Laying Down Mulch...under-trellis

    The crew at the NMSU Los Lunas Agriculture Science Center ( NMSU LL ASC )  helped install the latest applied viticulture study in the experimental vineyard there. Dr. Marisa Thompson, NMSU Urban Horticulture Extension Specialist and I have designed and will follow and document the differences in vine performance and soil health due to mulch compared to herbicide treated strip as a control under-trellis.  The mulch treatments we will evaluate are: commercially available wood-chip mulch and pecan shells, donated by Stahmann's Pecans Inc., Las Cruces NM. The two cultivars are: Touriga Nacional, a traditional port wine cultivar and Refosco, an Italian red  that has performed well in southern New Mexico in the Mesilla Valley AVA and at the Farmington ASC, located on NAPI (Navajo Agricultural Products Industry, Farmington, NM, NAPI ) lands in the four corners region of New Mexico. Notice that I used the descriptor, "under-trellis" instead of a more common term, "under-vine". I think this distinction is important as "under-vine" may infer to some that the treatment is subterranean in nature and physically below the vines. This is obviously not the case, but the mulch placement is more accurately described as being located under the trellis. Take a look at the photos below and decide for yourself. 

Loading the 'gator' to transport wood-chip mulch down the plot rows

Tom Place, Los Lunas ASC Superintendent, brings front-loader bucket of mulch to
be off-loaded by Carl (front center) and Chuck (right).

A typical plot before application of wood-chip mulch

A typical plot after application of the wood-chip mulch laid down
the vine row in a ~3 ft. wide strip about 4 inches deep under the trellis. 

This is crown gall; abnormal gall growth on a grapevine at the graft union. Crown gall is a disease that causes the plant to produce these initially fleshy tumors. The environmental insult that typically induces this disease to present itself is low winter temperatures. The primary crown gall disease of grape is caused the bacterium Agrobaterium vitis. Will the mulch treatments mitigate the occurrence of this disease if it is 'hilled up' over the graft to "protect" it over the winter?