The effects of herbicides and plant growth regulators on Phymatotrichum omnivorum (Shear) Duggar /
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1990.
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| Subjects: | |
| Online Access: | ProQuest, Abstract Link to OAKTrust copy |
| Abstract: | Experiments were conducted to determine if herbicides or a seed safener that are applied during cotton and sorghum production affect the mycelial growth and sclerotial production of P. omnivorum. Other experiments investigated foliarly -applied, basipetally translocating herbicides and plant growth regulators abilities to reduce the incidence and severity of Phymatotrichum root rot (PRR). Effects of the chemicals on respiration, amino acid and carboxylic acid content of P. omnivorum mycelium were investigated. Most of the chemicals reduced mycelial growth a t 100.0 and 1000.0 ug ai/ml. Propazine had no effect at any concentration (0.1 to 100.0 ug ai/ml) and trifluralin increased sclerotial production at (0.1 ug/ml). From mycelial growth experiments, herbicides and/or plant growth regulators that move basipetally (fluazifop-butyl, sethoxydim, dicamba, benazolin, fosamine ammonium, imazapyr, imazaquin and dikegulac-sodium), and flurazole, a herbicide safener applied to seed, were selected to determine their effects on in situ sclerotial production and disease development of cotton in plexiglass cylinders called sclerotiatrons. Sclerotial yields were not statistically different than the control treatments. Cotton, in sclerotiatrons treated with flurazole, died more quickly than cotton in soil with any of the other treatments. Dicamba, propazine, prometryn, and trifluralin had little effect on sclerotial yield or disease incidence in crop rotations with sorghum and cotton in greenhouse tests. Propazine, trifluralin, benazolin, dicamba, flurazole, and kinetin, had no effect on respiration of P. omnivorum mycelium, whereas abscisic acid, (ABA) (10^-7,10^-5,10^-3M) reduced respiration. Amino acid and organic acid content of mycelium treated with imazaquin (0.01 ug ai/m l) benazolin (0.1 ug ai/m l), flurazole (1.0 ug ai/ml), trifluralin (0.1 ug ai/ml), propazine ( 0.1,1.0,10.0 ug ai/m l), and ABA or kinetin (10^-6M) were investigated. Propazine, imazaquin and benazolin showed the lowest amino acid content of treated mycelium, while levels of tyrosine and phenylalanine were highest in ABA and kinetin treated mycelium. Organic acid content of mycelium was reduced most by the absence of a nitrogen source. Mycelium grown in the highest level of trifluralin (10.0 ug ai/ml) had the lowest levels of ascorbic acid content and other organic acids. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Plant pathology." |
| Physical Description: | xiii, 138 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |