JOURNAL OF ROOT CROPS 2021-07-14T07:39:50+00:00 Dr. V.Ravi Open Journal Systems <p>Journal of Root Crops, the official publication of the Indian Society for Root Crops, publishes scientific papers, short scientific reports, original reviews and book reviews on all aspects pertaining to tropical root and tuber crops. One volume consisting of two issues is published annually. The articles forwarded to the Editor for publication are understood to be offered exclusively to the Journal of Root Crops. The authors are advised to refer to the previous issues of the Journal of Root Crops and prepare the manuscripts. Detailed instructions to the authors are being issued in the Journal from time to time. The LIFE time subscription fee for Journal of Root Crops in India is Rs.5000/- and US$700 outside India.The annual subscription for the Journal of Root Crops for non-members is Rs.1000/- in India and US$200/-outside India. For institutions, annual subscription fee is Rs.4000/- in India and US$500 outside India. All manuscripts, communications consisting of editorial matters and books for review may please be uploaded in the Online manuscript submission portal</p> <p>For further details please contact:<br />Indian Society for Root Crops<br />Central Tuber Crops Research Institute<br />Sreekariyam, Thiruvananthapuram 695 017<br />Kerala, India.<br />Tel. No.: 2598551-2598554<br />Fax: 0091-471-2590063<br />E-mail:; <a href="" target="_blank" rel="noopener"></a></p> Phenology of Greater Yam (Dioscorea alata L.) Under Humid Tropical Conditions of Kerala 2021-07-14T07:36:32+00:00 Sunitha S. Santhosh Mithra V. S. Sreekumar J. Sheela M. N. <p>Phenology of greater yam (<em>Dioscorea alata </em>L.) was studied by planting two greater yam varieties viz., Sree Keerthi and Sree Karthika for three seasons (2013, 2014 and 2015) at ICAR-CTCRI, Thiruvananthapuram, Kerala. Sree Keerthi took 16 to 23 days for sprouting, 88 days for tuber initiation, 236 to 243 days for senescence, which lasted for 24 to 39 days. Sree Karthika took 17 to 28 days for sprouting, 83 days for tuber initiation, 236 days for senescence which lasted for 26 to 45 days. Active tuber development was noticed between 6 to 8 months of planting (180 to 240 days). Timely planting resulted in more tuber yield in Sree Keerthi (26.4 to 31.5 t ha-1) than Sree Karthika (22.65 to 29.3 t ha-1). Delayed planting although resulted in early emergence and tuber initiation, senescence was also early resulting in yield loss in both the varieties. However, Sree Keerthi resulted in less yield loss compared to Sree Karthika, indicating its suitability for delayed planting.</p> 2020-07-08T00:00:00+00:00 Copyright (c) Soil Enzyme Activities and Yield of Elephant Foot Yam [Amorphophallus paeoniifolius (Dennst.) Nicolson] as Influenced by Weed Management Practices in Alfisols 2021-07-14T07:36:32+00:00 Moharana Manaswani Laxminarayana K. Nedunchezhiyan M. <p>A field experiment was conducted during 2015-16 at the Regional Centre of ICAR-Central Tuber Crops Research Institute, Bhubaneswar, Odisha, India, to study the effect of various weed management practices on soil quality, microbial activities, and yield performance of elephant foot yam [<em>Amorphophallus paeoniifolius </em>(Dennst.) Nicolson] in an Alfisol. The results revealed that weed control ground cover resulted in lower weed biomass and greater weed control efficiency. Significantly higher corm yield was obtained with weed control ground cover treatment (37.4 t ha-1), with an increase of 335% over control, followed by four manual weedings at 30, 60, 90 and 120 days after planting (DAP) (33.7 t ha-1) and two manual weedings at 30 and 60 DAP along with post-emergence application of glyphosate at 90 DAP (32.9 t ha-1). Use of weed control ground cover resulted in higher post-harvest soil available N, P, K, Fe, Cu, Mn and Zn, microbial population (fungi, bacteria and actinomycetes) and soil enzyme (dehydrogenase, fluorescein diacetate, acid and alkaline phosphatase) activities. Two manual weedings at 30 and 60 DAP along with application of glyphosate at 90 DAP resulted in higher soil organic carbon.