Journal of Plantation Crops <p>As a multidisciplinary journal, Journal of Plantation Crops (JPC)&nbsp;aims at dissemination of research findings in plantation crops (coconut, arecanut, cocoa, cashew, oil palm, coffee, tea, rubber, date palm), including cropping systems, as well as various spices. Since its inception in 1973, 45 volumes have been published. The journal is published thrice a year during April, August and December and publication of the articles is subject to peer reviewing and recommendation by experts in the field.</p> en-US (Editorial Office) (Editor) Fri, 30 Sep 2022 00:00:00 +0530 OJS 60 Farmer-friendly technology for mass production of Trichoderma harzianum (CPTD28) V.H. Prathibha, Daliyamol, M. Monisha, Vinayaka Hegde Copyright (c) 2022 Journal of Plantation Crops Fri, 30 Sep 2022 00:00:00 +0530 Cryopreservation of coconut plumule using droplet vitrification <p>In the present investigation, four types of explants from mature zygotic embryos of coconut, <em>viz</em>., whole upper cotyledonary region without haustorium, half of the upper cotyledonary region without haustorium, plumule with a portion of radicle and exclusively plumular tissue, were cultured in 12 different media combinations to find a suitable explant which could be regenerated after cryopreservation. Explants were pre-cultured in medium with 0.4 and 0.5 M sucrose for three days followed by dehydration in PVS<sub>3</sub> solution for different durations on a sterile aluminum strip after treating with loading solution. Strips were treated with liquid nitrogen inside a cryoflask until bubbling stopped and quickly transferred to a cryovial and stored for a minimum period of 24 hours in liquid nitrogen. It was observed that plumule alone or with a small portion of outer tissue was ideal for fast <em>in vitro</em> growth and recovery of whole plantlets of coconut in a medium supplemented with NAA alone. Addition of glutamine (5 mg L-1), TDZ (1 mg L-1) and NAA (18 mg L-1) aided the vigorous growth of plantlets. In control, the survival rate ranged from 60 to 90 per cent in plumule pre-grown in media containing 0.5 M sucrose after dehydration with PVS<sub>3</sub> for various durations, whereas it was 14 to 75 per cent in cryopreserved ones. Considering the high survival (75%) and regrowth (35%) of cryopreserved plumule in the present study, there is much scope for further improvement of the procedure to find the right combination of factors so as to enhance complete recovery of plantlets without much injury to plumules during cooling and rewarming.</p> Anitha Karun, K.K. Sajini, K.S. Muralikrishna, M.K. Rajesh Copyright (c) 2022 Journal of Plantation Crops Fri, 30 Sep 2022 00:00:00 +0530 Survey for incidence of coffee white stem borer, Xylotrechus quadripes (Chevrolet) on robusta coffee (Coffea canephora Pierre ex A. Froehner) plantations at Kodagu region of Karnataka state, India <p>Coffee is an important commercial crop attacked by various insect pests. Among them, coffee white stem borer (CWSB), <em>Xylotrechus quadripes</em> (Coleoptera: Cerambycidae), is the most serious and economically important pest of arabica coffee. The incidence of CWSB has been noticed in arabica coffee, whereas the other commercial variety, <em>viz</em>., robusta, has been tolerant against this pest so far. Of late, the incidence of CWSB is reported regularly in robusta plantations in the Kodagu region of Karnataka State, India. To understand the extent of CWSB incidence in robusta coffee, a systematic survey was conducted in 40 estates of Polibetta and Siddapura liaison Zones during the year 2019. CWSB infestation and the details on the percentage of CWSB, cultivar types, and age of the plants were recorded. The results of the survey revealed that the incidence was more in aged plants of Old Peridenia and S.274 (&gt;50 years) compared to young plants and C × R hybrid (<em>Coffea congensis</em> × <em>Coffea canephora</em>). Data on the percentage infestation was found more in Old Peridenia (16.81%), followed by S.274 (4.8%) and C × R (0.88%). The infested plants of Old Peridenia and S.274 showed typical symptoms as in the case of arabica plants like ridge formation, drooping and yellowing of leaves, wilting, defoliation, exit holes and death of branches and whole plants. Hence, Indian coffee farmers are shifting slowly from arabica to robusta coffee because of CWSB infestation. This survey emphasized that a complete shift from arabica to robusta cultivation may face a similar infestation problem unless management practices are followed promptly.