Internal Phosphorus Flows During Development of Phosphorus Stress in Stylosanthes hamata

1990 ◽  
Vol 17 (4) ◽  
pp. 451 ◽  
Author(s):  
FW Smith ◽  
WA Jackson ◽  
PJV Berg
Keyword(s):  
Root Growth ◽  
Growth Rates ◽  
Shoot Growth ◽  
Phosphorus Content ◽  
Phosphorus Deficiency ◽  
Root Weight ◽  
Maximal Growth ◽  
Apparent Lack ◽  
Phosphorus Stress ◽  
Stylosanthes Hamata

Partitioning and net transfer of phosphorus between shoots and roots in the tropical forage legume Stylosanthes hamata cv. Verano during the development of phosphorus deficiency has been studied. Plants were stressed by either growing them in dilute flowing culture on continuously maintained external phosphorus concentrations that were inadequate for maximal growth, or by transferring plants of varying phosphorus status to phosphorus-free media. An external phosphorus concentration of 1 �M P was found to be just adequate for maximal growth of S. hamata. Phosphorus stress caused rapid and substantial increases in root weight percentage. It is proposed that this represents an important adaptive mechanism for maximising phosphorus uptake by S. hamata growing in phosphorus-deficient soils. Roots contained the minimum proportion of the plant's phosphorus content when root phosphorus concentrations were 8-10 �mol P g-1 root, and shoot phosphorus concentrations were 16-20 �mol P g-1 shoot. When tissue concentrations were less than these values, plants suffered from phosphorus stress and phosphorus was either preferentially retained by the roots or rapidly transferred from shoots to roots, reducing the growth rates of shoots, but permitting root growth to continue. Upon reducing the external phosphorus supply to plants whose root phosphorus concentrations exceeded 8 to 10 �mol P g-1 root, excess phosphorus was rapidly transferred from the root to the shoot to maintain shoot growth rates. The mobility of phospborus within the plant, and the apparent lack of any delay in transferring phosphorus from shoots to roots as phosphorus stress developed, represent another adaptive feature that is likely to be important to the successful growth of S. hamata in low phosphorus soils. When the phosphorus supply was limited, the plant's resources were directed toward maintaining root growth. Even extremely phosphorus deficient plants, in which shoot growth had ceased, maintained linear rates of root growth. These linear rates were related to the total phosphorus content of the plant. In the latter stages of phosphorus deprivation, linear rates of root growth were maintained by remobilisation of phosphorus from the older parts of the root system to sustain the phosphorus supply to the root meristems.

scholarly journals Copper-treated Plug Flats Influence Root Growth and Flowering of Bedding Plants

HortScience ◽  
1996 ◽  
Vol 31 (6) ◽  
pp. 941-943 ◽  
Author(s):  
A.M. Armitage ◽  
P.M. Gross
Keyword(s):  
Root Growth ◽  
Flowering Time ◽  
Shoot Growth ◽  
Optimal Time ◽  
Root Weight ◽  
Seedling Height ◽  
Copper Hydroxide ◽  
Bedding Plants ◽  
Flowering Date ◽  
Shoot Weight

A copper hydroxide formulation (0%, 3.5%, 7%, 11% Cu) was applied to plug trays before sowing seeds of Impatiens ×hybrida L. `Accent Red', Pelargonium ×hortorum Bailey `Scarlet Elite', and Petunia ×hybrida Hort.Vilm.-Andr. `Ultra White' to investigate the influence of the formulations on ease of transplant, root growth, and shoot growth. These factors also were investigated in Cu-treated seedling plugs held past optimal transplanting stage. Root spiraling and seedling height at transplant were reduced for all taxa grown in Cu-treated trays, regardless of concentration, compared to seedlings from nontreated trays. Root weight and shoot weight responses to Cu treatments at transplant and at flowering varied among taxa. Mature heights of all taxa were unaffected by Cu treatment; however, flowering date was delayed for impatiens and geraniums transplanted at optimal time from Cu-treated trays. In general, petunias displayed little response to Cu treatment. Root spiraling was reduced and plugs were removed more easily from Cu-treated than from control trays stored for 2 weeks in the greenhouse, but flowering time was delayed for 12 days for impatiens and petunias and 21 days for geraniums, regardless of Cu concentration.