</p> 2020-07-08T00:00:00+00:00 Copyright (c) Optimum Nutrient Requirement of Elephant Foot Yam (Amorphophallus paeoniifolius (Dennst.) Nicolson) Under Coconut Gardens 2021-07-14T07:36:32+00:00 Anju P. S. Susan John K. Bhadraray S. Mathew Jeena Sunitha S. Veena S. S. <p>Among the tropical tuber crops, elephant foot yam (EFY) (<em>Amorphophallus paeoniifolius </em>(Dennst.) Nicolson) is a highly potential and ideal intercrop for the coconut gardens of Kerala. Being highly efficient biologically with good yield potential to the tune of 30-100 t ha-1, it is high nutrient demanding too. Though, there are different nutrient management approaches for the cultivation of this crop, taking into account both crop productivity as well as soil health, balanced nutrition based on soil nutrient status and crop requirement deserves special mention. In this regard, customization of nutrients specific to regions and crops can be considered as one of the key approaches. In the protocol for arriving at the grades of the customized fertilizer formulations, one component is evolving the actual optimum of all nutrients of a particular soil by conducting nutrient omission experiments for major nutrients and nutrient level experiments for secondary and micronutrients. Such experiments were conducted for elephant foot yam under intercropping in coconut gardens of the major tuber crops growing soils of Kerala viz., laterite (AEU 9) and sandy plains (AEU 3). The theoretical optimum (based on weighted average data of the soil test) was N : P : K : Mg : Zn : B : Dolomite @ 71 : 12.5 : 106.5 : 16 : 5.25 : 1.31 : 1000 (AEU 3) and 78 : 12.5 : 90 : 16 : 5.25 : 1.31 : 1000 kg ha-1 (AEU 9) respectively. The weighted average data of nutrients was 0.95 and 1.50% (organic carbon), 61.97 and 69.27 kg ha-1 (available P), 213.96 and 295.87 kg ha-1 (available K), 113.32 and 600.16 ppm (exchangeable Ca), 37.53 and 114.99 (exchangeable Mg), 5.07 and 21.46 ppm (available S), 3.94 and 5.68 ppm (available Zn), 0.70 and 0.82 ppm (available B), 1.79 and 3.79 ppm (available Cu), 101.20 and 64.66 ppm (available Fe) and 18.82 and 37.65 ppm (available Mn) respectively for AEU 3 and AEU 9. Different sub optimal and super optimal levels of the theoretical optimum of nutrients viz., N,P, K, Mg, Zn, B and Dolomite was kept as treatments for conducting these experiments in the two locations of AEU 9 and one location in AEU 3. Based on the corm yield data from these experiments, the actual optimum derived by conducting the NOP (Nutrient Omission Plot) and NLE (Nutrient Level Experiment) was N: P: K: Mg: Zn: B: Dolomite @ 140: 20: 225: 19.2: 4.2: 1.575: 1500 kg ha-1 for AEU 3 and 160:12.5:180: 19.2:6.3:1.975:1500 kg ha-1 for AEU 9 respectively and these experiments formed the basis for calculating the different nutrient use parameters for arriving at the grades of the customized fertilizer formulations.</p> 2020-07-08T00:00:00+00:00 Copyright (c) Status and Requirement of Boron for Tropical Tuber Crops Under Laterite (Typic Kandi Ustult) Soils 2021-07-14T07:36:32+00:00 Susan John K. Karthika D. Sruthi T. Sreekumar J. Sunil Kumar K. Anju P. S. <p>Tropical tuber crops also require the micronutrient B for its growth and productivity as in the case of all other crops. The very low B content in the major tropical tuber crops growing soils of Kerala could cause the manifestation of B deficiency symptoms both in vegetative parts and tubers in the case of cassava and sweet potato. The recent occurrence of symptoms akin to hollow/brown heart of potato, in yams (<em>Dioscorea</em>), necessitated to take up experiments related to B nutrition to understand the etiology of this problem. Since the manifestation was noticed in a typical laterite soil (Typic Kandi