14 



Ring nematodes, Criconemoides and Macroposthonia , are root 

 surface feeders. Injury is not severe, but helps to slow down 

 the growth of young trees. Other species of ring nematodes are 

 part of the "Slow Decline of Peach" complex in South Carolina. 



Soil sampling . Because nematodes are distributed in clusters 

 throughout the field, it is important to collect soil from 

 several areas. For each 5000 sq. ft. area, 10 or more subsamples 

 taken to a depth of 8-10" from the strip where trees are to be 

 planted should be collected with a trowel or spade. Mix the soil 

 in a bucket and then put one quart of mixed soil in a plastic 

 container. If a sampling tube is used, about one quart of soil 

 should be collected. 



Soi] samples may be taken at any time during the year although 

 winter and spring populations will be low and less representative 

 of the potential of the population to build up. Samples should 

 be sent to one of the Regional Fruit Specialists or directly to 

 the Department of Plant Pathology, University of Massachusetts, 

 Amherst, 01003. Remember, dried out soil is useless . 



Sampling soil and extracting, identifying and counting nema- 

 todes is time-consuming and requires a fair amount of experience 

 and training. But the most difficult step comes next, when a 

 prediction should be made about how much injury might be expected 

 and what control methods, if any, should be used. The experience 

 of the grower is invaluable at this point because he will often 

 know if problems have occurred in this area in the past and the 

 overall potential of the area to produce fruit trees. 



Soil fumigation . Treatment before planting to reduce all 

 disease organisms is probably still the best procedure and has been 

 discussed at length before ( Fruit Notes 41 (6): 3-5, 1976). 

 Fumigation is expensive, requires extensive preparation and special- 

 ized equipment, and does not always fit in well with the planting 

 schedule. 



Planting hole treatment . Several insecticide-nematicide chemi- 

 cals have been used as root dips or mixed with soil around thej^p,. 

 tree as it is planted.. All of these materials, oxamyl (Vydate^ ^ rp^ 

 phenamiphos (Nemacur^ ^), aldicarb (Temik^ ^), carbofuran (Furadan^ ^ 

 are highly toxic to humans and are at least partially systemic. At 

 present time, only oxamyl is registered for use in Massachusetts, 

 and only on non-bearing fruit trees. 



The "state of the art" at present calls for caution. There 

 is enough preliminary evidence to suggest that replant problems 

 exist and treatments will pay off. Because so many factors are 

 involved and because each orchard, indeed each block, is a different 

 ecosystem, small scale field trials are necessary in order to esta- 

 blish the value of any one particular treatment. 