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

scholarly journals Interrelationship of Nitrogen and Light on Episodic Growth of Ligustrum japonicum

1994 ◽  
Vol 12 (1) ◽  
pp. 43-46
Author(s):  
Jeff S. Kuehny ◽  
Dennis R. Decoteau
Keyword(s):  
Growth Rate ◽  
Root Growth ◽  
Relative Growth Rate ◽  
Growth Rates ◽  
Shoot Growth ◽  
Fertilizer Application ◽  
Relative Growth ◽  
Mature Leaves ◽  
Episodic Growth ◽  
Ligustrum Japonicum

Abstract Exclusion of nitrogen and light from existing leaves at initiation of an episode of shoot growth decreased shoot and root relative growth rate. The combination of both nitrogen and light exclusion synergistically impacted relative growth rate for shoot (RGRs) and relative growth rate for root (RGRr). The next episode of shoot growth provided sufficient leaf area for carbohydrate assimilation and maintaining shoot and root growth rates when light was excluded from mature leaves. A better understanding of the developmental and biochemical changes of this episodic species provided useful information for timing of fertilizer application and transplanting of Ligustrum and other episodic species.

scholarly journals BIOSTIMULANTS CAN INCREASE GROWTH OF GREEN-HOUSE-GROWN ORNAMENTAL ANNUALS

HortScience ◽  
1996 ◽  
Vol 31 (5) ◽  
pp. 744c-744 ◽  
Author(s):  
Brian P. Gibbons ◽  
Timothy J. Smalley ◽  
Allan M. Armitage
Keyword(s):  
Root Growth ◽  
Shoot Growth ◽  
Root Weight ◽  
Green House ◽  
Salvia Splendens ◽  
Organic Products ◽  
Shoot Weight ◽  
Begonia Semperflorens

Three biostimulants, Grow-plex (Menefee Mining Corp., Dallas), Roots 2 (LISA Product Corp., Independence, Mo.), and Root n' Shoot (Natural Organic Products International, Mount Dora, Fla.) were applied to transplanted plugs of Salvia splendens `Empire Red' and Begonia semperflorens `Varsity Pink' and `Varsity Brite Scarlet'. Root n' Shoot drench (0.78%) solutions at transplant increased root weight, but a 1.56% solution decreased root weight of Salvia, although shoot growth was unaffected. Root n' Shoot decreased shoot growth of Begonia, but did not affect root growth. Roots 2 treatments (0.25% or 2.00%) increased shoot weight of Salvia, but did not affect the root growth of Salvia or the root or shoot growth of Begonia. Spraying Grow-plex (0.78% or 1.56%) to runoff at transplanting and 2 weeks after transplanting did not affect root or shoot growth of Salvia or Begonia.

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.

Effects of subsoil acidity on the shoot and root growth of some tropical and temperate forage legumes

1981 ◽  
Vol 32 (3) ◽  
pp. 453 ◽  
Author(s):  
A Pinkerton ◽  
JR Simpson
Keyword(s):  
Root Growth ◽  
Root Length ◽  
Shoot Growth ◽  
Fine Root ◽  
Tropical Species ◽  
Root Weight ◽  
Subsoil Acidity ◽  
Fine Root Length ◽  
Shoot Weight ◽  
Carbonate Species

The root and shoot growth of four tropical and two temperate summer-growing legumes were assessed when plants were grown in deep profiles of an acidic soil modified by additions of calcium carbonate. Species tested over three harvests were Desmodium intortum, Glycine wightii, Stylosanthes humilis (Townsville stylo), Macvoptilium atvopuvpureum (Siratro), Trifolium repens and Medicago sativa (lucerne). There were large and more immediate effects on root growth, particularly on fine root length, than on shoot growth. The species differed in their root responses to lime, the tropical species in general being more tolerant of subsoil acidity than the temperate species. There were marked differences between species in their responses when expressed as the ratio of fine root length to total shoot weight. The ratio of root weight to shoot weight showed much less variation with lime rate, and it is suggested that the ratio of fine root length to shoot weight is the better indicator of tolerance to subsoil acidity. S. humilis showed little response to lime at any time, and was notable for its length of fine root. Siratro grew well at first but later there was little increase in shoot weight or in length of fine root, although tap root weight increased greatly. Roots of D. intorturn, T. repens and lucerne were slow to penetrate beyond 55 cm depth. At later harvests the root lengths of these species and of G. wightii were highly responsive to lime. Agronomic implications of the results are discussed.