Ustult) of the farm of ICAR-CTCRI and under similar soils of the State, a rapid nutrient status appraisal was made for the five blocks of CTCRI farm for nutrients viz., available B and exchangeable Ca as there exists a synergism between these two nutrients. A sorption study too was conducted to predict the rate of application of B for soils of varying B status. A total of 95 soil samples collected from these blocks taking into account the terrain and present cropping/fallow were analysed. Wide variation was seen in the available B status ranging from 0.14-0.419 ppm for block I and II, 0.172-0.419, 0.172- 0.848, 0.150-1.052 ppm for block III, IV and V respectively with mean values as 0.317, 0.242, 0.289, 0.331 and 0.356 ppm respectively. The mean exchangeable Ca content of the soils of these blocks were 0.896, 1.015, 0.640, 0.989, 0.877 meq 100 g-1 soil with ranges as 0.565-1.303, 0.741-1.387, 0.534-0.866, 0.762-1.215 and 0.591-1.254 meq 100 g-1 soil respectively. To understand the interaction between these nutrients, the correlation worked out indicated synergism or significant positive correlation (r=0.537) only in block V. Sorption study could find a linear increase in the quantity of B extracted in the soils of varying B contents ranging from 0.1-1.0 ppm under addition of incremental rates of B from 0.25 to 4.0 ppm. The inverse prediction function method employed to predict the quantity of B to be applied to attain soil B status to either the soil critical level of B (0.5 ppm), double (1.0 ppm) and thrice (1.5 ppm) the critical levels in soils of the above B status (0.1-1.0 ppm) was found as 0.78-3.09, 1.80-7.21 and 7.4-11.33 ppm respectively. Though the low soil available B and exchangeable Ca content can be attributed as one of the reasons for the problem manifested in yams, detailed studies are needed to explore the role of abiotic factors especially moisture and heat stress in the dynamics of these nutrients at different growth stages of the crop.</p> 2020-07-08T00:00:00+00:00 Copyright (c) Mineralization of Thippi (Cassava Starch Factory Solid Residue) Compost Under Incubation 2021-07-14T07:36:32+00:00 Chithra S. Susan John K. Sreekumar J. Manikantan Nair M. <p>Cassava (<em>Manihot esculenta </em>Crantz) is an important tropical tuber crop, the tubers of which are used both for edible purpose and for industrial uses. In Tamil Nadu, more than 500 cassava based small to large scale starch and sago producing factories are generating more than 250 tonnes of solid residue called ‘thippi’ per annum. This is an environmental pollutant affecting soil and human health and was found very difficult to dispose too. At ICAR-CTCRI, the same was converted to a nutritious organic manure through different composting methods where comosting resulted in the highest nutrient increase and the C: N ratio narrowed to 8:1 from 82:1. Experiments conducted in cassava showed its suitability as a good organic manure alternative to the commonly used organic manures like farm yard manure, green manuring <em>in situ </em>with cowpea, vermicompost, coir pith compost and crop residue as well as can substitute for 50% of the NPK requirement as per package of practices (PoP) and secondary nutrient Mg and micronutrient Zn to a great extent. While using any organic manure, the decomposition of the same to release the nutrients (mineralization) especially during the critical growth stage of the crop or as per the nutrient requirement of the crop needs to be understood. Hence, to understand the nutrient release pattern of thippi compost, a pot study was conducted by incubating the soil mixed with thippi compost and analysed the soil samples at monthly intervals for pH, organic carbon, electrical conductivity (EC), available N, P and K, exchangeable Ca, Mg, Fe, Cu, Mn and Zn for one year. The mean data of the soil chemical properties for one year indicated the pH, EC, available N, P and K, exchangeable Ca, Mg, available S, Fe, Cu, Mn, Zn and B increased to the tune of 0.64, 0.055 dS m- 1, 99.8, 46.1, 87.2 kg ha-1, 0.73, 0.99 meq 100g-1, 15.8, 9.4, 0.18, 1.07, 3.07 and 0.19 mg kg- 1 which in turn was 13.8 , 35.4, 46, 88.3, 107.5, 68.2, 176.7, 158, 23.5, 16.4, 72.8, 56.7 and 17.9% over the initial status. Among the nine composting options, vermicomposted thippi compost had the highest nutrient release and the maximum nutrient release was found during 5 to 8th month of incubation.