JOURNAL OF ROOT CROPS

Protected cultivation in tropical tuber crops – A review

J. Suresh Kumar — 2024-08-28

Protected cultivation is being promoted as an innovative solution to address challenges of increasing demand in food production to commensurate with the population increase, limited cultivable area and unfavorable growing conditions. The advantages of protected cultivation include efficient use of water and nutrients, higher yield per unit area, year-round and offseason production, reduction in pests and diseases, and assured produce quality. Specific to tuber crops, protected cultivation offers benefits such as in vivo rapid multiplication of virus-indexed planting material, increased production and productivity and business opportunities in production systems. Different techniques have been explored for protected cultivation of specific tuber crops. Hydroponics and aeroponics have been used for cassava and yams resulting in improved survival rates, multiplication rates and root/tuber development. Sandponics systems have been developed for sweet potato pre-basic seed production, leading to higher vine multiplication rates and storage root yields. Hydroponics studies also revealed the pivotal role of potassium fertilizers in tuber crops, especially sweet potato. Optimum potassium doses can help to promote storage root development while maintaining a balanced shoot growth. It also helps to improve the quality characteristics of sweet potatoes, and tolerate stress including environmental stresses such as drought, salinity and diseases. The prospects of protected cultivation in tuber crops include standardization of production technology, including biofortified varieties and the integration of different methods of seed production to meet the required quality of planting materials. Ongoing research and development efforts are expected to drive innovation in hydroponics and aeroponics, leading to increased efficiency and productivity in tuber crops.

Keywords : Root and tuber crops, Protected cultivation, Hydroponics, Aeroponics, Soilless cultivation, Seed multiplication

Comparison of amino acid sequence profiles and 3-D structure prediction of Coat Protein of Sweet potato feathery mottle virus (SPFMV) reveal strain variation

Jayanta Tarafdar — 2024-08-28

Sweet potato feathery mottle virus (SPFMV) under Potyviridae family is the most widespread disease in sweet potato (Ipomoea batatas L.) across the world and causes differential symptoms of feathery mottle and degeneration of leaves and deformed storage root. The present study highlights the enhanced molecular resolution and 3-D prediction of amino acid of coat protein of seven SPFMV strains. Viral coat protein (CP) derived from an isolate (Gene bank Accession No.HM035545 and poly protein ID D6R1L4_9POTV) BCKV, India showed close relationship with RC (Russet Crack) strain and diverged from the strains 4C, EA, S, O and K1 of SPFMV. Protein Feature View of PDB entries mapped with watermelon mosaic virus (WMV) Polyprotein (PF00767) to a UniProtKB sequence S480335 predicted structural similarities for the SPFMV strains in PDB ID 5ODV for WMV. Analysis of Nuclear Localization Signal (NLSs) and its prediction of CP sequences unveiled the key amino acids in the corresponding amino acid sequences of SPFMV strains required for systemic infection, viral particle formation and insect transmission and showed typically rich in arginine and lysine residues. SPFMV,
BCKV isolate revealed a significant correlation between clustering of the viruses and geographical origin and sequence variation in coat protein gene of SPFMV from different subcontinents of the world is an interesting natural mutational phenomenon compared to the conserved coat protein domain of several plant viruses instead. Thelogenetic studies of polyprotein of SPFMV, BCKV isolate showed evolutionary compatibility with other viral taxa and a motif Asp-Ala-Gly (DAG) with the nucleotide sequence GATGCGGGA (nt 31-39) was found at the N-terminal region of coat protein (CP) gene of BCKV are same to other isolates and highly conserved domain which is required for aphid transmissibility. About 20 amino acids downstream from the DAG motif, there is a potential trypsin cleavage cited that is conserved in all potyviruses.

Keywords : Sweet potato, Coat protein, SPFMV, Amino acid profile, 3-D Structure

Performance of promising sweet potato genotype NSP-7 in South Gujarat

Himani B. Patel — 2024-08-28

Sweet potato has a great potential for productivity and energy output. The demand for sweet potato is increasing due to nutritional concerns leading to the availability of diverse genotypes for tuber colour, taste, quality parameters etc. In present study, one promising genotype NSP-7, was identified with higher tuber yield (23.39 t ha^-1), resistance to sweet potato weevil and slight pink skin colour having pale yellow flesh suitable for cultivation in south Gujarat, India. The morphological, biochemical and molecular analysis revealed NSP-7 as distinct genotypes. It has a high amount of starch (17.28%), fibre (3.97%) and protein (1.68%) as well as good cooking quality as compared to checks. Based on quality parameters and yield performance over the years and location, the NSP-7 genotype is recommended for cultivation in the south Gujarat region for maximum economic benefits.
Keywords : Sweet potato, NSP-7, Sweet potato weevil, Yield, Organoleptic score

