scholarly journals Weed flora in organically grown spring cereals in Finland

2001 ◽  
Vol 10 (3) ◽  
pp. 231-242 ◽  
Author(s):  
J. SALONEN ◽  
T. HYVÖNEN ◽  
H. JALLI
Keyword(s):  
Chenopodium Album ◽  
Control Measures ◽  
Grass Species ◽  
Total Biomass ◽  
Weed Species ◽  
Stellaria Media ◽  
Weed Flora ◽  
Elymus Repens ◽  
Spring Cereals ◽  
Organically Grown

The weed flora in organically grown spring cereals was investigated in southern and central Finland in 1997-1999 with the primary purpose of determining the species composition and the level of weed infestation. Altogether 165 fields were surveyed in the middle of the growing season. A total of 126 weed species were found, of which 42 exceeded the frequency level of 10%. The most frequent weed species were Chenopodium album, Stellaria media, Galeopsis spp. and Viola arvensis. Elymus repens was the most frequent grass species. The average density of weeds was 469 plants m-2 (median 395), and the air-dry biomass was 678 kg ha-1 (median 567) which accounted for 17% of the total biomass of the crop stand. Infestation by Chenopodium album and the perennial species Elymus repens, Cirsium arvense and Sonchus arvensis is of major concern. Weed control strategies should include direct control measures to overcome weed problems related to the conversion period from conventional to organic growing.

scholarly journals Composition of weed flora in spring cereals in Finland - a fourth survey

2008 ◽  
Vol 20 (3) ◽  
pp. 245 ◽  
Author(s):  
J. SALONEN ◽  
T. HYVÖNEN ◽  
H. JALLI
Keyword(s):  
Crop Production ◽  
Average Density ◽  
Grass Species ◽  
Species Number ◽  
Weed Species ◽  
Stellaria Media ◽  
Weed Flora ◽  
Elymus Repens ◽  
Spring Cereals ◽  
Galium Spurium

The weed flora in conventionally and organically grown spring cereals was investigated in southern and central Finland during 2007–2009. The survey was conducted in 16 regions, 283 farms and 595 fields (72 organically cropped and 523 conventionally cropped fields, of which 503 were treated with herbicides). The occurrence of weeds was assessed in late July–early August. Altogether 148 weed species were identified, of which 128 were broad-leaved and 20 grass species. In organically cropped fields, the average species number per field was 21 and the most frequent species were Chenopodium album 96%, Stellaria media 94%, Viola arvensis 94% and Elymus repens 89%. In conventionally cropped fields, the average species number was 12 and the most frequent weed species were Viola arvensis 83%, Stellaria media 65%, Galeopsis spp. 59% and Galium spurium 59%. The average density of weeds was 160 m-2 (median = 112) in sprayed conventional fields and 519 m-2 (468) in organic fields. The average air-dry biomass of weeds was 167 kg ha-1 (median = 82) and 775 kg ha-1 (563), respectively. Elymus repens, the most frequent and abundant grass species, produced the highest proportion (about 30%) of the total weed biomass in both cropping systems. The frequency of Galium spurium in conventional cropping and Fumaria officinalis in organic cropping had increased substantially since the previous survey in 1997–1999. The average size of the weed seedbank in the 5 cm surface layer was about 1 700 seeds m-2, the most predominant seeds being of C. album. Although the weed flora in Finnish spring cereal fields consists of numerous species, only a fraction of them severely threaten crop production in terms of their frequency and abundance. Weeds in conventional cropping were effectively controlled with available herbicides whereas weed management in organic cropping calls for urgent measures such as direct mechanical weed control in crop stands, which was not practised at all in survey fields.;

scholarly journals Weed flora and weed management of field peas in Finland

2008 ◽  
Vol 14 (2) ◽  
pp. 189 ◽  
Author(s):  
J. SALONEN ◽  
T. HYVÖNEN ◽  
H. JALLI
Keyword(s):  
Weed Management ◽  
Chenopodium Album ◽  
Good Control ◽  
Organic Production ◽  
Grass Species ◽  
Weed Species ◽  
Stellaria Media ◽  
Cropping Practices ◽  
Weed Flora ◽  
Crop Stand

