scholarly journals A Field Test of Corn Cultivars for Insect and Disease Resistance

1969 ◽  
Vol 61 (3) ◽  
pp. 319-325
Author(s):  
O. J. Webster ◽  
D. W. Walker
Keyword(s):  
Puerto Rico ◽  
Disease Resistance ◽  
Field Test ◽  
Corn Earworm ◽  
Pests And Diseases ◽  
Corn Silk ◽  
Sugarcane Borer ◽  
Pest Infestation ◽  
Corn Crop ◽  
Corn Pests

Eighteen corn cultivars were tested for resistance to three corn pests (corn earworm, sugarcane borer, and corn silk maggot), and two diseases (corn rust and corn blight) at Mayagüez, Puerto Rico. Armyworm control with methomyl was necessary to produce a corn crop. Eighteen cultivars from Georgia were less resistant to pests and diseases than Mayorbela, Ibadan A, and Ibadan B. Significant differences were found between sprayed and unsprayed plots in yield and pest infestation.

scholarly journals Spatial and temporal distribution of Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) and Euxesta spp. (Diptera: Otitidae) in the corn crop

2021 ◽  
Vol 14 ◽  
pp. e919
Author(s):  
Jessica Vasconcelos Ferreira ◽  
Ivan Carlos Fernandes Martins ◽  
Raiana Rocha Pereira ◽  
Rayane Rocha Pereira ◽  
Mateus Higo Daves Alves ◽  
...  
Keyword(s):  
Spatial Dependence ◽  
Helicoverpa Zea ◽  
Reproductive Period ◽  
Corn Earworm ◽  
Spatial Behavior ◽  
Sample Population ◽  
Distribution Models ◽  
Corn Silk ◽  
Corn Crop ◽  
Area Of Influence

The aim of this study was to verify the pattern and the spatial and temporal behavior of the corn earworm and corn-silk fly in the corn crop. Hybrid corn was planted without chemical insect control in one hectare, this area was divided into 100 plots of 100 m². For the occurrence of Euxesta spp. all parts of the plants were visually analyzed, whereas for Helicoverpa zea (Boddie) 10 ears were removed at random from each plot, totaling 1,000 ears per sample. Population fluctuation was related to the phenological stages of corn. For spatial behavior, the dispersion indices, frequency distribution models and geostatistics (Krigagem) were analyzed. The corn earworm (small and large) and corn-silk fly showed aggregate pattern and spatial behavior. The reach of caterpillars <1 cm had an area of influence greater than caterpillars > 1 cm, with spatial dependence being considered moderate. The corn-silk fly had a maximum area of influence of 1.33 ha with moderate and weak spatial dependence. The maps demonstrated that these insects occur dispersed throughout the corn area, but with aggregations influenced by the adjacent areas and edges of the crop. The largest occurrence of corn earworms was at the R3 stage. It was also found that the corn-silk fly followed the occurrence of the corn earworm. It is concluded that the studied pests have an aggregate spatial tendency in the corn crop and with the influence of adjacent areas, in addition to presenting related population peaks in the reproductive period of the corn crop.

scholarly journals Breeding for Flue – Cured Tobacco (Nicotiana Tabacum L) Foliar Pest and Disease Resistance in Zimbabwe: A Review

2019 ◽  
Author(s):  
Justify Gotami Shava ◽  
Susan Richardson Kageler ◽  
Shorai Dari ◽  
Frank Magama ◽  
Dzingai Rukuni
Keyword(s):  
Disease Resistance ◽  
Nicotiana Tabacum ◽  
Financial Resources ◽  
Early 20Th Century ◽  
Quality Loss ◽  
Pests And Diseases ◽  
Field Crops ◽  
Yield And Quality ◽  
Nicotiana Tabacum L ◽  
The World

Since its introduction to Zimbabwean farmers in the early 20th Century, flue –cured tobacco has grown to become one of the most profitable field crops to cultivate in the country. However, pests and diseases have been reported as some of the major contributors to yield and quality loss in the business of tobacco farming in Zimbabwe and across the world reducing the profitability of the tobacco business. This has resulted in large sums of financial resources being invested in research aimed at controlling pests and diseases in different crops. In Zimbabwe millions of litres of pesticides have been pumped into the environment in an effort to control pests and diseases in flue-cured tobacco fields. There have also been efforts to incorporate inherent pest and disease resistance in the varieties of flue-cured tobacco developed in the country since the early 1940s. This paper is a review of the breeding efforts to incorporate pest and disease resistance in the elite flue-cured tobacco germplasm used to develop some of the popular varieties in Zimbabwe.