Spacio-temporal fertigation effects on yield, nutrient use efficiency and economics of greater yam+maize intercropping system

Kalidas Pati — 2024-08-28

A field experiment was conducted for three seasons (2017-2018, 2018-2019 and 2019-2020) at the Regional Centre of Indian Council of Agricultural Research ICAR-Central Tuber Crops Research Institute (CTCRI) at Bhubaneswar, Odisha, India to find out the spacio-temporal fertigation effects on yield, nutrient use efficiency and economic of greater yam (Dioscorea alata L.) + maize (Zea mays L.) intercropping system. The experiment was laid out in split plot design with fertigation interval in main plots (I₁-2 days, I₂-3 days and I₃-4 days) and in sub plots number of splits (S₁-40 splits, S₂-50 splits and S₃-60 splits). Control (soil application at basal (40%), 45 (30%) and 90 (30%) days after planting) also included to compare the treatments. The treatments were replicated thrice. The results revealed that treatment I₁ resulted in significantly higher maize seed yield compared to other treatments. However, maximum greater yam tuber and tuber equivalent yield was noticed in treatment I₂. The treatment S₃ resulted in lower maize seed yield and higher greater yam tuber, and tuber equivalent yield. The interaction effect was found significant. The treatment I₁S₁ resulted in greater maize seed yield (3.2 t ha^-1) compared to other treatments. However, the treatment I₂S₃ resulted in higher greater yam tuber yield (37.0 t ha^-1) and tuber equivalent yield (39.4 t ha^-1). The treatment I3S1 was statistically on par with I₂S₃ regarding greater yam tuber (35.9 t ha^-1) and tuber equivalent yield (37.9 t ha^-1). The drip fertigation treatments I₂S₃ resulted in higher nutrient use efficiency of 106.5 kg of greater yam tuber equivalent yield per kg of nutrient (NPK) application. The treatment I₂S₃ resulted in higher gross (`5,91,000 ha^-1) and net (`3,80,000 ha^-1) returns compared to other treatments. Thus, fertigation of N-P₂O₅-K₂O @ 140-90-140 kg ha^-1 in 60 splits at 3 days interval was recommended for greater yam + maize intercropping system for higher system yield, nutrient use efficiency, gross and net returns.

Keywords : Fertigation interval, Greater yam, Maize, Nutrient use efficiency, Split application, Tuber equivalent yield

Integrated nutrient management in taro in relation to nutrient dynamics and fractionation of major nutrients in an Alfisol of Eastern India

K. Laxminarayana — 2024-08-28

Taro (Colocasia esculenta L.) is an important tropical tuber crop widely grown in many locations of northeastern India particularly due to the popular use of both its leaves and cormels as a traditional food. Moreover, the nutritive significance of the crop with respect to many valuable phytochemicals too helped in the widespread cultivation of this crop in these areas. The integrated nutrient management strategy for the crop is standardised and efforts were made to determine the different organic and inorganic fractions of the major nutrients under different combinations of nutrients on the yield
and proximate composition of the cormels. Hence, field experiments were conducted for two kharif seasons during 2018-2020 with 14 treatments replicated thrice in RBD in an Alfisol of eastern India. The soil of the experimental site is Typic Haplaqualf, which is slightly acidic, non-saline, very low in organic carbon (0.20%), and medium in available P and K. The effect of the treatments revealed that the inorganic fractions and available N, P and K contents were highest under integrated application of FYM along with half the recommended dose of N:P:K @ 40:15:40 kg ha^-1 followed by application of chemical fertilizer alone as N:P:K @ 80:30:80 kg ha^-1. Available N in the soil was contributed mostly by NO₃-N and transformation of total N into inorganic fractions. The available P fractions occurred as reductant soluble P (42.39 mg kg^-1) > Fe-P (38.10 mg kg^-1) > Ca-P (30.23 mg kg^-1) > Al-P (23.71 mg kg^-1) > Bray’s-1-P (17.86 mg kg^-1) > water soluble P (2.94 mg kg^-1). All the inorganic P fractions contributed significantly to the available P pool and the correlation coefficient (r₂) was
found in the order of water soluble P (0.97**) > Fe-P (0.96**) > RS-P (0.95**) > Al-P (0.94**) > Ca-P (0.90**). Occurrence of different K fractions was in the order of NH₄OAc-K (210.05 kg ha^-1) > exchangeable-K (186.56 kg ha^-1) > non-exchangeable K (111.54 kg ha^-1) > water soluble-K (23.49 kg ha^-1). However, exchangeable K and total K contributed significantly towards the available K content of the soil. Ammoniacal N showed highly positive and significant relationship with corm yield and biochemical constituents. Iron bound P and Al-P fractions contributed mostly towards the P nutrition of taro as these two fractions showed highly positive and significant correlation with yield and proximate composition. Of all the K fractions, non-exchangeable K recorded higher ‘r’ values for corm yield and biochemical constituents of taro. Integrated application of FYM and half the recommended dose of NPK not only enhanced the yield and quality of cormels and sustained the soil quality, but also influenced the NPK transformations for plant uptake in Alfisols.
Keywords : Integrated nutrient management, Organic manures, Inorganic fertilizers, Taro, NPK fractions

