Hostname: page-component-78c5997874-mlc7c Total loading time: 0 Render date: 2024-11-06T02:41:30.970Z Has data issue: false hasContentIssue false
  • English
  • Français

Foliar Penetration of Herbicides—Review and Present Status

Published online by Cambridge University Press:  12 June 2017

H. B. Currier  and
C. D. Dybing
H. B. Currier
Affiliation:
Department of Botany, University of California, Davis
C. D. Dybing
Affiliation:
Department of Botany, University of California, Davis
Get access

Extract

Systemic herbicides applied to leaves must move from the leaf surface into uninjured phloem in sufficient quantity to be translocated throughout the plant. Contact herbicides must at least enter the leaf. Leaves of terrestrial plants are adapted to exchange of gases —water vapor, CO2, O2—but are not adapted to absorb foreign solutes in applied solutions and to translocate them systemically; insectivorous species and some water plants may be exceptions. Failure of herbicidal effectiveness often may be due to lack of penetration. However, selectivity towards herbicides is not clearly related to differential absorption (5, 82, 172, 176).

Type
Research Article
Information
Weeds , Volume 7 , Issue 2 , April 1959 , pp. 195 - 213
Copyright
Copyright © 1959 Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

1. Albert, A. Selective Toxicity. Methuen & Co., Ltd., London. 228 pp. 1951.Google Scholar
2. Antognini, J. The effect of temperature, relative humidity and wind on the control of Purslane with Aero Cyanate. Proc. Northeastern Weed Control Conf. 5:125–129. 1951.Google Scholar
3. Arisz, W. H. Significance of the symplasm theory for transport in the root. Protoplasma 46:5–62. 1956.Google Scholar
4. Arzt, T. Untersuchungen über das Vorkommen einer Kutikula in den Blättern dikotyler Pflanzen. Ber. deutsch. bot. Ges. 51:470–500. 1933.Google Scholar
5. Ashton, F. M. Absorption and translocation of radioactive 2,4–D in sugarcane and bean plants. Weeds 6:257–262. 1958.Google Scholar
6. Åslander, A. Sulfuric acid as a weed spray. J. Agr. Res. 34:1065–1091. 1927.Google Scholar
7. Bald, J. G. Stomatal droplets and the penetration of leaves by plant pathgens. Amer. J. Bot. 39:97–99. 1952.CrossRefGoogle Scholar
8. Bangham, D. H., and Lewis, F. J. Wettability of the cellulose walls of the mesophyll in the leaf. Nature 139:1107–8. 1937.Google Scholar
9. Barrier, G. E., and Loomis, W. E. Absorption and translocation of 2,4–dichlorophenoxyacetic acid and P32 by leaves. Plant Physiol. 32:225–231. 1957.CrossRefGoogle Scholar
10. Bauer, L. Zur Frage der Stoffbewegungen in der Pflanze mit besonderer Berücksichtigung der Wanderung von Fluorochromen. Planta 42:367–451. 1953.Google Scholar
11. Behrens, R. Influence of various components on the effectiveness of 2,4,5–T sprays. Weeds 5:183–196. 1957.Google Scholar
12. Bennett, S. H., and Thomas, W. D. E. Absorption, translocation and breakdown of Schradan applied to the leaves, using P32-labelled material. II. Evaporation and absorption. Ann. Appl. Biol. 41:484–500. 1954.Google Scholar
13. Blackman, G. E. The principles of selective toxicity and the action of selective herbicides. Science Prog. 150:637–651. 1950.Google Scholar
14. Blackman, G. E. Studies in the principles of phytotoxicity. J. Exp. Bot. 3:1–27. 1952.Google Scholar
15. Blair, B. O., and Fuller, W. H. Translocation of 2,4–dichloro–5–iodophenoxyacetic acid in velvet mesquite seedlings. Bot. Gaz. 113:368–372. 1952.Google Scholar
16. Boynton, D. Nutrition by foliar application. Ann. Rev. Plant Physiol. 5:31–54. 1954.Google Scholar
17. Brown, L. C. Chemical defoliation of cotton. VII. Effectiveness of adjuvants under several specific plant and environmental conditons. Agron. J. 49:563–566. 1957.Google Scholar
