Eelworms

There are two main groups of eelworms.

1.Fungus feeding: Ditylenchus myceliophagus and Aphelenchiodes composticola.

2.Saprophagus: Rhabditida.

Eelworms are small colourless worms up to 1 mm long that swim in the surface films of water in compost and casing. When they occur in vast numbers they can be seen glistening under a torch light. If a few eelworms are present during spawn run, there is likely to be a heavy infestation at the end of cropping.

The fungus feeding species (which are uncommon locally) are the most harmful of the two groups. They feed on mushroom mycelium by piercing the hyphae with their tiny mouth spears and sucking out the contents. Under normal hygienic conditions and short cropping cycles they rarely cause serious trouble, but if there is a severe infestation early on, it is usually noticeable by dark patches of compost in the bag with no visible mycelium. These dark patches usually have a bad small and the size of these parches increase in the second or later flushes. Buttons may also turn brown and die and crop production falls.

2. Saprophagous

(Rhabiditida)

The Saprophagous eelworms which are mostly Rhabiditids are most common locally. This group feed on decaying material and are not generally regarded as primary pests. Their presence, however, in large numbers indicates a poor growing compost and because of this crops are likely to be reduced.

1. Once the eelworms are noticed in the spawned compost or casing little can be done to control the infestation. Prevention is the best form of control. It is important therefore to kill eelworms with high temperatures at peak heating (Phase 2). For a complete kill it is necessary that a temperature of 57-60°C (135-140°F) is held for 5-6 hours throughout the compost and especially the surface layer of the compost. It is also important that the compost surface is kept moist as eelworms can survive even at very high temperatures in dry conditions.

2. All casing that arrives at the farm should be tested for eelworms before it is applied to the compost. The casing should be unloaded onto a clean surface and applied to the bags as soon as possible.

3. Eelworms are easily spread on pickers clothes, knives and any other tool that may be used. It is important that they are not spread to other houses. It may be necessary, therefore, to have a change of overalls before working in clean houses, and all equipment should be sterilised in formaldehyde before use.

4. The house should be thoroughly sterilised at the end of cropping and crop debris disposed off at a distant location.