Factors affecting Rodents' responses to odours of strangers encountered in the field: Experiments with odour-baited traps

AbstractLaboratory and field experiments indicate that the female spruce budworm (Choristoneura fumiferana (Clem.)) pupal stadium requires approximately 122C degree-days above a threshold of 7.2 °C (45°F), the male 124. Emergence time on any given day depends on temperature but is independent of photoperiod. Under field conditions male and female budworm mate only once per 24-h period. In the laboratory under continuous illumination females mate repeatedly and males readily mate a second time within a few hours, but the duration of the second copulation is abnormally long. The probability of multiple matings under field conditions is reduced by the restricted period of sexual activity coupled with the duration of copulation and the lower competitiveness of mated insects. Antennae are essential to the male for successful copulation.

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The anthochron as a building block of flower development

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x2016000800001 ◽

2016 ◽

Vol 51 (8) ◽

pp. 899-904

Author(s):

Nereu Augusto Streck ◽

Natalia Teixeira Schwab

Keyword(s):

Building Block ◽

Flower Development ◽

Field Experiments ◽

Linear Regression Analysis ◽

Time Interval ◽

Simple Linear Regression ◽

Vegetative Development ◽

Flower Opening ◽

Factors Affecting ◽

Opening Phase

Abstract: Plant vegetative development has been widely described using the phyllochron concept, but little effort has been made to describe flower development during the reproductive phase. The objective of this work was to present the anthochron, through a review of the literature, as a building block of flower development, mainly during the flower opening phase. The anthochron is the time interval needed for two subsequent flowers to achieve the same developmental stage, with units of time in days or in ºC day per flower. The concept of anthochron fulfills part of the lack of studies on flower development, since it is considered a building block of the flower opening process. The anthochron can be measured from field experiments or estimated by a simple linear regression analysis. So far, the anthochron has only been quantified in Gladiolus x grandiflorus Hort. Therefore, factors affecting the anthochron still need to be determined in order to pinpoint their effect on the flower opening rate.

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Factors affecting the herbage iodine content.

Netherlands Journal of Agricultural Science ◽

10.18174/njas.v22i3.17222 ◽

1974 ◽

Vol 22 (3) ◽

pp. 195-206 ◽

Cited By ~ 2

Author(s):

J. Hartmans

Keyword(s):

Soil Type ◽

Dry Matter ◽

Field Experiments ◽

Iodine Content ◽

Single Species ◽

Residual Effects ◽

Grass Species ◽

Yield Response ◽

N Application ◽

Factors Affecting

In pot and field experiments, N application somewhat increased the I content of the harvested crop, although I concentrations in the herbage decreased considerably (diluting effect of increased dry matter yields). Herbage I contents were not consistently affected by chemical fertilizers which produced no yield response. I contents were up to 13 times higher in dicotyledenous pasture species than in grasses. I contents varied between grass species and to less extent between varieties of a single species. Contrary to earlier New Zealand data, good quality grasses were lower in I content than medium-value and inferior grasses. Small I dressings were less effective than larger amounts in terms of percentage return in the harvested crop; residual effects in later cuts were always small. The effectiveness of I dressings depended on soil type and tended to be lowest on soils of low natural I content. ADDITIONAL ABSTRACT: Studies were with ryegrass in pots and pastures. N dressing increased I uptake by the crop but reduced the I content considerably because of the diluting effect of higher DM yields. Dressing with fertilizers which did increase yield did not affect herbage I content consistently. Dicotyledonous species in pasture had I contents up to 13 times that of grasses. The I content of grasses varied over a 2-fold range but variation was smaller in a given species. Good quality grasses had a lower I content than inferior grasses. Smaller I dressings gave a smaller percentage return in the crop than larger amounts; the efficiency depended on soil type and tended to be less for soils with the lowest natural I content. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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Use of a simple model to study factors affecting the size distribution of tubers in potato crops

The Journal of Agricultural Science ◽

10.1017/s0021859600081788 ◽

1987 ◽

Vol 109 (3) ◽

pp. 563-571 ◽

Cited By ~ 15

Author(s):

K. Z. Travis

Keyword(s):

Mathematical Model ◽

Size Distribution ◽

Field Experiments ◽

Tuber Yield ◽

Tuber Size ◽

Simple Mathematical Model ◽

Factors Affecting ◽

Tuber Size Distribution ◽

Two Parameters ◽

Potato Crops

SummaryA simple mathematical model of the distribution of potato tuber yield between size grades is presented. It has two parameters, μ, a measure of crop tuber size and σ, a measure of the spread of yield across size grades. The model is shown to be useful for the analysis of field experiments, the prediction and physiological study of tuber size distribution, and the economic analysis of management decisions. The model is applied to a variety of dataandthe practical control of tuber size discussed.