18. Buscalioni, L., and Pollacci, G. Ulteriori ricerche sull'applicazione delle pellicole die collodio allo studio di alcuni processi fisiologici delle piante ed in particular modo della transpirazione vegetale. Atti R. Istit. Bot. dell'universita di Pavia, 2. ser 7, 44. 1901.Google Scholar
19. Butterfass, T. Fluoroskopische Untersuchungen an Keulenhaaren von Vicia faba L. und Phaseolus coccineus L. Protoplasma 47:415–428. 1956.Google Scholar
20. Buvat, R. L'infrastucture des plasmodesmes et la continuité des cytoplasmes. Acad. des Sci. Compt. Rend. 245:198–201. 1957.Google Scholar
21. Colwell, R. N. The use of radioactive phosphorus in translocation studies. Amer. J. Bot. 29:798–807. 1942.CrossRefGoogle Scholar
22. Cook, J. A., and Boynton, D. Some factors affecting the absorption of urea by McIntosh apple leaves. Proc. Amer. Soc. Hort. Sci. 59:82–90. 1952.Google Scholar
23. Crafts, A. S. A theory of herbicidal action. Science 108:85–86. 1948.Google Scholar
24. Crafts, A. S. Movement of assimilates, viruses, growth regulators, and chemical indicators in plants. Bot. Rev. 17:203–284. 1951.Google Scholar
25. Crafts, A. S. Herbicides. Ann. Rev. Plant Physiol. 4:253–282. 1953.Google Scholar
26. Crafts, A. S. Herbicides, their absorption and translocation. Agric. and Food Chem. 1:51–55. 1953.Google Scholar
27. Crafts, A. S. Composition of the sap of xylem and phloem in and its relation to nutrition of the plant. Analyse des Plantes et Problèmes des Engrais minéraux. 8th International Bot. Cong., Paris. p. 18–21. 1954.Google Scholar
28. Crafts, A. S. Weed control: applied botany. Amer. J. Bot. 43:548–556. 1956.CrossRefGoogle Scholar
29. Crafts, A. S. Translocation of herbicides. I. The mechanism of translocation: methods of study with C14-labeled 2,4–D. Hilgardia 26:287–334. 1956.CrossRefGoogle Scholar
30. Crafts, A. S., Currier, H. B., and Drever, H. R. Some studies on the herbicidal properties of maleic hydrazide. Hilgardia 27:723–757. 1958.Google Scholar
31. Crafts, A. S. and Kennedy, P. B. The physiology of Convolvulus arvensis (morning-glory or bindweed) in relation to its control by chemical sprays. Plant Physiol. 3:329–334. 1930.Google Scholar
32. Crafts, A. S. and Reiber, H. G. Studies on the activation of herbicides. Hilgardia 16:487–500. 1945.Google Scholar
33. Crafts, A. S. and Yamaguchi, S. Comparative tests on the uptake and distribution of labeled herbicides by Zebrina pendula and Tradescantia fluminensis. Hilgardia 27:421–454. 1958.CrossRefGoogle Scholar
34. Currier, H. B. Wetting agents and other additives. Proc. 6th Calif. Weed Conf., Sacramento, pp. 10–15. 1954.Google Scholar
35. Currier, H. B. Greenhouse tests with maleic hydrazide and dalapon. Res. Prog. Rept., Western Weed Control Conf., pp. 46–47. 1954.Google Scholar
36. Currier, H. B. and Dybing, C. D. Pathways of foliar penetration. Res. Prog. Rept., Western Weed Control Conf., pp. 97–98. 1957.Google Scholar
37. Currier, H. B. and Peoples, S. A. Phytotoxicity of hydrocarbons. Hilgardia 23:155–173. 1954.Google Scholar
38. Currier, H. B. and Peoples, S. A. Callose substance in plant cells. Amer. J. Bot. 44:478–488. 1957.Google Scholar
39. Day, B. E. The absorption and translocation of 2,4–dichlorophenoxyacetic acid by bean plants. Plant Physiol. 27:143–152. 1952.Google Scholar
40. Dorschner, K. P., and Buchholtz, K. P. Wetting ability of aqueous herbicidal sprays as a factor influencing stands of alfalfa seedlings. Agron. J. 48:59–63. 1956.Google Scholar
41. Dunn, S., and Datta, S. C. Light effects on phytotoxicity with respect to herbicides. Proc. Northeastern Weed Control Conf. 10:246–251. 1956.Google Scholar
42. Dybing, C. D., and Currier, H. B. A fluorescence method in foliar penetration studies. Res. Prog. Rept., Western Weed Control Conf. p. 90. 1956.Google Scholar
