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THE DEVELOPMENT OF INTERNAL BOLL DISEASE OF COTTON IN RELATION TO TIME OF INFECTION
Author(s) -
PEARSON E. O.
Publication year - 1947
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1947.tb06386.x
Subject(s) - biology , lint , inoculation , basidiospore , protoplasm , botany , staining , fecundity , horticulture , germination , agronomy , microbiology and biotechnology , population , demography , sociology , cytoplasm , genetics
Inoculations of Nematospora spp. into cotton bolls at successive weekly intervals from flowering to maturity show that the symptoms produced are closely dependent upon the stage of development reached by the boll when infected. Details are given of the nature and degree of the staining and of the effects upon weights of seed and lint finally produced. During the first 4 weeks of life bolls are in the stage of rapid growth and differentiation, and infection is followed by severe disorganization of all boll structures and complete commercial loss. Bolls infected later in life develop typical stained lint, but without general breakdown of other tissues, and the degree of staining diminishes steadily with the age when infected, until, towards maturity, little or no effect is produced. Subsidiary experiments show that inoculations of sterile water can cause death of the seed embryos, presumably by plasmolysis, in bolls up to 3 weeks of age. The effects upon the seed and consequently upon the lint following death of the embryo caused by such treatment are shown to be similar to those following feeding by uninfected insects of the genus Dysdercus , which are the normal vectors of internal boll disease. Staining of the lint by Nematospora is due to the post‐mortem discoloration of the protoplasm of the lint hair, and its extent consequently varies inversely with the degree of vacuolation, which increases with maturity. The mode of action of the fungus and the evidence suggesting that a toxin is involved are discussed. The bearing of the age‐damage relationship on the losses due to internal boll disease in African cotton‐growing countries is considered, and the advantages of promoting a steep flowering curve are emphasized.