Author
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Elmore, Carroll |
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Gibson, Darion |
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Submitted to: Proceedings of Southern Weed Science Society
Publication Type: Abstract Only Publication Acceptance Date: 1/25/1998 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Soybean isolines for the leaf pubescence characters dense, normal, and glabrous were studied for their comparative morphology by scanning electron microscopy (SEM) and for the effects of leaf pubescence on spray solution, contact angle, and droplet spread. Spray solutions of water, crop oil concentrate, two nonionic surfactants, and a paraffinic oil were used. Contact angle was determined with a goniometer and droplet spread was determined by computing area covered after deposition relative to initial droplet size. Observations by the SEM indicated that the glabrous leaf had normal appearing and a similar number of glandular trichomes, but the hairs were deformed and the leaf was crinkled. Dense leaves were similar to normal for glandular trichomes, but had over three times as many hairs. Water would not adhere to the leaf surface of either isoline for measurements of contact angle or droplet spread. For the crop oil concentrate, the contact angle was over 90 degrees and the spread coefficient was less than 1, indicating a droplet that beaded up and did not spread. Isolines did not differ among the nonionic surfactants with a spread coefficient of 2.5 and a contact angle of 45 degrees, but the nonionic surfactants were more easily applied than the crop oil concentrate. The paraffinic oil spread readily (75 times or greater) and produced a flat contact angle (10 degrees or less), which was statistically different from the other surfactants for spread coefficient. These effects were determined on mature, fully expanded leaves. |