43. Dybing, C. D., and Currier, H. B. A fluorescent dye method for foliar penetration studies. Plant Physiol. 32(Suppl.):xxxix. 1957.Google Scholar
44. Dybing, C. D., and Currier, H. B. A fluorescent dye method for foliar penetration studies. Weeds 7:214–222. 1959.Google Scholar
45. Eames, A. J., and MacDaniels, L. H. An Introduction to Plant Anatomy. McGraw-Hill Book Company, N. Y. 1947.Google Scholar
46. Ebeling, W. The role of surface tension and contact angle in the performance of spray liquids. Hilgardia 12:665–698. 1939.Google Scholar
47. Eckerson, S. H. The number and size of the stomata. Bot. Gaz. 46:221–224. 1908.Google Scholar
48. Englund, K. L. Atomic energy in agriculture. Agric. and Food Chem. 3:826–833. 1955.Google Scholar
49. Ennis, W. B. Jr. Influence of different carriers upon the inhibitory properties of growth-regulatory sprays. Weeds 1:43–47. 1951.Google Scholar
50. Ennis, W. B. Jr. and Boyd, F. T. The response of kidney-bean and soybean plants to aqueous spray applications of 2,4–dichlorophenoxyacetic acid with and without carbowax. Bot. Gaz. 107:552–559. 1946.Google Scholar
51. Ennis, W. B. Jr., Williamson, R. E., and Dorschner, K. P. Studies on spray retention by leaves of different plants. Weeds 1:274–286. 1952.CrossRefGoogle Scholar
52. Esau, K. Plant Anatomy. John Wiley and Sons, New York. 1953.Google Scholar
53. Esau, K., Currier, H. B., and Cheadle, V. I. Physiology of phloem. Ann. Rev. Plant Physiol. 8:349–374. 1957.Google Scholar
54. Fang, S. C., Freed, V. H., Johnson, R. H., and Coffee, D. R. Absorption, translocation, and metabolism of radioactive 3–(p–chlorophenyl)–1,1–dimethylurea (CMU) by bean plants. Agric. and Food Chem. 3:400–402. 1955.Google Scholar
55. Ferri, M. G., and Lex, A. Stomatal behavior as influenced by treatment with β–naphthoxyacetic acid. Contrib. Boyce Thompson Inst. 15:283–290. 1948.Google Scholar
56. Fisher, C. E., Meadors, C. H., and Behrens, R. Some factors that influence the effectiveness of 2,4,5–trichlorophenoxyacetic acid in killing mesquite. Weeds 4:139–147. 1956.Google Scholar
57. Fisher, E. G., and Walker, D. R. The apparent absorption of phosphorus and magnesium from sprays applied to the lower surface of McIntosh apple leaves. Proc. Amer. Soc. Hort. Sci. 65:17–24. 1955.Google Scholar
58. Fogg, G. E. The penetration of 3:5–dinitro-o-cresol into leaves. Ann. Appl. Biol. 35:315–330. 1948.CrossRefGoogle ScholarPubMed
59. Freed, V. H., and Montgomery, M. The effect of surfactants on foliar absorption of 3–amino–1,2,4–triazole. Weeds 6:386–389. 1958.Google Scholar
60. Freiberg, S. R., and Payne, P. Foliar absorption of urea and urease activity in banana plants. Proc. Amer. Soc. Hort. Sci. 69:226–234. 1957.Google Scholar
61. Frey, G. Aktivatät und Lokalisation von saurer Phosphatase in den vegetativen Teilen einiger Angiospermen und in einigen Samen. Ber. schweiz. bot. Ges. 64:390–452. 1954.Google Scholar
62. Garreau, M. Recherches sur l'absorption et l'exhalation des surfaces aeriennes des plantes. Ann. des Sci. Nat. Bot. Ser. III 13:321–346. 1849.Google Scholar
63. Gast, R., and Early, J. Phytotoxicity of solvents and emulsifiers used in insecticide formulations. Agric. Chemicals 11 (4):42–45, 136–137. 1956.Google Scholar
64. Gauch, H. G., and Duggar, W. M. Jr. The role of boron in the translocation of sucrose. Plant Physiol. 28:457–466. 1953.Google Scholar
65. Gauch, H. G., and Duggar, W. M. Jr. The physiological action of boron in higher plants: a review and interpretation. Maryland Agric. Exp. Sta. Bull. A–80 (Technical). 1954.Google Scholar
66. Gertsch, M. E. The influence of various carriers upon the inhibitory effectiveness of 2,4–D sprays. Weeds 2:33–42. 1953.Google Scholar
67. Gray, R. A. Increasing the absorption of streptomycin by leaves and flowers with glycerol. Phytopath. 46:105–111. 1956.Google Scholar
