scholarly journals Quantification of Weed Seed Contamination and Weed Development in Container Nurseries

1992 ◽  
Vol 10 (3) ◽  
pp. 159-161
Author(s):  
Gene B. Cross ◽  
Walter A. Skroch

Abstract An investigation was conducted at seven North Carolina nurseries to evaluate the possibility that container substrates serve as weed infestation sources. Container substrate treatments consisted of sand/pasteurized bark, bark/pasteurized sand, pasteurized bark/pasteurized sand, and bark/sand. No differences were observed between numbers of weed seedlings found in the four substrate combinations. Differences were observed across nursery sites and the nursery by date interactions. Five weed species most frequently observed were yellow woodsorrel (Oxalis stricta L.), hairy bittercress (Cardamine hirsuta L.), common groundsel (Senecio vulgaris L.), spotted spurge (Euphorbia maculata L.), and mouseear chickweed (Cerastium vulgatum L.).

1999 ◽  
Vol 13 (3) ◽  
pp. 554-560 ◽  
Author(s):  
Christian Andreasen ◽  
Leif Hansen ◽  
Jens C. Streibig

Under greenhouse conditions, annual bluegrass (Poa annua L.), common groundsel (Senecio vulgaris L.), shepherd's purse [Capsella bursa-pastoris (L.) Medicus], small nettle (Urtica urens L.), canola (Brassica napus L. ssp. napus), and pea (Pisum sativa L.) differed in sensitivity to ultraviolet (UV) radiation. Of the weed species, annual bluegrass was the least sensitive; whereas, among the crop species, canola was about sevenfold more sensitive than was pea. The sensitivity of a species to UV radiation was highly dependent upon its stage of development. The study indicates some potential for using UV radiation to control weeds, but the method needs further investigation to unravel the selectivity of the methods and potential health hazards.


EDIS ◽  
1969 ◽  
Vol 2004 (16) ◽  
Author(s):  
Alejandro Bolques ◽  
Jeffrey G. Norcini ◽  
James Aldrich ◽  
Courtney E. Gist

Common groundsel (Senecio vulgaris L.) is a weed that needs to be monitored year-round in container nurseries since these conditions are ideal for common groundsel. Seed can germinate only a few days after they land on the container medium surface (Figure 1). This document is ENH980, one of a series of the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date September 2004. https://edis.ifas.ufl.edu/ep237


2018 ◽  
pp. 195-199
Author(s):  
Tamás Tóth ◽  
György Kövics ◽  
Arnold Szilágyi

Weeds cause serious problems in agriculture on a global scale. These plants reduce yield and the quality of crops by competing for water, nutrients and sunlight. The improper or excessive usage of herbicides have led to development of resistance in some weed species while contaminating the environment; therefore, biological control has an increasing role as an alternative method for controlling special weed species. The aim of this study is to make a brief review of biological control of weeds by pathogens and to characterize two rust fungi (Puccinia lagenophorae and Puccinia xanthii) which are broadly examined recently in a biological control concept and have been found on their hosts, such as common groundsel (Senecio vulgaris L.) and common cocklebur (Xanthium strumarium L.), two common and difficult to manage weeds both in horticultural and agricultural lands also in Hungary.


2020 ◽  
pp. 1-22
Author(s):  
Michael J. Walsh ◽  
Annie E. Rayner ◽  
Annie Rutledge ◽  
John C. Broster

Abstract Chaff lining and chaff tramlining are harvest weed seed control (HWSC) systems that involve the concentration of weed seed containing chaff material into narrow (20 to 30 cm) rows between or on the harvester wheel tracks during harvest. These lines of chaff are left intact in the fields through subsequent cropping seasons in the assumption that the chaff environment is unfavourable for weed seed survival. The chaff row environment effect on weed seed survival was examined in field studies, while chaff response studies determined the influence of increasing amounts of chaff on weed seedling emergence. The objectives of these studies were to determine 1) the influence of chaff lines on the summer-autumn seed survival of selected weed species; and 2) the influence of chaff type and amount on rigid ryegrass seedling emergence. There was frequently no difference (P>0.05) in survival of seed of four weed species (rigid ryegrass, wild oat, annual sowthistle and turnip weed) when these seed were placed beneath or beside chaff lines. There was one instance where wild oat seed survival was increased (P<0.05) when seed were placed beneath compared to beside a chaff line. The pot studies determined that increasing amounts of chaff consistently resulted in decreasing numbers of rigid ryegrass seedlings emerging through chaff material. The suppression of emergence broadly followed a linear relationship where there was approximately a 2.0% reduction in emergence with every 1.0 t ha-1 increase in chaff material. This relationship was consistent across wheat, barley, canola and lupin chaff types, indicating that the physical presence of the chaff was more important than chaff type. These studies indicated that chaff lines may not affect the over summer-autumn survival of the contained weed seeds but the subsequent emergence of weed seedlings will be restricted by high amounts of chaff (>40 t ha-1).


