Cardamom Plantations Research Articles

Identification and Screening of New Generation Insecticides against Cardamom Thrips (<i>Sciothrips cardamomi</i>) in Cardamom Cultivations in Sri Lanka

Two thrips species were identified from cardamom (Elettaria cardamomum) cultivations in Sri Lanka. They are the cardamom leaf thrips, Panchaetothrips indicus Bagnall (1912) and the cardamom thrips, Sciothrips cardamomi (Ramakrishna, 1935). Sciothrips cardamomi collected from Nuwara Eliya district is emerging as a devastating pest of cardamom (Elettaria cardamomum) in the district. Both adults and larvae damage panicles, flowers and capsules of cardamom. Injury to panicles leads to stunted growth, and damaged flowers fall prematurely. Affected tender capsules show scabby growth on the surface as they mature and hence have no market value. To manage this problem and as an immediate control measure, damage causing thrips were identified, damage estimated and seven new generation insecticides were screened at Kabragala Estate in Elamulla, Nuwara Eliya. The estimated direct pod damage was 91.7 ± 3.2%. Severely damaged pods showed significantly lower pod weight than undamaged pods. No significant difference in the pod weight was observed between undamaged pods and pods with less than 2/3 of scabby area. The insecticides Actara (thiamethoxam), Match (lufenuron), Regent (fipronil) and Calypso (thiacloprid) successfully reduced the pod damage while Matric (chromafenozide), Mimic (tebufenozide) and Mospilan (acetamiprid) did not reduce the damage percentage. But higher yields of 335.54 and 304.98 g/bush/harvest were obtained from the plots treated with Actara or Match respectively, in comparison to all other treatments. Therefore, either Actara or Match could be recommended for the management of S. cardamomi in cardamom plantations. Key words: Sciothrips cardamomi, Panchaetothrips indicus, Elettaria cardamomum doi: 10.4038/cjsbs.v37i2.501 Cey. J. Sci. (Bio. Sci.) 37 (2): 137-142, 2008

Honey bees of the cardamom ecosystem and the selective toxicity of diafenthiuron to four different bee species in the laboratory

SummaryBees are important pollinators necessary for fruit set in cardamom (Elettaria cardamomum). Apis cerana indica, Apis dorsata, Trigona iridipennis and Amegilla spp. were observed in cardamom plantations of south India. Since cardamom is attacked by an array of insect pests, synthetic insecticides were used in crop management. Diafenthiuron is one such insecticide found to be very effective against the cardamom borer, Conogethes punctiferalis and thrips, Sciothrips cardamomi. Most insecticides used in crop protection are reported to be hazardous to bees, so diafenthiuron was also tested for its toxicity to bees. Diafenthiuron was found to be slightly harmful to A. dorsata, A. cerana indica, A. foreaand moderately harmful to T. iridipennis. In particular, it was slightly to moderately toxic to bees on contact with treated surfaces in the laboratory. T. iridipennis and A. dorsata are found abundantly in the cardamom ecosystem and unfortunately highly susceptible to the insecticide. It was found that diafenthiuron is highly toxic when applied to the thorax of bees but it is less toxic on ingestion, i.e, contact toxicity is higher than oral toxicity. The labellum, the attractive part of the cardamom flower, where the bees land is not heavily exposed to pesticide sprays in the field because of its position and other reasons, so bees have a reduced chance of exposure to the pesticide in the field. Under critical situations, however, spraying of the chemical during peak bee activity should be avoided.

Responses of tropical rainforest birds to abandoned plantations, edges and logged forest in the Western Ghats, India

AbstractThis study examined the effects of alteration of tropical rainforest vegetation structure and composition on bird community structure and the influence of life‐history traits on species persistence in the Kalakad‐Mundanthurai Tiger Reserve, Western Ghats. Systematic sampling for vegetation and point count surveys for birds were carried out in cardamom plantations abandoned for 5 and 15 years, plantation‐rainforest edges, a selectively logged forest patch and adjoining undisturbed rainforest sites. Principal components analysis of vegetation variables revealed clear differences between undisturbed and altered sites in woody plant and cane densities, canopy cover and vertical stratification. Bird species richness was lowest in cardamom plantations abandoned for 5 years and highest in logged and undisturbed forest. Bird species richness and similarity with undisturbed forest were significantly positively related to the vegetation component representing woody plant and cane (Calamus spp.) densities. Sites that were more similar in tree species composition had more similar bird communities whereas similarity in foliage profile between sites did not influence bird community similarity. Birds that were rare, were large‐bodied and belonged to the carnivore, omnivore, bark‐surface feeder and terrestrial insectivore guilds were adversely affected by habitat alteration. Restoring woody plant and cane densities and rainforest floristic composition in disturbed habitats may be required for management and conservation of bird communities typical to the region.

The occurrence of arboreal mammals in the rain forest fragments in the Anamalai Hills, south India

The occurrence and abundance of five species of arboreal mammals in 25 rain forest fragments ranging from <1 ha to 2500 ha in area in the Anamalai Hills in south India, were examined in relation to several habitat and landscape variables. The lion-tailed macaque ( Macaca silenus) was the most affected, being absent from 15 fragments while the Nilgiri langur ( Trachypithecus johnii) was absent from six and the Malabar giant squirrel ( Ratufa indica) from only three fragments. The densities of the giant squirrel, the large brown flying squirrel ( Petaurista petaurista) and the Travancore flying squirrel ( Petinomys fuscocapillus) increased with decreasing area and increasing disturbance level. In logistic regression, canopy height and tree density were the best predictors of the occurrence of the lion-tailed macaque and the Nilgiri langur, respectively. Area of the fragment may be an important predictor of occurrence of these species only when the fragments are very small. Once initially present, their continued occurrence is better predicted by habitat variation, consistent with the ecology of the species. It is possible to retain the arboreal mammals in the rain forest fragments through improving habitat quality. The suggested measures include (a) prevention of degradation due to lopping and felling of trees; (b) assisted regeneration in forest fragments; and (c) retention of orchards of jack fruit trees ( Artocarpus integrifolia), guava ( Psidium guajava), etc., in the labour settlements around the fragments. Land use policies that would prevent conversion of cardamom plantations into tea or coffee plantations are also needed.

Field Evaluation of Trichoderma Isolates in the Biocontrol of Rhizome Rot Disease of Small Cardamom

Small cardamom ( Elettaria cardamomum Maton), ... the Queen of Spices is au important spice crop cultivated on a large scale in the Western ghats of South India. Rhizome rot is a major disease caused by Rhizoctonia solani Kuhn in cardamom plantations. The disease occurs in a severe form during monsoon and results in heavy crop losses. In the present study, exotic and native isolates of Trichoderma viride Pers. Fr. and T.harzianum Rifai were tested against the pathogen under in vitro conditions. These isolates were further evaluated in disease-prone areas in the field. Results showed that all the isolates tested showed antagonistic activity through hyphal coiling, penetration and lysis of the hyphae of the pathogen besides inducing growth inhibition of the laller. Among the nine isolates tested in the field, eight were found effective in controlling the disease incidence. An exotic isolate of T. harzianum and a native isolate of T. viride were found to be most effective, the reduction in disease incidence being upto 52 to 69 per cent.

Site Index and Biomass Productivity Estimates for Himalayan Alder-Large Cardamom Plantations: A Model Agroforestry System of the Middle Hills of Eastern Nepal

Site Index and Biomass Productivity Estimates for Himalayan Alder-Large Cardamom Plantations: A Model Agroforestry System of the Middle Hills of Eastern Nepal