Fertilizers, Mycorrhizal Inoculation and Atrazine Interactions on Weed Biomass and Yield of Maize

AbstractIn a recent paper by one of the authors and collaborators, motivated by the Olive Quick Decline Syndrome (OQDS) outbreak, which has been ongoing in Southern Italy since 2013, a simple epidemiological model describing this epidemic was presented. Beside the bacterium Xylella fastidiosa, the main players considered in the model are its insect vectors, Philaenus spumarius, and the host plants (olive trees and weeds) of the insects and of the bacterium. The model was based on a system of ordinary differential equations, the analysis of which provided interesting results about possible equilibria of the epidemic system and guidelines for its numerical simulations. Although the model presented there was mathematically rather simplified, its analysis has highlighted threshold parameters that could be the target of control strategies within an integrated pest management framework, not requiring the removal of the productive resource represented by the olive trees. Indeed, numerical simulations support the outcomes of the mathematical analysis, according to which the removal of a suitable amount of weed biomass (reservoir of Xylella fastidiosa) from olive orchards and surrounding areas resulted in the most efficient strategy to control the spread of the OQDS. In addition, as expected, the adoption of more resistant olive tree cultivars has been shown to be a good strategy, though less cost-effective, in controlling the pathogen. In this paper for a more realistic description and a clearer interpretation of the proposed control measures, a spatial structure of the epidemic system has been included, but, in order to keep mathematical technicalities to a minimum, only two players have been described in a dynamical way, trees and insects, while the weed biomass is taken to be a given quantity. The control measures have been introduced only on a subregion of the whole habitat, in order to contain costs of intervention. We show that such a practice can lead to the eradication of an epidemic outbreak. Numerical simulations confirm both the results of the previous paper and the theoretical results of the model with a spatial structure, though subject to regional control only.

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Spring-planted cover crops for weed control in soybean

Renewable Agriculture and Food Systems ◽

10.1017/s1742170521000107 ◽

2021 ◽

pp. 1-8

Author(s):

Katja Koehler-Cole ◽

Christopher A. Proctor ◽

Roger W. Elmore ◽

David A. Wedin

Keyword(s):

Weed Control ◽

Biomass Production ◽

Cover Crops ◽

Weed Management ◽

Block Design ◽

Weed Suppression ◽

Crop Species ◽

Cold Temperatures ◽

Weed Biomass ◽

Small Grains

Abstract Replacing tillage with cover crops (CC) for weed management in corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] systems with mechanical weed control has many soil health benefits but in the western Corn Belt, CC establishment after harvest is hampered by cold temperatures, limited labor and few compatible CC species. Spring-planted CC may be an alternative, but information is lacking on suitable CC species. Our objective was to evaluate four spring-planted CC with respect to biomass production and weed suppression, concurrent with CC growth and post-termination. Cover crop species tested were oat (Avena sativa L.), barley (Hordeum vulgare L.), brown mustard [Brassica juncea (L.) Czern.] and yellow mustard (Brassica hirta Moench). They were compared to no-CC treatments that were either tilled pre- and post-planting of soybean (no-CC tilled) or not tilled at all (no-CC weedy). CC were planted in late March to early April, terminated 52–59 days later using an undercutter, and soybean was planted within a week. The experiment had a randomized complete block design with four replications and was repeated for 3 years. Mustards and small grains produced similar amounts of biomass (1.54 Mg ha−1) but mustard biomass production was more consistent (0.85–2.72 Mg ha−1) than that of the small grains (0.35–3.81 Mg ha−1). Relative to the no-CC weedy treatment, mustards suppressed concurrent weed biomass in two out of 3 years, by 31–97%, and small grains suppressed concurrent weed biomass in only 1 year, by 98%. Six weeks after soybean planting, small grains suppressed weed biomass in one out of 3 years, by 79% relative to the no-CC weedy treatment, but mustards did not provide significant weed suppression. The no-CC tilled treatment suppressed weeds each year relative to the no-CC weedy treatment, on average 87%. The ineffective weed control by CC reduced soybean biomass by about 50% six weeks after planting. While spring-planted CC have the potential for pre-plant weed control, they do not provide adequate early season weed suppression for soybean.

