Does seed mass drive interspecies variation in the effect of management practices on weed demography?

10.1101/2020.01.08.898247 ◽

2020 ◽

Author(s):

Kazakou Elena ◽

Fried Guillaume ◽

Cheptou Pierre-Olivier ◽

Gimenez Olivier

Keyword(s):

Seed Bank ◽

Management Practices ◽

Seed Mass ◽

Demographic Parameters ◽

Weed Species ◽

Plant Populations ◽

Interspecies Variation ◽

Weed Population Dynamics ◽

Do So

AbstractOptimizing the effect of management practices on weed population dynamics is challenging due to the difficulties in inferring demographic parameters in seed banks and their response to disturbance. Here, we used a long-term plant survey between 2006 and 2012 in 46 French vineyards and quantified the effects of management practices (tillage, mowing and herbicide) on colonization, germination and seed survival of 30 weed species in relation to their seed mass. To do so, we used a recent statistical approach to reliably estimate demographic parameters for plant populations with a seed bank using time series of presence–absence data, which we extended to account for interspecies variation in the effects of management practices on demographic parameters. Our main finding was that when the level of disturbance increased (i.e., in plots with a higher number of herbicide, tillage or mowing treatments), colonization and survival in large-seeded species increased faster than in small-seeded species. High disturbance through tillage increased survival in the seed bank of species with high seed mass. The application of herbicides, considered as an intermediate disturbance, increased germination, survival and colonization probabilities of species with high seed mass. Mowing, representing habitats more competitive for light, increased the survival of species with high seed mass. Overall, the strong relationships between the effects of management practices and seed mass provides an indicator for predicting the dynamics of weed communities under disturbance.

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Reproductive output of ponderosa pine in response to thinning and prescribed burning in western Montana

Canadian Journal of Forest Research ◽

10.1139/x07-203 ◽

2008 ◽

Vol 38 (4) ◽

pp. 844-850 ◽

Cited By ~ 14

Author(s):

Gregory Peters ◽

Anna Sala

Keyword(s):

Pinus Ponderosa ◽

Prescribed Fire ◽

Ponderosa Pine ◽

Reproductive Output ◽

Management Practices ◽

Prescribed Burning ◽

Seed Mass ◽

Reproductive Traits ◽

Western Montana ◽

Cone Production

Thinning and thinning followed by prescribed fire are common management practices intended to restore historic conditions in low-elevation ponderosa pine ( Pinus ponderosa Dougl. ex P. & C. Laws.) forests of the northern Rocky Mountains. While these treatments generally ameliorate the physiology and growth of residual trees, treatment-specific effects on reproductive output are not known. We examined reproductive output of second-growth ponderosa pine in western Montana 9 years after the application of four treatments: thinning, thinning followed by spring prescribed fire, thinning followed by fall prescribed fire, and unthinned control stands. Field and greenhouse observations indicated that reproductive traits vary depending on the specific management treatment. Cone production was significantly higher in trees from all actively managed stands relative to control trees. Trees subjected to prescribed fire produced cones with higher numbers of filled seeds than trees in unburned treatments. Seed mass, percentage germination, and seedling biomass were significantly lower for seeds from trees in spring burn treatments relative to all others and were generally higher in trees from fall burn treatments. We show for the first time that thinning and prescribed-burning treatments can influence reproductive output in ponderosa pine.

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Nitrogen Fertilizer Management Practices to Enhance Seed Production by `Anaheim Chili' Peppers

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.115.2.245 ◽

1990 ◽

Vol 115 (2) ◽

pp. 245-251 ◽

Cited By ~ 3

Author(s):

J.O. Payero ◽

M.S. Bhangoo ◽

J.J. Steiner

Keyword(s):

