JOURNAL OF ROOT CROPS

Emerging Cassava Root and Stem Rot: A Challenge to Wetland Farmers in Kerala

2022-10-25T10:00:58+00:00

Identification of duplicates in the germplasm of sweet potato (Ipomoea batatas (L.) Lam.) using morphological and molecular markers

2022-10-21T11:24:40+00:00

Fifty accessions of sweet potato from National Active germplasm site of ICAR-CTCRI were selected for morphological and molecular analysis and to identify duplicates. Morphological analysis was performed by using twenty IPGRI descriptors. The data analysed using R package separated the accessions into five principal clusters at a Euclidean distance of 15 and resulted in the identification of three pairs of morphological duplicates (S-236 and S-256, S-203 and S-295, S-772 and S-747). The PCA analysis
revealed predominant vine colour and secondary vine colour, abaxial vein pigmentation and petiole pigmentation as the major factors that contributed to the clustering of the sweet potato accessions. Molecular characterization using 11 ISSR primers resulted in 162 polymorphic bands with a mean value of 14.7 bands per primer. The dendrogram based on ISSR markers dendrogram grouped the accessions into six clusters at a Jaccard distance of 0.9. The third principal cluster comprised of 20
accessions which were assembled in 5 sub-groups which indicates high intraclusteral variability. The fourth principal cluster comprised of 15 accessions in 4 groups. In this principal cluster S-236 and S-256 grouped together with 100% similarity. This pair can be considered as true duplicates which were also found similar in morphological characterization. The similarity between the different accessions ranged between 52-100%. The least similar accessions were SD-39 and S-298 (52%). Thus it can be inferred that maximum of 48% variability existed within the selected accessions which can be considered as a low to moderate diversity. Based on morphological and molecular analysis three pairs of duplicates were identified and may be culled out from the germplasm.

Growth, Dry Matter Production and Yield Characteristics of Greater Yam+Maize Intercropping System Under Varied Drip Irrigation and Fertigation Levels

2022-10-21T12:03:27+00:00

Field experiments were conducted during 2015-16 and 2016-17 to study the influence of drip irrigation and fertigation on growth, dry matter production and yield characteristics of greater yam+maize intercropping system. The treatments comprised of a combination of three levels of drip irrigation [I1- at 80% of cumulative pan evaporation (CPE) during 1-270 days after planting (DAP), I2-at 100% of CPE during 1-90 DAP + at 80% of CPE during 91-270 DAP and I3-at 100% of CPE during 1-270 DAP] in main plots and four levels of fertigation (F1-N-P2O5-K2O @ 100-90-100 kg ha-1, F2-N-P2O5-K2O @ 120-90-120 kg ha-1, F3-N-P2O5-K2O @ 140-90-140 kg ha-1 and F4-N-P2O5-K2O @ 160-90-160 kg ha-1) in sub plots along with a control (surface irrigation treatment at 100% of CPE; soil application of N-P2O5-K2O @ 120-90-120 kg ha-1). Drip irrigation at I3 resulted in higher maize and greater yam growth and dry matter production. The treatment F4 resulted in greater yam and maize growth and dry matter production. The interaction effects revealed that highest maize yield was recorded in I3F4 whereas the treatment I2F4 resulted in higher greater yam yield. However, maize and greater yam yield in the treatment I2F3 was found statistically at par with I3F4 in maize and I2F4 in greater yam. The treatments control (surface irrigation at 100% of CPE with soil application of N-P2O5-K2O @ 120-90-120 kg ha-1) and I1F2 [drip irrigation at I1 with fertigation of same level of nutrients (F2)] resulted in same level of maize and greater yam yields. Thus, drip irrigation saved 0.684-0.710 million litre (17.9-25.9%) of water per ha. Same level of maize and greater yam yields with the treatments control and I2F1/I3F1 also indicated a saving of nutrients N-K2O @ 20-20 kg ha-1 (20%) under drip fertigation. Considering water and fertilizer use efficiency and response, the treatment I2F3 (irrigation at 100% of CPE during 1-90 DAP + at 80% of CPE during 91-270 DAP with N-P2O5-K2O @ 140-90-140 kg ha-1) is recommended for greater yam+maize intercropping system

Nutrient Uptake, Tuber Yield and Soil Physicochemical Properties as Influenced by Tillage and Nutrition for Tannia (Xanthosoma sagittifolium (L.) Schott) in the Red Soils of Southern Kerala

