Author
Schreiner, Roger - Paul | |
Linderman, Robert |
Submitted to: Agricultural Experiment Station Oregon State University Progress Reports
Publication Type: Proceedings Publication Acceptance Date: 3/1/2001 Publication Date: 3/1/2000 Citation: page 127-134 Interpretive Summary: . Technical Abstract: Our evaluation of the timing and location of root growth in a 20-year-old block of Pinot noir grapevines at Woodhall Research Vineyard showed that the majority of fine roots occurred within the upper 50 cm of the soil profile. Sixty percent of the total fine roots found occurred within the vine row and 30 % of the total occurred in the alley-way at 0-50 cm depth. Only 10 % of the total fine roots were found below 50 cm. Woody roots were more evenly distributed to a depth of 100 cm. Colonization of fine roots by vesicular arbuscular mycorrhizal (VAM) fungi was consistently high in the vine row throughout the entire growing season, but was reduced in roots growing in the alley-way. Arbuscular colonization (a measure of the "activity" of the mycorrhiza) increased throughout the growing season and did not decline until after leaf fall. Arbuscular colonization was also lower in roots from the alley-way compared to roots collected from the vine erows. The density of fine roots containing active mycorrhizal fungi (arbuscules) increased just after budbreak, reached a maximum density in early August, declined during veraison, and peaked again after harvesting the fruit. Relationships between mycorrhizal fungi, roots, and leaf nutrient levels indicated that VAM fungi may be enhancing Mg uptake, either directly or in combination with P uptake or transport. Leaf nutrient analysis also showed that N and K were the only nutrients actively re-absorbed from senescing leaves late in the season. Fruit yield was strongly correlated to root length density, arbuscular root length density, cane lengths at bloom, and the number of fruiting canes per vine. |