Flowering and pollination biology in coconut

Coconut is a seed propagated crop and knowledge on its flowering and pollination biology will be of significance for optimizing the pollination techniques and also to design efficient conservation strategies in gene banks. Coconut palm is monoecious, with inflorescence bearing both staminate and pistillate flowers. The male flowers are the first to open, beginning at the top of each spikelet and proceeding towards the base. The male phase is followed by female phase and in tall varieties there is a gap between these two phases within the same inflorescence. Although both wind and insects bring about pollination, insect pollination is more predominant. Strategies for employing honey bee colonies in coconut plantations and seed gardens for enhancing pollination and fruit set are discussed. Future lines of work with regard to pollination biology aiming increasing fruit set in coconut seed gardens are also pointed out

Discovery of a new Steinernema sp. (Rhabditida: Steinernematidae) with higher shelf life and better efficacy against red palm weevil under laboratory conditions

Entomopathogenic nematodes (EPN) are excellent bio-control agents for the management of insect pests of soil and cryptic habitat. One of the greatest challenges in the successful utilization of EPN is the poor shelf life of infective juveniles (IJs) under ambient temperature. The present study aimed to evaluate the survival and virulence of different EPN species for determining a superior one in the bio-suppression of red palm weevil (RPW). Among the five species of Steinernematids and two Heterorhabditid isolates evaluated, Steinernema sp. (S0804) sustained up to 13 months, with a desirable survival of 100 per cent during the first five months to about 64 per cent ten months after storage at ambient temperature. Virulence of Steinernema sp. (S0804) sustained up to ten months of storage, was confirmed using Galleria mellonella inoculation test. However, the viable IJs were observed only up to one month in both the Heterorhabditids and up to a period of four to six months of storage in all other Steinernematids. The Steinernema sp. (S0804) was also found to be efficacious against the grubs of RPW in filter paper bio-assay inducing 100 per cent larval mortality in 72 h when applied @ 200 IJs per grub and confirmed further by leaf petiole bioassay. The study thus revealed higher survival and virulence of Steinernema sp. (S0804) and also found to be a potential bio-control agent against RPW. To the best of our knowledge, this is the first EPN isolate reported, which could survive for more than one year at ambient temperature without any additives

Evaluation of bacterial antagonists for the management of rhizome rot of cardamom (Elettaria cardamomum Maton)

Among the 90 rhizobacterial isolates screened against rhizome rot pathogens (Pythium vexans, Fusarium oxysporum and Rhizoctonia solani) of cardamom (Elettaria cardamomum) two bacterial strains viz., Pseudomonas fluorescens Pf 51 and Bacillus subtilis B45 were highly inhibitory. P. fluorescens Pf 51 exhibited highest inhibition (42.5%, 44.2% and 41.4% respectively) against P. vexans, F. oxysporum and R. solani. B. subtilis B45 also exhibited highest inhibition (43.2%, 41.2% and 42.4% respectively) against these three pathogens. P. fluorescens Pf51 was compatible with B. subtilis Bs 45. Peat formulation supported the survival of both the strains up to 270 days with a viable population of 4.3 × 107 cfu g-1 and 6.2 × 107 cfu g-1 respectively. Application of antagonists in combination with rhizome bacterization and soil application resulted in 54.0% reduction in rhizome rot over control as compared to single method such as rhizome bacterization (43.0%) or soil application (39.0%). Application of copper oxychloride and carbendazim resulted in 68.0% reduction of rhizome rot. Maximum height (167.21 cm) and number of tillers (30.14) were recorded due to the application of mixture of both the strains through rhizome bacterization and soil application. &nbsp

Yield and nutrient rontent of chilli (Capsicum annuum L.) in responu to sources of P ilnd levels of P and N

The highest yield of chilli dry pods (2770 kg ha-1) was obtained by the application of 120, 60 and 35 kg N, P2O5 and K2O ha-1. The response to N and P application was linear up to 120 and 60 kg ha-1 N and P2O5, respectively. The protein content of dry pod increased in the higher levels of N and the highest value (12.2.5%) was recorded at 120 kg ha-1. N and P application increased protein and mineral contents of dry pods. Among the sources of P, rock phosphate registered maximum calcium content compared to single super phosphate. The efficiency of incubated rock phosphate was similar to that of single super phosphate. However, rock phosphate with phosphobacteria did not enhance yield. Farm yard manure incubated rock phosphate proved to be a cheaper source of phosphatic fertilizer for soils with higher pH (>8). &nbsp

