Back in July Napa County UCCE Weed Science Advisor John Roncoroni visited Long Island. His specialty is in weed control and vegetation management for perennial crops, cover crops and aquatic and riparian weed control. We took him to see both trials in this project, the under trellis mowing at LIHREC and the under trellis cover crops at Martha Clara. We also took him out to Bedell where they had planted no mow and red clover. Interestingly he mentioned that in his experience with no mow it isn't a completely no mow situation. It can get up to 16 in high (when it is flowering) so would benefit from a single mowing in the fall. He also felt that even without mowing or incorporation, the clover may add some nitrogen to the soil. Hopefully we will see this is our soil and petiole test results. Last year we mowed the trial at Martha Clara in an attempt to knock back the weeds and allow the cover crop to becom established. This year we will mow and not mow a few replications of each treatment to see the different growth patterns of our cover crops.
In August we took more data from the two trials. We took petiole samples at veraison to give us a snapshot of the nutritional status of the vines going into harvest. Petioles combined with soil samples will allow us to see if the cover crops are having an impact on the nutrional needs of the plant. It is thought that plants grown under the vine will compete with the vine for nutrients and impact the overall health of the vine. In Martha Clara where vigor is an issue this might not be such a bad thing, but at LIHREC where vigor is not as much of an issue it could be a problem.
Also at veraison we took samples of the cover crops, dried and weighed them. This will give us a better idea on their growth over time. The potential problem is that the weeds will start to move in and crowd out the planted covers. Or they don't reseed themselves and start to die out. This gives us an opportunity to better track this.
