A Comparison of Phytophthora cinnamomi Infection in Eucalyptus sieberi, a Susceptible Species, and Eucalyptus maculata a Field Resistant Species

1978 ◽  
Vol 26 (5) ◽  
pp. 643 ◽  
Author(s):  
DM Halsall
Keyword(s):  
Root Growth ◽  
Shoot Growth ◽  
Phytophthora Cinnamomi ◽  
Growth Reduction ◽  
Resistant Species ◽  
Eucalypt Species ◽  
Root And Shoot Growth ◽  
Seedling Roots ◽  
Eucalyptus Maculata

Zoospores of Phytophthora cinnamomi Rands were attracted, in almost equal numbers, to seedling roots of Eucalyptus sieberi (a susceptible species) and Eucalyptus maculata (a field resistant species). Germinating zoospores penetrated and mycelium developed within seedling roots of both species. The root and shoot growth of both eucalypt species were reduced by P. cinnamomi infection. In E. sieberi the growth reduction was greater than in E. maculata seedlings and other symptoms of infection were evident. Cell-free extracts of P. cinnamomi were able to produce some of the symptoms of infection in the absence of parasitism. Root growth of both eucalypt species was reduced at high extract dilutions and seedling deaths occurred at low extract dilutions.

scholarly journals Growth Enhancement of shrunken-2 (sh2) Sweet Corn by Trichoderma harzianum 1295-22: Effect of Environmental Stress

1998 ◽  
Vol 123 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Thomas Björkman ◽  
Lisa M. Blanchard ◽  
Gary E. Harman
Keyword(s):  
Root Growth ◽  
Trichoderma Harzianum ◽  
Root Rot ◽  
Shoot Growth ◽  
Sweet Corn ◽  
Cold Treatment ◽  
Subsequent Treatment ◽  
Growth Enhancement ◽  
Growth Reduction ◽  
Root And Shoot Growth

Sweet corn (Zea mays L.) varieties carrying the sh2 gene are in high demand, but such varieties have poor stress tolerance, especially during plant establishment. Trichoderma harzianum Rifai strain 1295-22 is a biocontrol fungus developed to provide season-long colonization of crop roots. It has the potential to reduce root rot and increase root growth. In the absence of detectable disease, colonization by Trichoderma increased root and shoot growth by an average of 66%. The enhancement was not uniform among the plants. Low- and intermediate-vigor plants were larger in the presence of Trichoderma, but high-vigor plants were not further enhanced by the fungus. Seeds that were subjected to oxidative stress with 0.05% NaOCI had much-reduced vigor; subsequent treatment with Trichoderma fully restored vigor. This result indicates that the damage caused by hypochlorite is specifically repaired by Trichoderma. Treatment of imbibed but unemerged seeds with cold (5/10 °C night/day) for varying periods reduced subsequent growth. Plants with Trichoderma-colonized roots were 70% larger at all durations of cold treatment. The absence of interation indicates the growth reduction due to cold and the growth enhancement due to Trichoderma are by different mechanisms. Allelopathic reduction in root growth by rye was mimicked by applying benzoxazolinone to the soil. Trichoderma-colonized roots grew faster, but the characteristic shortening of the radicle still occurred. There was no interaction between Trichoderma and allelopathy, indicating that these two treatments affect growth by independent mechanisms. The different ways that growth was enhanced by Trichoderma lead us to propose that this fungus acts, in part, by reversing injurious oxidation of lipids and membrane proteins. Root growth is markedly enhanced by colonization with Trichoderma harzianum. This enhancement can restore some stress-induced growth reduction and may directly reverse oxidative injury.

scholarly journals Root and Shoot Growth Periodicity of Green Ash, Scarlet Oak, Turkish Hazelnut, and Tree Lilac

1995 ◽  
Vol 120 (2) ◽  
pp. 211-216 ◽  
Author(s):  
J. Roger Harris ◽  
Nina L. Bassuk ◽  
Richard W. Zobel ◽  
Thomas H. Whitlow
Keyword(s):  
Root Growth ◽  
Root Length ◽  
Shoot Growth ◽  
Lateral Roots ◽  
Growth Patterns ◽  
Extension Rate ◽  
Green Ash ◽  
Growth Measurement ◽  
Root And Shoot Growth ◽  
Growth Periodicity