</p> 2021-07-14T00:00:00+00:00 Copyright (c) Identification of Cassava (Manihot esculenta Crantz.) miRNAs Targeting the Genome of Cassava Mosaic Virus 2021-07-14T07:36:32+00:00 Haridas Anjana Makeshkumar T. Sreekumar J. <p>Cassava Mosaic Disease caused by cassava mosaic virus is one of the most devastating crop diseases affecting cassava cultivation. Bioinformatics approach was applied to search cassava (<em>Manihot esculenta </em>Crantz.) miRNAs that targeted the cassava mosaic virus genome. Nucleotide sequences representing the genome of cassava mosaic virus were screened against a set of mature cassava miRNAs. Efficacy of cassava miRNAs against putative viral mRNA targets was analysed based on complementarity of miRNA-mRNA target pairing. This study revealed 14 cassava miRNA families to have putative targets in the cassava mosaic virus with nearly perfect complementarity. These miRNAs when artificially designed may have the potential to confer effective resistance against cassava mosaic disease infection in transformed cassava</p> 2021-07-14T00:00:00+00:00 Copyright (c) Occurrence of Papaya Mealybug (Paracoccus marginatus Williams and Granara de Willink) and the Field Efficacy of the Parasitoid (Acerophagus papayae Noyes and Schauff) on Mealybug Infestation in Cassava 2021-07-14T07:36:32+00:00 Geetha B. Venkatachalam S. R. <p>Papaya mealybug, <em>Paracoccus marginatus </em>Williams and Granara de Willink, an invasive insect pest, causes severe damage in cassava growing areas of Salem and Namakkal districts of Tamil Nadu. Field surveys conducted on the incidence of <em>P. marginatus </em>in Salem and Namakkal districts of Tamil Nadu showed the incidence of mealybug, which was above 60% in 13 villages of Salem district and 6 villages in Namakkal district during 2019. A field experiment on the efficacy of <em>Acerophagus papayae </em>on <em>P. marginatus </em>infestation in cassava showed 90.2 to 98% parasitization efficiency after a month of parasitoid release. The parasitoid population varied between 60 and 212 parasitoids per leaf and between 24 and 80 parasitoids per 5 cm stem. Among the ten locations studied, parasitoids recovered from the released fields ranged from 8250 to 16500 from 50 plants per acre from Aaripalayam, Pethanaickanpalayam and Ottapatti fields at 5 to 7 months after release which indicates faster multiplication of the parasitoid. The activity of the parasitoids in the released fields persisted for a longer period, till the harvest of the plant (November - December) and prevented further population build-up of the mealybug. The present investigation revealed that <em>A. papayae </em>as a successful biocontrol agent in sustained management of papaya mealybug.</p> 2021-07-14T00:00:00+00:00 Copyright (c) A Comparative Study on Host Range of Tribolium castaneum (Herbst) and Rhyzopertha dominica (Fabricius) to Cassava (Manihot esculenta Crantz) and Selected Stored Grains 2021-07-14T07:36:32+00:00 Ajesh G. Jayaprakas C.A. Krishnan Jithu. U. <p>Host range of <em>Tribolium castaneum </em>and <em>Rhyzopertha dominica </em>to cassava chips were compared with stored grains such as wheat, black gram and rice. Test insects (20 Nos., 1M: 1F) were reared in splintered and flour forms of host samples under laboratory conditions. The parental adults were removed after 10th day of exposure and emergence of grub was noticed. Flour forms of wheat, black gram, rice and cassava were found more suitable for the adult emergence