68. Gustafson, F. G. Absorption of Co80 by leaves of young plants and its translocation through the plant. Amer. J. Bot. 43:157–160. 1956.Google Scholar
69. Gustafson, F. G. Comparative absorption of cobalt–60 by upper and lower epidermis of leaves. Plant Physiol. 32:141–142. 1957.Google Scholar
70. Gustafson, F. G. and Schlessinger, M. J. Jr. Absorption of cobalt–60 by leaves of bean plants in the dark. Plant Physiol. 31:316–318. 1956.Google Scholar
71. Hamilton, J. M., and Palmiter, D. H. Orchard tests for apple scab control in New York State. I. Sulfur fungicides. N. Y. Agric. Exp. Sta. Bull. 747. 1951.Google Scholar
72. Hamm, P. C., and Speziale, A. J. Effect of variations in the acyl moiety on herbicidal activity of N-substituted alpha-chloroacetamides. Agric. and Food Chem. 5:30–36. 1957.Google Scholar
73. Hamner, C. L., Lucas, E. H., and Sell, H. M. The effect of different acidity levels on the herbicidal action of the sodium salt of 2,4–dichlorophenoxyacetic acid. Mich. Agric. Exp. Sta. Quart. Bull. 29:337–342. 1947.Google Scholar
74. Hansen, J. R., and Buchholtz, K. P. Absorption of 2,4–D by corn and pea seeds. Agron. J. 44:493–496. 1952.Google Scholar
75. Harley, C. P., Moon, H. H., and Regeimbal, L. O. Effects of the additive Tween 20 and relatively low temperatures on apple thinning by naphthaleneacetic acid sprays. Proc. Amer. Soc. Hort. Sci. 69:21–27. 1957.Google Scholar
76. Harley, C. P., Regeimbal, L. O., and Moon, H. H. Absorption of nutrient salts by bark and woody tissues of apple and subsequent translocation. Proc. Amer. Soc. Hort. Sci. 67:47–57. 1956.Google Scholar
77. Hauser, E. W. Penetration of 2,4–D compounds. Res. Rpt. North Central Weed Control Conf. 9:157. 1952.Google Scholar
78. Häusermann, E. Über die Benetzungsgrösse der Mesophyllinterzellularen. Schweiz bot. Ges. Ber. 54:541–578. 1944.Google Scholar
79. Hay, J. R. Translocation of herbicides in marabu. II. Translocation of 2,4–dichlorophenoxyacetic acid following foliage application. Weeds 4:349–356. 1956.Google Scholar
80. Helgeson, E. A. Effects of various 2,4–D concentrations and formulations on crop plants. Proc. North Central Weed Control Conf. 3:95. 1946.Google Scholar
81. Hitchcock, A. E., and Zimmerman, P. W. Activation of 2,4–D by various adjuvants. Contr. Boyce Thompson Inst. 15:173–193. 1948.Google Scholar
82. Holly, K. Penetration of chlorinated phenoxyacetic acids into leaves. Ann. Appl. Biol. 44:195–199. 1956.Google Scholar
83. Hopp, H., and Linder, P. J. Laboratory studies on glycerin as a supplement in water-soluble herbicidal sprays. Amer. J. Bot. 33:598–600. 1946.Google Scholar
84. Hull, H. M. Studies on herbicidal absorption and translocation in velvet mesquite (Prosopis) seedlings. Weeds 4:22–42. 1956.Google Scholar
85. Hull, H. M. Cuticle development in field- and greenhouse-grown mesquite, and its effect on overall herbicidal response. Weed Soc. Amer. Abs. 1958:37–38. 1958.Google Scholar
86. Hülsbruch, M. Die Wasserleitung in Parenchymen. Encyclopedia of Plant Physiology 3:522–540. 1956.Google Scholar
87. Jaworski, E. G., Fang, S. C., and Freed, V. H. Studies in plant metabolism of radioactive 2,4–D in etiolated bean plants. Plant Physiol. 30:272–275. 1955.Google Scholar
88. Kamerling, Z. Kleine Notizen. Deutsch. bot. Ges. Ber. 31:483–493. 1913.Google Scholar
89. Knight, H., Chamberlin, J. C., and Samuels, C. D. On some limiting factors in the use of saturated petroleum oils as insecticides. Plant Physiol. 4:299–321. 1929.Google Scholar
90. Koontz, H., and Biddulph, O. Factors affecting absorption and translocation of foliar applied phosphorus. Plant Physiol. 32:463–470. 1957.Google Scholar
91. Kuykendall, J. R., and Wallace, A. Absorption and hydrolysis of urea by detached citrus leaves immersed in urea solutions. Proc. Amer. Soc. Hort. Sci. 64:117–127. 1954.Google Scholar