In vitro evaluation of twelve fungicides against three major fungal pathogens of tropical tuber crops

Prakash M. Patel — 2024-08-28

The productivity of tropical tuber crops is significantly threatened by a variety of diseases caused by fungi and viruses. These pathogens not only reduce yield but also affect the quality of the tubers, leading to substantial economic losses. Fungal pathogens, such as Sclerotium rolfsii, Colletotrichum gloeosporioides and oomycete, Phytophthora colocasiae are among the most destructive, causing diseases like collar rot in elephant foot yam, anthracnose in yam and taro leaf blight. Mancozeb is a broadly used fungicide for the control of plant diseases, including taro leaf blight and it has been banned for agricultural use by few countries due to its hazardous effects to humans and the environment. In a search for replacement of fungicides, twelve fungicides at different concentrations (100, 200, 400, 800 and 1600 ppm) were tested for their ability to arrest the major fungal pathogens of tropical tuber crops viz., Colletotrichum gloeosporioides, P.colocasiae and Sclerotium rolfsii. The chemicals recommended for the management of the diseases, mancozeb and carbendazim alone and their combinations with other chemicals were included to get the comparative efficiency of alternative options. The results suggest use of fungicides, difenoconazole, hexaconazole and metalaxyl-M+ chlorothalonil to manage diseases caused by Colletotrichum gloeosporioides. Metalaxyl-M+ chlorothalonil (Folio Gold) and cymoxanil+famoxadone (Equation Pro) can provide better protection from Phytophthora colocasiae. Hexaconazole and difenoconazole showed highest mycelial growth inhibition of S.rolfsii even at the lowest concentration tested. The lead obtained from the study will be a stepping stone to revisit the chemical management strategy followed to combat the pathogens.

Keywords : Fungicide, Sclerotium rolfsii, Colletotrichum gloeosporioides, Phytophthora colocasiae, Tuber crops

Women in Cassava Cultivation in Kerala- A Critical Analysis

D. Jaganathan — 2024-08-28

Women play a major role in agriculture as well as in cultivation of tuber crops. Cassava is a tropical tuber crop which grows well in Tamil Nadu, Kerala, Andhra Pradesh, Odisha and other northeastern states of India. In Kerala, cassava is mostly cultivated as a homestead crop and hence women raise this crop within their backyards. Women play a multifaceted role including management of household activities and caring the family. This study was conducted in Kerala state of India to analyse the profile characteristics of women involved in cassava farming along with their needs, preferences and opportunities in cassava cultivation. Two districts namely Thiruvananthapuram and Pathanamthitta were selected for the study as these districts occupy a major share of area under cassava in Kerala. A cluster of villages comprising two to three villages from each district were selected with a total sample of 65 women respondents. It was observed that 89.30 percent of the women belonged to middle aged category, and nearly 45 percent of the women were educated up to high school. Majority of the women were marginal farmers having less than 2.5 acres. Majority of the women’s level of aspiration was medium and only 12.30 percent had high level of aspiration. The needs, preferences and opportunities of the farm women were assessed to formulate strategies and action plan to empower women in cassava cultivation.
Keywords : Cassava, Women, Profile characteristics, Needs, Preferences, Opportunities