of <em>T. castaneum </em>whereas <em>R. dominica </em>preferred whole and broken forms of selected food except cassava. The number of adult emergence of <em>T. castaneum </em>and <em>R. dominica </em>was higher in wheat flour (67.4 ±6.2) and whole form of black gram (164.2 ±4.7) respectively. In the case of <em>T. castaneum, </em>the number of adult emergence was 51.8 ±5.8 and 57.6 ±2.0 in flours of black gram and rice respectively, whereas it decreased to 5.4 ±1.5 and 5.0 ±1.5 in whole forms of black gram and rice respectively. In the case of <em>R. dominica,</em>the number of adult emergence was 147.0 ±6.1 and 67.0 ±3.5 in whole forms of wheat and rice whereas it was only 11.6 ±2.0 and 12.8 ±2.7 when reared in flour forms of wheat and rice respectively. Among all the selected forms of cassava, only the flour forms supports the adult emergence of <em>T. castaneum </em>and <em>R. dominica</em>.</p> 2021-07-14T00:00:00+00:00 Copyright (c) Estimation of Optimum Plot Size and Shape for Branching Variety of Cassava (Manihot esculenta Crantz) Using Statistical Methods 2021-07-14T07:36:32+00:00 Rakhi T. Chandran Arya V. Kumar Vijayaraghava Joseph Brigit <p>Knowledge of optimum size and shape of plots is an important factor in improving precision while conducting agricultural field experiments. An experiment for determination of optimum plot size in a branching variety of cassava (Vellayani Hraswa) was carried out using the Maximum curvature, Smith’s variance law and Modified curvature methods in an area of 200 m2 at Instructional Farm, Department of Agricultural Statistics, College of Agriculture, Vellayani, Thiruvananthapuram, India during 2015-2017. The experimental area selected was having 15 rows and 16 columns (240 plants). The maximum curvature method and Fairfield Smith’s variance method gave most appropriate results. For branching type of varieties, the optimum plot size obtained was 24 units (plants) by these methods under a spacing of 90 cm x 90 cm. Regarding plot shape, 8 x 3 (length as 8 units and breadth as 3 units) is recommended as it gave less coefficient of variation than 6 x 3 units in the maximum curvature method.</p> 2021-07-14T00:00:00+00:00 Copyright (c) Problem Diagnosis and Research Priority Setting for Cassava in India 2021-07-14T07:36:32+00:00 Anantharaman M. Sethuraman Sivakumar P. Srinivas T. Ramanathan S. <p>Cassava is the most widely cultivated root crop in tropics and continues to be a crop of food security. It is the major tropical tuber crop in India , cultivated in peninsular region and North eastern hill states. Once seen as the food security crop, is now becoming increasingly a multipurpose crop acting as a major raw materials for a range of industrial uses. Cassava area is declining in India and its role in food security and economic growth is diminishing gradually. However, its significance to small and marginal farmers and its growing industrial use could not be ignored and overlooked and maximum advantage of this crop need to be explored through strategic R &amp; D efforts. The funds allocated for cassava R &amp; D should be judiciously used to reap the maximum benefits to the farming community. Research priority setting and monitoring is an effective method to efficiently allot scarce resources. The purpose of this paper is to develop a methodology for setting research priorities for cassava and to delineate the prioritised areas of research. The study suggested to have participatory problem diagnosis, converting problems to researchable issues, using Principle Component analysis for grouping the issues and judges rating and economic assessment for priority setting. The major areas prioritised are development of Cassava Mosaic Disease resistant varieties and its management, lowering the cost of production of cassava, germplasm collection, maintenance, and evaluation of tropical tuber crops (cassava) etc.</p> 2021-07-14T00:00:00+00:00 Copyright (c)