The composition of the weed flora of dry pea (Pisum sativum L.) fields and cropping practices were investigated in southwestern Finland. Surveys were done in 2002–2003 in 119 conventionally cropped fields and 64 fields under organic cropping. Herbicides were applied to 92% of conventionally cropped fields where they provided relatively good control but were costly. Weeds were controlled mechanically only in five fields under organic production. A total of 76 weed species were recorded, of which 29 exceeded the 10% frequency level of occurrence. The average number of weed species per field was 10 under conventional cropping and 18 under organic cropping. The most frequent weed species in both cropping practices were Chenopodium album, Stellaria media and Viola arvensis. Elymus repens was the most frequent grass species. The difference in species composition under conventional and organic cropping was detected with Redundancy Analysis. Under conventional cropping, features of crop stand and weed control explained 38.7% and 37.6% of the variation respectively. Under organic cropping the age of crop stand and field location (y co-ordinate) respectively explained best the variation. Weeds could be efficiently managed with herbicides under conventional cropping, but they represented a significant problem for organic production. Mixed cultivation of pea with cereals is recommended, particularly for organic cropping, as it favours crop competition against weeds.;

scholarly journals Weeds in spring cereal fields in Finland - a third survey

2001 ◽  
Vol 10 (4) ◽  
pp. 347-364 ◽  
Author(s):  
J. SALONEN ◽  
T. HYVÖNEN ◽  
H. JALLI
Keyword(s):  
Average Density ◽  
Grass Species ◽  
Species Number ◽  
Total Biomass ◽  
Weed Species ◽  
Stellaria Media ◽  
Organic Farms ◽  
Weed Biomass ◽  
Cereal Fields ◽  
Crop Stand

A survey of weeds in spring cereal fields was conducted in 16 regions of southern and central Finland in 1997-1999. Data were collected from conventional and organic farms, both of which applied their normal cropping practices. A total of 690 fields were investigated by counting and weighing the weed species from ten sample quadrats 0.1 m2 in size in late July - early August. Altogether 160 weed species were found, of which 134 were broad-leaved and 26 grass species. The total number of weed species ranged from 41 to 84 between regions. In organically farmed fields, the average species number was 24 and in conventionally farmed fields 16. The most frequent weed species were Viola arvensis 84%, Stellaria media 76% and Galeopsis spp. 70%. Only 18 species exceeded the frequency level of 33%. The average density of weeds was 136 m-2 (median= 91) in sprayed conventional fields, 420 m-2 (374) in unsprayed conventional fields and 469 m-2 (395) in organic fields. The average air-dry above-ground biomass of weeds was 163 kg ha-1 (median=63), 605 kg ha-1 (413) and 678 kg ha-1 (567), respectively. Weed biomass accounted for 3% of the total biomass of the crop stand in sprayed conventional fields and for 17% in organic fields. Elymus repens, the most frequent grass species, produced the highest proportion of weed biomass.

Weed seed contamination in white clover seedlots

1990 ◽  
pp. 99-102
Author(s):  
J.S. Rowarth ◽  
A.A. Johnson ◽  
P.T.P. Clifford ◽  
M.P. Rolston
Keyword(s):  
White Clover ◽  
Chenopodium Album ◽  
Cirsium Arvense ◽  
Weed Seed ◽  
Weed Species ◽  
Stellaria Media ◽  
Seed Testing ◽  
Rumex Acetosella ◽  
Weed Seeds ◽  
Californian Thistle

Weed seeds are the major reason for white clover (Trifolium repens) seedlots being downgraded or rejected from certification. The occurrence of weed species in 537 white clover seedlots tested at the Official Seed Testing Station, Palmerston North, was analysed. The most commonly occurring species were field madder (Sherardia arvensis), chickweed (Stellaria media), fathen (Chenopodium album), sheep's sorrel (Rumex acetosella) and scarlet pimpernel (Anagaflis arvensis). The percentage occurrence of four specified undesirable weeds including Californian thistle (Cirsium arvense) and dodder (Cuscuta epithymum) are reported, and the implications of seed contamination are discussed. Keywords: white clover, contamination, weed seeds

scholarly journals STUDIES ON THE WEED FLORA OF AGASTYAMUNI BLOCK, RUDRAPRAYAG DISTRICT, UTTARAKHAND

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Kamlapati Chamoli
Keyword(s):  
Local Community ◽  
Cynodon Dactylon ◽  
Chenopodium Album ◽  
Abundant Species ◽  
Crop Productivity ◽  
Eupatorium Adenophorum ◽  
Stellaria Media ◽  
Weed Flora ◽  
Siegesbeckia Orientalis ◽  
Survey Results

