During recent years especially, leaders in sugarcane borer control investigations have strongly advocated the utilization of seed stock which is as free from borer infestation as it is possible to secure. However, no actual studies measuring the effects of borer infestation in seed cane upon the resulting stands and yields during the following season had been made until 1928-1929. At this time a plantation field test was made with POJ. 213 cane, including three acres or more in each area, and using practically borer free seed in one field and all lightly infested seed cane in the other field. The following August there was found to be a decrease amounting to approximately 14% in the number of canes per 1000 row-feet. There was an excess amounting to 13.5% in the unoccupied ground or "skips" included in excess of three feet along the rows. At harvest time the lightly infested seed field averaged 9% less in weight of cane, or approximately three tons per acre less yield than in the borer free seed field. In 1931-1932 six varieties of cane were tested in a very detailed and accurate way at the Louisiana Sugar Experiment Station. Seed of each variety was selected for three classes of infestation, representing (1) practically borer "free," as based upon evidence of borer burrows in the cane, (2) "light" or "medium" infestation and (3) "heavy" infestation. Before the cane was covered, a close examination was made to determine the condition of eyes, the number of eyes planted, borer burrows, emergence holes, etc., in each plat. Replicated plats of 50 feet were used and the cane was planted single stalk and butt to tip. The rate of seed per acre required on this basis ranged from 1837 pounds with longest jointed, most slender type of cane, to 3240 pounds with the shortest jointed, heaviest stalks. The winter was exceedingly mild with no killing frost until March 6, 1932. In February there was a very evident decrease in germination or retardation in germination in the more heavily infested plats as compared with the borer free seed plats. There was a consistent trend in the direction of increase in "skips" (in this case taken as the excess above 18 inches space between stools) as infestation in the seed increased, and a correlating decrease in the number and total weight of millable stalks produced. The loss in yield, as computed from the plat to the per-acre basis, showed a loss ranging up to 8.5 tons per acre with the most susceptible variety. The more vigorous growing types of cane suffered less than those of medium-vigorous growth, but in all groups it is very evident that the increase of borer infestation in seed cane produces an important loss in following yields. The average loss in three varieties of medium vigorous growth was 17.5%, or over 4 tons per acre. With the three varieties of more vigorous growth the loss amounted to practically 21/2 tons, or an average of 7.1% of the yield secured in the borer free plats of the same varieties.
Document Type: Research Article
Publication date: October 1, 1933
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Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.