Rhizome Yield Research Articles

Effect of growth regulators on the growth and yield of ginger (Zingiber officinale Rosc.) under polyhouse condition

The experiment has been conducted to resolve the poor partitioning of dry matter towards rhizome by using plant growth regulators (PGRs). Therefore, two pot culture experiments were conducted during 2020-22 using the variety IISR Varada to investigate the effects of foliar application of PGRs (6-BAP, cycocel, GA3 and PBZ at five different concentrations viz. control, 50ppm, 100ppm,150ppm and 200ppm in three replications) on growth and yield. The experiment was laid out in Factorial CRD design under polyhouse condition. The results revealed that 6-BAP at 100ppm significantly increased the number of tillers, secondary rhizomes, tertiary rhizomes, length, diameter of rhizomes, and rhizome yield (322.3g/ plant) which is 240% more than the control.

Multivariate analysis for various agro-morphological traits of turmeric (Curcuma longa L.)

Turmeric is one of the potential spice crops having importance in culinary, colouring in textiles and therapeutic in pharmaceutical industries. The present investigation was carried out to estimate the genetic diversity of 21 turmeric genotypes representing different geographical locations of India. The principal component (PC) analysis indicated that the most of the variation among the genotypes was contributed by the first two principal components (61.38%), which were largely governed by plant height, number of leaves per plant, leaf lamina length, leaf area, total leaf area, collar girth and weight of the mother rhizomes per clump. These traits showed high positive correlation with first two PCs and influenced significantly for grouping. Based on PC correlation analysis, it is evident that morphological and yield attributing traits of PC1 and PC2 are influenced and contributed for most of the variation among the genotypes. The cluster analysis revealed that the 21 genotypes fall into five clusters, and among them most divergent with distinct genotypes were cluster I, III and cluster IV. However, IISR Pragati, Rajendra Sonali and NDH 8 were found superior for fresh rhizome yield and Acc. 849 was found unique with robust mother rhizome. The present study contributes to the knowledge of genetic diversity and defining strategies for yield improvement in turmeric.

Evaluation of Performance of Turmeric (Curcuma longa L.) Varieties in Dharmapuri District of Tamil Nadu, India

Turmeric is an important spice crop cultivated in various states of India and Tamil Nadu is one of the leading producers of Turmeric. The productivity of Turmeric in Tamil Nadu was 3.80 MT/ha (cured rhizome yield) which is lower than the national productivity. Though there are various factors affecting productivity, choice of varieties was one of the important factors among them. On farm trials were conducted to study the performance of Turmeric varieties viz. BSR 1, BSR 2, CO 2, Allepey Supreme, PTS 10 and Roma at Krishi Vigyan Kendra, Papparapatty of Dharmapuri district. The experiment was conducted in randomized block design with three replications. The crop management practices are carried out as per Crop Production Guide 2020 of Tamil Nadu Agricultural University, Coimbatore recommendation. The yield data revealed that there was significant variation among the turmeric varieties in various growth and yield determining parameters. Among the varieties CO 2 performed better than the other varieties with highest yield per plant (468.99 g), cured rhizome yield per hectare (6.82 tonnes/ha) followed by BSR 2. The results of the study show that CO 2 performed better in Dharmapuri district when compared to other varieties and hence can be preferably recommended to the farmers for better yield. The yield attributing factors viz. plant height, leaf size, weight of mother rhizome, weight and number of primary and secondary fingers are positively correlated with the yield per plant and hence can be used as criteria for varietal selection.

