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Seed biology, economic impact, and interference characteristics of shattercane (Sorghum bicolor)
Abstract
Shattercane infested 63% of the irrigated and 43% of the nonirrigated corn fields in field surveys conducted in Nebraska in 1987, 1988, and 1989. Nonirrigated sorghum had 67% infestation compared to 53% for irrigated sorghum. Shattercane infestation in soybean fields was lowest at 30 and 29% of the irrigated and nonirrigated fields, respectively. Rotation of corn or sorghum into soybeans reduced shattercane infestation 9 and 20% compared to continuous corn or sorghum, respectively. Rectangular hyperbolic models were constructed to describe shattercane interference with corn, sorghum, and soybeans. Total crop loss from shattercane interference exceeded $14 million annually for thirty counties in Nebraska. Shattercane interference in irrigated soybeans was evaluated during 1987, 1988, and 1989 at Clay Center, Nebraska. Shattercane interference with soybeans began when shattercane height exceeded soybean height. Significant soybean yield loss occurred before the height differential reached 30 cm. Soybean nodes/stem, pods/stem, and beans/pod decreased as duration of interference increased. Soybean plant height, biomass, nodes/stem, pods/stem, pods/node, and beans/pod decreased as shattercane density increased. A shattercane interference model for estimation of soybean yield and economic loss was developed utilizing rectangular hyperbolic models. Shattercane seed survival during soil burial was highly dependent on attached glumes. Shattercane seed tightly enclosed by glumes averaged 5 and 53% germination after four months of winter burial in 1988 and 1989. Shattercane caryopsis survival averaged 0.5 and 17% compared to 17 and 41% when treated with seed fungicides. Shattercane caryopsis tannin and lignin content were significantly higher than for cultivated sorghum caryopsis. Glume tannin was four times higher and glume lignin was five times higher than in the caryopsis. Shattercane seed survival was positively correlated with glume tightness, caryopsis lignin, and glume tannin. Tannin and lignin appear to function as barriers to microbial invasion and moisture uptake resulting in higher shattercane seed resistance to overwinter seed demise. Attempts to isolate fungal inhibitors from shattercane seed were unsuccessful.
Subject Area
Agronomy
Recommended Citation
Fellows, Gary Milton, "Seed biology, economic impact, and interference characteristics of shattercane (Sorghum bicolor)" (1990). ETD collection for University of Nebraska-Lincoln. AAI9108220.
https://digitalcommons.unl.edu/dissertations/AAI9108220