Feeding by Cassida rubiginosa (Coleoptera: Chrysomelidae) and the Effects of Defoliation on Growth of Musk Thistles

1990 ◽  
Vol 25 (4) ◽  
pp. 538-547 ◽  
Author(s):  
Bob Cartwright ◽  
Loke T. Kok
Keyword(s):  
Plant Growth ◽  
Leaf Tissue ◽  
Plant Response ◽  
Laboratory Studies ◽  
Feeding Rates ◽  
Temperature Dependent ◽  
Leaf Consumption ◽  
Growth And Reproduction ◽  
Cassida Rubiginosa ◽  
Effect On Growth

Plant response studies were conducted to determine the effects of feeding by Cassida rubiginosa Müller and mechanical defoliation on the growth and reproduction of musk thistle (Carduus thoermeri Weinmann). Mortality of thistles was highest with 75% mechanical defoliation at the rosette stage; defoliation of thistles after bolting had little effect on growth and reproduction. Thistle growth was more adversely affected by multiple than single defoliations, particularly when 50% or more of the leaf tissue was removed. Single defoliation produced little reduction in plant growth except at the 75% level. Defoliation by C. rubiginosa produced effects on thistles that were intermediate to those resulting from 50 and 75% multiple mechanical defoliations, even though only 23% of the leaf tissue was removed. Laboratory studies of leaf consumption showed that C. rubiginosa larvae consumed more thistle leaf tissue as they matured and that their feeding rates were temperature dependent.

Effect of plant growth regulators on growth and reproduction in the fungus Dipodascopsis uninucleata

1989 ◽  
Vol 67 (8) ◽  
pp. 2425-2428 ◽  
Author(s):  
Esmat Elwy Aly Elwy
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Lateral Branch ◽  
Branch Formation ◽  
Growth And Reproduction ◽  
Effect On Growth

Different concentrations of IAA, GA3, 4CPA, kinetin, and 2,4-D were used to study their effect on growth and reproduction in Dipodascopsis uninucleata. Most of the concentrations of IAA, kinetin, and 2,4-D tested promoted growth, whereas GA3 had no effect. All substances used stimulated lateral branch formation and 2,4-D had the greatest effect. Most concentrations of the growth regulators either inhibited or had no effect on ascus formation; only 10−8 M 4CPA, 10−6 M 2,4-D, and 10−6 M GA3 enhanced ascus formation. The percentage of hyphae with aborted gametangia increased in cultures treated with most concentrations of the tested substances except 10−8 M 4CPA, which decreased the percentage of failure. Also, growth regulators either delayed or had no effect on sporulation.

scholarly journals EUSTOMA GRANDIFLORUM RESPONSE TO pH OF GROWING MEDIA

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1107a-1107
Author(s):  
Brent K. Harbaugh
Keyword(s):  
Plant Growth ◽  
Leaf Tissue ◽  
Plant Response ◽  
Eustoma Grandiflorum ◽  
Stunted Growth ◽  
Interveinal Chlorosis ◽  
Tissue Levels ◽  
The Media ◽  
Delayed Flowering ◽  
Fertilizer Solutions

Symptoms of foliar chlorosis or bleaching, interveinal chlorosis of lower leaves, leaf edge and tip necrosis, stunted growth and delayed flowering of Eustoma increased as pH decreased below 6.5 in various peat-vermiculite based media for all cultivars tested. Symptoms were evident with or without microelement amendments in the media or fertilizer. A 5×5 factorial with pH of media and fertilizer solutions ranging from 5.1 to 7.5 indicated fertilizer pH did not negate plant response to low media pH. Leaf tissue levels of Zn were elevated at low media pH and negatively correlated to plant growth and flowering characteristics, while imbalances in tissue levels of N, P, K, Ca, Mg, Fe, Mn, Cu and B appeared to be less important. Symptomatic plants grown in media with a pH from 5.0 to 5.8 had tissue levels of Zn ranging from 200 to 1200 ppm, and plants without symptoms in media with a higher pH had leaf tissue levels from 40 to 100 ppm Zn.