92. Lambertz, P. Untersuchungen über das Vorkommen von Plasmodesmen in den Epidermisaussenwänden. Planta 44:147–190. 1954.Google Scholar
93. Laning, E. R. Jr., and Aldrich, R. J. Increasing the effectiveness of herbicides by the addition of wetting agents. Proc. Northeastern Weed Control Conf. 5:175–180. 1951.Google Scholar
94. LaRue, C. D. The water supply of the epidermis of leaves. Papers Michigan Acad. Sci. Arts and Letters 13:131–139. 1931.Google Scholar
95. Leonard, O. A. Studies of factors affecting the control of chamise (Adenostoma fasiculatum) with herbicides. Weeds 4:241–254. 1956.Google Scholar
96. Leonard, O. A. Studies on the absorption and translocation of 2,4–D in bean plants. Hilgardia 28:115–160. 1958.Google Scholar
97. Leonard, O. A. and Crafts, A. S. Translocation of herbicides. III. Uptake and distribution of radioactive 2,4–D by brush species. Hilgardia 26:366–415. 1956.Google Scholar
98. Lewis, F. J. Water movement in leaves. Faraday Soc. Discuss. 3:159–162. 1948.Google Scholar
99. Linder, P. J., Brown, J. W., and Mitchell, J. W. Movement of externally applied phenoxy compounds in bean plants in relation to conditions favoring carbohydrate translocation. Bot. Gaz. 110:628–632. 1949.CrossRefGoogle Scholar
100. Linkskens, H. F. Quantitative Bestimmung der Benetzbarkeit von Blattoberflächen. Planta 38:591–600. 1950.Google Scholar
101. Lucas, E. H., Felber, I. M., Hamner, C. L., and Sell, H. M. The effect of buffers on the growth inhibiting properties of sodium 2,4–dichlorophenoxyacetate. Mich. Agric. Exp. Sta. Quart. Bull. 30:289–297. 1948.Google Scholar
102. Mankowich, A. M. Physicochemical properties of surfactants. Ind. and Engineer. Chem. 45:2759–2766. 1953.CrossRefGoogle Scholar
103. Mason, T. G., and Maskell, E. J. Studies on the transport of carbohydrates in the cotton plant. I. A study of diurnal variation in the carbohydrates of leaf, bark, and wood, and the effects of ringing. Ann. Bot. 42:189–253. 1928.Google Scholar
104. McBain, J. W. Organization of crystals and micelles of soap; solubilization and detergency. In: Frontiers in Colloid Chemistry (Burk, R. E. and Grummit, O., editors) Chap. 6. Interscience Publ., New York. 1950.Google Scholar
105. Minshall, W. H., and Helson, V. A. The herbicidal action of oils. Div. Bot., Sci. Serv., Dominion Dept. Agric., Ottawa, Canada, Contrib. No. 959. 1948.Google Scholar
106. Minshall, W. H., and Helson, V. A. The herbicidal action of oils. Proc. Amer. Soc. Hort. Sci. 53:294–298. 1949.Google Scholar
107. Mirimanoff, A. Le comportement de la cellule végétale en présence de toxiques additionnés substances tensio-actives. Protoplasma 42:250–260. 1953.Google Scholar
108. Mitchell, J. W., and Brown, J. W. Movement of 2,4–dichlorophenoxyacetic acid stimulus and its relation to the translocation of organic food materials in plants. Bot. Gaz. 107:393–407. 1946.Google Scholar
109. Mitchell, J. W., Dugger, W. M., and Gauch, H. G. Increased translocation of plant-growth-modifying substances due to application of boron. Science 118:354. 1953.Google Scholar
110. Mitchell, J. W., Dugger, W. M., and Hamner, C. L. Polyethylene glycols as carriers for growth-regulating substances. Bot. Gaz. 105:474–483. 1944.Google Scholar
111. Mitchell, J. W., Dugger, W. M., and Linder, P. J. Absorption and translocation of radioactive 2,4–DI by bean plants as affected by cosolvents and surface agents. Science 112:54–55. 1950.Google Scholar
112. Mitchell, J. W., Dugger, W. M., and Linder, P. J. Absorption and translocation of plant regulating compounds. In: Atomic Energy and Agric., AAAS Symposium No. 49: 165–182. 1957.Google Scholar