Evaluation of high yielding accessions of small cardamom (Elettaria cardamomum Maton) for suitability in the high ranges of Idukki District

Ten high yielding small cardamom accessions were collected from RRS, Mudigere; ICRI, Saklespur and CRS, Pampadumpara and evaluated for their suitability in Idukki District, Kerala. M-1 and PV -1 were found to be high yielding varieties since both of them recorded the highest yield consistently for four consecutive years. M-l was relatively tolerant to thrips infestation. The biometrical traits such as plant height, tiller number, panicle number, panicle length and seed number showed high positive correlation with yield. These characters are likely to be the ideal selection criteria in small cardamom. &nbsp

Evaluation of bacterial antagonists for the management of rhizome rot of cardamom (Elettaria cardamomum Maton)

Among the 90 rhizobacterial isolates screened against rhizome rot pathogens (Pythium vexans, Fusarium oxysporum and Rhizoctonia solani) of cardamom (Elettaria cardamomum) two bacterial strains viz., Pseudomonas fluorescens Pf 51 and Bacillus subtilis B45 were highly inhibitory. P. fluorescens Pf 51 exhibited highest inhibition (42.5%, 44.2% and 41.4% respectively) against P. vexans, F. oxysporum and R. solani. B. subtilis B45 also exhibited highest inhibition (43.2%, 41.2% and 42.4% respectively) against these three pathogens. P. fluorescens Pf51 was compatible with B. subtilis Bs 45. Peat formulation supported the survival of both the strains up to 270 days with a viable population of 4.3 × 107 cfu g-1 and 6.2 × 107 cfu g-1 respectively. Application of antagonists in combination with rhizome bacterization and soil application resulted in 54.0% reduction in rhizome rot over control as compared to single method such as rhizome bacterization (43.0%) or soil application (39.0%). Application of copper oxychloride and carbendazim resulted in 68.0% reduction of rhizome rot. Maximum height (167.21 cm) and number of tillers (30.14) were recorded due to the application of mixture of both the strains through rhizome bacterization and soil application. &nbsp

Concurrent emergence of exotic whitefly incursions on arecanut (Areca catechu L.) in India

Field incidence of exotic whitefly complex comprising two Neotropical nesting whiteflies viz., Paraleyrodes bondari Peracchi and Paraleyrodes minei Iaccarino, in association with invasive rugose spiralling whitefly Aleurodicus rugioperculatus Martin and native areca whitefly, Aleurocanthus arecae David & Manjunatha, on arecanut was reported from Karnataka, India during 2020. These arecanut palms were previously infested by A. arecae which was earlier reported from Karnataka during 2003. To our knowledge, this is the first report on the infestation of P. bondari and P. minei on arecanut as highlighted in this current investigation. Morphological identification based on pupal taxonomy and male genitalia as well as molecular characterization of the mitochondrial cytochrome oxidase I (COI) gene confirmed the identity of nesting whiteflies. The Bondar’s nesting whitefly, P. bondari is the most predominant whitefly species with 87.5 per cent active colonies followed by the nesting whitefly, P. minei (13.64%) and the rugose spiralling whitefly, A. rugioperculatus (6.25%). Co-occurrence of these three non-native whitefly species on arecanut in synergy with the native A. arecae indicates a kind of competitive regulation of one species over the other upsetting biodiversity. Due to the polyphagous nature of the pest coupled with increased trade and transport in a climate change scenario, this whitefly complex may become a serious threat to arecanut production in India and elsewhere. This requires strict quarantine protocols to avert its spread to other arecanut growing areas

Varietal evaluation of black pepper (Piper nigrum L.) for yield, quality and anthracnose disease resistance in Idukki District, Kerala

Fourteen accessions of black pepper were evaluated at the Cardamom Research Station, Pampadumpara for yield, quality and disease resistance. Out of the fourteen cultivars, CuI. 239 (Panniyur-5) recorded the highest wet (906.5 g) and dry (310.1 g) yield of berries per plant. The maximum volatile oil (5.06%) and oleoresin (9.4%) contents in dry berries were observed in CuI. 5128 and Panniyur-1, respectively. A positive correlation existed between the number of spikes and berries per plant and yield. However, yield and quality characters are negatively correlated, though not significant. The results showed that Panniyur-5 is the most suitable black pepper variety for high range conditions of Idukki District. &nbsp

Conservation of biological control and bioscavenging: in Rugose Spiralling Whitefly management in coconut

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