B. K. Das ¹, A. K. Sahoo ¹

Affiliations
1 Betelvine Bidan Chandra Krishi Viswavidyalaya, Kalyani, 741 235, Nadia, West Bengal, IN

Abstract

A survey of parasitoids of scale and mealybug pests of mango was conducted in Malda district of West Bengal, India during 1999-2000. Chartocerus sp., Azotus sp. and Gyranusoidea tebygi Noyes was recorded on Rastrococcus invadens Williams. On Rastrococcus iceryoides Green, Chartocerus walkeri Hayat, Aproslocetus sp., Promuscidea unfascMtiventris Girault, Anagyrus pseudocacci Girault and Anagyrus mirzai Agarwal and Alam were recorded. Two species of Aprostocetus, Encyrtus sp. and Austroterobia maldica Narendran and Das were recorded on lcerya minor Green. Coccophagus ceropktstae (Howard) and Promuscidea unfascMtiventris were recorded from Pulvinaria polygonata (Cockll.).

Keywords

Icerya minor, Mango Pests, Parasitoids, Pulvinaria polygonata, Rastrococcus spp.

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B. C. Das ¹, B. K. Das ¹, Pranab Dutta ¹, D. K. Sarmah ¹

Affiliations
1 Department of Plant Pathology, Assam Agricultural University, Jorhat, 785 013, Assam, IN

Abstract

In vitro osmoticant (manitol) amended and osmoticant free media of potato dextrose broth (PDB), modified Richard's broth (MRB) and Czapek dox broth (CDB) were tested for biomass production of Trichoderma harzianum Rifai. Osmoticant amended MRB was found best for production of maximum sporulation, cfu and dry weight of biomass of the antagonist, Osmoticant amended media produced higher biomass of T. harzianum than osmoticant free media. Growth and sporulation of T. harzianum was assessed in different carrier viz. starch, talc and molasses enriched charcoal powder (MECP) based formulation. Starch and MECP based formulation of T. harzianum showed increased trend in sporulation of the antagonist upto 60 days, but after this, viability of T. harzianum was abruptly decreased. Talc based formulation-exhibited gradual declining trend in multiplication and sporulation of T. harzianum after 30 days onwards. Among the nine formulation evaluated for growth and sporulation, starch based formulation alone performed best upto 60 days, followed by MECP based formulation. But after 60 days onwards, talc based formulation @ 3: 1 dose showed highest sporulation and maximum cfu, followed by starch formulation @ 1: 1 dose. The overall performance of talc-based formulation was better for growth and sporulation of the antagonist. Potentiality of T. harzianum as seed treatment with talc based T. harzianum and chemical were assessed field condition against Rhizoctonia solani causing stem rot disease of soybean. Lowest disease index and highest % seed germination was observed when seeds were treated with formulation of T. harzianum + talc + osmoticant formulation with enhanced plant vigour and yield of the crop.

Keywords

Biomass, Osmoticant, Rhizoctonia solani, Soybean, Stem Rot, Trichoderma harzianum.

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