Sensitivity of grapevines to injury by atmospheric sulfur dioxide

Abstract

Sensitivity of grapevines to injury by sulfur dioxide were studied. One or two-years old plants were exposed to different concentrations of the gas (0.26, 0.13, 0.065, 0ppm) at different season in a green house. The results obtained are summarized as follows:1. Sulfur dioxide injury emerged on the middle leaves of grapevine at first, however the degree of leaf lesion was remarkable on the lowest leaves. Leaf lesion and early leaf fall increased in proportion to the gas concentrations.2. Six varieties of grapevine used varied considerably in their sensitivity to the gas. Variety of Fredonia was highly sensitive and Delaware grape was fairly sensitive. Kyoho and Neo muscat grapes were intermediate. Kyogei grape was resistant, Koshu grape was the most resistant and was not suffered from leaf injury through exposure periods. Fredonia grape was absorbed the gas more than Koshu grape.3. Sensitivity of Fredonia grape varied with season (stage) and increased from spring to autumn. Absorption of the gas also increased.4. Fredonia and Delaware grapes were exposed to the gas from May 23 to Oct. 29 of 1967 to clarify the effect of preceding year exposure on shoot growth and cluster formation. Degree of leaf lesion of Fredonia grape became remarkable in proportion to the gas concentrations and the extention of exposure duration. Also leaf lesion of Delaware grape formed abundantly at the concentration of 0.26ppm after extension of the exposure duration. After terminating the gas exposure, new shoot growth and cluster formation of Fredonia grape decreased in 1968 with increasing gas concentrations, corresponding the degree of leaf lesion and falling in 1967. Shoot growth of Delaware grape decreased at 0.26ppm and cluster formation also decreased at 0.13ppm and above.