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Trapping female cabbage root flies (Delia radicum (L.)) (Diptera: Anthomyiidae) with allylisothiocyanate-Baited traps

Bulletin of Entomological Research ◽

10.1017/s0007485300050392 ◽

1982 ◽

Vol 72 (1) ◽

pp. 165-173 ◽

Cited By ~ 5

Author(s):

S. Finch ◽

G. Skinner

Keyword(s):

Field Experiments ◽

Liquid Paraffin ◽

Point Sources ◽

Delia Radicum ◽

Brassica Crops ◽

Baited Traps ◽

Odour Plume

AbstractField experiments in England with traps baited with allylisothiocyanate (ANCS) showed that females of Delia radicum (L.) were distributed more or less evenly through established brassica crops. Reducing the quantity of ANCS released from the traps either by diluting the concentrate with liquid paraffin or by presenting the concentrate in Wädenswil dispensers reduced the numbers of females caught. There was no indication that ANCS became repellent, even when released at a rate of 24 ml/trap per day. For maximum effectiveness, the ANCS dispenser had to be placed at the centre rather than at the edge of the trap. Attempts to make traps more effective by releasing the ANCS from several point sources around a trap, in the hope that this broader odour plume would ‘ attract ’ more flies, were unsuccessful. The ANCS-baited trap had an effective zone only 5 m in radius.

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Factors Affecting the Toxicity of Glyphosate Applied in the Recirculating Sprayer to Johnsongrass (Sorghum halepense)and Soybeans (Glycine max)

Weed Science ◽

10.1017/s0043174500027776 ◽

1980 ◽

Vol 28 (1) ◽

pp. 59-63 ◽

Cited By ~ 2

Author(s):

C. G. McWhorter ◽

J. R. Williford

Keyword(s):

Glycine Max ◽

Field Experiments ◽

Sorghum Halepense ◽

Soybean Yield ◽

Factors Affecting ◽

Over The Top ◽

Uniform Droplet ◽

Better Than

Field experiments were conducted to determine optimum nozzle settings for applying glyphosate [N-(phosphonomethyl)glycine] in the recirculating sprayer for postemergence control of johnsongrass [Sorghum halepense(L.) Pers.] in soybeans [Glycine max(L.) Merr.]. Herbicide sprays were directed across the row to johnsongrass growing taller than soybeans in July and August. Herbicide not sprayed on johnsongrass was trapped and reused. Glyphosate at 0.56, 1.12, and 2.24 kg/ha applied with commercially available 25° spray nozzles provided johnsongrass control and soybean yields equal to those following applications with specialized uniform droplet nozzles. Glyphosate at 1.7 kg/ha applied in the recirculating sprayer using only one nozzle per row provided control of johnsongrass equal to or better than that from applications made with two, three, or four nozzles per row. Soybean yield following application of glyphosate at 1.7 kg/ha with one nozzle per row was equal to yields obtained following its application with two, three, or four nozzles per row, with or without surfactant at 0.1% in spray solutions. Soybean yield was higher with four nozzles per row than with one nozzle per row when 0.5% surfactant was included in spray solutions. Soybean injury was lower and yield was higher when glyphosate was applied in the recirculating sprayer rather than over-the-top with a conventional sprayer. Glyphosate at 1.12 kg/ha applied in the recirculating sprayer caused more injury to ‘Hill’ and ‘Bragg’ than to ‘Forrest’ or ‘Tracy’ soybeans.