Effect of Fertilizer Doses on Turmeric at Madhupur Tract under AEZ-28

A field experiment was conducted at MLT site, Madhupur (AEZ-28), Tangail during 2020-21 and 2021-22 to find out an optimum fertilizer dose of turmeric in Madhupur tract and increase productivity and economic return of the farmers. The experiment was laid out in a randomized complete block design with five compact replications. The tested six treatment combinations were as T1: STB as per FRG’ 2018 (116-27-77-8-1.5-1.2 kg NPKSZnB ha-1 ), T2 : T1 + 20% extra NK (139-27-92-8-1.5-1.2 kg NPKSZnB ha-1), T3 :T1 + 20% extra NKS (139-27-92-9.6-1.5-1.2 kg NPKSZnB ha-1), T4 :T1 + 20% extra NKSZn (139-27-92-8-1.8-1.2 kg NPKSZnB ha-1), T5 : IPNS basis fertilizer with 5 t ha-1 cow dung (91-20-66-8-1.5-1.2 kg NPKSZnB ha-1) and T6 : Farmers’ practice (115-50-125 kg NPK ha-1). BARI Halud-5 was used as test crop in this experiment. The unit plot size was 8m × 5m and spacing was maintained as 50 cm apart rows with plant to plant 25 cm. Seeds (rhizome) were planted @ 2000 kg ha-1 during 14-20 April, 2020 and 10-15 April 2021. The treatments showed significant differences in terms of yield and yield contributing characters. The highest fresh rhizome yield (17.13 t ha-1) was recorded from IPNS basis fertilizer with 5 t ha-1 cow dung i.e. (91-20-66-8-1.5-1.2 kg NPKSZnB ha-1) treatment combination. The highest gross return (Tk.256950 ha-1) and gross margin (Tk.136740 ha-1) were recorded from the (T5) same treatment The marginal benefit cost ratio (3.79) was also highest in IPNS basis fertilizer with 5 t ha-1 cow dung i.e. (91-20-66-8-1.5-1.2 kg NPKSZnB ha-1) which further indicated the superiority among the treatments.

Effects of topping on rhizome, and analysis of chemical composition, antioxidant activity and α-amylase and α-glucosidase inhibition of the aerial parts in Polygonatum cyrtonema.

Polygonatum cyrtonema is a perennial plant, and it has long been used in traditional Chinese medicine for food and medicine. The medicinal part of P.cyrtonema is the rhizome; however, the aerial part has not been studied. To understand the effect of the topping of aerial parts on the yield and chemical components of rhizomes, as well as the chemical constituents, antioxidant, and in vitro hypoglycemic activities of the aerial stem, leave, and flower parts of P.cyrtonema, the present study was conducted. The results showed that compared to the control (CK) treatment, the topping of the aerial part increased rhizome weight gain coefficient (3.43) and the total saponin content (37.60 mg/g) significantly (P<0.01) than the CK treatment. The contents of total phenols and total flavonoids in PCL and PCF were significantly (P<0.01) higher than those in rhizomes; however, the polysaccharide content (10.47%) in PCR (whole rhizome) was higher than that in PCS (3.65%), PCL (5.99%), and PCF (4.76%) content. The protein and amino acid contents in PCS, PCL, and PCF were higher than those in rhizomes. The protein and amino acid contents in PCS, PCL, and PCF were higher than those in rhizomes. PCS, PCL, and PCF showed strong antioxidant activity (DPPH, ·OH, ABTS, and FRAP), which were better than traditional medicinal parts (the rhizome).In vitro hypoglycemic results showed that PCS, PCL, and PCF had certain inhibitory activities on α-amylase and α-glucosidase (66.25% and 52.81%), which were close to the hypoglycemic activity of rhizomes (67.96% and 52.22%). The leaf extracts also showed better inhibitory activity. To sum up, the topping measures can improve yield and total saponin content of the rhizomes from P.cyrtonema, which can be applied to improve production. The stems, leaves, and flowers had a much stronger antioxidant and hypoglycemic activities and higher the total polyphenols, flavonoids, proteins, and amino acid content. Therefore, stems, leaves, and flowers of Polygonatum can be fully developed according to different needs. they are typically used in animal feed, food storage and cosmetics.

Genetic Divergence among On-farm Collections for Yield and Yield-related Traits in Ginger (Zingiber officinale R.)

The present investigation was carried out at the farmer’s field Neshwi village, Haveri District of Karnataka, India during kharif season (May, 2021 to January, 2022). The improvement of crop relies heavily on genetic diversity. The objective of the study was to assess the genetic divergence of 76 diverse genotypes of ginger collected from different parts of the Karnataka, India which including four checks. The genetic divergence of ginger genotypes was assessed using Mahalanobis D2 statistics. Genetic divergence studies revealed considerable genetic diversity among 76 genotypes of ginger for a set of ten quantitative traits pertaining to the growth and yield characters viz., height of the shoot (cm), leaf area (cm2), number of primary rhizomes, length of the primary rhizome (cm), girth of the primary rhizome (cm), number of secondary rhizomes, length of the secondary rhizome (cm), girth of the secondary rhizome (cm), crop duration (number of days) and rhizome yield plant-1 (g). Analysed 76 ginger genotypes were clustered based on similarities between their D2 values using Tocher’s method, resulting in 14 distinct groups. Considerable diversity within and between 14 clusters was observed among the genotypes. The characteristics such as average rhizome yield plant-1, girth of the primary rhizome and length of the primary rhizome were the main factors in differentiating the genotypes of ginger studied. Utilizing genotypes from clusters with high inter-cluster distances, such as clusters VI and XIII, VI and XIV and X and XIV can form potential pre-breeding material for the improvement of ginger crop.