Weed commonly called ‘khar- kabad’ in Uttarakhand or ‘kharpatvar’ in India, and is one of the major biological constraints that limits crop productivity. The present communication pertains to survey and inventory of weed flora in Agastyamuni block of district Rudraprayag, Uttarakhand. The study was based on extensive and intensive field survey made during July 2018 to October 2019. During the study period the authors have reported a total 312 species belonging to 188 genera and 54 families from dicots, monocots and pteridophyta. Asteraceae was found to be the most dominant family followed by Poaceae, Lamiaceae and Fabaceae respectively. Survey results also revealed that most of the recorded species were annuals followed by perennials and biennials. Most abundant species were Bidense pilosa, Chenopodium album, Erigeron canadensis, Cynodon dactylon, Gallinsogo parviflora, Eupatorium adenophorum, Oxalis conrniculata, Parthenium hysterophorus, Lantana camara, Soncchus arvensis, Ageratum conozoides, Plantago major, Ganaphallium lutealbum, Siegesbeckia orientalis, Youngia japonica, Amaranthus virids, Stellaria media and Phalaris minor. Many weeds are ethnobotanically important and utilized by the local community.

Weed Species Shifts with Increasing Field Age in Alaska

Weed Science ◽  
1983 ◽  
Vol 31 (4) ◽  
pp. 520-524 ◽  
Author(s):  
Jeffery S. Conn ◽  
John A. Delapp
Keyword(s):  
Introduced Species ◽  
Native Species ◽  
Management Practices ◽  
Chenopodium Album ◽  
Vegetative Cover ◽  
Weed Species ◽  
Stellaria Media ◽  
Multivariate Statistical ◽  
Hordeum Jubatum ◽  
Polygonum Pensylvanicum

Vegetative cover of weeds was determined in 84 agricultural fields representing a number of crops in Alaska. Multivariate statistical techniques were used with weed, soil, and management data to determine if weed vegetation was related to particular environmental and management variables. Field age was the variable that best explained the variation in vegetation composition. In fields recently cleared, native species were most important, being replaced by introduced weed species with increasing field age. Field horsetail (Equisetum arvense L.) was an exceptional native species that persisted under cultivation. Total weed cover was low in the first few years of cultivation, but increased as introduced species such as common lambsquarters (Chenopodium album L.), common chickweed [Stellaria media (L.) Cyrillo], quackgrass [Agropyron repens (L.) Beauv.], and foxtail barley (Hordeum jubatum L.) became more prevalent. A number of introduced species such as hempnettle (Galeopsis tetrahit L.) and Pennsylvania smartweed (Polygonum pensylvanicum L.) were restricted to just a few fields, emphasizing the importance of using weed-free seed and other management practices to minimize the spread of introduced weeds.

scholarly journals Effects of tillage and reduced herbicide doses on weed biomass production in winter and spring cereals

2011 ◽  
Vol 49 (No. 9) ◽  
pp. 414-421 ◽  
Author(s):  
M. Knežević ◽  
M. Đurkić ◽  
KneževićI ◽  
O. Antonić ◽  
S. Jelaska
Keyword(s):  
Biomass Production ◽  
Spring Barley ◽  
Chenopodium Album ◽  
Ambrosia Artemisiifolia ◽  
Weed Species ◽  
Weed Biomass ◽  
Polygonum Aviculare ◽  
Growing Seasons ◽  
Spring Cereals ◽  
Annual Weeds

The effects of different tillage systems and dose reduction on the efficacy of triasulfuron & chlortoluron mixture in the post-emergence control of annual broad-leaved weeds in winter wheat and spring barley were studied on lessive pseudogley soil in north-eastern Croatiaduring 1997–2000. Total dry biomass production in untreated plots was significantly influenced by tillage and it was lowest in continuous mouldboard ploughing (99 kg/ha), medium and similar in mouldboard ploughing/disk harrowing alternating every second year and in chisel ploughing (218 kg/ha) whereas the biomass was highest in continuous disk harrowing (422 kg/ha). Thereby the proportion of annual broad-leaved weed biomass was 70, 63, and 28%, respectively. Chenopodium album L., Ambrosia artemisiifolia L., Ch. polyspermum L. and Polygonum aviculare L. are the most abundant annual weed species in all tillage treatments. One half and one quarter of the recommended rate decreased the control efficacy of total weed biomass by 12 and 19%, respectively in wheat and by 6 and 15%, respectively in barley compared to the highest dose but they still provided a very good biomass control of main annual weeds (94–96 percentage units). The efficacy of reduced herbicide doses in the control of annual broad-leaved weeds did not vary significantly between tillage treatments and growing seasons. Significant interaction with continuous disk harrowing tillage and one-quarter herbicide dose was detected in the last year of wheat trial when perennial weeds increased their biomass proportion 8 times compared to four years before.