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Responses of Red Flour Beetle Adults, Tribolium castaneum (Coleoptera: Tenebrionidae), and Other Stored Product Beetles to Different Pheromone Trap Designs

Insects ◽

10.3390/insects11110733 ◽

2020 ◽

Vol 11 (11) ◽

pp. 733

Author(s):

Carl W. Doud ◽

Thomas W. Phillips

Keyword(s):

Tribolium Castaneum ◽

Field Experiments ◽

Pitfall Trap ◽

Pheromone Trap ◽

Sticky Trap ◽

Red Flour Beetle ◽

Blow Down ◽

Trap Design ◽

Baited Traps ◽

Coleoptera Tenebrionidae

A series of laboratory and field experiments were performed to assess the responses of Tribolium castaneum (Herbst) and other stored-product beetles to pheromone-baited traps and trap components. A commercial Tribolium pitfall trap called the Flit-Trak M2, the predecessor to the Dome trap, was superior in both laboratory and field experiments over the other floor trap designs assessed at capturing walking T. castaneum. In field experiments, Typhaea stercorea (L.) and Ahasverus advena (Stephens) both preferred a sticky trap to the pitfall trap. Although the covered trap is effective at capturing several other species of stored product beetles, the synthetic Tribolium aggregation pheromone lure is critical for the pitfall trap’s efficacy for T. castaneum. Although the food-based trapping oil used in the pitfall trap was not found to be attractive to T. castaneum when assayed alone, it had value as an enhancer of the pheromone bait when the two were used together in the trap. A dust cover modification made to go over the pitfall trap was effective in protecting the trap from dust, although the trap was still vulnerable to dust contamination from sanitation techniques that used compressed air to blow down the mill floors. Capture of T. castaneum in the modified trap performed as well as the standard trap design in a non-dusty area of a flour mill, and was significantly superior over the standard trap in a dusty area. T. castaneum responded in flight outside a flourmill preferentially to multiple funnel traps with pheromone lures compared to traps without pheromone.

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Response of Chickpea to Nitrogen, and a Comparison of the Factors Affecting Chickpea Seed Yield with those Affecting Wheat Grain Yield

Experimental Agriculture ◽

10.1017/s0014479700024996 ◽

1995 ◽

Vol 31 (1) ◽

pp. 39-47 ◽

Cited By ~ 12

Author(s):

D. J. Bonfil ◽

M. J. Pinthus

Keyword(s):

Seed Development ◽

Seed Yield ◽

Dry Matter ◽

Growth Analysis ◽

Field Experiments ◽

Limiting Factors ◽

Wheat Grain ◽

Factors Affecting ◽

Wheat Grains ◽

Adjacent Field

SummaryChickpea yields in Israel are usually considerably lower than wheat yields under comparable conditions. This study aimed to examine the possible yield limiting factors in chickpeas. Increasing the availability of nitrogen during seed development by a pre-sowing application of nitrate or by nitrogen top dressing at the onset of flowering led to an increase in the percentage of nitrogen in the straw but had no significant effect on seed yield. Growth analysis of chickpeas and wheat grown in two adjacent field experiments revealed that during the fruiting period these crops accumulated similar amounts of dry matter. However, the proportion of total wheat dry matter accumulated in the wheat grains was twice the proportion of total chickpea dry matter accumulated in the chickpea seeds. It was concluded that the main intrinisic factor limiting the seed yield of chickpeas is the continuation of vegetative growth during the period of seed development, which reduces the amount of assimilate allocated to the seeds.Los factores restrictivos del rendimiento en el garbanzo

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Factors affecting the operation of the weed-sensing Detectspray system

Weed Science ◽

10.1017/s0043174500090287 ◽

1998 ◽

Vol 46 (1) ◽

pp. 127-131 ◽

Cited By ~ 11

Author(s):

Robert E. Blackshaw ◽

Louis J. Molnar ◽

Duane F. Chevalier ◽

C. Wayne Lindwall

Keyword(s):

Near Infrared ◽

Field Experiments ◽

Crop Residues ◽

Soil Surface ◽

Physical Factors ◽

Weed Detection ◽

Factors Affecting ◽

Green Foxtail ◽

Infrared Wavelengths ◽

Herbicide Use

Field experiments were conducted for 3 yr to determine the effect of various biological and physical factors on the operation of the weed-sensing Detectspray system. Plant detection is achieved by sensors measuring differential reflectance of red and near-infrared wavelengths of light from green plants, crop residues, and soil. Weed detection was greatly reduced 70 to 80 min after sunrise and before sunset when operated at lat 50°N because of reduced solar irradiance. Tall, dense-standing crop stubble limited detection of small weeds at the soil surface. Weed detection varied with plant species. Canola with three to four leaves consistently was detected, but wheat or green foxtail usually required five to six leaves to be detected. Small weeds were detected if present at densities greater than 70 plants m−2. Growers and commercial applicators need to be aware of the limitations of the Detectspray system to use it effectively to control weeds with concurrent reductions in herbicide use.

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