The objectives of this study were to determine root and shoot growth periodicity for established Fraxinus pennsylvanica Marsh. (green ash), Quercus coccinea Muenchh. (scarlet oak), Corylus colurna L. (Turkish hazelnut), and Syringa reticulata (Blume) Hara `Ivory Silk' (tree lilac) trees and to evaluate three methods of root growth periodicity measurement. Two methods were evaluated using a rhizotron. One method measured the extension rate (RE) ofindividual roots, and the second method measured change in root length (RL) against an observation grid. A third method, using periodic counts of new roots present on minirhizotrons (MR), was also evaluated. RE showed the least variability among individual trees. Shoot growth began before or simultaneously with the beginning of root growth for all species with all root growth measurement methods. All species had concurrent shoot and root growth, and no distinct alternating growth patterns were evident when root growth was measured by RE. Alternating root and shoot growth was evident, however, when root growth was measured by RL and MR. RE measured extension rate of larger diameter lateral roots, RL measured increase in root length of all diameter lateral roots and MR measured new root count of all sizes of lateral and vertical roots. Root growth periodicity patterns differed with the measurement method and the types of roots measured.

Napropamide Uptake, Transport, and Metabolism in Corn (Zea mays) and Tomato (Lycopersicon esculentum)

Weed Science ◽  
1981 ◽  
Vol 29 (6) ◽  
pp. 697-703 ◽  
Author(s):  
Michael Barrett ◽  
Floyd M. Ashton
Keyword(s):  
Zea Mays ◽  
Lycopersicon Esculentum ◽  
Root Growth ◽  
Shoot Growth ◽  
Root Tissue ◽  
Tomato Root ◽  
Corn Roots ◽  
Tomato Roots ◽  
Absorption Studies ◽  
Root And Shoot Growth

Napropamide [2-(α-napthoxy)-N,N-diethylpropionamide] inhibited root and shoot growth in corn (Zea maysL. ‘NC+ 59’) and tomato (Lycopersicon esculentumMill. ‘Niagara VF315’) seedlings. Shoot growth was reduced less than root growth in both species. Corn roots were approximately 10 times more sensitive to napropamide than were tomato roots. Translocation of napropamide from the roots to the shoot of tomato occurred within 0.5 h and followed an apoplastic pattern. Little movement of napropamide from the roots to the shoots occurred in corn. Metabolism of napropamide was not evident in either species during an 8-h exposure. Absorption studies showed that total napropamide levels were 60% higher in corn root tissue than in tomato root tissue. The greater napropamide content in the corn roots was associated with a tightly bound fraction of the total napropamide influx.

scholarly journals Root and shoot growth in safflower as affected by soil compaction

2020 ◽  
pp. 1443-1448
Author(s):  
Caroline Beal Montiel ◽  
Deonir Secco ◽  
Araceli Ciotti Marins ◽  
Luiz Antônio Zanão Junior ◽  
Jeikson Rafael Deggerone ◽  
...  
Keyword(s):  
Root Growth ◽  
Crop Yield ◽  
Soil Compaction ◽  
Shoot Growth ◽  
Soil Bulk Density ◽  
Carthamus Tinctorius ◽  
Field Conditions ◽  
Compacted Soils ◽  
Tillage Practices ◽  
Root And Shoot Growth

Soil compaction, induced by no-tillage practices, can negatively impact soil properties important for plant growth. Compacted soils can restrict root growth depth, resulting in reduced crop yield. Although safflower (Carthamus tinctorius) has a deep root system, yield may still be affected by soil compaction. Therefore, this study aimed to evaluate safflower root and shoot growth when submitted to soil compaction in an Oxisol soil under controlled (greenhouse) and field conditions. Five soil bulk density measures were performed in a greenhouse (1.1, 1.2, 1.3, 1.4 and 1.5 Mg m–3). Four compaction levels (established by the number of passes of a farm tractor: 0, 1, 3, and 5 passes consecutively) were performed to evaluate the effect of soil compaction in the field. Root and shoot growth were measured after harvesting the plants. Safflower root growth was reduced when soil compaction increased from 1.1 to 1.5 Mg m–3 under controlled (greenhouse) conditions. In field conditions, we observed a decrease in root length, and fresh and dry matter in roots and shoots of safflower as the soil compaction increased to 5P (1.28 Mg m–3). The results of our study suggest safflower root and shoot growth can be impacted by soil compaction which could affect crop yield.