Probiotic and Anthocyanin Rich Purple Sweet Potato Frozen Yogurt

C. Pradeepika — 2024-08-28

Sweet potatoes are a rich source of diverse bioactive compounds, essential minerals, and dietary fibre and can be rationally targeted for wider human health-focused dietary solutions, especially to address diet-linked non-communicable chronic disease challenges. Therefore, the development of probiotic and anthocyanin-rich purple-fleshed sweet potato-based frozen yogurt to preserve and improve sweet potato-based human health-relevant nutritional qualities for health-targeted food application was
studied. Purple fleshed sweet potato (PSP) variety Bhu Krishna was selected based on its high baseline phenolic content and antioxidant activity. Full factorial design with five levels of PSP puree and yogurt resulted in 25 experimental runs employed in this study. Nutritional and microbial data of frozen yogurt was recorded before storage and 10thday of storage at -4°C. Among 25 combinations frozen yogurt samples with a higher percentage of PSP showed significantly (p<0.05) higher nutritional value. The combination, 70:30 showed higher anthocyanin content of 55.24 and 51.14 mg100 g^-1, protein content of 6.56 and 5.64%, and a fibre content of 0.69 and 0.33% on zero and tenth day of storage. In addition, the viable beneficial microbial count of formulations was ranged between 5.45 to 7.22 log CFU ml^-1 at tenth day of storage. Results suggested that beneficial lactobacillus (LAB) based
frozen yogurt development was an effective post-harvest processing strategy for higher retention of anthocyanin content and its associated antioxidant and anti-hyperglycaemic functionalities in sweet potatoes. Additionally, such frozen yogurt with probiotic as well as prebiotic potential can be integrated into health-focused dietary solution strategies, especially to improve human gut health and to mitigate chronic oxidative stress-linked non-communicable disease challenges.
Keywords : Frozen yogurt, Purple sweet potato, Probiotic, Viable cell count, Anthocyanins

Performance of growth regulators on breaking dormancy and to induce early and uniform sprouting in elephant foot yam

R. Muthuraj — 2024-08-28

Elephant foot yam [Amorphophallus paeoniifolius (Dennst.) Nicolson] is a popular tropical tuber crop grown for its starchy corms. It is propagated through both corms and cormels. Lack of sufficient planting materials of uniform size, non-availability of good quality planting materials and corm dormancy are the major constraints in the production of elephant foot yam. Corms are not suitable for immediate planting due to the dormancy period and also the slow development of buds which takes about 2-3 months after harvest. Field experiment was conducted at ICAR-Central Tuber Crops Research Institute (CTCRI) , Sreekariyam, Thiruvananthapuram, Kerala during crop seasons 2017-18 and 2018-19 to find out the performance of growth regulators and chemical treatments on dormancy breaking to induce uniform sprouting and enhance yield in elephant foot yam. The results revealed that the corms subjected to fumigation treatment with carbon disulphide @ 80 ml per 100 kg corm resulted in maximum uniform sprouting with 89.75%, 99.89% sprouting at 15, 40 days after planting followed by Gibberellic acid (GA3 200 ppm). The growth parameters indicated that maximum plant height (58.75cm), pseudo stem girth (86.25cm) and canopy spread (77.65cm) were recorded in plants raised from corms fumigated
with carbon disulphide @ 80 ml per 100 kg corm at 90 days after planting. The corm yield data revealed that plants raised from fumigated corms produced significantly higher corm yield (34.85 t ha^-1), followed by plants raised from corms treated with GA3 (200 ppm) (29.25 t ha^-1), in comparison to 14.93 t ha^-1 from plants raised from untreated corm.
Keywords : Germination, Dormancy breaking, Fumigation, Growth regulator, Corm yield

Tuber crops based cropping system for western Himalayan region of India

Manpreet Kaur — 2024-08-28

To study productivity, profitability, livelihood, and sustainability, the traditional maize-wheat system was compared with a cropping system, including tuber crops on a 1.0 ha area. The percent share of tuber crops and other horticultural crops was 35.84%. The major tuber crop in the studied system was elephant foot yam. The total elephant foot yam equivalent yield in the existing maize wheat system and cropping system involving tuber crops were 27.33 q ha^-1 and 59.07 q ha^-1, respectively. The gross returns were more than ten times higher in the studies system over the existing maizewheat
system. Production efficiency of cropping system involving tuber crops was increased by two times over the maize-wheat system. The study model can be replicated over different locations by inclusions of site-specific agri-enterprises.
Keywords : Cropping system, Tubers, Vegetable, Cereals, Diversification, Sustainability

Influence of mini seed corms and spacing in elephant foot yam on corm size and yield

Dr. C. Thangamani — 2024-08-28