Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-29T00:26:48.740Z Has data issue: false hasContentIssue false
  • English
  • Français

Jassid Resistance and Hairiness of the Cotton Plant

Published online by Cambridge University Press:  10 July 2009

F. R. Parnell ,
H. E. King  and
D. F. Ruston
F. R. Parnell
Affiliation:
Empire Cotton Growing Corporation, Cotton Experiment Station, Barberton, South Africa.
H. E. King
Affiliation:
Empire Cotton Growing Corporation, Cotton Experiment Station, Barberton, South Africa.
D. F. Ruston
Affiliation:
Empire Cotton Growing Corporation, Cotton Experiment Station, Barberton, South Africa.
Get access Rights & Permissions [Opens in a new window]

Extract

A wide range of material has been studied in an investigation of the relationship between “resistance” to attack by Empoasca facialis and “hairiness” of the cotton plant.

A continuous range has been found between full susceptibility and very high resistance.

In general relative susceptibility, as gauged by visual assessment of symptoms, has been found to correspond closely with relative infestation, determined by counts of nymphs.

With attention confined to grown plants, the relative susceptibility of varieties has been found substantially constant under varying levels of exposure to infestation.

Hairiness of the cotton plant has been found to show an extremely wide range in degree, style and distribution. A method has been devised for expressing hairiness numerically, taking into account both length and density of hairs.

A very close and consistent relationship has been found between degree of hairiness of the under surface of the leaf, and degree of resistance to Jassid. Without exception, all thoroughly hairy types have been found highly resistant, and all non-hairy types fully susceptible. Intermediate degrees of hairiness ate associated with intermediate degrees of resistance.

The relationship has been found to hold good between varieties and between plants within varieties, of the species G. hirsutum; also between plants of G. barbadense, and in segregating progenies of hybrids between these two species.

The hairiness of resistant strains of cotton has been found to develop gradually with the growth of the plant; the first few leaves on the seedlings being virtually non-hairy. This lack of hairiness in the early stages of growth is associated with a lack of resistance. Hairiness and resistance to Jassid develop concurrently.

The conclusion is reached that hairiness of the leaf confers resistance to Jassid and that degree of leaf hairiness, measured in an appropriate manner, is a thoroughly reliable guide to degree of resistance.

Length of hairs is shown to be of prime importance, and high densities without adequate length are ineffective.

The relative importance of hairs on lamina and midrib has not been conclusively determined. Both have an influence on resistance but a high degree of midrib hairiness is not essential if the lamina is hairy.

Hairs on stem and petiole are shown to be of very little direct importance.

Type
Original Articles
Information
Bulletin of Entomological Research , Volume 39 , Issue 4 , March 1949 , pp. 539 - 575
Copyright
Copyright © Cambridge University Press 1949

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

Afzal, M. (1941). Present position as regards breeding for Jassid resistance in cotton.—Publ.Indian cent. Cott. Comm., 2nd Conf. sci. Res. Wkrs. India.Google Scholar
Afzal, M. & Manzoor, Abbas. (1944). Cotton Jassid (E. devastans Dist.) in the Punjab. V. A. note on the characters of the plant associated with Jassid resistance.—Indian J. Ent., 5, pp. 41–51.Google Scholar
Husain, M. A. (1938). The cotton Jassid.— Publ. Indian cent. Cott. Comm., 1st Conf. sci. Res. Wkrs. India.Google Scholar
Husain, M. A. & Lal, K. B. (1940). The bionomics of Empoasca devastans Distant on some varieties of cotton in the Punjab.—Indian J. Ent., 2, pp. 123–136.Google Scholar
King, H. E. & Ruston, D. F. (1945). Progr. Rep. Exp. Stas Emp. Cott. Gr. Corp., 1943–44, p. 36.Google Scholar
Lal, K. B. (1941). Cotton Jassids and their control.—Indian Fmg., 11, p. 465.Google Scholar
Lal, K. B. & Husain, M. A. (1945). Hairiness of cotton leaves and anti-Jassid resistance.—Curr. Sci., 14, pp. 153–154.Google Scholar
MacDonald, D., Fielding, W. L., Ruston, D. F. & King, H. E. (1946). Progr. Rep. Exp. Stas Emp. Cott. Gr. Corp., 1944–45, pp. 14–28.Google Scholar
MacDonald, D., Ruston, D. F. & King, H. E. (1944). Progr. Rep. Exp. Stas Emp. Cott. Gr. Corp., 1942–43, pp. 18–36.Google Scholar
Parnell, F. R. (1927). Rep. Exp. Stas Emp. Cott. Gr. Corp., 1925–26 pp. 19–44.Google Scholar
Parnell, F. R.. (1928). Rep. Exp. Stas Emp. Cott. Gr. Corp., 1926–27, pp. 52–62.Google Scholar
Parnell, F. R.. (1935). Emp. Cott. Gr. Rev., 12, pp. 177–182.Google Scholar
Parnell, F. R. & MacDonald, D. (1942). Progr. Rep. Exp. Stas Emp. Cott. Gr. Corp., 1941–42, p. 23.Google Scholar
Peat, J. E. (1928). Rep. Exp. Stas Emp. Cott. Gr. Corp., 1926–27, p. 119.Google Scholar
Verma, P. M. & Afzal, M. (1940). Studies on the cotton Jassid (Empoasca devastans Distant) in the Punjab. I. Varietal susceptibility and development of the pest on different varieties of cotton.—Indian J. agric. Sci., 10, pp. 911–926.Google Scholar
Williams, C. B. (1937). The use of logarithms in the interpretation of certain entomological problems.—Ann. appl. Biol., 24, pp. 404–414.CrossRefGoogle Scholar