Sprouting capacity from intact root systems ofCirsium arvenseandSonchus arvensisdecrease in autumn

Weed Research ◽  
2013 ◽  
Vol 53 (3) ◽  
pp. 183-191 ◽  
Author(s):  
L Andersson ◽  
U Boström ◽  
J Forkman ◽  
I Hakman ◽  
J Liew ◽  
...  
Keyword(s):  
Root Systems ◽  
Sprouting Capacity ◽  
Intact Root

Conversaziones 1974

1975 ◽  
Vol 29 (2) ◽  
pp. 163-171
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Cell Walls ◽  
Structural Changes ◽  
Vascular Tissue ◽  
Root Systems ◽  
Plant Roots ◽  
Tracer Studies ◽  
Water Move ◽  
Intact Root

CONVERSAZIONES were held this year on 9 May and 27 June. At the first conversazione twenty-seven exhibits and two films were shown. The fine structure of plant roots in relation to transport of nutrient ions and water was demonstrated by Dr D. T. Clarkson of the A.R.C. Letcombe Laboratory, Wantage and Dr A. W. Robards of the Department of Biology, University of York. Two major pathways by which nutrients and water move radially across the cortex towards the central vascular tissue have been distinguished by the use of tracer studies of adsorption by different zones of intact root systems, microautoradiography and electron microscopy. Movement can be apoplastic through cell walls, or symplastic between cells joined by plasmodesmata. As the root ages, structural changes in the endodermis reduce movement in the former pathway but the symplast is not interrupted by the elaboration of endodermal walls because plasmodesmatal connexions remain intact. These observations help explain the contrasting extent to which different ions and water reach the shoot from young and mature parts of root systems.

scholarly journals Evidence of Association of Salmonellae with Tomato Plants Grown Hydroponically in Inoculated Nutrient Solution

2002 ◽  
Vol 68 (7) ◽  
pp. 3639-3643 ◽  
Author(s):  
Xuan Guo ◽  
Marc W. van Iersel ◽  
Jinru Chen ◽  
Robert E. Brackett ◽  
Larry R. Beuchat
Keyword(s):  
Nutrient Solution ◽  
Root Systems ◽  
Plant Roots ◽  
Tomato Plants ◽  
Agronomic Practices ◽  
Stems And Leaves ◽  
Pathogen Populations ◽  
Hoagland Nutrient Solution ◽  
Hydroponically Grown ◽  
Intact Root

ABSTRACT The possibility of uptake of salmonellae by roots of hydroponically grown tomato plants was investigated. Within 1 day of exposure of plant roots to Hoagland nutrient solution containing 4.46 to 4.65 log10 CFU of salmonellae/ml, the sizes of the pathogen populations were 3.01 CFU/g of hypocotyls and cotyledons and 3.40 log10 CFU/g of stems for plants with intact root systems (control) and 2.55 log10 CFU/g of hypocotyls and cotyledons for plants from which portions of the roots had been removed. A population of ≥3.38 log10 CFU/g of hypocotyls-cotyledons, stems, and leaves of plants grown for 9 days was detected regardless of the root condition. Additional studies need to be done to unequivocally demonstrate that salmonellae can exist as endophytes in tomato plants grown under conditions that simulate commonly used agronomic practices.

A Method for Simulating Subsurface Disposal of Herbicides

Weed Science ◽  
1977 ◽  
Vol 25 (4) ◽  
pp. 368-372
Author(s):  
J.M. Cupello ◽  
A.L. Young ◽  
J.C.H. Smith
Keyword(s):  
Acetic Acid ◽  
Plant Height ◽  
Control Plant ◽  
Soil Layer ◽  
Root Systems ◽  
Butyl Esters ◽  
Phenoxy Herbicides ◽  
Dichlorophenoxy Acetic Acid ◽  
Subsurface Injection ◽  
Intact Root

Specially designed growth boxes were used to simulate field subsurface injection of phenoxy herbicides. Sorghum (Sorghum vulgarePers.) seedlings were grown in stainless steel containers (inserts) which were placed in plexiglass boxes containing a soil layer that had received 2,240 kg/ha of a 50:50 mixture of then-butyl esters of 2,4-D [(2,4-dichlorophenoxy)-acetic acid] and 2,4,5-T [(2,4,5-trichlorophenoxy)-acetic acid]. Plant height data were collected periodically for all treatments. Subsurface herbicide application to both intact and cut root systems significantly altered root growth. Plants with treated, intact root systems showed retarded growth which became more pronounced with time. Plants whose root systems were treated, and cut on day 22, showed an initial acceleration of growth; a trend which eventually reversed itself and resulted in control plant height exceeding that of treated plants.

scholarly journals A Wet Excavation Method for Root/Shoot Studies of Pearl Millet on the Sandy Soils of the Sahel

1994 ◽  
Vol 30 (3) ◽  
pp. 329-336 ◽  
Author(s):  
M. V. K. Sivakumar ◽  
S. A. Salaam
Keyword(s):  
Pearl Millet ◽  
Pennisetum Glaucum ◽  
Plant Root ◽  
Sandy Soils ◽  
Root Systems ◽  
Rooting Depth ◽  
Exponential Growth Rate ◽  
Promising Technique ◽  
Rapid Removal ◽  
Intact Root

SUMMARYRoot/shoot relations of two cultivars of pearl millet (Pennisetum glaucum) were studied on a sandy soil at Sadore in Niger using a wet excavation method. For the first 10 days after emergence (DAE), the length of the seminal root showed an exponential growth rate while plant height increased more or less linearly. The maximum rooting depth for millet was 168 cm and the maximum number of root axes and primary laterals, 172 per plant. Root length continued to increase up to 75 DAE, the maximum length exceeding 5000 cm per plant. The proportion of total day matter accumulated in the roots decreased from 30% in the early stages to less than 20% by maturity. The wet excavation method is a promising technique for the rapid removal of intact root systems of pearl millet from the sandy soils of the Sahel.