Early Root and Shoot Development of Nine Plant Species

Weed Science ◽  
1973 ◽  
Vol 21 (4) ◽  
pp. 289-291 ◽  
Author(s):  
L. L. Evetts ◽  
O. C. Burnside
Keyword(s):  
Growth Rate ◽  
Root Growth ◽  
Seed Weight ◽  
Shoot Growth ◽  
Root Weight ◽  
Weed Species ◽  
Emergence Rate ◽  
Shoot Growth Rate ◽  
Broadleaf Species ◽  
Root Growth Rate

The root growth rate index of velvetleaf (Abutilon theophrastiMedic.) was significantly greater than that of five other weed species. The root growth rate index of sorghum [Sorghum bicolor(L.) Moench ‘RS-626’] was found to be significantly higher than that of soybeans [Glycine max(L.) Merr. ‘Ford’]. Shoot growth rate indexes of three perennial broadleaf species studied were significantly lower than shoot growth rate indexes of six annual species. Root weights of perennial broadleaf species were not significantly different from root weights of velvetleaf and soybeans. Soybeans were found to have a significantly higher shoot to root ratio than seven weed species but not higher than sorghum. All other species had larger leaf weights and leaf areas than the three broadleaf perennials. While there were significant differences in leaf weights among six species, there were no significant differences in leaf area. Seed weight was not significantly correlated with emergence rate index and root weight but was correlated to all other factors studied. Emergence rate index was correlated with root growth rate index but not with shoot growth rate index.

scholarly journals 298 Root Restriction and Fertilizer Effects on Young Peach Trees

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 494A-494 ◽  
Author(s):  
T. Daw ◽  
T.J. Tworkoski ◽  
D.M. Glenn
Keyword(s):  
Root Growth ◽  
Root Length ◽  
Shoot Growth ◽  
Prunus Persica ◽  
Specific Root Length ◽  
Nonwoven Fabric ◽  
Soil Conditions ◽  
Root Weight ◽  
Root Volume ◽  
Peach Trees

Shoot growth of peach trees can be managed by manipulating edaphic conditions such as root volume and soil fertility. In this experiment, 2-year-old peach trees (Prunus persica L. cv. Sentry on `Lovell' rootstock) were planted in pots with a split root design, so that half the roots were not treated and the other half received one of four treatments: root volume restricted with polypropylene nonwoven fabric (FAB), fertilizer alone (FER), FAB + FER, and untreated control (UTC). Total shoot growth and root growth were measured, and root growth in the split halves was compared. FER increased leaf number and weight by 48% and 60%, respectively, but not stem growth. Leaf nitrogen concentration and photosynthesis were greatest in FER treatment. FAB did not affect shoot weight or reduce total root weight or length, although roots did not grow past the fabric barrier. FER increased root weight and length (116% and 57%, respectively, compared to UTC) on the treated half but did not affect root growth on the untreated half. Greatest root growth occurred in the root half that received FAB + FER, particularly in the 5-cm soil segment proximal to the fabric (4.6 cm•cm-3 compared to 0.8 cm.cm-3 in UTC). Shoot length was greater in FAB + FER than FAB. Thus, fertilizer applied near fabric increased root growth and the combination of fertilizer and fabric may be used to regulate shoot growth. Specific root length (root length per gram dry weight) was highest in trees with no treatment, suggesting root acclimation to low nutrient soil conditions. Lower specific root length resulted in soils that were fertilized. The results indicate that nonwoven fabric restricts root growth in peach trees and reduces shoot elongation. The combined effect of fabric plus selected application of fertilizer may be used to regulate growth of peach trees.

scholarly journals Biostimulants can Increase Growth of Greenhouse-grown Ornamental Annuals

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 701c-701
Author(s):  
Brian P. Gibbons ◽  
Timothy J. Smalley ◽  
Allan M. Armitage
Keyword(s):  
Root Growth ◽  
Shoot Growth ◽  
Root Weight ◽  
Salvia Splendens ◽  
Organic Products ◽  
Shoot Weight ◽  
Begonia Semperflorens

Three biostmulants, Grow-plex (Menefee Mining Corp., Dallas, Texas), Roots 2 (LISA Product Corp., Independence, Mo.), and Root n' Shoot (Natural Organic Products International, Mount Dora, Fla.) were applied to transplanted plugs of Salvia splendens `Empire Red' and Begonia semperflorens-cultorum `Varsity Pink' and `Varsity Brite Scarlet'. Root n' Shoot drench (0.78%) solutions at transplant increased root weight, but a 1.56% solution decreased root weight of salvia; however, shoot growth was unaffected. Root n' Shoot decreased shoot growth of begonia, but did not affect root growth of begonia. Roots 2 treatments (0.25% or 2.00%) increased shoot weight of salvia, but did not affect salvia root growth or root or shoot growth of begonia. Spraying Grow-plex (0.78% or 1.56%) to runoff at transplanting and 2 weeks after transplanting did not affect root or shoot growth of salvia or begonia.

Sign in / Sign up

Export Citation Format

Share Document