Greens issue

A few greens were damaged by the nematicide Multi-Guard that was applied last Tuesday evening. This chemical was applied in an attempt to control plant parasitic stunt nematodes which are extremely small, yet potentially destructive wormlike creatures that feast on plant roots. Left unchecked, greens with high nematode populations can fail during the prime playing season of summer. Soil nematodes are the most populous animal on earth and most species are not destructive to plants. Soil samples were sent to the University of Massachusetts on May 31st. Here are the numbers of stunt nematodes they counted from those samples:

Green 1 5024 adults per 100 cc's of soil
Green 3 4660 adults per 100 cc's of soil
Green 15 6660 adults per 100 cc's of soil

A count of 800 nematodes per 100 cc's of soil is the threshold number suggested by UMASS where turf damage may occur. At this level, turfgrass damage can be expected, especially on close cut greens during the heat of summer. With the high observed population of nematodes present, you can see why we decided to pursue a chemical control option.

The green that took the most severe hit is 15, followed by 16 and the practice green. A few others are affected as well. The most common damage looks like pimples or speckling in a few spots. Overall, damage is minor and will heal over during the next two or three weeks. We will re-seed 15 to aid its recovery. I am not writing to alarm anyone because overall the greens are still very nice, but I just wanted to explain why a few greens aren't looking their best at this time.

Previously, Bayer's Nemacur was a wonderful, yet extremely hazardous nematode control product. Nemacur was pulled for sale in Spring 2005 leaving no chemical control options until mid 2011 when Agrium Advanced Technologies released a product named Multi-Guard. Multi-Guard (chemical name of furfural) has demonstrated positive control results in university testing, especially with the species present at Potowomut, the dastardly stunt nematode. (There are five or six species that affect turfgrass.) Because nematodes can devastate greens practically overnight, Superintendents have enthusiastically purchased and applied Multi-Guard during the last few weeks to control nematode populations just before they typically skyrocket.

Unfortunately, we are not the only golf course with greens' damage from Multi-Guard. We have heard of another golf course in the northeast with damaged greens. This golf course applied the product last Monday (one day sooner than us) with similar results. Because of these two negative results, representatives of the South African manufacturer of the material and from nationwide seller Agrium will spend time Thursday at Potowomut to assess and discuss the situation. We will keep you posted with any updates.

In the meantime, greens were fertilized Saturday evening and will be fertilized again as early as tomorrow (Wednesday) to hasten growth and recovery. Again, greens are still in wonderful condition and we expect them to continue to improve in coming weeks.

****We can assure you that left over Multi-Guard will be sent back....and this chemical will not be used at Potowomut again because this result in unacceptable.

Thanks for your patience and understanding.

Patrick M. Gertner CGCS