2022-10-25T06:33:40+00:00

A study was undertaken at College of Agriculture, Vellayani, Thiruvananthapuram, Kerala during 2014- 2016 to identify an ideal tillage system and plant nutrition for tannia for improving the nutrient uptake and tuber yield of tannia and also to evaluate their effects on the physico-chemical properties of soil. The design used was split plot and was replicated four times. The main plot treatments were conventional tillage followed by pit system, conventional tillage followed by mound system, deep tillage followed by pit system and deep tillage followed by mound system. The sub plot treatments were combinations of soil conditioners (control, coir pith, rice husk) and nutrient management systems (integrated nutrient management (INM) and organic nutrition). The results revealed that deep tillage to a depth of 30 cm followed by pit or mound system of planting, application of coir pith as soil conditioner (@ 500 g plant-1) and organic nutrition (FYM @ 37.5 t ha-1 + wood ash @ 2 t ha-1) is ideal for enhancing nutrient uptake and tuber uptake of tannia without depletion of soil nutrient status

Effect of Native AMF inoculation on Nutrient Composition, Uptake and Quality Attributes in Cassava

2022-10-25T09:03:46+00:00

Results of the potted cassava experiment conducted during the crop season of 2018 and 2019 to determine the influence of native AMF inoculation in cassava revealed that inoculation of Glomus fasciculatum (AMF culture No 3) with P nutrition at 100 per cent combined with application of N and K at recommended dose had remarkably increased the concentration of N, P, K, content in leaf P and K content in tuber. However, inoculation of G. fasciculatum (AMF culture No 3) had shown higher values for nutrient concentration, and it was statistically on par with inoculation of G. fasciculatum with P nutrition at 50 per cent and N and K at recommended dose. Uptake of NPK in leaf, stem and tuber was studied for this experiment which showed that inoculation of G. fasciculatum (AMF culture No 3) had higher values. Hence G. fasciculatum (AMF culture No 3) can be recommended for inoculation
in cassava and the application of P fertilizer can be reduced to 50 per cent of the recommended dose for realizing maximum tuber yield and quality.

Physiological Efficiency of Cassava as Influenced by Genotypes Over Period of Maturity in the Screening of K Use Efficient Genotypes

2022-10-25T09:17:26+00:00

Plant nutrition of cassava is important on account of its high yield to the tune of 30-50 t ha-1. Among the major nutrients, the key nutrient, K plays a significant role in enhancing tuber yield and improving tuber quality. This relevance of K urged in undertaking research to screen K use efficient cassava genotypes with a view to reduce the external application of K. The initial evaluation of 83 elite cassava genotypes conducted at ICAR-CTCRI to exploit their physiological efficiency (PE) of K grouped the genotypes into five clusters with 9, 48, 17, 5 and 4 genotypes respectively in each cluster. The parameters contributing to PE viz., biological yield and total plant nutrient uptake were influenced by plant dry matter yield, dry matter percentage and K contents of the genotypes. This paper narrates the genetic diversity among clusters, among the intervals of maturity and their interaction as well as the significant effect of the parameters associated with PE under different clusters and stage of maturity in the identification of K efficient genotypes. The study revealed significant effect of number of storage roots and tuber length at 6 MAP under cluster 1, tuber girth at 10 MAP, leaf and stem K at 6 MAP under cluster 2, storage root dry matter percentage at 6 MAP under cluster 3, leaf and stem dry matter percentage at 8 MAP under cluster 4, storage root K at 10 MAP under cluster 5 in affecting the PE. As most of these attributes are significantly high during 6 MAP, it can be established that, screening for NUE should be done at 6 MAP. Since the tuber quality attributes being important in the selection of genotypes, the analysis indicated lowest cyanogen under cluster 2 at 10MAP and highest starch under cluster 4 at 6 MAP. Among the six genotypes identified as K efficient through preliminary evaluation, Aniyoor, 7 Sahya (2) and 7III E3-5 came under cluster 1 and W-19, CR 43-8, 6-6 under cluster 2. This information with respect to each cluster towards their contribution in influencing the inherent PE of the genotypes as well as the variability in growth stages in influencing the associated attributes can form crucial factors in selecting parent materials for breeding purpose in evolving K efficient genotypes.

