Comparison of Field Corn Varieties for Resistance to Corn Earworm and Stored Grain Insect Injury in the Everglades

Abstract

The literature on resistance of field corn varieties to attack by various insects has been extensively reviewed by Painter (1951, 1958). Dixie 18 has been described as the leading yellow hybrid of the southern Unite, States and possessing resistance to both the corn earworm, Heliothis zea (Boddie), and the rice weevil, Sitophilus oryza (L.) (Douglas and Eckhardt, 1957). Although Dixie 18 has been recommended and used widely throughout most of Florida (Horner, 1954), Corneli 54 has been found to be agronomically superior in south Florida and is widely used (Green, 1956; Green, Forsee, Thames, and Boyd, 1957). Green et al reported that Corneli 54 has much more resistance to corn earworm attack than Dixie 18 or Big Joe and is about equal in resistance to Francisco Flint. Horner recognized that although Dixie 18 was adaptable to north Florida, it was not suitable for south Florida. He presented no data on resistance to attack by insects. The authors conducted their studies on established varieties in an effort to find a variety suitable for cultivation in south Florida. Adaptability from the standpoint of insect attack was studied and the varieties were compared as to origin and yield of grain corn in bushels per acre (Table 1). Two field experiments were conducted in 1957 to compare several varieties (Table 1) for adaptability to culture in the Everglades. This included a study of varietal resistance to corn earworm and stored grain insect attack. The only stored grain insect causing noticeable damage was the rice weevil. Seed for the first experiment was planted on February 8 and that for the second on February 13, 1957, on Everglades peaty, muck soil that had been planted in corn every year for the preceding 15 years. Aldrin was applied for wireworm control at the rate of 5 pounds per acre before planting. Budworms were controlled by one application of DDT, 25'% emulsion concentrate at 1 quart, and two applications of toxaphene, 40% wettable powder, at 21/2 pounds per acre in 100 gallons of water. No insecticides were applied after the corn began to silk. Each plot consisted of a single 50 foot row. The rows were spaced three feet apart and plants were spaced one foot apart in the row. Each variety was replicated six times in each planting. Nine varieties were compared in the first planting and ten were compared in the second. Six of these varieties were compared in both experiments. The corn from both plantings was harvested, husked, and stored in mesh bags on July 24 in an open bin where it remained for approximately 61/2 weeks before it was examined for corn earworm and stored grain

Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗

The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.