Patterns in genetic variation and character association of yield components in turmeric (curcuma longa L.)

Understanding genetic variability patterns of turmeric yield traits is essential to develop new genotypes with improved traits. The objective of the present study was to investigate the genetic variability, heritability, genetic advance and association of various yield components in turmeric genotypes. The experiment was conducted for two seasons during 2021-22 and 2022-23 using 21 turmeric genotypes at ICAR-IISR, Experimental farm, Peruvannamuzhi, Kerala. The results indicate that the genotypes exhibited significant variation across two seasons for most traits, with the exception of collar girth, weight of primary rhizomes per clump, and number of primary rhizomes per clump, which suggests the presence of genetic variability in the genotypes. Maximum fresh rhizome yield per clump was recorded in the genotype, IISR Pragati. The Genotypic Coefficient of Variation (GCV) was found to be moderate to high for most of the traits except plant height, leaf lamina length, collar girth and fresh rhizome yield per plant, whereas, Phenotypic Coefficient of Variation (PCV) was found to be moderate to high for all the traits except plant height. Heritability was observed moderate to high for all the traits except collar girth, number of primaries per clump, weight of primaries rhizomes per clump and fresh rhizome yield per plant. The petiole length, total leaf area, weight of mother rhizomes per clump and number of mother rhizomes per clump showed high heritability along with genetic advance. Correlation analysis suggested that weight of mother rhizomes per clump had a strong positive association with plant height, number of leaves, leaf lamina length, leaf lamina width, leaf area, total leaf area, and collar girth and had a weak positive relationship with fresh rhizome yield per plant and petiole length. The path analysis revealed, total leaf area, fresh rhizome yield per plant and number of primaries per clump have high direct positive effects with weight of mother rhizomes per clump. The high heritability and genetic advance observed for above mentioned traits suggest that exercising a simple selection could indirectly improve the low heritable low genetic advance traits such as fresh rhizome yield per plant as indicated by correlation and path analysis.

Improvement of ginger for yield and quality traits under the hill ecosystem of Mizoram

The field study on ginger was carried out at ICAR Research Farm, Mizoram Centre, for three consecutive years (2019-2021). The best selection criteria for crop improvement were determined based on genetic component analyses and Principal Component Analysis (PCA). There exists highly significant variation for all traits due to genotypes based on analysis of variance. The highest extent of variability was recorded in oleoresin content. The magnitude of heritability and genetic gain was moderate to high for LAI, leaves per hill, tillers per plant, fresh weight of clump, rhizomes per plant, dry recovery, total chlorophyll, total phenol content, 6-gingerol and oleoresin content, indicating the additive gene control for which choosing of these traits will be beneficial. The rhizome yield exhibited the highest positive correlation with leaves per hill, followed by LAI and tillers per plant. Direct selection of characters like LAI, fresh weight of clump, rhizomes per plant and 6-gingerol content could be most reliable for yield improvement. Based on PCA and bi-plot figures, LAI, tillers per plant, leavesper hill, rhizomes per plant, fresh weight of clump, and yield of rhizomes contributed mostly to genetic diversity among the ginger genotypes and ‘Bold Nadia’, ‘Bhaise’ and ‘PGS 102’ were identified as the best genotypes possessing optimum combinations of yield and quality traits for exploitation in future programmes under Mizoram condition

Residue of Chlormequat and Regulatory Effects on the Specialized Metabolites of Astragali Radix.