113. Muir, R. M., and Hansch, C. Chemical constitution as related to growth regulator action. Ann. Rev. Plant Physiol. 6:157–176. 1955.Google Scholar
114. Neely, P. M., and Phinney, B. O. The use of the mutant dwarf–1 of maize as a quantitative bioassay for gibberellin activity. Plant Physiol. 32 (Suppl.) xxxi. 1957.Google Scholar
115. Nelson, C. D., and Gorham, P. R. Uptake and translocatíon of C14-labelled sugars applied to primary leaves of soybean seedlings. Canadian J. Bot. 35:339–347. 1957.Google Scholar
116. Norman, A. G., Minarik, C. E., and Weintraub, R. L. Herbicides. Ann. Rev. Plant Physiol. 1:141–168. 1950.Google Scholar
117. Normand, W. C. Studies of some effects of herbicides on cotton. Diss. Abs. 15:1989. 1955.Google Scholar
118. Orgell, W. H. The isolation of plant cuticle with pectic enzymes. Plant Physiol. 30:78–80. 1955.Google Scholar
119. Orgell, W. H. Sorptive properties of plant cuticle. Proc. Iowa Acad. Sci. 64:189–198. 1957.Google Scholar
120. Orgell, W. H. and Weintraub, R. L. Influence of some ions on foliar absorption of 2,4–D. Bot. Gaz. 119:88–93. 1957.Google Scholar
121. Palmiter, D. H., Roberts, E. A., and Southwick, M. D. Apple leaf structure in relation to penetration by spray solutions. (Abstract). Phytopathology 36:681. 1946.Google Scholar
122. Rademacher, B. Verstärkung der Herbizidwirkung durch vorherige Verletzung der Unkräuter am Beispiel von Colchicum autumnale L. Z. für Pflanzenkrankheiten und Pflanzenschutz 62:605–611. 1955.Google Scholar
123. Absorption and translocation of ammonium 2,4–dichlorophenoxyacetate by bean plants. Bot. Gaz. 109:301–314. 1948.Google Scholar
124. Harley, C. P. and Rohrbaugh, L. M. Effect of kerosene on movement of 2,4–dichlorophenoxyacetic acid and some derivatives through destarched bean plants in darkness. Bot. Gaz. 115:76–81. 1953.Google Scholar
125. Rich, S., and Horsfall, J. G. The relation between fungitoxicity, permeation, and lipid solubility. Phytopath. 42:457–460. 1952.Google Scholar
126. Roberts, E. A., Southwick, M. D., and Palmiter, D. H. A microchemical examination of McIntosh apple leaves showing relationship of cell wall constituents to penetration of spray solutions. Plant Physiol. 23:557–559. 1948.Google Scholar
127. Rodney, D. R. The entrance of nitrogen compounds through the epidermis of apple leaves. Proc. Amer. Soc. Hort. Sci. 59:99–102. 1952.Google Scholar
128. Rohrbaugh, P. W. Penetration and accumulation of petroleum spray oils in the leaves, twigs, and fruit of citrus trees. Plant Physiol. 9:699–730. 1934.Google Scholar
129. Rohrbaugh, P. W. and Rice, E. L. Effect of application of sugar on the translocation of sodium 2,4–dichlorophenoxyacetate by bean plants in the dark. Bot. Gaz. 111:85–89. 1949.Google Scholar
130. Rouschal, E., and Strugger, S. Der fluoreszenzoptisch-histochemische Nachweis der Kutikularen Rekretion und des Salzweges im Mesophyll. Ber. deut. bot. Gesell. 58:50–69. 1940.Google Scholar
131. Rudolph, K. Epidermis und epidermale Transpiration. Bot. Arch. 9:49–94. 1925.Google Scholar
132. Santelmann, P. W., and Willard, C. J. The absorption and translocation of dalapon. Res. Rpt. North Central Weed Control Conf. 11:159–160. 1954.Google Scholar
133. Schieferstein, R. H., and Loomis, W. E. Wax deposits on leaf surfaces. Plant Physiol. 31:240–247. 1956.Google Scholar
134. Schieferstein, R. H., and Loomis, W. E. Leaf surfaces and herbicide penetration. Res. Rpt. North Central Weed Control Conf. 14:168. 1957.Google Scholar
135. Schumacher, W. Ueber plasmodesmenartige Strukturen in Epidermisaussenwänden. Jahrb. f. wiss. Bot. 90:530–545. 1942.Google Scholar
136. Schumacher, W. and Lambertz, P. Über die Beziehungen zwischen der Stoffaufnahme durch Blattepidermen und der Zahl der Plasmodesmen in den Aussenwänden. Planta 47:47–52. 1956.Google Scholar
137. Scott, F. M. Internal suberization of tissues. Bot. Gaz. 111:378–394. 1950.Google Scholar