scholarly journals Direct and indirect effects of episodic frost on plant growth and reproduction in subalpine wildflowers

2017 ◽  
Vol 24 (2) ◽  
pp. 848-857 ◽  
Author(s):  
Gabriella L. Pardee ◽  
David W. Inouye ◽  
Rebecca E. Irwin
Keyword(s):  
Plant Growth ◽  
Indirect Effects ◽  
Direct And Indirect Effects ◽  
Growth And Reproduction

scholarly journals Eco-friendly plant growth and development regulators on the basis of derivatives 1,2,4-triazines

2021 ◽  
Vol 36 ◽  
pp. 02003
Author(s):  
E.A. Builova ◽  
A.K. Mazitova ◽  
G.K. Aminova ◽  
I.I. Zaripov ◽  
A.H. Alibakova
Keyword(s):  
Plant Growth ◽  
Growth And Development ◽  
Target Product ◽  
Optimal Conditions ◽  
Laboratory Studies ◽  
Plant Growth And Development ◽  
Effect Of Solvents ◽  
Etiolated Seedlings ◽  
Working Solution ◽  
Derivatives Of

The article considers the application of plant growth and development regulators, in particular, derivatives of asymmetric triazines. A method for obtaining hexahydro-1,2,4-triazinone-3 is given. Optimal conditions for the reaction of 1,2-dichloroethane with semicarbazide are determined: reaction time, process temperature, and the effect of solvents on the yield of the target product. The results of laboratory and vegetation tests of 1,2,4-triazinone-3 for biological activity are presented. Laboratory studies were carried out on seeds of wheat, cucumbers, radish and vetch, which were laid out in Petri dishes and poured with a working solution, the concentration of the drug is 1, 10 mg/l. Two days later, the length and weight of etiolated seedlings were determined. Vegetation tests were carried out on seeds of barley, wheat and rye with a concentration of 10 mg/l. After two weeks, the length and weight of the plants were measured.

Micronutrients

1999 ◽  
Author(s):  
Robert F. Keefer
Keyword(s):  
Plant Growth ◽  
Plant Tissue ◽  
Internal Drainage ◽  
Secondary Minerals ◽  
Soil Particles ◽  
Ring Compounds ◽  
Poorly Drained Soils ◽  
Iron Manganese ◽  
Primary Minerals ◽  
Growth And Reproduction

Micronutrients needed by plants are Cu, Fe, Mn, Zn, B, Mo, Cl, Ni, Co, V, Si, and Na. The required amounts of each of these elements is very small but still essential for desirable plant growth and reproduction. These elements must be applied to soils cautiously for the range between deficient and toxic is very small. It is unwise to use a fertilizer containing all of these micronutrients. Any one of them may already be high enough in soils to cause toxicity from that particular element. If a micronutrient is suspected of being deficient, it would be wise to get soil tests and plant tissue tests to corroborate your suspicions. If a micronutrient is deficient, one should apply only the amount recommended but no more. Sometimes a toxicity of an element is more difficult to correct than a deficiency. Copper, iron, manganese, cobalt, and zinc can be present in soils as (a) several types of precipitates, (b) adsorbed onto the surface of soil particles, (c) present in primary minerals (rocks) and secondary minerals (clays), and (d) present as complex ring compounds. These forms may or may not be available to plants. Precipitates of Cu, Fe, Mn, or Zn often form in soils at high pH (after liming Fig. 14.1). This may occur in soils near buildings from the lime used in the mortar. Soil acids dissolve the lime into Ca++ or Mg++ that migrate into the soil raising the pH and cause these micronutrients to precipitate. Often an Fe deficiency is evident, particularly on acid-loving plants, such as azaleas, rhododendrons, or hollies. If this is extensive, the soil near the buildings may need to be replaced. With limited areas, the soil can be acidified by adding elemental S near the plants affected. The elements Cu, Fe, Mn, and Zn can exist as soluble forms or precipitates, depending on the pH of the soil. The soluble forms as cations are present when soils have poor internal drainage (poorly drained soils), whereas the oxides of these elements are present where the soil is well aerated.