Presently, the utilization of chlormequat in Astragalus mongholicus Bunge (Leguminosae) cultivation is prevalent for augmenting rhizome (Astragali Radix) yield. However, indiscriminate and excessive chlormequat employment can detrimentally influence Astragali Radix quality and safety. This research aimed to comprehensively comprehend chlormequat risks and its influence on Astragali Radix metabolites. Diverse chlormequat concentrations were employed in Astragalus mongholicus cultivation, with subsequent analysis of residual chlormequat levels in Astragali Radix across treatment groups. Astragali Radix metabolic profiling was conducted through UPLC-QTOF-MS, and thirteen principal active components were quantified via UFLC-MS/MS. Findings revealed a direct correlation between chlormequat residue levels in Astragali Radix and application concentration, with high-dose residue surpassing 5.0 mg/kg. Metabolomics analysis identified twenty-six distinct saponin and flavonoid metabolites. Notably, the application of chlormequat led to the upregulation of seven saponins (e.g., astragaloside I and II) and downregulation of six flavonoids (e.g., methylnissolin-3-O-glucoside and astraisoflavan-7-O-β-d-glucoside). Quantitative analysis demonstrated variable contents of active ingredients due to differing chlormequat concentrations, leading to astragaloside I increase (14.59-62.55%) and isoastragaloside II increase (4.8-55.63%), while methylnissolin-3-O-glucoside decreased (22.18-41.69%), as did astraisoflavan-7-O-β-d-glucoside (21.09-47.78%). In conclusion, chlormequat application influenced multiple active components in Astragali Radix, causing constituent proportion variations. Elevated chlormequat concentrations led to increased active components alongside heightened chlormequat residues in Astragali Radix. Consequently, prudent chlormequat application during Astragali Radix production is imperative to avert potential detriments to its quality and safety.

Estimation of Genetic Variability and Character Association Analysis of Underutilized Ornamental Canna Lily (Canna indica L.)

Background: Canna lily (Canna indica L.) is an edible herbaceous perennial plant in which flowers and rhizomes were commonly used as a food additive and its potentiality was not fully utilized in India. To stun these hindrances, morphological characterizations are needed to determine the genetic variability to improve flower quality and rhizome yield in canna lily. Methods: In the present research, a field experiment was conducted during 2022-2023 in Botanical Garden, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu. Twelve accessions were investigated by using a randomized block design with 3 replications. All the observations for 23 quantitative traits were carried out at 0.05 and 0.01 probability. Results: The wide range of genetic variability was observed, a high genetic coefficient of variation ranged from 8.49 to 75.62 % and a phenotypic coefficient of variation ranged from 8.83 to 76.50 % was observed in 20 traits except in time taken for first flowering, rhizome diameter, number of nodes per rhizome. High heritability coupled with high genetic advance as a percent of mean was observed for 21 traits except in time taken for flowering and number of nodes per rhizome. Character association analysis revealed that stem diameter and inflorescence length showed highly significant and positively correlated with flower yield and rhizome yield per plant. Path analysis specified that the number of leaves per clump had a very high and positive direct effect on fresh flower yield per plant.

Effect of Drip Irrigation Levels and Weed Management Practices on Quality Parameters and Yield of Turmeric (Curcuma longa L.) under Mango Orchard

A field experiment, aimed to study the effect of drip irrigation levels and weed management practices on quality and productivity of turmeric (Curcuma longa L.) in mango orchard was carried out at Pt. K.L. S. College of Horticulture and Research Station, Rajnandgaon (Chhattisgarh) during two consecutive years (2019-20 and 2020-21). The results indicated that all the quality parameters like total carbohydrate in rhizomes, volatile oil yield in rhizomes, oil yield and curcumin content in turmeric were significantly higher values observed when the crop imposed to drip irrigation at 1.0 Epan and hand weeding thrice at 25, 50 and 75 DAP in 2019-20 and 2020-21. However, flood irrigation at 1.0 Epan and weedy check plot recorded the lowest values of these parameters during both years. The combination of drip irrigation at 1.0 Epan with hand weeding thrice at 25, 50 and 75 DAP recorded significantly the highest fresh rhizomes yield (29.10, 32.40 and 30.75 t ha-1) and cured rhizomes yield (6.58, 6.93 and 6.76 t ha-1) during kharif -rabi 2019-20 and 2020-21and on mean basis, respectively.

Assessment of selection criteria using multi-year study for effective breeding program of Zingiber officinale L.

Ginger has been an important cash crop with numerous applications since ancient times. As the demand for ginger is ever-growing and being a seasonal crop, a high-yielding variety of ginger would be economically profitable. In this study, 150 germplasm were collected from different regions of NE India and evaluated for three years in CRBD design with three replications. The present study thus focused on the variability, association, and diversity studies for the first time on 150 ginger germplasm from across North East India. The genotypic and phenotypic coefficient of variation, heritability, correlation, and path analysis were evaluated for the germplasm. Analysis of variance (ANOVA) revealed considerable differences among the studied germplasm for studied characters, revealing sufficient variability in the materials. The Mahalanobis D2 and Tocher methods grouped the 150 ginger germplasm into ten clusters. Based on the results of the path coefficient analysis determined for essential oil yield and rhizome yield per plant, it can be concluded that the characters' initial rhizome weight, the weight of mother rhizome, and weight of secondary rhizome were the most important and appeared promising in improving the overall yield potential of ginger rhizome and essential oil yield. Thus, selection based on the identified traits would lead to an effective ginger breeding program for higher rhizome and essential oil yield.