138. Scott, F. M., Hamner, K. C., Baker, E., and Bowler, E. Electron microscope studies of the epidermis of Allium cepa. Amer. J. Bot. 45:449–461. 1958.Google Scholar
139. Scott, F. M., Hamner, K. C., Baker, E., and Bowler, E. Electron microscope studies of cell wall growth in the onion root. Amer. J. Bot. 43:313–324. 1956.Google Scholar
140. Scott, F. M., and Lewis, M. Pits, intercellular spaces, and internal “suberization” in the apical meristems of Ricinus communis and other plants. Bot. Gaz. 114:253–264. 1953.Google Scholar
141. Scott, F. M., Schroeder, M. R., and Turrell, F. M. Development, cell shape, suberization of internal surface, and abscission in the leaf of the Valencia orange, Citrus sinensis . Bot. Gaz. 109:381–411. 1948.Google Scholar
142. Silversides, W. H. The rate and mode of penetration of herbicides. I. Copper nitrate solutions. Sci. Agric. 20:419–423. 1940.Google Scholar
143. Simon, E. W., Roberts, H. A., and Blackman, G. E. III. Studies on the principles of phytotoxicity. The pH factor and the toxicity of 3,5–dinitro–o–cresol, a weak acid. J. Exp. Bot. 3:99–109. 1952.Google Scholar
144. Sivadjian, J. Action du glycérol sur la transpiration des feuilles et sur la permeabilité cuticulaire. Acad. des Sci. Compt. Rend. 242:2478–2479. 1956.Google Scholar
145. Skogley, C. R. The influence of wetting agents on the phytotoxicity of several herbicides. Proc. Northeastern Weed Control Conf. 8:293–299. 1954.Google Scholar
146. Skoss, J. D. Structure and composition of plant cuticle in relation to environmental factors and permeability. Bot. Gaz. 117:55–72. 1955.Google Scholar
147. Staniforth, D. W., and Bryan, A. M. Absorption of 2,4–D by leaves. Res. Rpt. North Central Weed Control Conf. 7:276–7. 1950.Google Scholar
148. Staniforth, D. W., and Loomis, W. E. Surface action in 2,4–D sprays. Science 109:628–629. 1949.Google Scholar
149. Steubing, L. Beiträge zur Tauwasser-aufnahme höherer Pflanzen. Biol. Zentr. 68:252–259. 1949.Google Scholar
150. Stout, P. R., and Hoagland, D. R. Upward and lateral movement of salt in certain plants as indicated by radioactive isotopes of potassium, sodium, and phosphorus absorbed by roots. Amer. J. Bot. 26:320–324. 1939.Google Scholar
151. Strugger, S. Fluoreszenzmikroskopische Untersuchungen über die Speicherung und Wanderung des Fluorescein-Kaliums in pflanzlichen Geweben. Flora 132:253–304. 1938.Google Scholar
152. Strugger, S. Die lumineszenzmikroskopische Analyse des Transpirationsstromes in Parenchymen. Biol. Zbl. 59:409–442. 1939.Google Scholar
153. Strugger, S. Elektronenmikroskopische Beobachtungen an den Plasmodesmen des Urmeristems der Wurzelspitze von Allium cepa; ein Beitrag zur Kritik der Fixation und zur Beurteilung elektronenmikroskopischer Grössenangaben. Protoplasma 48:365–367. 1957.Google Scholar
154. Swanson, C. A., and Whitney, J. B. Jr. Studies on the translocation of foliar-applied P32 and other radioisotopes in bean plants. Amer. J. Bot. 40:816–823. 1953.Google Scholar
155. Swets, W. A., and Addicott, F. T. Experiments in the physiology of defoliation, Proc. Amer. Soc. Hort. Sci. 65:291–295. 1955.Google Scholar
156. Switzer, C. M., and Bibbey, R. O. The additive effect of urea on the physiological activity of 2,4–D acid. Res. Rpt. North Central Weed Control Conf. 10:164. 1953.Google Scholar
157. Szabo, S. S., and Buchholtz, K. P. Effect of ionic additives on the activity of 2,4–D when applied to soybeans. Res. Rpt. North Central Weed Control Conf. 12:185–186. 1955.Google Scholar
158. Szabo, S. S., and Buchholtz, K. P. The effect of ionic additives upon the penetration of 2,4–D relative to living and non-living surfaces. Weed Soc. of Amer. Abs., pp. 43–44. 1958.Google Scholar