scholarly journals 355 REDUCING MECHANICAL IMPEDANCE OF ROOTS IN COMPACTED SOILS INCREASES ROOT AND SHOOT GROWTH

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 481e-481
Author(s):  
Susan D. Day ◽  
Nina L. Bassuk
Keyword(s):  
Root Growth ◽  
Shoot Growth ◽  
Sandy Loam ◽  
Mechanical Impedance ◽  
Compacted Soils ◽  
Vertical Drains ◽  
Pyrus Calleryana ◽  
Vertical Drainage ◽  
Root And Shoot Growth ◽  
Surrounding Soil

Four techniques for compaction amelioration were studied: 1) Vertical drainage panels; 2) vertical gravel-filled sump drains; 3) soil trenches filled with sandy loam; and 4) peat amended back fill. The control was backfilled with existing soil on the site. Vertical drainage mats and vertical gravel-filled sump drains were shown to increase O2% in surrounding soil; however, all O2 levels regardless of treatment were above what is considered limiting. Shoot and root growth of Pyrus calleryana `Redspire' was greatest for treatments that alleviated mechanical impedance (soil trenches and amended back fill) and least for treatments that did not (controls and vertical drains). Vertical drainage mats which alleviated mechanical impedance to a lesser degree showed intermediate growth.

scholarly journals 531 CMN-Pyrazole-induced Abscission of Mature `Valencia' Oranges in Relation to Young Fruit, Root, and Shoot Growth

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 487A-487
Author(s):  
Rongcai Yuan ◽  
Ulrich Hartmond ◽  
Walter J. Kender
Keyword(s):  
Root Growth ◽  
Ethylene Production ◽  
Citrus Sinensis ◽  
Shoot Growth ◽  
Young Fruit ◽  
Detachment Force ◽  
Root And Shoot Growth ◽  
Shoot And Root Growth

The seasonal abscission response of mature `Valencia' oranges [Citrus sinensis (L.)Osb.] to 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMN-Pyrazole) was examined in relation to young fruit, shoot, and root growth. CMN-Pyrazole dramatically increased ethylene production in fruit and effectively reduced the fruit detachment force (FDF), except in a period of reduced response to CMN-Pyrazole in early May. Root growth was inhibited by trunk girdling, in combination with removal of spring vegetative flushes and flowers, but not by their removal alone. During the responsive period, there was no difference in both ethylene production and FDF of CMN-Pyrazole-treated mature oranges between 1) the unmanipulated trees and those manipulated by either 2) girdling, removal of spring flushes and flowers, or 3) removal of flushes and flowers alone. However, during the less-responsive period, ethylene production in CMN-Pyrazole-treated mature oranges was significantly lower while the FDF was higher from non-manipulated trees than from trees treated by either girdling and removal of flush, or only removal of flush. There was no difference in either ethylene production or FDF of CMN-Pyrazole-treated mature oranges between trees manipulated by girdling and removal of flush, and those by removal of flush alone. Flush growth terminated at least 2 weeks before the onset of the less responsive period. This suggests that the hormones from rapidly growing young fruit may be responsible for the less responsive period.

scholarly journals Species and Their Relationships with Air and Soil Temperatures

1999 ◽  
Vol 9 (1) ◽  
pp. 131
Author(s):  
Timothy K. Broschat
Keyword(s):  
Root Growth ◽  
Growth Rates ◽  
Shoot Growth ◽  
Cocos Nucifera ◽  
Primary Root ◽  
The Other ◽  
Date Palms ◽  
Primary Roots ◽  
Root And Shoot Growth ◽  
Soil Temperatures

Royal palms [Roystonea regia (HBK.) O.F. Cook], coconut palms (Cocos nucifera L. `Malayan Dwarf'), queen palms [Syagrus romanzoffiana (Chamisso) Glassman], and pygmy date palms (Phoenix roebelenii O'Brien) were grown in a rhizotron to determine the patterns of root and shoot growth over a 2-year period. Roots and shoots of all four species of palms grew throughout the year, but both root and shoot growth rates were positively correlated with air and soil temperature for all but the pygmy date palms. Growth of primary roots in all four species was finite for these juvenile palms and lasted for only 5 weeks in royal palms, but ≈7 weeks in the other three species. Elongation of secondary roots lasted for only 9 weeks for coconut palms and less than half of that time for the other three species. Primary root growth rate varied from 16 mm·week-1 for coconut and pygmy date palms to 31 mm·week-1 for royal palms, while secondary root growth rates were close to 10 mm·week-1 for all species. About 25% of the total number of primary roots in these palms grew in contact with the rhizotron window, allowing the prediction of the total root number and length from the sample of roots visible in the rhizotron. Results indicated that there is no obvious season when palms should not be transplanted in southern Florida because of root inactivity.

scholarly journals Effect of mechanical impedance on root and shoot growth of rice at time intervals

1970 ◽  
Vol 19 (2) ◽  
pp. 119-128
Author(s):  
AHMZ Ali
Keyword(s):  
Root Growth ◽  
Growth Rates ◽  
Shoot Growth ◽  
Leaf Growth ◽  
Mechanical Impedance ◽  
Growth Time ◽  
Time Interval ◽  
Night Time ◽  
Time Intervals ◽  
Root And Shoot Growth

In a phytotron chamber the effect of mechanical impedance on root and shoot growth of BR?29 variety of rice at different time intervals reaveled that length of the seminal axis and length of the longest leaf extended linearly in both unimpeded and impeded treatments. Diameter of roots increased in impeded treatment. The number of first order laterals also increased linearly with time in both unimpeded and impeded treatments. Although there were always significantly more laterals on the unimpeded root axes, lateral spacing does not show any tendency to change with time. Root growth rate was nearly half in impeded than in unimpeded treatment. The pattern of root length in unimpeded (UI) did not differ from that of the pattern in impeded (I) treatment as the ratios (I/UI) were more or less constant with time. The time of leaf appearance was delayed by one ? two days and leaf growth period was shortened by one day in impeded than in unimpeded treatment. Leaf growth rates did not differ significantly between day and night time although night time growth rates were always slightly less than day time. Key words: Mechanical impedance; Pattern of root growth; Time interval; Shoot growth; Rice DOI: http://dx.doi.org/10.3329/dujbs.v19i2.8953 DUJBS 2010; 19(2): 119-128

Duration of zinc uptake inhibition by chlorsulfuron in wheat

1992 ◽  
Vol 43 (5) ◽  
pp. 1169 ◽  
Author(s):  
LD Osborne ◽  
AD Robson
Keyword(s):  
Root Growth ◽  
Zinc Deficiency ◽  
Root Exudates ◽  
Shoot Growth ◽  
Zinc Uptake ◽  
Root Weight ◽  
Uptake Inhibition ◽  
Root And Shoot Growth ◽  
Shoot Weight ◽  
Hydrolysis Of

The duration of inhibition of zinc uptake by chlorsulfuron was examined in wheat plants in a glasshouse experiment. Chlorsulfuron decreased shoot weight, root weight and zinc uptake. Plants that were treated with chlorsulfuron and adequately supplied with zinc partially recovered from root and shoot growth inhibition by 6 weeks and zinc uptake was recovering by 8 weeks. Plants that were seriously zinc deficient did not recover. In this experiment, potential grain yield was only reduced by chlorsulfuron when zinc supplies were inadequate. It is suggested that the recovery of plants from zinc deficiency may be the result of two processes; hydrolysis of chlorsulfuron with time removing constraints to root growth and functioning, and the release of root exudates from zinc deficient plants effective at mobilizing zinc from soil. In the field, chlorsulfuron is only likely to induce zinc deficiency and reduce yield in wheat where supplies of this trace element are marginal for growth.

scholarly journals Shoot and root responses of Trifolium vesiculosum to boron fertilization in an acidic Brazilian soil

2007 ◽  
Vol 50 (4) ◽  
pp. 597-604 ◽  
Author(s):  
Nerilde Favaretto ◽  
Antônio Carlos Vargas Motta ◽  
Cristina Barcik ◽  
Sebastião Brasil Campos Lustosa ◽  
Jucinei José Comin
Keyword(s):  
Root Growth ◽  
Soil Profile ◽  
Shoot Growth ◽  
Acid Soil ◽  
Low Ph ◽  
Al Toxicity ◽  
Root And Shoot Growth ◽  
Root Responses ◽  
Trifolium Vesiculosum ◽  
Boron Fertilization

To analyze the influence of boron fertilization on shoot and root growth of Trifolium vesiculosum (arrowleaf clover), an acid soil profile (60 cm depth with 67% Al saturation) was recreated in a column (three layers of 20 cm each). Lime and fertilizer (P and K) were incorporated into the top 20 cm. The treatments consisted of six boron rates where boric acid was mixed throughout the profile. Addition of boron to soil with low pH and high Al increased the root and shoot growth, independent of the rate applied. Boron inhibited Al toxicity, but no effect was observed in the root length when Al was not present in the soil. It was also observed that there was more root growth below the plow layer (0-20 cm,) suggesting better root distribution in the soil profile which could be important for the plant growth, especially under drought conditions.

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