Weed Science ◽  
1999 ◽  
Vol 47 (2) ◽  
pp. 175-183 ◽  
Author(s):  
George O. Kegode ◽  
Frank Forcella ◽  
Sharon Clay

Approaches to crop production that successfully reduce weed seed production can benefit farming systems by reducing management inputs and costs. A 5-yr rotation study was conducted in order to determine the effects that interactions between crop rotation, tillage, and amount of herbicide and fertilizer (management inputs) have on annual grass and broad-leaved weed seed production and fecundity. There were 10 crop rotation and tillage system combinations and three levels of management inputs (high, medium, and low). Green and yellow foxtail were the major weed species, and together they yielded between 76 and 93% of collected weed seeds. From 1990 to 1994, average grass weed seed productions were 7.3 by 103, 3.7 by 1036.1 by 103and 5.7 by 103seeds m−-2, whereas average broad-leaved weed seed productions were 0.4 by 103, 0.4 by 103, 1.4 by 103, and 0.4 by 103seeds m−-2in crop rotations using conventional tillage (moldboard plow), conservation tillage, no tillage, and ridge tillage, respectively. Crop rotations using conventional or ridge tillage consistently produced more grass and broad-leaved weed seeds, especially in low-input plots. There was little difference in weed seed production among input levels for crop rotations using conservation tillage. Comparing rotations that began and ended with a corn crop revealed that by increasing crop diversity within a rotation while simultaneously reducing the amount of tillage, significantly fewer grass and broad-leaved weed seeds were produced. Among the rotations, grass and broad-leaved weed fecundity were highly variable, but fecundity declined from 1990 to 1994 within each rotation, with a concomitant increase in grass and broad-leaved weed density over the same period. Crop rotation in combination with reduced tillage is an effective way of limiting grass and broad-leaved weed seed production, regardless of the level of management input applied.


1988 ◽  
Vol 2 (4) ◽  
pp. 499-504 ◽  
Author(s):  
Randall S. Currie ◽  
Thomas F. Peeper

Seed of three weed species collected from the grain bins of combines while standing hard red winter wheat was harvested germinated better than hand-harvested seed. Combine-harvested curly dock seed germinated from 4 to 24% more than hand-harvested seed. Curly dock seed harvested with a commercial-type combine germinated better than those harvested with a small-plot combine. Harvesting slimleaf lambsquarters and Venice mallow seed with a commercial-type combine also enhanced germination compared to hand-harvested seed.


2021 ◽  
Vol 29 (4) ◽  
Author(s):  
Nor Athirah Roslin ◽  
Nik Norasma Che’Ya ◽  
Nursyazyla Sulaiman ◽  
Lutfi Amir Nor Alahyadi ◽  
Mohd Razi Ismail

Weed infestation happens when there is intense competition between rice and weeds for light, nutrients and water. These conditions need to be monitored and controlled to lower the growth of weeds as they affected crops production. The characteristics of weeds and rice are challenging to differentiate macroscopically. However, information can be acquired using a spectral signature graph. Hence, this study emphasises using the spectral signature of weed species and rice in a rice field. The study aims to generate a spectral signature graph of weeds in rice fields and develop a mobile application for the spectral signature of weeds. Six weeds were identified in Ladang Merdeka using Fieldspec HandHeld 2 Spectroradiometer. All the spectral signatures were stored in a spectral database using Apps Master Builder, viewed using smartphones. The results from the spectral signature graph show that the jungle rice (Echinochloa spp.) has the highest near-infrared (NIR) reflectance. In contrast, the saromacca grass (Ischaemum rugosum) shows the lowest NIR reflectance. Then, the first derivative (FD) analysis was run to visualise the separation of each species, and the 710 nm to 750 nm region shows the highest separation. It shows that the weed species can be identified using spectral signature by FD analysis with accurate separation. The mobile application was developed to provide information about the weeds and control methods to the users. Users can access information regarding weeds and take action based on the recommendations of the mobile application.


