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ARS Home » Northeast Area » University Park, Pennsylvania » Pasture Systems & Watershed Management Research » Research » Publications at this Location » Publication #159882
Title: EFFECTS OF IRRIGATION AND PRUNING ON CONCORD GRAPE PRODUCTIVITY AND SEASONAL ROOT DEVELOPMENT

Author
item LASKO, A - CORNELL UNIV.
item EISSENSTAT, D - PENN STATE UNIV.
item Comas, Louise
item DUNST, R - CORNELL UNIV.

Submitted to: International Water and Irrigation Review
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2003
Publication Date: 12/20/2003
Citation: Lasko, A.N., Eissenstat, D.M., Comas, L.H., Dunst, R. 2003. Effects of irrigation and pruning on Concord grape productivity and seasonal root development. International Water and Irrigation Review. 23(2):32-34.

Interpretive Summary: A trial of conventional vs minimal pruning, with and without supplemental irrigation was initiated in a mature Concord grape (Vitis labruscana Bailey) vineyard in 1990. The study site was Fredonia, New York, which has a cool humid climate. In the main trial minimal pruning gave significantly higher and more stable crop yields than with conventional pruning, but fruit sugar levels were lower. Irrigation had its most positive effects in the minimal pruning treatment and few long-term effects on the conventional pruning treatment. Root observation tubes were installed in fall of 1996, and seasonal root production patterns were observed at 2 week intervals for 5 years. Patterns of root production varied from season to season. Root production was more impacted by drought than by pruning. In irrigated vines, total new root production varied from year to year. Root production in August was best correlated to the amount of crop ripening on the vines. Non-irrigated vines in dry years typically lacked substantial root production in late July and August. Computer simulations of carbohydrate supply from the canopy and demands of the shoot and crop growth suggest that the period before fruit ripening would provide the most available carbon for root growth. Irrigation maintained vine production so that there was carbon available for root growth.

Technical Abstract: A trial of heavy vs minimal pruning with and without supplemental irrigation was established in a mature Concord (Vitis labruscana Bailey) grape vineyard in a cool humid climate in Fredonia, New York in 1990. In the main trial minimal pruning gave significantly higher and more stable yields than with balance pruning, but fruit Brix levels were lower. Irrigation had its most positive effects in the minimal pruning treatment, but had few long-term effects on the severe pruning treatment. Clear butyrate minirhizotron tubes were installed in fall of 1996, and seasonal root production patterns were observed with remote video monitoring at 2 week intervals for the past 5 years. Patterns of root production varied from season to season. Root production was not apparently affected by pruning, but was strongly impacted by drought, or irrigation. In irrigated vines, total new root production varied from year to year; the variation in total numbers appeared to be best related to the amount of August root growth as influenced by crop level. Differences in new root production due to drought were primarily related to the lack of a pre-veraison August peak of root growth in the dry treatments. Computer simulations of carbon supply from the canopy and demands of the shoot and crop growth suggest that the pre-veraison period would provide the most available carbon for root growth. Irrigation maintained vine production so that there was carbon available for root growth. Irrigation did not consistently affect fine root production.