159. Teubner, F. G., Wittwer, S. H., Long, W. G., and Tukey, H. B. Some factors affecting absorption and transport of foliar applied nutrients as revealed by radioactive isotopes. Mich. Agric. Exp. Sta. Q. B. 39:398–415. 1957.Google Scholar
160. Thimann, K. V. Use of 2,4–dichlorophenoxyacetic acid herbicides on some woody tropical plants. Bot. Gaz. 109:334–340. 1948.Google Scholar
161. Turrell, F. M. The area of the internal exposed surface of dicotyledon leaves. Amer. J. Bot. 23:255–264. 1936.Google Scholar
162. Turrell, F. M. Citrus leaf stomata: structure, composition, and pore size in relation to penetration of liquids. Bot. Gaz. 108:476–483. 1947.Google Scholar
163. van Overbeek, J. Studies on the relation between molecular structure and penetration of growth regulators into plants. In: Wain, R. L., and Wightman, F., (editors), The Chemistry and Mode of Action of Plant Growth Regulators. Pages 205–210. 1956.Google Scholar
164. van Overbeek, J. Absorption and translocation of plant regulators. Ann. Rev. Plant Physiol. 7:355–372. 1956.Google Scholar
165. van Overbeek, J. and Blondeau, R. Mode of action of phytotoxic oils. Weeds 3:55–65. 1954.Google Scholar
166. Veldstra, H. The relation of chemical structure to biological activity in growth substances. Ann. Rev. Plant Physiol. 4:151–198. 1953.Google Scholar
167. Volk, R., and McAuliffe, C. Factors affecting the foliar absorption of N15 labeled urea by tobacco. Proc. Soil Sci. Soc. Amer. 18:308–312. 1954.Google Scholar
168. Wallihan, E. F., and Heymann-Herschberg, L. Some factors affecting absorption and translocation of zinc in citrus plants. Plant Physiol. 31:294–299. 1956.Google Scholar
169. Wanner, H. Phosphataseverteilung und Kohlenhydrattransport in der Pflanze. Planta 41:190–194. 1952.CrossRefGoogle Scholar
170. Weaver, R. J., and DeRose, H. R. Absorption and translocation of 2,4–dichlorophenoxyacetic acid. Bot. Gaz. 107:509–521. 1946.Google Scholar
171. Weaver, R. J., Minarik, C. E., and Boyd, F. T. Influence of rainfall on the effectiveness of 2,4–dichlorophenoxyacetic acid sprayed for herbicidal purposes. Bot. Gaz. 107:540–544. 1946.Google Scholar
172. Weintraub, R. L. Relation of chemical structure to herbicidal action. Weed Soc. Amer. Abs. 1956:41–42. 1956.Google Scholar
173. Weintraub, R. L. and Brown, J. W. Translocation of exogenous growth-regulators in the bean seedling. Plant Physiol. 25:140–149. 1950.Google Scholar
174. Weintraub, R. L., Yeatman, J. N., Brown, J. W., Throne, J. A., Skoss, J. D., and Conover, J. R. Studies on entry of 2,4–D into leaves. Proc. Northeastern Weed Control Conf. 8:5–10. 1954.Google Scholar
175. Went, F. W., and Carter, M. Growth response of tomato plants to applied sucrose. Amer. J. Bot. 35:95–106. 1948.Google Scholar
176. Williams, M. C. Absorption and translocation of 2,4–dichlorophenoxyacetic acid in certain annual dicotyledons. Diss. Abs. 16:1771. 1956.Google Scholar
177. Wittwer, S. H. Nutrient uptake, with special reference to foliar absorption. In: Atomic Energy and Agric., AAAS Symposium No. 49:139–164. 1957.Google Scholar
178. Woodford, E. K., Holly, K., and McCready, C. C. Herbicides. Ann. Rev. Plant Physiol. 9:311–358. 1958.Google Scholar
179. Wylie, R. B. The role of the epidermis in foliar organization and its relations to the minor venation. Amer. J. Bot. 30:273–280. 1943.Google Scholar
180. Young, D. W. Toxicity and translocation of herbicides. Iowa State College Jour. Sci. 28:424–425. 1954.Google Scholar
181. Zukel, J. W., Smith, A. E., Stone, G. M., and Davies, M. E. Effect of some factors on rate of absorption of maleic hydrazide. Plant Physiol. 31 (suppl.):xxi. 1956.Google Scholar
182. Ziegenspeck, H. Fluoroskopische Versuche an Blättern, über Leitung, Transpiration, und Abscheidung von Wasser. Biol. Gen. (Vienna) 18:254–326. 1945.Google Scholar