Growth Responses of Musk and Plumeless Thistles (Carduus nutansandC. acanthoides) to Damage byTrichosirocalus horridus(Coleoptera: Curculionidae)

Weed Science ◽  
1985 ◽  
Vol 33 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Bob Cartwright ◽  
Loke T. Kok
Keyword(s):  
Growth Pattern ◽  
Apical Dominance ◽  
Sublethal Effects ◽  
Plant Response ◽  
Growth Responses ◽  
Field Plot ◽  
Growing Conditions

Plant response studies were conducted from 1980 to 1982 under pasture and field plot conditions to determine the sublethal effects of the thistle rosette weevil [Trichosirocalus (Ceuthorynchidius) horridus(Panzer)] onCarduusthistles. Response to weevil damage was dependent upon thistle size and growing conditions. Damage byT. horridusdestroyed apical dominance, which altered the thistle growth pattern. Infested plants consistently produced more stems and a larger crown than uninfested thistles. Large thistles were stimulated by weevil damage, producing heavier stems and more heads. Small infested thistles developed more quickly than small uninfested thistles. Small and medium infested thistles were shorter and produced fewer seeds and heads than uninfested thistles. The extent of thistle reduction by this weevil will ultimately be determined by the conditions under which thistles grow.

scholarly journals Allocation of added selenium in lettuce and its impact on roots

2003 ◽  
Vol 12 (3-4) ◽  
pp. 155-164 ◽  
Author(s):  
A. SIMOJOKI ◽  
T. XUE ◽  
K. LUKKARI
Keyword(s):  
Root Morphology ◽  
Specific Volume ◽  
Dry Matter ◽  
Lateral Roots ◽  
Large Scatter ◽  
Growth Responses ◽  
Endogenous Ethylene ◽  
Morphological Variables ◽  
Length And Area ◽  
Growing Conditions

Allocation of selenium (Se) in lettuce and its impact on root morphology were studied to better understand the growth responses of plants to added Se. Lettuce was grown in vermiculite under controlled growing conditions for seven weeks, and the allocation in the shoots and roots of selenate added in increasing dosages (0, 1, 10, 100, 500 and 1000 µg Se per 3.5-litre pot) as well as morphological variables of the roots were determined. The intermediate additions of 100 and 500 µg Se per pot seemed to produce the highest biomasses, although this was nearly masked by large scatter in the data. The Se contents both in roots and shoots increased roughly proportionally to the amount of Se added. However, at small additions Se was preferentially allocated to roots, whereas at larger additions the contents in roots and shoots (mg kg-1 dry matter) were roughly equal. Se treatments did not change the morphology of hypocotyls. On the contrary, the specific length and area of basal and lateral roots were smallest at intermediate Se additions, whereas the specific volume was largest at the largest Se addition. These effects of Se on root morphology were, however, not unambiguously related to plant growth. As the Se contents in roots increased, the roots grew thicker and the specific volume of lateral roots increased in agreement with a hypothesis of increased endogenous ethylene production.;

Needle demography and growth pattern of Corsican pine

1982 ◽  
Vol 60 (2) ◽  
pp. 105-116 ◽  
Author(s):  
Lucie Maillette
Keyword(s):  
Frequency Distribution ◽  
Growth Pattern ◽  
Apical Dominance ◽  
Pine Needles ◽  
Tree Age ◽  
Climatic Variations ◽  
Activity Schedule ◽  
Log Normal ◽  
Needle Senescence ◽  
Different Parts

A study of the demography of the needles and the growth pattern of Corsican pine is presented in relation to other studies of foliage dynamics. The construction of life tables is explained and applied to populations of Corsican pine needles. Needles from different trees as well as from different parts of trees had different survivorship. Leader needles had a much lower survivorship than all other needles. The frequency distribution of shoot lengths was log-normal, with the leader as the longest shoot. Climatic variations, tree age, apical dominance, and growth pattern appeared to be some of the factors involved in needle survivorship. Possible causes of needle senescence are considered with respect to an "activity schedule" derived from the work of other authors.

scholarly journals THE EFFECT OF SEVERE PRUNING ON THE NEW GROWTH OF TWO TREE SPECIES.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1114g-1114
Author(s):  
Mary Ann Rose ◽  
Larry J. Kuhns
Keyword(s):  
Tree Species ◽  
Apical Dominance ◽  
Average Length ◽  
Growth Increment ◽  
Shoot Length ◽  
Equivalent Amount ◽  
Seasonal Growth ◽  
Growth Responses ◽  
Pyrus Calleryana ◽  
Bare Root

