Integrated management of Eriophyid mite, Aceria guerreronis Keifer on coconut in Tamil Nadu, India

Abstract

A field experiment was conducted at Vellalore from January 2002 to December 2004 to evaluate the influence of organic and inorganic nutrients and the effect of botanicals and insecticide against coconut eriophyid mite. Soil application of nutrients along with spraying of Triazophos 40 EC (5 ml/lit.), azadirachtin 1% (5 ml/lit.) and neem oil (30 ml/lit.) as first, second and third round of sprayings, respectively were evaluated. The results revealed that there was a significant reduction in mite population (65%) after two years in the Integrated Management (IM) treated trees (application of organic and inorganic nutrients, basin cultivation of sunnhemp and three rounds of spraying) followed by trees treated with Nitrogen: Phosphorus: Potash (1.3:2.0:3.5 kg/palm/year) + Farm Yard Manure 50 kg/palm/year + neem cake 5 kg /palm/year + micronutrients + three rounds of sprayings (52.8%). Similarly, there was also a significant reduction in the per cent damaged green nuts after two years. After second year, the per cent damaged nut was lowest (41.9) in the IM treated trees which was statistically on par with treatment 6 (42.9) as against control (71.8). A similar trend was also recorded after third year. IM package treated trees recorded the lowest nut damage grade of 2.8, 2.4 and 2.1 at harvest followed by IM package without sunnhemp as basin crop 3.0, 2.6 and 2.2 as against 4.3, 4.3 and 4.5 in the check after first, second and third year, respectively.

Removal of Bunches or Spikelets Is Not Effective for the Control of Aceria guerreronis

“…The spikelets from different bunches touch each other naturally as a result of wind action and the bending of the structure with the increased weight of the fruits. Some authors (Galvão et al, 2012;Moore and Alexander, 1987;Sumangala and Haq, 2005) have reported that the pathway of A. guerreronis through the spikelets is a relevant process in the infestation of new bunches. However, as evaluated by the present study, the removal of the spikelets had no significant effect on the damage level of newly produced bunches.…”

“…The coconut mite [Aceria guerreronis Keifer (Acari: Eriophyidae)] is a serious pest of coconuts in the Americas and Africa, and it has rapidly become established in some major coconut-producing countries in Asia (Lawson-Balagbo et al, 2008;Moore and Howard, 1996;Ramaraju et al, 2002). The mite damages the fruit during the early developmental stages, causing surface scars and premature fruit fall (Moore and Howard, 1996).…”

“…Currently, the only way to control this pest is through chemical control (Julia and Mariau, 1979;Moore et al, 1989). However, as a result of the height of the plant and the fact that the pest is hidden under the perianth, which is not reachable by many acaricides, chemical control seems impracticable for small-scale farmers, who lack the appropriate equipment and supplies (Moore and Howard, 1996;Ramaraju et al, 2002). In addition, frequent use of such a practice could raise the cost of production excessively and eventually cause problems as a result of residue on the coconut products (Moore and Howard, 1996).…”

<p><strong>Coconut destiny after the invasion of </strong><strong><em>Aceria guerreronis </em></strong><strong>(Acari: Eriophyidae) in India*</strong></p>

“…It seems possible that many coconut varieties grown earlier in India were tolerant to the coconut mite (Haq et al, 2002). Studies on varietal purification have been conducted by several authors in the past (Grinwood, 1975;Thampan, 1984;Ramaraju et al, 2002) with regard to general crop improvement and disease resistance, but specific attention to varieties showing less or no susceptibility to the coconut mite has been dedicated only recently in India. Considering the extensive variation of coconut plants in this country, comprehensive studies to determine varieties resistant to the coconut mite are warranted.…”

“…Attempts to develop hybrids resistant to this pest have been initiated. Several hybrids, namely Laccadive Ordinary (LO), Cochin China (CC), Andaman Ordinary (AO), Gangabandan (GB) (Muthiah & Bhaskaran, 1999), Kenthali, Tiptur tall, Saint Vincent ECT, WCT, WCTxCOD (Ramaraju et al, 2002;Kannaiyan et al, 2002), have been identified as promising. Among these, GB x WCT and ECT x GB have shown the lowest levels of susceptibility.…”