each sediment addition to the substratum caused an increase of the biomass production, both tops as well as the roots of the plant. Larger sediment additions (7% and more) caused a significant increase of the yield, of both the individual plant species and the total biomass during the two years of the experiment. The bottom sediment added to the light, very acid soil distinctly improved the plant yielding and the way of biomass utilisation should be assessed on the basis of its chemical composition analysis.

Download Full-text

Resource Allocation in Annual Plants

10.1101/2021.04.19.440512 ◽

2021 ◽

Author(s):

David McMorris ◽

Glenn Ledder

Keyword(s):

Optimal Control ◽

Resource Allocation ◽

Control Theory ◽

Optimal Control Theory ◽

Initial Conditions ◽

Optimal Growth ◽

Growing Season ◽

Individual Plant ◽

Annual Plants ◽

Wide Range

The fitness of an annual plant can be thought of as how much fruit is produced by the end of its growing season. Under the assumption that annual plants grow to maximize fitness, we can use techniques from optimal control theory to understand this process. We introduce a model for resource allocation in annual plants which extends classical work by Iwasa and Roughgarden to a case where both carbohydrates and mineral nutrients are allocated to shoots, roots, and fruits in annual plants. We use optimal control theory to determine the optimal resource allocation strategy for the plant throughout its growing season as well as develop a numerical scheme to implement the model in MATLAB. Our results suggest that what is optimal for an individual plant is highly dependent on initial conditions, and optimal growth has the effect of driving a wide range of initial conditions toward common configurations of biomass by the end of a growing season.

Download Full-text

Relationships between age and biomass of individual plants and seed production in two grazed tropical legumes. 1. Derivation of relationships

Australian Journal of Agricultural Research ◽

10.1071/ar00174 ◽

2002 ◽

Vol 53 (2) ◽

pp. 91

Author(s):

C. K. McDonald ◽

R. M. Jones

Keyword(s):

Soil Water ◽

Seed Production ◽

Seed Set ◽

Plant Biomass ◽

Plant Age ◽

Stem Length ◽

Individual Plant ◽

Water Conditions ◽

Grass Biomass ◽

Soil Water Conditions

The distributions of individual plant age and biomass of Chamaecrista rotundifolia cv. Wynn and a mix of Stylosanthes scabra cvv. Seca and Fitzroy in grazed grass–legume pastures were examined to determine their effect on seed production. The effects of enhanced soil water conditions and severe defoliation on seed production were assessed in ungrazed plots. These experiments were part of a larger study to develop a demographic model of perennial forage legumes. The distribution of individual plant age and biomass was highly skewed towards a large number of young/small plants, with fewer old/large plants. Lack of seed set when stem length was less than approximately 200 mm, and in most small plants (<2 g), resulted in older/larger plants contributing far more to seed production and, to a lesser extent, legume biomass, than they did to legume plant numbers. C. rotundifolia seed production was linearly related to individual plant biomass but was highly varaiable and was greatly reduced in swards containing >3000 kg/ha of grass. Using log-transformed data, plant biomass accounted for 74% of the variation in seed production (SP), but together with grass biomass accounted for 91% of the variation [ln(SP) = 6.01 + 0.91*ln(BIOMASS) – 0.28*ln(GRASS BIOMASS), P < 0.001]. Total legume biomass accounted for only 44% of the variation in seed production. S. scabra herbage allowance (kg legume/head) had a major impact on seed production. Total legume biomass and individual plant biomass alone accounted for less than 40% of the variation in seed production. Using herbage allowance (HA) as well as individual plant biomass improved the prediction of seed production (SP) to account for 74% of the variation [ln(SP) = 0.11 + 1.14*ln(BIOMASS) + 0.24*ln(HA), P < 0.001]. Enhanced soil water conditions increased the biomass of individual plants of both species and increased the seed production per gram of plant in S. scabra but not in C. rotundifolia. Severe defoliation in early summer or autumn can greatly reduce or even eliminate seed production by some plants by removal of flowers, reducing individual plant biomass, or allowing insufficient time for plants to reach minimum stem lengths. The different factors affecting seed production in the 2 species highlight the complexity of legume seed set in grazed pasture systems, and some implications for grazing management and modelling are discussed.

Download Full-text

Increased Plant Density and Shade Affects Flowering and Fruiting of Pumpkin (C. pepo)

HortScience ◽

10.21273/hortsci.32.3.526a ◽

1997 ◽

Vol 32 (3) ◽

pp. 526A-526

Author(s):

R.O. Nyankanga ◽

H.C. Wien

Keyword(s):

Field Experiments ◽

Fruit Set ◽

Plant Density ◽

Plant Biomass ◽

Female Flower ◽

Individual Plant ◽

Complete Suppression ◽

Flower Production ◽

Male Flowers ◽

Female Flowers

Increase in plant density often results in reduction in reproductive potential of individual plants in cucurbits. The reduction may be due to reduced female flower production or a reduction or a delay in fruit set or to decreased fruit size. To determine the cause of the reduction, flowering, and fruiting of two pumpkin cultivars was evaluated in four field experiments under four plant densities ranging from 4483 plants/ha to 23,910 plants/ha and in a greenhouse using three levels of shade. Weekly flower and flower bud counts were made in the field experiment starting at first anthesis. Flowers were determined to have either set or aborted or not have reached anthesis. Increasing plant population from 4483 plants/ha to 23,910 plants/ha resulted in an increase in number of flowers per unit area up to 11,955 plants/ha, beyond which there was a steep decline. Increased plant density also resulted in an increase in aborted female flower buds that did not reach anthesis. Increase in plant density only reduced fruit set at very high populations. Number of fruits per area increased linearly with plant density up to 11,955 plants/ha, but decreased at higher plant populations. Reducing incident light by 30%, 60%, and 80% in a greenhouse experiment resulted in reduction of both male and female flowers. At 80% shade, there was a complete suppression of female flowers, whereas male flowers were still being produced. The number of female flowers reaching anthesis was positively correlated with total shoot dry weight while floral buds and male flowers were not. Reduction of individual plant biomass under high-density plantings might therefore be limiting female flower production and yield.

Download Full-text