Pest problems in root-trainer raised forest nurseries of selected species in Kerala

Abstract

In recent times, root trainers are being employed to produce the planting stock required to raise forest plantations. In the root-trainer raised nurseries, instead of soil, the potting medium is often vermiculite or compost. Though information on insect pests attacking conventional forest nurseries is available, we lack data on the nature and severity of pest attack in root-trainer raised nurseries. Data on this aspect was generated for three species – teak, eucalypts and acacias. In teak nurseries, the mite, Tetranychus sp. caused damage resulting in scorchy leaves and subsequent mortality in some cases. Other than the mite, the teak skeletoniser (Eutectona machaeralis), the Teak defoliator (Hyblaea puera) and the White fly (Aleurodicus sp.) were the insects recorded as feeding on teak foliage. An unidentified scolytid beetle boring the stem was the only insect problem noticed in Acacia auriculiformis. In the case of eucalypts, two leaf feeding beetles, Colasposoma sp. and Microserica sp. were observed to cause damage. These beetles are not reported earlier as attacking eucalypts. In general, the present observations indicate very less pest problems in root trainer raised nurseries than in conventional forest nurseries. Because of the lack of contact with soil, some of the soil insects like termites, white grubs etc. have not posed any problem in root trainer raised nurseries.