Thidiazuron: Effect of Applications on Boll Weevil and Bollworm Population Densities, Leaf Abscission, and Regrowth of the Cotton Plant1234

1980 ◽  
Vol 73 (6) ◽  
pp. 768-770 ◽  
Author(s):  
Alfred R. Hopkins ◽  
Raymond F. Moore
Keyword(s):  
Boll Weevil ◽  
Leaf Abscission ◽  
Population Densities

scholarly journals Evaluations Of Square Damage On Bollgard (Bt) Cotton, 1995

1996 ◽  
Vol 21 (1) ◽  
pp. 422-423
Author(s):  
Gene Burris ◽  
Don Cook ◽  
B. R. Leonard ◽  
J. B. Graves ◽  
J. Pankey
Keyword(s):  
Plant Height ◽  
Cotton Seed ◽  
Methyl Parathion ◽  
Boll Weevil ◽  
Compressed Air ◽  
Bt Cotton ◽  
Silt Loam ◽  
Population Densities ◽  
Loam Soil ◽  
Height Data

Abstract Plots were four rows (40-inch spacing) wide X 30 feet long and consisted of a randomized complete design with 4 replications. Cotton seed was planted on 15 May on a Commerce silt loam soil which was sidedress fertilized with 90 lb N/acre. Cotton seed was planted with a John Deere model 7100 series planter equipped with 10 inch seed cones mounted to replace the seed hoppers. The seed rate was 4 seeds/row ft. The granular in-furrow treatment (Temik 15G, 0.5 lb Al/acre) was applied with 8 inch belt cone applicators mounted to replace the standard granular applicators. Terraclor Super-X 2E, 2 quarts formulated/acre, was applied with a compressed air sprayer system attached to 2501 nozzles on the planter. The spray tips were positioned to thoroughly cover the sides and bottom of the seed furrow and were calibrated to deliver 5 GPA finished spray. Stand and plant height data were taken on 16 Jun (data not shown). BWTBW treatments (H. spp.) were applied to Coker 312 (Spray/H. spp.) and Bollgard­ (Spray/8%) on 17 Jul and 2, 10, 17, 24, and 31 Aug. Square and terminal infestation ratings were taken (larvae/25) on 3, 12, 17, 20, 24, 26 Jul and 1, 3, 9, and 14 Aug. Boll damage and foliage damage ratings were taken on 29 Aug. The test was conducted in the presence of high boll weevil population densities. Eight overspray treatments were used to control aphids, plant bugs, and boll weevils in all plots as follows: Provado 1.6F + Vydate 3.77L, 0.04 + 0.25 lb Al/acre, (20 June); Bidrin 8E + Ovasyn 1.5E, 0.4 + 0.25 lb Al/acre, (28 June); Guthion 2L, 0.25 lb Al/acre, (10 July); andMethyl parathion 4E, 0.33 lb Al/acre, (12 July); Methyl parathion 4E, 0.33 lb Al/acre, (28 July and 12, 18 August). Bollgard­ threshold treatments 2% and 5% were sprayed with Karate IE + Larvin 3.2F at 0.033 + 0.25 lb Al/acre on 10 August. Bollgard­ threshold treatments 2%, 5% and 8% were sprayed wit Baythroid 2E + Curacron 8E + Larvin 3.2Fat 0.04 + 1.0 + 0.4 lb Al/acre respectively (17 Aug). All Bollgard­ threshold treatments were sprayed with Methyl parathion 4E + Pirate 3SC + Curacron 8E at 0.33 + 0.25 + 1.0 lb Al/acre on 24 Aug.

GENETIC INSECT CONTROL METHODS INVOLVING THE RELEASE OF RELATIVELY FEW LABORATORY-REARED INSECTS

1971 ◽  
Vol 103 (10) ◽  
pp. 1387-1396 ◽  
Author(s):  
C. F. Wehrhahn ◽  
W. Klassen
Keyword(s):  
Boll Weevil ◽  
Insect Control ◽  
Control Methods ◽  
Agricultural Pests ◽  
Population Densities ◽  
Lethal Genes

AbstractSeveral genetic insect control methods are currently available, but they are practicable only when population densities are low.In this paper we describe ways of increasing the frequencies of dominant conditional lethal genes in populations. The proposed methods should be particularly valuable for the eradication of major agricultural pests controlled at present by frequent applications of insecticide.Eradication of boll weevil populations could be accomplished by the release of relatively small numbers of artificially reared insects. The number required can be less than it is for other proposed methods by a factor of 100 or more¡¡

Effects of Seed Treatments and a Soil-applied Nematicide on Corn Yields and Nematode Population Densities

2013 ◽  
Author(s):  
Gregory L. Tylka ◽  
Mychele Batista da Silva ◽  
Joel L. DeJong ◽  
Joshua L. Sievers ◽  
Ryan Rusk
Keyword(s):  
Nematode Population ◽  
Seed Treatments ◽  
Population Densities

Genetic Resistance to Boll Weevil Oviposition in Primitive Cotton 1

Crop Science ◽  
1987 ◽  
Vol 27 (2) ◽  
pp. 263-264 ◽  
Author(s):  
J. C. McCarty ◽  
J. N. Jenkins ◽  
W. L. Parrott
Keyword(s):  
Genetic Resistance ◽  
Boll Weevil

scholarly journals Boll Weevil Control Strategies: Regional Benefits and Costs

1977 ◽  
Vol 9 (1) ◽  
pp. 129-135 ◽  
Author(s):  
C. Robert Taylor ◽  
Ronald D. Lacewell
Keyword(s):  
Insect Pests ◽  
Control Strategies ◽  
Boll Weevil ◽  
Early Season ◽  
Trap Crops ◽  
Southern States ◽  
Baited Traps ◽  
Mexico Border ◽  
Benefits And Costs ◽  
The U.S