Energetics: the costs of living and reproducing for an individual cephalopod

1996 ◽  
Vol 351 (1343) ◽  
pp. 1083-1104 ◽  
Keyword(s):  
Specific Dynamic Action ◽  
Energy Budgets ◽  
Food Conversion ◽  
Laboratory Studies ◽  
Feeding Rates ◽  
Historical Factors ◽  
In The Wild ◽  
Excretion Rates ◽  
The Cost ◽  
Conversion Efficiencies

Cephalopods, like all other animals, have to decide how to allocate resources; maintenance processes, growth of somatic and reproductive tissues, and locomotor activity all have costs. We should like to be able to identify these costs and discover how efficiently cephalopods make use of the prey that they capture and digest. Cephalopods generally grow fast and mature rapidly; a first task is to determine how accurately laboratory studies reflect growth in the wild, because much of the information we need (such as food conversion efficiencies, excretion rates or the costs of locomotion) can be collected only from animals kept in the laboratory. Comparison of laboratory feeding and growth rates for octopods, sepioids and teuthoids with fisheries data suggests that data collected from cephalopods fed ad libitum in the laboratory may be used validly to construct energy budgets representative of individuals in the wild. The immediate cost of feeding (the specific dynamic action) has been thoroughly documented in Octopus , as has the longer-term elevation or depression of metabolic rate by feeding or starvation; it is assumed that similar costs will be found in squid. The cost of locomotion has been studied in both octopods and squid, but we have only limited data on how much time the animals spend moving, and how rapidly, in the wild. Excretory and faecal losses are assessed from laboratory studies, and maintenance costs estimated from feeding rates that just maintain body mass in the laboratory. Comparison of gross and net food conversion efficiencies suggest that squid convert food into tissues less efficiently than octopods, owing primarily to their greater time spent in locomotion. We present a representative series of energy budgets for octopods (based on Octopus ) and squids (based on Illex and Loligo ), for starving, feeding, migrating and maturing individuals. A major contrast is provided by Nautilus, which lives for ten or twenty years and grows only slowly. Finally we speculate on the possible biochemical and historical factors that may have limited the adaptive radiation of cephalopods, resulting in a group lacking herbivores, detritivores or filter-feeders but extremely successful as carnivores.

The flush development of evergreen recurrent flushing perennials: an experimental overview with insights into the flowering of olive

2020 ◽  
Vol 68 (5) ◽  
pp. 345
Author(s):  
Trevor Olesen ◽  
Michelle Wirthensohn
Keyword(s):  
Water Stress ◽  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Shoot Development ◽  
New Work ◽  
Temperature Dependent ◽  
Final Size ◽  
Stimulation Of

Recurrent flushing perennials are those that grow by episodic waves of shoot extension under conditions continuously favourable for growth. Here we review the habit for evergreen perennials. The commencement of a new flush appears to depend on the stimulation of buds by plant growth regulators. The determination of a new flush as vegetative or floral most likely occurs during early shoot development. Cool temperatures are usually florally inductive, but other factors such as periods of water stress before flush commencement, and low crop loads may also enhance induction. There is little evidence for the control of the final size of vegetative shoots, and even less for the size of floral shoots. The time between successive flushes is cyclic and temperature dependent. New work with olive is presented and shows that pruning increases the proportions of vegetative shoots to develop from comparable nodes of pruned and non-pruned branches. It also shows that immature vegetative flushes on olive branches in winter inhibit flowering to some extent, a result previously shown for other evergreen recurrent flushing trees.

Sign in / Sign up

Export Citation Format

Share Document