</p> B.V. Ranjeeth Kumar, C. Kathrivelu, Kencharaddi Copyright (c) 2022 Journal of Plantation Crops Fri, 30 Sep 2022 00:00:00 +0530 Antioxidant attributes of tea in North Bengal, India: Relation with its principal constituents and properties of soil <p>This study was performed in 18 tea gardens in North Bengal, India, from 2012 to 2017. The data were pooled to investigate the relationship with soil physico-chemical properties, phyto-constituents, antioxidant attributes and age of the tea bushes and principal component analysis (PCA). PCA and dendro-hit maps were also performed with each region. The 28 principal components were chosen based on their eigen values, explaining the total data variance for tea in Dooars, Terai and Darjeeling hill. In almost all cases, composite soil physico-chemical attributes were heavily loaded on the second principal component and clustered, as visual evidenced by the dendro-hit map. Different attributes were significantly correlated each other in case of Terai <em>i.e</em>. (value of “r’’ at P&lt;0.01 level) clay fraction (0.778), electrical conductivity (0.618), N (0.777), S (0.748), P (0.514 ppm), flavour index (0.918), total polyphenol (0.687) DPPH (0.794), nitric oxide (0.913), anti-lipid peroxidation (0.717) and metal chelating (0.665). In Dooars region, attributes were significantly correlated with silt (0.718), pH (0.875), P (0.615 ), chloride (0.858), TP (0.776), flavonol (0.923), quinone (0.666), tannins (0.865), DPPH (0.536), superoxide (0.576), ABTS (0.520) and MC (0.777) and in the case of Darjeeling hills, attributes were highly correlated with clay (0.812), sand (0.818), silt fraction (0.974), K (0.932), S (0.999), MC of soil (0.671), TP (0.853), tannins (0.912), DPPH (0.624), ABTS (0.661) and MC (0.633) repectively.</p> Tarun Kumar Misra, Aniruddha Saha, Ashis Kumar Nanda, Subhrajyoti Bagchi, Palash Mandal Copyright (c) 2022 Journal of Plantation Crops Fri, 30 Sep 2022 00:00:00 +0530 Influence of elevation and rainfall on leaf growth, bean characteristics and yield components of arabica and robusta coffee under changing climatic conditions in Karnataka state, India <p>The study was undertaken to analyze the behaviour of coffee under changing climatic conditions in different coffee liaison zones of Karnataka State, India, during 2017-2020. Sample estates were identified based on elevation and rainfall patterns in different zones of the Chikkamagaluru and Hassan districts. The leaf growth parameters, bean characteristics and yield components were recorded in all the sample estates. Correlation studies indicated a significant positive relationship between the elevation, rainfall with specific leaf area (r = +0.912) and productivity (r = 0.475) during the pre-monsoon period. The monthly summer rainfall during March and April showed a significant correlation with yield in robusta (r = 0.511) and arabica (r = 0.451), indicating that blossom shower during this period significantly influenced the productivity of coffee. The studies between elevation, the quantum of rainfall and bean defect parameters indicated a significant (p&lt;0.05) positive correlation. A positive relationship was also found between elevation and peaberry production in both robusta (r = 0.716) and arabica coffee (r= 0.456), respectively. However, there was also a significant relationship between rainfall (2020) and Jollu percentage (r = 0.386) in robusta coffee, indicating that higher elevation and rainfall-induced more peaberry content and Jollu percentage under changing climatic conditions. The overall result indicated that changes in climatic conditions such as excess rainfall and continuous soil moisture led to more vegetative growth than reproductive growth. This also produced more bean abnormalities which in turn affected the yield and quality of the coffee.</p> Somashekhargouda Patil, Jeena Devasia, George Daniel, N. Surya Prakash Rao Copyright (c) 2022 Journal of Plantation Crops Fri, 30 Sep 2022 00:00:00 +0530 Influence of different storage temperatures and packing material in extending shelf life and quality attributes of palmyrah (Borassus flabellifer L.) neera <p>Palmyrah <em>neera</em> (inflorescence sap) is susceptible to natural fermentation at ambient temperature within a few hours of extraction due to enzymatic and microbial activity. Once fermented, <em>neera</em> becomes toddy which is unsuitable as a health drink or as a value-added product. Therefore, a study was carried out to investigate the influence of different packing materials and storage conditions on the shelf life and to keep the quality of palmyrah <em>neera.