Throughout the southern states and at the federal level, much attention is being focused on the appropriate strategy for controlling cotton insect pests, particularly the boll weevil. This paper presents estimated economic impacts to farmers, regions and consumers of implementing three alternative boll weevil control strategies. One strategy evaluated is a proposed boll weevil eradication program which involves integrating many controls including insecticides, reproduction-diapause control by early season stalk destruction, pheromone-baited traps, trap crops, early season control with insecticide, and massive releases of sterile boll weevils. The plan is to eradicate the boll weevil in the U.S., and then indefinitely maintain a barrier at the U.S.-Mexico border to prevent future weevil immigration to the U.S.

scholarly journals High-Density Genetic Map Construction and Identification of QTLs Controlling Leaf Abscission Trait in Poncirus trifoliata

2021 ◽  
Vol 22 (11) ◽  
pp. 5723
Author(s):  
Yuan-Yuan Xu ◽  
Sheng-Rui Liu ◽  
Zhi-Meng Gan ◽  
Ren-Fang Zeng ◽  
Jin-Zhi Zhang ◽  
...  
Keyword(s):  
Qtl Mapping ◽  
Linkage Map ◽  
Genetic Map ◽  
Expression Patterns ◽  
High Density ◽  
Poncirus Trifoliata ◽  
Leaf Abscission ◽  
Comparative Genomic ◽  
Map Comparison ◽  
Genomic Studies

A high-density genetic linkage map is essential for genetic and genomic studies including QTL mapping, genome assembly, and comparative genomic analysis. Here, we constructed a citrus high-density linkage map using SSR and SNP markers, which are evenly distributed across the citrus genome. The integrated linkage map contains 4163 markers with an average distance of 1.12 cM. The female and male linkage maps contain 1478 and 2976 markers with genetic lengths of 1093.90 cM and 1227.03 cM, respectively. Meanwhile, a genetic map comparison demonstrates that the linear order of common markers is highly conserved between the clementine mandarin and Poncirus trifoliata. Based on this high-density integrated citrus genetic map and two years of deciduous phenotypic data, two loci conferring leaf abscission phenotypic variation were detected on scaffold 1 (including 36 genes) and scaffold 8 (including 107 genes) using association analysis. Moreover, the expression patterns of 30 candidate genes were investigated under cold stress conditions because cold temperature is closely linked with the deciduous trait. The developed high-density genetic map will facilitate QTL mapping and genomic studies, and the localization of the leaf abscission deciduous trait will be valuable for understanding the mechanism of this deciduous trait and citrus breeding.

scholarly journals Landscape heterogeneity buffers biodiversity of simulated meta-food-webs under global change through rescue and drainage effects

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Remo Ryser ◽  
Myriam R. Hirt ◽  
Johanna Häussler ◽  
Dominique Gravel ◽  
Ulrich Brose
Keyword(s):  
Habitat Fragmentation ◽  
Food Web ◽  
Food Webs ◽  
Landscape Heterogeneity ◽  
Landscape Connectivity ◽  
Biodiversity Loss ◽  
Mechanistic Explanation ◽  
Population Densities ◽  
Rescue Effect ◽  
Drainage Effect

AbstractHabitat fragmentation and eutrophication have strong impacts on biodiversity. Metacommunity research demonstrated that reduction in landscape connectivity may cause biodiversity loss in fragmented landscapes. Food-web research addressed how eutrophication can cause local biodiversity declines. However, there is very limited understanding of their cumulative impacts as they could amplify or cancel each other. Our simulations of meta-food-webs show that dispersal and trophic processes interact through two complementary mechanisms. First, the ‘rescue effect’ maintains local biodiversity by rapid recolonization after a local crash in population densities. Second, the ‘drainage effect’ stabilizes biodiversity by preventing overshooting of population densities on eutrophic patches. In complex food webs on large spatial networks of habitat patches, these effects yield systematically higher biodiversity in heterogeneous than in homogeneous landscapes. Our meta-food-web approach reveals a strong interaction between habitat fragmentation and eutrophication and provides a mechanistic explanation of how landscape heterogeneity promotes biodiversity.

scholarly journals The role of bacterial urease activity on the uniformity of carbonate precipitation profiles of bio-treated coarse sand specimens

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charalampos Konstantinou ◽  
Yuze Wang ◽  
Giovanna Biscontin ◽  
Kenichi Soga
Keyword(s):  
Calcium Carbonate ◽  
Calcium Chloride ◽  
Urease Activity ◽  
Coarse Sand ◽  
Carbonate Precipitation ◽  
Population Densities ◽  
Carbonate Cements ◽  
Microbially Induced Carbonate Precipitation

AbstractProtocols for microbially induced carbonate precipitation (MICP) have been extensively studied in the literature to optimise the process with regard to the amount of injected chemicals, the ratio of urea to calcium chloride, the method of injection and injection intervals, and the population of the bacteria, usually using fine- to medium-grained poorly graded sands. This study assesses the effect of varying urease activities, which have not been studied systematically, and population densities of the bacteria on the uniformity of cementation in very coarse sands (considered poor candidates for treatment). A procedure for producing bacteria with the desired urease activities was developed and qPCR tests were conducted to measure the counts of the RNA of the Ure-C genes. Sand biocementaton experiments followed, showing that slower rates of MICP reactions promote more effective and uniform cementation. Lowering urease activity, in particular, results in progressively more uniformly cemented samples and it is proven to be effective enough when its value is less than 10 mmol/L/h. The work presented highlights the importance of urease activity in controlling the quality and quantity of calcium carbonate cements.

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