scholarly journals Mycorrhizal Influence on Transpiration Rates of Detached Leaves of Cowpea, Rose, and Geranium Exposed to Varying Levels of Abscisic Acid (ABA), pH, Calcium, and Phosphorus

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 647e-647
Author(s):  
Craig D. Green ◽  
Ann Stodola ◽  
Robert M. Augé
Keyword(s):  
Mycorrhizal Fungi ◽  
Root Systems ◽  
Residual Effects ◽  
Soil Drying ◽  
Chemical Signal ◽  
Test Species ◽  
Leaf Transpiration ◽  
Detached Leaves ◽  
Stomatal Sensitivity ◽  
Intact Root

Mycorrhizal colonization can alter stomatal behavior of host leaves during drought. This may be related to an altered production or reception of a chemical signal of soil drying. We tested whether intact root systems were required to observe a mycorrhizal effect on leaf transpiration (E), or whether some residual mycorrhizal influence on leaves could affect E of foliage detached from root systems. Transpiration assays were performed in the presence of several possible candidates for a chemical signal of soil drying. In detached leaves of Vigna unguiculata (cowpea), colonization interacted significantly with ABA and pH in regulating transpiration. Colonization affected E of detached Rosa hybrida (rose) leaves but had no effect on E of detached leaves of Pelargonium hortorum (geranium). In each species tested, increasing the ABA concentration decreased E. In cowpea, calcium appeared to alter stomatal sensitivity to ABA, as well as regulate stomatal activity directly. The pH of the feeding solution affected E in rose, but did not change E independently in cowpea or geranium. Adding phosphorus to the feeding solution did not alter E or the apparent sensitivity of stomata to ABA in any of the test species. Colonization of roots by mycorrhizal fungi can result in residual effects in detached leaves, that can alter the stomatal reception of chemical signals in both rose and cowpea.

Comparative Leaf Water Potentiais of Plants in Burnt and Unburnt Dry Sclerophyll Vegetation

1993 ◽  
Vol 41 (6) ◽  
pp. 661 ◽  
Author(s):  
JM Guo ◽  
R Sinclair
Keyword(s):  
Surface Soil ◽  
South Australia ◽  
Root Systems ◽  
The Other ◽  
Burnt Area ◽  
Burnt Site ◽  
Water Potentials ◽  
And Control ◽  
Intact Root ◽  
Sampling Times

Leaf (xylem) water potentials were measured in summer and autumn on four species, Eucalyptus fasciculosa, Pultenaea daphnoides, Platylobium obtusangulum and Acacia myrtifolia growing in the understorey of sclerophyll stringybark vegetation in the Mt Lofty Ranges, South Australia. Plants regenerating in an area burnt by bushfire 2 years previously were compared with plants in an adjacent unburnt area. The Acacia was killed by fire and subsequently regenerated from seed. The other three species survived and resprouted from basal or epicormic buds. It was expected that shrubs regenerating from basal buds would be better hydrated in summer, as a large intact root system would supply a reduced canopy, and that seedlings, with smaller root systems than unburnt adults, would be more stressed. The Acacia was indeed significantly more stressed during summer in the burnt area. However the Platylobium was also more stressed than the controls, while the Pultenaea showed no significant differences between burnt and control areas. The Eucalyptus showed no differences between sites, nor between any of the three sampling times. The more negative water potentials of some of the regenerating plants are explained by greater exposure of surface soil on the burnt site, leading to more rapid drying of the surface soil in summer.

scholarly journals 577 Strawberry Runner Plant Root Pruning and Subsequent Growth and Yield in California

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 546B-546
Author(s):  
Kirk D. Larson
Keyword(s):  
Plant Root ◽  
Fruit Size ◽  
Root Systems ◽  
Dry Mass ◽  
Growth And Yield ◽  
Root Pruning ◽  
Critical Determinant ◽  
Bare Root ◽  
Root Tissues ◽  
Intact Root

Each year, 500,000,000 bare-root plants (crowns) are used to establish strawberry plantings in California. Careful placement of plants in the planting holes is a critical determinant of plant growth and productivity, but large-rooted crowns are difficult to plant correctly. Use of uniform plant material would facilitate proper planting. I conducted a study in 1997–98 to determine the influence of three root pruning treatments on performance of `Camarosa' bare-root strawberry plants. Crowns were machine-dug from a nursery on 27 Oct. 1997. Two-hundred-forty plants were selected for uniformity of size, and root systems of all selected plants were >12.7 cm in length. Root systems of individual plants were randomly subjected to three pruning treatments: nonpruned (NP), pruned to 8.9 cm in length (P1), or pruned to 4.45 cm in length (P2). Twenty plants were randomly selected from each pruning treatment, washed, divided into excised and intact root tissues, and dried at 70 °C for 6 days. Pruning resulted in the removal of 23% and 78% of root dry mass for plants in the P1 and P2 treatments, respectively. For each treatment, the 60 remaining plants were established in raised beds at the Univ. of California South Coast R.E.C. in Irvine on 1 Nov. 1997. Experimental design was a RCB, with one 20-plant plot per treatment in each of three replicate blocks. There was no plant mortality and no difference among treatments in plant canopy diameter in March (mean diam. = 36.7 cm). Fruit yields were determined for each plot at weekly intervals from 1 Feb. to 18 Apr. 1998. There was no effect of pruning on yield or fruit size, suggesting that strawberry root systems have considerable regenerative ability.

Sign in / Sign up

Export Citation Format

Share Document