2016 ◽  
Vol 69 (3) ◽  
Author(s):  
Eleonora Wrzesińska ◽  
Anna Komorowska ◽  
Grażyna Nurkiewicz

The condition and degree of weed infestation were determined in a spring barely crop grown in a short-term monoculture after mulching the soil with plants grown as a stubble crop (the control treatment without cover crop – lacy phacelia, white mustard, sunflower). The field experiment was carried out in 2010–2013 on good rye soil complex using a split-block design in four replications. The obtained results (the mean from all years of the experiment) showed that the stubble crop, especially sunflower, reduced the diversity of weed species without causing at the same time changes in weed species dominance. In all the control treatments of the experiment, <em>Chenopodium album</em> and <em>Fallopia convolvulus</em> were the dominant species. The degree of spring barley weed infestation depended on the species grown in the cover crop. White mustard and lacy phacelia slightly increased the number of weeds but their fresh matter significantly increased. However, the sunflower cover crop significantly increased the number of weeds without any substantial differentiation of their fresh mass.


Author(s):  
V. Olifirovich

The article investigated the species composition and dynamics of changes in the contamination of agrophytocenoses of perennial grasses, depending on the composition of the grass mixture and the mode of use of the grass stand. In the crops of perennial grasses, 34 weed species belonging to 12 botanical kind were found in the first three years of use of the grass stand. In the structure of weed infestation of perennial grasses, the species of the Astra kind of weeds dominated, which were represented by stanktis annual, dandelion, yarrow, field thistle.


Plant Disease ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 562-562 ◽  
Author(s):  
S. T. Koike ◽  
M. Scholler ◽  
Arthur Herbaria ◽  
Kriebel Herbaria

English daisy (Bellis perennis, family Asteraceae) is a flowering plant native to Europe. It is widely used as an ornamental in North America but is also a weed in lawns in the western and eastern United States. In December 2000, plants growing in urban landscapes in Monterey County, CA, were infected with rust. Orange aecia containing aeciospores that measured 14 to 18 × 12.5 to 15 μm developed profusely on leaves. Severely diseased leaves wilted and collapsed. Other spore states (pycnia, uredosori, and telia) were not observed. Based on the size and ornamentation of the aeciospores, reduced white peridium, apperance of the peridial cells, and arrangement of sori, we identified the pathogen as Puccinia lagenophorae Cooke (1,3), a rust fungus native to Australia and New Zealand that since 1960 has been introduced to other continents (2). On English daisy, the disease has been reported only in Australia and Europe (1). The pathogen also occurs on numerous other plants of the subfamily Asteroideae (family Asteraceae) (2). The occurrence of P. lagenophorae on English daisy follows the recent, first-time detection of the same pathogen on common groundsel (Senecio vulgaris) in California (3). To test cross infectivity, a spore suspension of a rust isolate from common groundsel was prepared and applied to various ornamental plants known to be hosts of P. lagenophorae. Inoculated plants were kept in a humidity chamber for 48 h, then maintained in a greenhouse. After 9 to 14 days, aecia developed on English daisy, cineraria (S. cruentus), and common groundsel but did not develop on dusty miller (S. cineraria) or pot marigold (Calendula officinalis). In addition, a single telium, surrounded by aecia, was observed on one of the infected English daisy plants. The telium contained two-celled teliospores that measured 31 to 36.5 × 16 to 19 (-22) μm and one-celled mesospores that measured 22 to 34 × 13.5 to 16 μm. At point of attachment, the widths of the stalks measured 7 to 8.5 (-9.5) μm. Some of the spores had surface ridges. The morphological features of the telio- and mesospores agree with those described for P. lagenophorae. To the authors' knowledge, this is the first record of a rust fungus on English daisy in North America. The inoculation experiments indicated that the rusts on English daisy and common groundsel are not biologically separated, casting doubt on the taxonomic concept of Weber et al. (4) that considered the rust on English daisy to be a distinct species, P. distincta McAlpine (although they did not examine type material of either P. lagenophorae or P. distincta). References: (1) M. Scholler. Sydowia 49:174, 1997. (2) M. Scholler. J. Plant Dis. Prot. 105:239, 1998. (3) M. Scholler and S. T. Koike. Plant Dis. 85:335, 2001. (4) R. W. S. Weber et al. Mycol. Res. 102:1227, 1998.


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