Seed Production ◽

Seed Yield ◽

Management Practices ◽

Irrigation System ◽

Seed Mass ◽

Fruit Production ◽

Trickle Irrigation ◽

Total N ◽

Leaf Petiole ◽

Total Seed

The effects of six applied N treatments differing by rates and frequencies of application on the yield and quality of pepper (Capsicum annuum var. annuum L. `Anaheim Chili') grown for seed was studied. The timing of N applications was based on crop phenology, leaf petiole nitrate-nitrogen concentrations (NO3-N) minimum thresholds, and scheduled calendar applications of fixed amounts of N. Solubilized NH4NO3 was applied through a trickle-irrigation system to ensure uniform and timely applications of N. Rate of mature (green and red) fruit production was unaffected by any treatment except weekly applications of 28 kg·ha-1 of N, which stopped production of mature fruit before all other treatments. Early season floral bud and flower production increased with increasing amounts of N. The two highest total N treatments produced more floral buds and flowers late in the season than the other treatments. Total fruit production was maximized at 240 kg N/ha. Differences in total fruit production due to frequency of N application resulted at the highest total N level. Red fruit production tended to be maximized with total seasonal applied N levels of 240 kg·ha-1 and below, although weekly applications of N reduced production. Total seed yield was a function of red fruit production. Pure-1ive seed (PLS) production was a function of total seed production. Nitrogen use efficiency (NUE) for red fruit production also decreased with N rates >240 kg·ha-1, but PLS yield and NUE decreased in a near-linear fashion as the amount of total seasonal applied N increased, regardless of application frequency. Season average NO3-N (AVE NO3-N) values >4500 mg·kg-1 had total seed and PLS yields less than those treatments <4000 mg·kg-1. Six-day germination percentage was reduced with weekly N applications of 14 kg·ha-1. Seed mass was reduced with weekly N applications of 28 kg·ha-1. Final germination percent, seedling root length and weight, and field emergence were unaffected by any of the N treatments. These findings indicate that different N management strategies are needed to maximize seed yield compared to fruit yield and, therefore, there may be an advantage to growing `Anaheim Chili' pepper specifically for seed.

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Cowpea Stover Yield, Seed Mass and Soil pH under Different Management Practices and Environmental Conditions

Journal of Agronomy ◽

10.3923/ja.2019.33.40 ◽

2018 ◽

Vol 18 (1) ◽

pp. 33-40

Author(s):

Erick Sebetha

Keyword(s):

Soil Ph ◽

Environmental Conditions ◽

Management Practices ◽

Seed Mass ◽

Stover Yield

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Relative importance of region, seasonality and weed management practices effects on the functional structure of weed communities in French vineyards

10.1101/2021.10.26.465884 ◽

2021 ◽

Author(s):

Marie-Charlotte Bopp ◽

Elena Kazakou ◽

Aurelie Metay ◽

Guillaume Fried

Keyword(s):

Weed Management ◽

Management Practices ◽

Environmental Gradients ◽

Cropping Systems ◽

Seed Mass ◽

Soil Disturbance ◽

Lateral Spread ◽

Maximum Height ◽

Weed Communities ◽

Mechanical Disturbance

Winegrowers have diversified their weed management practices over the last two decades changing the structure and the composition of weed communities. Complementary to taxonomic studies, trait-based approaches are promising ways for a better understanding of weed communities responses to environmental and agronomic filters. In the present study, the impacts of climate, soil characteristics, seasons and weed management practices (chemical weeding, tillage and mowing) were assessed on weed communities from 46 plots in three French wine-growing regions (Champagne, Languedoc and Rhone valley). These agro-environmental gradients structuring weed communities according to their combinations of traits were highlighted using multivariate analysis (RLQ). The impacts of these filters on Community Weighted Means (CWM) and Community Weighted Variance (CWV) of weed communities were analysed using mixed and null modelling. Our results showed that spatio-temporal and weed management practices variables explained from 13% to 48% of the total variance of CWM (specific leaf area, maximum height, seed mass, flowering onset and duration and lateral spread). Region, seasonality and management practices explained 53%, 28% and 19% of CWM marginal variance, respectively. Weed management impacted CWM and CWV through two main gradients: (i) a soil disturbance gradient with high mechanical disturbance of soil in tilled plots and low mechanical disturbance in chemically weeded plots and (ii) a vegetation cover gradient with high vegetation abundance in mowed plots compared to more bare soils in tilled and chemically weeded plots. In Languedoc, chemical weeding filtered weed communities with ruderal strategy trait values (low seed mass, small-stature) while mowed communities were more competitive (higher seed mass, higher stature and lower SLA). In Languedoc and Champagne, tillage favoured communities with high seed mass that increases the viability of buried seeds and high lateral spread values associated to the ability to resprout after tillage. This study demonstrated that trait-based approaches can be successfully applied to perennial cropping systems such as vineyards, in order to understand community assembly to better guide weed management practices.

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