Comparison of the Photosynthetic Capacity between Intact Leaves of Triazine-Resistant and -Susceptible Biotypes of Six Weed Species

1984 ◽  
Vol 39 (5) ◽  
pp. 440-442 ◽  
Author(s):  
J.L.P. van Oorschot ◽  
P.H. van Leeuwen
Keyword(s):  
Photosynthetic Capacity ◽  
Chenopodium Album ◽  
Amaranthus Retroflexus ◽  
Solanum Nigrum ◽  
Poa Annua ◽  
Weed Species ◽  
Stellaria Media ◽  
Rate Of Photosynthesis ◽  
Intact Leaves ◽  
Polygonum Lapathifolium

The rate of photosynthesis in intact leaves of a triazine-resistant biotype of Amaranthus retroflexus was about 15% lower than that of a triazine-susceptible biotype. Differences in photosynthesis between resistant and susceptible biotypes of Polygonum lapathifolium, Poa annua and Solanum nigrum were not significant, and absent in Chenopodium album and Stellaria media. The results are brought in relation to the appearance of resistant biotypes in the field.

scholarly journals Uptake of more important mineral components by common field weeds on loess soils

2013 ◽  
Vol 39 (1) ◽  
pp. 129-141 ◽  
Author(s):  
Leszek Malicki ◽  
Czesława Berbeciowa
Keyword(s):  
Spring Barley ◽  
Chenopodium Album ◽  
Cultivated Plants ◽  
Weed Species ◽  
Convolvulus Arvensis ◽  
Stellaria Media ◽  
Sugar Beets ◽  
Polygonum Convolvulus ◽  
Mineral Components ◽  
Sonchus Arvensis

We have determined the contents of N, P, K, Ca, Mg, Na, Fe, Cu, Mn and Zn in winter wheat, spring barley, sugar beets and winter rape, as well as in the most common weed species infesting these crops. It was established that the percentage of mineral components in the dry matter of the majority of weeds is higher than in that of the cultivated plants. The most dangerous weed species competing with plants for the investigated nutrients were: <i>Chenopodium album, Cirsium arvense, Convolvulus arvensis, Polygonum convolvulus, Sonchus arvensis</i> and <i>Stellaria media</i>.

scholarly journals Conventional and organic cropping systems at Suitia IV: weeds

1990 ◽  
Vol 62 (4) ◽  
pp. 331-337
Author(s):  
Raimo Kauppila
Keyword(s):  
Winter Wheat ◽  
Dry Matter ◽  
Cropping Systems ◽  
Chenopodium Album ◽  
First Year ◽  
Weed Species ◽  
Stellaria Media ◽  
Cultivated Barley ◽  
Almost All ◽  
Grass Ley

At Suitia, Southern Finland, weed populations in different crop rotations at conventional and organic cropping systems were investigated in 1982—1988. The number of weeds and the dry matter yields of weeds were greater in organic cropping (on average 324 weeds/m2 and 425 kg DM/ha) compared to conventional cropping (94 weeds/m2 and 61 kg DM/ha). There were least weeds in the conventionally cultivated ley. The first year, clover ley in organic cropping prevented the growth of weeds as well as the grass ley in conventional cropping. Overwintering damages in organically cultivated leys increased the amounts of weeds in the following ley years. Organically cultivated winter wheat reduced the amount and weight of weeds almost as well as conventionally cultivated winter wheat although its biomass was three-fourths of the conventionally cultivated winter wheat. The biomass of organically cultivated barley later on in the rotations was only one-fifth of the conventionally cultivated barley and had five times more weeds. In conventional cropping, the number of weeds in almost all weed species was decreased or stayed at the same level during the experiment. In organic cropping, the number of most weeds in weed species increased from the level for 1982. Most increased Stellaria media, Fallopio convolvulus, Lamium sp and Chenopodium album.

Sign in / Sign up

Export Citation Format

Share Document