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Effects of Soil Tillage and Post-Emergence Weed Control on Weed Biomass and Maize Yield

Cereal Research Communications ◽

10.1007/bf03543265 ◽

2003 ◽

Vol 31 (1-2) ◽

pp. 177-184

Author(s):

Mira Knežević ◽

Marija Đurkić ◽

Ivan Knežević ◽

Oleg Antonić ◽

Sven Jelaska

Keyword(s):

Weed Control ◽

Maize Yield ◽

Soil Tillage ◽

Weed Biomass

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Interference and Seed Production by Common Lambsquarters (Chenopodium album) in Soybeans (Glycine max)

Weed Science ◽

10.1017/s004317450005623x ◽

1990 ◽

Vol 38 (2) ◽

pp. 113-118 ◽

Cited By ~ 40

Author(s):

S. Kent Harrison

Keyword(s):

Seed Production ◽

Seed Yield ◽

Chenopodium Album ◽

Soybean Seed ◽

Dry Weight ◽

Threshold Level ◽

Yield Reduction ◽

Significant Treatment ◽

Weed Biomass ◽

Common Lambsquarters

Multiple regression and response surface plots were used to analyze the effects of common lambsquarters population density and interference duration on weed growth and soybean seed yield. Under favorable growing conditions in 1986, weed biomass production at all population densities and interference durations was four to five times that produced in 1987, under less favorable conditions. However, there was no significant treatment by year interaction for soybean seed yield reduction by common lambsquarters, and production of each kg/ha weed biomass resulted in an average soybean yield reduction of 0.26 kg/ha. Utilizing 5% yield loss as an arbitrary threshold level, the regression equation predicted a common lambsquarters density threshold of 2 plants/m of row for 5 weeks of interference after crop emergence and 1 plant/m of row for 7 weeks. Seed production by individual common lambsquarters plants was highly correlated (r=0.92) with weed dry weight, and seed production ranged from 30 000 to 176 000 seeds/plant.

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TILLAGE AND RESIDUE MULCHING EFFECT ON PRODUCTIVITY OF MAIZE (ZEA MAYS)–TORIA (BRASSICA CAMPESTRIS) CROPPING SYSTEM IN FRAGILE ECOSYSTEM OF NORTHEAST INDIAN HIMALAYAS

Experimental Agriculture ◽

10.1017/s0014479714000179 ◽

2014 ◽

Vol 51 (1) ◽

pp. 107-125 ◽

Cited By ~ 7

Author(s):

ANUP DAS ◽

P. K. GHOSH ◽

M. R. VERMA ◽

G. C. MUNDA ◽

S. V. NGACHAN ◽

...

Keyword(s):

Zea Mays ◽

Soil Moisture ◽

Brassica Campestris ◽

Poultry Manure ◽

Ambrosia Artemisiifolia ◽

Eastern Region ◽

Maize Crop ◽

Weed Biomass ◽

Indian Himalayas

SUMMARYThe north eastern region (NER) of India receives a high amount of rainfall (2450 mm) both in terms of intensity and frequency. Most of the precipitation goes waste because of improper conservation measures and inadequate rainwater harvesting. Growing a second crop during winter (rabi) season on hill slopes and uplands without moisture conservation measure is almost impossible. A simple and very low-cost technique of in situ soil moisture conservation in maize (Zea mays L.)–toria (Brassica campestris L.) system has been developed using residue of preceding rainy season maize crop and mulching with locally available weed biomass Ambrosia artemisiifolia. Six residue mulching combinations tested were viz. control, Maize stalk cover (MSC), MSC + Ambrosia sp. 5 t/ha, MSC + Ambrosia sp. 10 t/ha, MSC + farmyard manure (FYM) 10 t/ha and MSC + Ambrosia sp. 5 t/ha + poultry manure 5 t/ha under zero tillage (ZT) and conventional tillage (CT) systems. Results showed that in situ residue retention of preceding maize crop along with green biomass of Ambrosia sp., applied before sowing of toria, maintained optimum soil moisture for good growth and higher yield of toria. The soil moisture content was consistently higher under residue mulched plots than that under control. All the residue mulching measures recorded higher crop yield for maize and toria than those observed under residue removal (control). The productivity of toria was enhanced by about 99%, only due to retention of MSC as mulch. Mulching with MSC + Ambrosia sp. 5 t/ha + poultry manure 5 t/ha recorded the highest seed yield of toria (four-year average: 641 kg/ha), which was 228% and 64% higher than no mulching (control) and MSC alone. MSC + FYM 10 t/ha (568.3 t/ha) and MSC + Ambrosia sp. 10 t/ha (517.4 t/ha) were found equally effective and produced significantly higher toria yield than that of control. MSC + Ambrosia mulch 10 t/ha gave the highest net returns and B:C ratio of the maize–toria system. The overall B:C ratios were better under ZT than CT. Thus, the study indicated that the integrated management of crop residues and weed biomass (Ambrosia sp.) under ZT created favourable soil moisture to support double cropping with high yield in hill eco-system of northeastern Indian Himalayas.