Large bare-root liners of Gleditsia triacanthos `Moraine' and Pyrus calleryana `Aristocrat' were planted in spring, 1989. Five trees of each species were pruned by removing 50% of the length of each shoot at planting; 5 control trees were not pruned. After 4 months the trees were harvested and the following measurements were taken on the season's new growth increment: total number of elongated shoots and unelongated shoots (< 1 cm in length), total and average length of elongated new shoots, stem and leaf dry weights.Growth responses of the 2 species to treatments were nearly identical. Pruned trees had fewer shoots than controls but a much higher proportion of elongated to unelongated shoots. This could be the result of a release of apical dominance. The average new shoot length of pruned trees was 2-3 times that of controls, and the total new shoot length was significantly greater. New stem dry weights of the pruned trees were also greater than the controls, but leaf dry weights were not significantly different. Total shoot weights (stems plus leaves) were not different. In this study there was no difference between treatments in the total seasonal growth increment as measured by weight. An equivalent amount of new growth was distributed on fewer, but more rapidly-elongating branches in the pruned trees.

Plant Response of Strawberry to Intra-row Spacing and Growing Conditions in South of Jordan

2013 ◽  
Vol 12 (5) ◽  
pp. 201-207 ◽  
Author(s):  
E. Al-Ramamne ◽  
Z. Al-Rawashd ◽  
M. Karajeh ◽  
S. Abu-Romman
Keyword(s):  
Plant Response ◽  
Row Spacing ◽  
Growing Conditions

Apical dominance and apical control in multiple flushing of temperate woody species

2007 ◽  
Vol 37 (1) ◽  
pp. 74-83 ◽  
Author(s):  
Morris G Cline ◽  
Constance A Harrington
Keyword(s):  
Apical Dominance ◽  
Woody Species ◽  
Second Phase ◽  
Control Mechanisms ◽  
Hormone Activity ◽  
Stem Form ◽  
Two Phase ◽  
Apical Control ◽  
Terminal Shoot ◽  
Growing Conditions

In young plants of many woody species, the first flush of growth in the spring may be followed by one or more flushes of the terminal shoot if growing conditions are favorable. The occurrence of these additional flushes may significantly affect crown form and structure. Apical dominance (AD) and apical control (AC) are thought to be important control mechanisms in this developmental response. A two-phase AD – AC hypothesis for the factors controlling a subsequent flush is presented and evaluated on the basis of currently known studies. The first, very early phase of this additional flush consists of budbreak and the very beginning of outgrowth of the newly formed current buds on the first flushing shoot. There is evidence that this response often involves the release of AD, which is significantly influenced by the auxin:cytokinin ratio as well as by other signals including nutrients and water. This first phase is immediately followed by a second phase, which consists of subsequent bud outgrowth under the influence of apical control. Although definitive data for hormone involvement in this latter process is sparse, there is some evidence suggesting nutritional mechanisms linked to possible hormone activity. Stem-form defects, a common occurrence in multiple-flushing shoots, are analyzed via the AD – AC hypothesis with suggestions of possible means of abatement.

scholarly journals Geographic variation in larval cold tolerance and exposure across the invasion front of a widely established forest insect

2021 ◽  
Author(s):  
Petra Hafker ◽  
Lily M Thompson ◽  
Dylan Parry ◽  
Jonathan A Walter ◽  
Kristine L Grayson
Keyword(s):  
Cold Tolerance ◽  
Thermal Tolerance ◽  
Sublethal Effects ◽  
Single Point ◽  
Cold Climate ◽  
Cold Temperature ◽  
Growth Responses ◽  
Forest Insect ◽  
Cold Temperatures ◽  
Chill Coma

As the global climate changes, high and low temperature extremes can drive changes in species distributions. Across the range of a species, thermal tolerance can experience plasticity and may undergo selection, shaping resilience to temperature stress. In this study, we measured variation in the lower thermal tolerance of early instar larvae of an invasive forest insect, Lymantria dispar dispar L. (Lepidoptera: Erebidae), using populations sourced from the climatically diverse invasion of the Eastern United States. In two chill coma recovery experiments, we recorded recovery time following a period of exposure to a non-lethal cold temperature. A third experiment quantified growth responses after chill coma recovery to evaluate sublethal effects. Our results indicate that cold tolerance is linked to regional climate, with individuals from cold climate populations recovering faster from chill coma. While this geographic gradient is seen in many species, detecting this pattern is notable for an introduced species founded from a single point-source introduction. We demonstrate that the cold temperatures used in our experiments occur in nature from cold snaps after spring hatching, but negative impacts to growth and survival appear low. We expect that population differences in cold temperature performance manifest more from differences in temperature-dependent growth than acute exposure. Evaluating intraspecific variation in cold tolerance increases our understanding of the role of climatic gradients on the physiology of an invasive species, and contributes to tools for predicting further expansion.