</em> The experiment was conducted in a completely randomised factorial design with two factors at unequal levels replicated thrice. HDPE 50 micron pouch (P<sub>1</sub>), PET bottle (P<sub>2</sub>) and glass bottle (P<sub>3</sub>) and cold storage at 2 oC (S<sub>1</sub>), cold storage at 4 oC (S<sub>2</sub>) and refrigerated storage (8-10 oC) (S<sub>3</sub>) were the packing material and storage conditions respectively used during experimentation. Physio-chemical properties <em>viz.,</em> total soluble solids, pH and reducing sugars showed an increasing trend up to the 4th week of storage. At the same time, phenols, titrable acidity and alcohol content increased up to the 6th week of storage. Maximum total soluble solids (10.80 oBrix), reducing sugars (5.76%), minimum phenolic content (0.323 mg) and titrable acidity (1.116%) were recorded when palmyrah <em>neera</em> was packed in HDPE 50 micron pouch, whereas the maximum total soluble solids (10.83oBrix), reducing sugars (5.75%), minimum phenolic content (0.322 mg) and titrable acidity (1.14%) were recorded when palmyrah <em>neera</em> was stored at 2 oC. Among the different packing material and storage conditions, HDPE 50 micron and storage at 2 oC was effective in extending the shelf life and quality attributes of palmyrah <em>neera</em>.</p> M. Chandra Surya Rao, D.V. Swami, P. Ashok, D.R. Salomi Suneetha, R.V. Sujatha, V. Sekhar Copyright (c) 2022 Journal of Plantation Crops Fri, 30 Sep 2022 00:00:00 +0530 Phytochemical profile and toxicity of thyme-derived (Thymus vulgaris) essential oil against the exotic rugose spiraling whitefly (Aleurodicus rugioperculatus Martin) infesting coconut <p>Microwave-assisted heat extraction of thyme (<em>Thymus vulgaris</em>) yielded 1.64 per cent w/v of yellow to amber coloured and less viscous oil with a peculiar aroma. GC-MS analysis revealed the presence of 20 compounds, out of which thymol (51.94%), p-cymene (14.5%), γ-terpinene (10.09%), linalool (3.48%), and endo-borneol (3.95%) were the major compounds. Eggs, second instar nymphs and pupae of rugose spiraling whitefly (RSW) were subjected to contact toxicity assessment by complete immersion (dip method) in various concentrations of thyme oil. The results showed that essential oils at 0.35 per cent concentration exhibited 100 per cent mortality in the second instar nymphs. Thyme oil (0.5%) inhibited egg hatching and adult emergence to the tune of 100 per cent when the eggs and pupal stages were treated. Probit analysis indicated that the median lethal concentration (LC<sub>50</sub>) of thyme oil to eggs, second instar nymph sand pupal stages were 0.19, 0.13 and 0.21 per cent, respectively. Thyme oil proved to be an excellent toxicant to different developmental life stages of RSW; hence it can be successfully incorporated into the integrated pest management (IPM) programme for whitefly management in the coconut ecosystem.</p> E.K. Saneera, S. Raguraman, A. Suganthi, K. Venkatesan Copyright (c) 2022 Journal of Plantation Crops Fri, 30 Sep 2022 00:00:00 +0530 Molecular characterisation and structural assessment of an RXLR effector from Phytophthora palmivora, the coconut bud rot pathogen <p><em>Phytophthora</em> species are phytopathogenic oomycetes that damage a wide variety of crops. <em>Phytophthora</em> delivers effectors, which are secretory proteins, into the host cells. Effectors promote infection by reprogramming the host cellular machinery and are key determinants of oomycete virulence. The major class of <em>Phytophthora</em> effector proteins contains the RXLR motif. In this study, we have carried out the molecular and structural characterisation of an <em>RXLR</em> effector <em>(RXLR6744)</em> from a virulent <em>P</em>. <em>palmivora</em> isolated from bud rot disease-affected coconut palm. The open reading frame (ORF) of the <em>RXLR6744,</em> amplified using RT-PCR, had a length of 411 bp. The gene was found to encode a predicted protein of 136 amino acids and had a molecular weight of 15.52 kDa. Phylogenetic analysis of the amino acid sequence revealed that it was closely related to RXLR proteins from <em>P. palmivora</em> (causing black pod disease in cocoa) and related species <em>P. megakarya</em>. Topology analysis revealed that the protein was composed of six α-helices. The structural prediction was undertaken by computer-aided homology modelling. From the Ramachandran plot analysis, it could be observed that the majority (96.3%) of amino acids were present in the preferred region, 3.7 per cent of amino acid residues were present in the allowed region, and no residues were observed in the disallowed region. The structure showed an average quality of 94.4 per cent, indicating it to be a high-quality structure. This study provides the detailed characterisation of an RXLR effector from <em>P. palmivora</em>. It will aid the elucidation of its role in pathogenesis and facilitate further refined investigations of the structure/function relationships of oomycete effectors.</p> K.P. Gangaraj, M.K. Rajesh Copyright (c) 2022 Journal of Plantation Crops Fri, 30 Sep 2022 00:00:00 +0530