scholarly journals Effects of silicon amendment on the occurrence of rice insect pests and diseases in a field test

2018 ◽  
Vol 17 (10) ◽  
pp. 2172-2181 ◽  
Author(s):  
Yong-qiang HAN ◽  
Ji-hui WEN ◽  
Zhao-pu PENG ◽  
De-yong ZHANG ◽  
Mao-lin HOU
Keyword(s):  
Field Test ◽  
Insect Pests ◽  
Pests And Diseases ◽  
Rice Insect Pests

Control of the Sugarcane Borer in Puerto Rico by Laboratory-Reared Parasites.

1943 ◽  
Vol 36 (3) ◽  
pp. 460-464
Author(s):  
George N. Wolcott ◽  
Luis F. Martorell
Keyword(s):  
Puerto Rico ◽  
Sugarcane Borer

Sequential sampling plan for corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), in corn fields on the south coast of Puerto Rico.

1969 ◽  
Vol 92 (3-4) ◽  
pp. 207-214
Author(s):  
Lymari M. Calero-Toledo ◽  
Raúl Macchiavelli ◽  
Ángel L. González
Keyword(s):  
Puerto Rico ◽  
Helicoverpa Zea ◽  
Sequential Sampling ◽  
Corn Earworm ◽  
Sampling Plan ◽  
South Coast ◽  
Effective Control ◽  
The South ◽  
Sequential Sampling Plan ◽  
Corn Fields

The corn earworm, Helicoverpa zea (Boddie), is the major insect pest of corn, Zea mays L., in Puerto Rico. The objective of this study was to design a sequential sampling plan with fixed precision levels for H. zea (Boddie) in corn fields on the south coast of Puerto Rico. For determining the presence (= 1) or absence (= 0) of H. zea eggs, 25 corn plants were randomly sampled from December 2003 to March 2004. Data were analyzed by using the beta binomial distribution. Critical density levels of 0.10 and 0.08 infested plants, before and after the emergence of ear silks, were used for Iwao's and converging lines formulae. A converging line sampling plan is recommended because it selected a smaller average sample size. This plan can be used to make cost effective control decisions on field corn in Puerto Rico.

scholarly journals Managing the Sugarcane Borer,Diatraea saccharalis, and Corn Earworm,Helicoverpa zea, using Bt Corn and Insecticide Treatments

2013 ◽  
Vol 13 (109) ◽  
pp. 1-10 ◽  
Author(s):  
Juliano R. Farias ◽  
Ervandil C. Costa ◽  
Jerson V. C. Guedes ◽  
Alessandro P. Arbage ◽  
Armando B. Neto ◽  
...  
Keyword(s):  
Helicoverpa Zea ◽  
Corn Earworm ◽  
Bt Corn ◽  
Sugarcane Borer ◽  
Diatraea Saccharalis

Corn Earworm Larval Feeding Response to Corn Silk and Kernel Extracts

1965 ◽  
Vol 58 (1) ◽  
pp. 74-76 ◽  
Author(s):  
K. J. Starks ◽  
W. W. McMillian ◽  
A. A. Sekul ◽  
H C Cox
Keyword(s):  
Corn Earworm ◽  
Larval Feeding ◽  
Feeding Response ◽  
Corn Silk

scholarly journals THE INTRODUCTION OF PARASITES OF THE SUGARCANE BORER INTO PUERTO RICO

1969 ◽  
Vol 21 (2) ◽  
pp. 237-241
Author(s):  
S. M. Dohanian
Keyword(s):  
Puerto Rico ◽  
Laboratory Work ◽  
Sugarcane Borer ◽  
Diatraea Saccharalis ◽  
Actual Field ◽  
American Tropics

Search for the parasites of the sugarcane borer (Diatraea saccharalis Fab.) was conducted in five countries in the American Tropics, in three of which actual field and laboratory work was performed. Three dipterous and two hymenopterous parasites were found and shipped to Puerto Rico and Florida, the former receiving 19,063 adults and the latter 3,142. The shipments to Puerto Rico comprised 8,296 flies and 10,767 wasps, while the shipments to Florida totaled 314 flies and 2,828 wasps.

Sign in / Sign up

Export Citation Format

Share Document