scholarly journals 489 Using Plant Nutrition Experiments as Models for Exploring Multiple Factor Interactions

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 478D-478
Author(s):  
Ellen T. Paparozzi ◽  
Walter W. Stroup ◽  
M. Elizabeth Conley ◽  
Reid D. Landes
Keyword(s):  
Response Surface ◽  
Analysis Data ◽  
Plant Response ◽  
Response To Treatment ◽  
Nutrient Analysis ◽  
Response Surface Designs ◽  
Central Composite Designs ◽  
Response Surface Regression ◽  
Growing Conditions ◽  
Factor Interactions

Horticulturists are often interested in evaluating the effect of several treatment factors on plant growth in order to determine optimal growing conditions. Factors could include three or more nutrient elements, or types and rates of irrigation, pesticides or growth regulators, possibly in combination with one another. Two problems with such experiments are how to characterize plant response to treatment combinations and how to design such experiments so that they are manageable. The standard statistical approach is to use linear and quadratic (a.k.a. response surface) regression to characterize treatment effects and to use response surface designs, e.g., central-composite designs. However, these often do a poor job characterizing plant response to treatments. Hence the need for more generally applicable methods. While our goal is to be able to analyze three and higher factor experiments, we started by tweaking two-factor nutrient analysis data. The result was a hybrid model which allows for a given factor to respond linearly or non-linearly. We will show how this was done and our current “in progress” model and analysis for analyzing three quantitative factors.

scholarly journals THE EFFECT OF SEVERE PRUNING ON THE NEW GROWTH OF TWO TREE SPECIES.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1114G-1114
Author(s):  
Mary Ann Rose ◽  
Larry J. Kuhns
Keyword(s):  
Tree Species ◽  
Apical Dominance ◽  
Average Length ◽  
Growth Increment ◽  
Shoot Length ◽  
Equivalent Amount ◽  
Seasonal Growth ◽  
Growth Responses ◽  
Pyrus Calleryana ◽  
Bare Root

Large bare-root liners of Gleditsia triacanthos `Moraine' and Pyrus calleryana `Aristocrat' were planted in spring, 1989. Five trees of each species were pruned by removing 50% of the length of each shoot at planting; 5 control trees were not pruned. After 4 months the trees were harvested and the following measurements were taken on the season's new growth increment: total number of elongated shoots and unelongated shoots (< 1 cm in length), total and average length of elongated new shoots, stem and leaf dry weights. Growth responses of the 2 species to treatments were nearly identical. Pruned trees had fewer shoots than controls but a much higher proportion of elongated to unelongated shoots. This could be the result of a release of apical dominance. The average new shoot length of pruned trees was 2-3 times that of controls, and the total new shoot length was significantly greater. New stem dry weights of the pruned trees were also greater than the controls, but leaf dry weights were not significantly different. Total shoot weights (stems plus leaves) were not different. In this study there was no difference between treatments in the total seasonal growth increment as measured by weight. An equivalent amount of new growth was distributed on fewer, but more rapidly-elongating branches in the pruned trees.

scholarly journals POST-TRANSPLANT WATER RELATIONS AND GROWTH RESPONSES OF `RED SUNSET' RED MAPLE TREES TO ROOT PRUNING AND Cu (OH)2-TREATED CONTAINER PRODUCTION

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 569d-569
Author(s):  
Michael A. Arnold. ◽  
G. Kim Stearman ◽  
Reed W. Cripps
Keyword(s):  
Soil Water ◽  
Water Relations ◽  
Root Pruning ◽  
Red Maple ◽  
Growth Responses ◽  
Field Plot ◽  
Latex Paint ◽  
Rooted Cuttings ◽  
Post Transplant ◽  
Water Potentials

Rooted cuttings of Acer rubrum `Red Sunset' grown in containers treated on interior surfaces with 100 g Cu(OH)2/liter white interior latex paint, or left untreated, were root pruned or not root pruned and planted in a field plot. A pseudo-bareroot treatment, trees from untreated containers shaken free of media, was included. Height (115 vs. 108 cm) and caliper (12.0 vs. 10.7 mm) at transplant was slightly greater for copper treated trees than for untreated trees. Leaf water potentials (LWP) at transplant were similar for all treatments. Mid-day LWP of trees transplanted from untreated containers tended to be lower than that of trees grown in copper treated containers at days 3, 14, 28, and 53 after transplant. Pseudo-bareroot trees had the most negative mid-day and pre-dawn LWP through day 92. Soil water potentials were from -0.01 to -0.03MPa.

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