Evaluation of Plant Nutrition Traits Based Genetic Variability to Identify N-P-K Use Efficient Genotypes in Cassava

2022-10-25T09:24:48+00:00

A total of 132 elite genotypes were evaluated to identify N-P-K use efficient genotypes in cassava. The genetic variation was studied through the principal component, cluster, biplot and dendrogram analysis. Principal component analysis (PCA) extracted seven principal components with a cumulative variability of 73.3% with the highest variability (24.1%) in PC1 and the least in PC7 (4.7%). Hierarchical cluster analysis resulted in eight clusters having 62, 29,13,18, 2,5,2 and 1 genotypes in clusters one to eight respectively with each cluster having genotypes with almost similar characters. Biplot indicated the characters important for each genotype and the dendrogram had eight groups with the same genotypes composition as in cluster analysis. These analyses revealed the distinct variation among these genotypes and the genotypes in clusters 1, 2, 3, and 4 were later screened as nutrient use efficient (NUE) too. These included NPK efficient genotypes viz., Acc. No. 7, 775, 788, 796 (cluster 1), Acc. No. 130, 766 (cluster 2), Acc. No. 696 (cluster 3), NP efficient genotypes viz., Acc. No. 890, 896 (cluster 1), Acc. No. 115 (cluster 4) and PK efficient genotypes viz., Acc. No. 662, 905, 906, 908 (cluster 1), Acc. No. 750 (cluster 3). Biplot analysis revealed the characters linked to the genotypes are significant for genotypes in clusters 1,2,3 and 4 which in turn were later delineated as NUE genotypes. These accessions can form a broad genetic base in breeding programmes to evolve genotypes with better NUE.

Polyhalites (Polysulphates): Best Soil Ameliorant for Cassava (Manihot esculenta Crantz) in the Ultisols and Entisols of Kerala

2022-10-25T09:31:08+00:00

Among the tropical tuber crops, cassava is important due to its higher biological efficiency, larger area under cultivation both for edible and industrial uses, ability to withstand biotic and abiotic stresses, quality starch in the preparation of many value added products including ethanol and biodegradable plastics. In India, cassava is cultivated mainly in Kerala, Tamil Nadu, Andhra Pradesh, Maharashtra and North Eastern States. In Kerala, it is grown as an edible crop and more than 90% of the soils under cassava are acidic (Ultisols), deficient in nutrients like K, Ca, Mg and B. Polysulphate, a natural mineral product containing 18.5% S,13.5% K2O, 5.5% MgO and 16.5% CaO was evaluated in agroecological unit (AEU) 3, AEU 8 and AEU 9 in Kerala for two seasons in five farmers’ fields and one at on station since June 2018 to explore its possibility as a good soil amendment by studying its effect on tuber yield, tuber quality and soil physico-chemical properties. Polysulphate application can be done either as half lime and half dolomite as per lime requirement along with 1-2 t ha-1 polysulphate which resulted in a tuber yield of 53.33 t ha-1 on par with full dolomite along with polysulphate (50.32 t ha- 1) and polysulphate alone (49.24 t ha-1).The yield increase with polysulphate application over PoP, and lime together with dolomite was to the tune of 17.10% and 15.55% respectively. Polysulphate improved bulking of tubers in good form with better quality in terms of cooking, improvement of starch and lowering of bitterness. Though there is no substantial improvement in soil pH, the exchangeable soil K, Ca, Mg and S showed an increase of 80.93, 91, 2.54 and 59.84% over initial compared to 17.84, 90, -11, -0.66% under PoP and 42.39, 82, 18.95 and -3.28% under lime along with dolomite respectively for these nutrients.

Response of Potassium Use Efficient Cassava Genotypes under Different Levels of N and K in an Ultisol of Kerala, India

2022-10-25T09:36:55+00:00

Among the different factors contributing to the production potential of a crop, the genetic potential of the crop in terms of nutrient acquisition, transport and utilization is important with respect to its nutrient use efficiency in reducing the external application of fertilizers. The research work conducted on screening K efficient cassava genotypes resulted in the identification of six genotypes viz., Aniyoor, W-19, 7 Sahya-2, 6-6, CR 43-8 and 7 III E3-5 based on their inherent physiological efficiency. These six genotypes were evaluated under different levels of K and N (0, 50, 100, 150 kg ha-1) to standardise the optimum dose of these nutrients for economic yield and also to confirm the N use efficiency potential of the K efficient genotypes. In this regard, observations were taken on nutrient use efficiency (NUE) parameters viz., HI, nutrient HI, nutrient uptake ratio, tuber yield and tuber quality. Since leaf and root architecture are the major contributors to NUE, LAI as well as the root parameters were also studied. Correlation among these different parameters were also studied especially to understand the effect of leaf and root characters on yield, NUE parameters including physiological efficiency. The study revealed significant differences among genotypes in the case of LAI and was higher under N than K levels. But, nutrient HI was higher under K. K levels significantly influenced the NUE parameters and K @ 50 kg ha-1 had highest impact on these parameters. Though no significant effect of K levels was seen on tuber yield, N @ 150 kg ha-1 resulted in significantly the highest tuber yield. The study of different root types in the root system of the crop under controlled conditions and in field over periodic growth intervals of cassava showed that, parameters viz., number of tuberous roots, its fresh weight and dry weights as well as root hairs were highest for the selected K efficient genotype Aniyoor. In the case of these genotypes under N levels, the identified genotypes viz., W-19 and CR 43-8 possessed larger volume of white roots, root length and diameter. Correlation studies revealed significant positive correlation of tuber yield with LAI, K/N uptake ratio and harvest index. Based on these parameters, the genotype Aniyoor and 7III E3-5 were identified as K efficient and the genotype W-19 and CR43-8 as N efficient.