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Contrasting response of seedlings of two tropical species Clusia minor and Clusia multiflora to mycorrhizal inoculation in two soils with different pH

Trees ◽

10.1007/s00468-006-0074-2 ◽

2006 ◽

Vol 20 (5) ◽

pp. 593-600 ◽

Cited By ~ 6

Author(s):

Alicia Cáceres ◽

Gisela Cuenca

Keyword(s):

Tropical Species ◽

Mycorrhizal Inoculation

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Predicting the competitive effects of weed and crop density on weed biomass, weed seed production and crop yield in wheat

Weed Research ◽

10.1111/j.1365-3180.1995.tb01789.x ◽

2006 ◽

Vol 35 (4) ◽

pp. 265-278 ◽

Cited By ~ 56

Author(s):

B. J. WILSON ◽

K. J. WRIGHT ◽

P. BRAIN ◽

M. CLEMENTS ◽

E. STEPHENS

Keyword(s):

Seed Production ◽

Crop Yield ◽

Weed Seed ◽

Weed Biomass ◽

Competitive Effects ◽

Crop Density

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First Insights into the Effect of Mycorrhizae on the Expression of Pathogen Effectors during the Infection of Grapevine with Plasmopara viticola

Sustainability ◽

10.3390/su13031226 ◽

2021 ◽

Vol 13 (3) ◽

pp. 1226

Author(s):

Ana Cruz-Silva ◽

Andreia Figueiredo ◽

Mónica Sebastiana

Keyword(s):

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Plasmopara Viticola ◽

Vitis Vinifera L ◽

Wine Production ◽

Grapevine Downy Mildew ◽

Pathogen Effectors ◽

Rxlr Effectors ◽

Mycorrhizal Inoculation ◽

And Control

Grapevine (Vitis vinifera L.), widely used for berry and wine production, is highly susceptible to the pathogenic oomycete Plasmopara viticola, the etiological agent of grapevine downy mildew disease. The method commonly used to prevent and control P. viticola infection relies on multiple applications of chemical fungicides. However, with European Union goals to lower the usage of such chemicals in viticulture there is a need to develop new and more sustainable strategies. The use of beneficial microorganisms with biocontrol capabilities, such as the arbuscular mycorrhizal fungi (AMF), has been pointed out as a viable alternative. With this study, we intended to investigate the effect of AMF colonization on the expression of P. viticola effectors during infection of grapevine. Grapevine plants were inoculated with the AMF Rhizophagus irregularis and, after mycorrhizae development, plants were infected with P. viticola. The expression of P. viticola RxLR effectors was analyzed by real-time PCR (qPCR) during the first hours of interaction. Results show that pre-mycorrhizal inoculation of grapevine alters the expression of several P. viticola effectors; namely, PvRxLR28, which presented decreased expression in mycorrhizal plants at the two time points post-infection tested. These results suggest that the pre-inoculation of grapevine with AMF could interfere with the pathogen’s ability to infect grapevine by modulation of pathogenicity effectors expression, supporting the hypothesis that AMF can be used to increase plant resistance to pathogens and promote more sustainable agriculture practices, particularly in viticulture.

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