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Full-Text Articles in Entomology
Arthropod Populations And Rice Yields In Direct-Seeded And Transplanted Lowland Rice In West Africa, I. O. Oyediran, E. A. Heinrichs
Arthropod Populations And Rice Yields In Direct-Seeded And Transplanted Lowland Rice In West Africa, I. O. Oyediran, E. A. Heinrichs
Department of Entomology: Faculty Publications
Two methods for planting rice in irrigated lowland were evaluated during the wet seasons of 1994 and 1995 to determine their effect on rice arthropod numbers, insect-caused rice plant damage, and rice grain yield. The six treatments tested were: hand transplanting of seedlings at spacings of 14 cm × 14 cm, 20 cm × 20 cm, and 30 cm × 30 cm; and direct-seeding of rice at 60 kg seeds ha–1, 90 kg seeds ha–1, and 120 kg seeds ha–1. The most abundant arthropods in the study were the diopsid flies, Diopsis longicornis Maquart …
Response To Selection For Virulence Of Nephotettix Virescens (Homoptera: Cicadellidae) On Resistant Rice Cultivars, E. A. Heinrichs, H. R. Rapusas
Response To Selection For Virulence Of Nephotettix Virescens (Homoptera: Cicadellidae) On Resistant Rice Cultivars, E. A. Heinrichs, H. R. Rapusas
Department of Entomology: Faculty Publications
Rate of response to selection for Nephotettix virescens (Distant) virulence was studied for 20 generations on five rice cultivars with different levels of resistance. Rate of response to selection on all cultivars varied depending on the measurement criteria. Survival, growth, progeny production, and weight increased, and developmental period decreased, with selection time. Based on survival, the N. virescens population became highly virulent within one to four generations, whereas high virulence as measured by progeny production generally required more generations of selection. Virulence as measured by the ability to vector tungro virus also increased with selection time.