Growth Promotion in Elephant Foot Yam (Amorphophallus paeoniifolius (Dennst.) Nicolson) Consequent to Colonization by the Root Endophytic Fungus, Piriformospora indica

2022-10-25T09:42:38+00:00

Elephant foot yam (EFY) is widely cultivated in many states of India due to its high production potential; acceptability as a vegetable in many delicious recipes and use in Ayurvedic medicines. Piriformospora indica is an endophytic mycorrhiza like fungus which has shown pronounced growth promotional and disease suppressing activities in many crops. The potential of P. indica to colonize elephant foot yam roots was explored for the first time and growth promotion in elephant foot yam plants consequent to root colonization by P. indica was also studied. Among twelve solid media evaluated for growth, maximum radial growth of P. indica was obtained on cassava starch and wheat extract + Jaggery (9 mm day-1). Among the ten liquid media tested, maximum mycelial mass was observed in wheat extract + jaggery and wheat extract + PDA media. The colonization ability of P. indica in elephant foot yam (var. Gajendra) was studied by trypan blue staining and further confirmation of colonization was done by amplifying species specific Pitef1 gene. Incorporation of P. indica resulted in promotion of all growth parameters like shoot length, root length, biomass, girth, leaf area etc. of host plant. P. indica is known to inhibit many pathogens in various crops apart from causing growth promotion. Hence, studies on the effect of P. indica colonization on various diseases of elephant foot yam will help in tapping the full potential of the organism in organic cultivation of EFY

Yam Bean Seed Extract: An Alternative to Chemical Insecticide in Managing Cereal Aphid in Barley

2022-10-25T09:49:14+00:00

Barley is an important cereal grown in Northern India, particularly during the rabi season. Nowadays, the aphid (Sitobium avenae) has emerged as a major key pest because of anthropogenic climate change and natural variability, which was considered as a minor pest during the past decade. An experiment was conducted at Research farm, Tirhut College of Agriculture,Dholi to evaluate the efficacy of tuber crop based bio-pesticide against aphid in barley. Bio-pesticides based on yam bean and cassava such as yam bean seed extract and powder, cassava leaf extract, and tuber rind extract along with chemical insecticide (dimethoate) were evaluated. Among them, two sprays of yam bean seed extract @ 5% at an interval of 15 days was found to be the most effective in managing the aphid population, which was at par with that of chemical insecticide dimethoate @ 0.05% and found to be safe for natural enemies particularly ladybird beetle and spider which are considered as a major predator of aphid in this ecosystems.

Post-Harvest Physiological Deterioration of Cassava Roots (Manihot esculenta Crantz) During Storage Under Different Temperatures

2022-10-25T09:54:31+00:00

Cassava storage roots are highly perishable owing to a phenomenon called post harvest physiological deterioration (PPD). PPD is thought to be result of failed wound response involving various biochemical pathways, reactive oxygen production, changes in phyto-hormones, oxidative enzymes and secondary metabolite production etc,. Storage temperature alter the biochemical processes in root tissue and hence three different storage temperatures such as low (8±2°C), ambient (28±4°C) and high temperature (40±2°C) on the onset of PPD in five different varieties of cassava were studied. Root respiratory rate, oxidative enzymes such as catalase, peroxidase activities were studied for 1, 3 and 6 DAS and correlated with PPD scores. Storage temperatures influenced the respiratory rate as well as the activities of CAT and POX during storage. Varietal variations were noted for respiratory rate and enzyme activities with different storage temperatures. High temperature storage reduced the respiratory rate of roots compared to ambient temperature storage. CAT and POX activities were correlated positively during 1 and 3 DAS and negatively at 6 DAS. PPD positively associated with POX at 6 DAS. Storage of roots under high temperature (40°C) with high RH (80-90%) delayed the onset of PPD and extended shelf-life of cassava roots for a week.