Author
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Darrah, Larry |
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Submitted to: Pioneer Hibred International Brittle Snap Workshop
Publication Type: Abstract Only Publication Acceptance Date: 3/31/1999 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Stalk brittle snapping refers to snapping at a node from 30 to 60 cm above the ground when high winds occur. Brittle snapping usually happens when plants are turgid and during a window of susceptibility one to two weeks long, just before flowering. Working from a suggestion that density in the nodal plate area might be associated with brittle snapping, we evaluated a non-destructive method of measuring density by using gamma-ray attenuation Of six points measured on the stalk, only the measurement at 3rd node (1/8" above the nodal plate line) above ground level was consistent with test hybrid rankings for brittle snapping score. Lower density was associated with less brittle snapping. But, there should be a more highly correlated and far less time-consuming procedure. Thus, we fabricated a tractor- mounted device with ATV wheels/tires placed horizontally to bend the stalk as it passed between the offset wheels. The top wheel was powered by a finely-regulated hydraulic motor so as to match ground speed and the botto wheel was an idler. In operation, the idler wheel was kept against the row of stalks by using a guide bar mounted on the front of the tractor. Data observed in a cooperative study with Pioneer Hi-Bred International were in good agreement with their brittle snapping ratings. A correlation of brittle snapping score and percentage brittle snapping of r = -0.86* was obtained for combined data from three locations. Coefficients of variation of 22-26% were found across the three locations. With a high-boy carrier, the device can be effectively used for selection as well as hybrid characterization. |