Evaluation of Different Arrowroot (Maranta arundinacea L.) Accessions for High Rhizome Yield with Good Quality and Starch Content

Aim: Arrowroot (Maranta arundinacea L) is an underutilized tuber crop belonging to the family marantaceae. This study mainly aims to evaluate different arrowroot accessions for quality starch and best yield.&#x0D; Study of Design: The field experiment was conducted in randomized block design with total ten accessions and three replications.&#x0D; Place and Duration of Research: The present investigation was undertaken at the College Orchard, Department of Vegetable Science, Horticultural College &amp; Research Institute, TNAU, Coimbatore during the year 2022-2023.&#x0D; Methodology: In this study, ten arrowroot accessions viz.,TAr18-01, TAr18-02,TAr18-04,TAr18-05,TAr18-10, TAr18-11, TAr18-12, TAr18-13, TAr18-14 and Local were evaluated for their growth, yield and quality parameters.&#x0D; Results: The statistical results revealed that all the accessions significantly differ from each other. Results obtained as maximum height in the accession TAr18-14(132.01cm), maximum number of leaves in TAr18-10 (109.33), number of tillers in TAr18-14 (8.45) and biggest rhizome weight in TAr18-14(198.81g) respectively. The yield traits like rhizome length (25.49 cm), diameter (9.46cm) and number of rhizome per plant (30.00), rhizome yield per plant (1.49kg) were maximum in TAr18-10. The quality parameters viz., dry matter (%) was highest for TAr18-10(56.76%),TSS in TAr18-12 (27.83%), ash contents in TAr18-10 (3.88%). These parameters mainly decide the quality and nutritive value of Arrowroot. There is a significant variation in the quality parameters like starch, TSS, dry matter, protein, crude fiber. Among various accessions TAr18-04 recorded the highest starch (54.62%) and TAr18-14recorded highest protein content (6.194%). Amylose content (21.88%) was maximum in TAr18-01.&#x0D; Conclusion: It can be concluded from the following study that TAr18-10 recorded highest rhizome yield, dry matter content with quality starch and can be selected for further evaluation and exploitation in industrial applications.

NnNF-YB1 induced by the potassium fertilizer enhances starch synthesis in rhizomes of Nelumbo nucifera

Lotus (Nelumbo nucifera Gaertn.) is one of the most important aquatic vegetables in China, which is rich in starch and is important sources of energy for livings. Potassium fertilizer has important effects on physiological characteristics, yield and quality of lotus rhizomes. However, the relationship between starch and potassium fertilizer remains unclear. Here, we investigated the relationship between starch quality and potassium fertilizer. Compared with the treatment without potassium fertilizer (CK), the total starch content, amylose content, and amylopectin content of potassium fertilizer treatment 30 kg/667 m2 (K30) were significantly increased. RNA-seq showed that K30 induces more than 2000 differentially expressed genes (DEGs), which mainly enriched in biosynthesis of starch and sucrose metabolism, secondary metabolites, photosynthesis. Meanwhile, K30 significantly promoted the expression of most of key genes and transcription factors involved in the regulation of starch synthesis. We identified a NF-YB transcription factor NnNF-YB1, induced by potassium fertilizer could activate the expression of NnGBSSII by directly bind to its promoter. Transient overexpression of NnNF-YB1 resulted in the increase of total starch, amylose and amylopectin content in rhizomes of lotus. NnNF-YB1 positively regulated the expression of NnGBSSII and plays an important role in starch synthesis under potassium fertilizer treatment. Collectively, our study provides a reference for fertilizer application in lotus production. At the same time, we revealed a new mechanism of potassium fertilizer increasing starch content and improving the quality of starch in rhizomes.

Performance of Valeriana jatamansi in Hill Zone of West Bengal Concerning Manure Sources

The organic source of nutrients would be a promising practice for Valeriana jatamansi cultivation which maintains its curative value. A set of experiments was conducted at Hill Zone of West Bengal, Kalimpong for two consecutive cycles to standardize organic nutrient management in V. jatamansi for optimum growth and economic yield. Different organic sources of nutrients such as farm yard manure (FYM), bio-fertilizer (BF), and vermicompost (VC) were applied at various doses along with a recommended dose. We applied the treatments as follows: T1= FYM (5 t.ha-1), T2= VC (2 t.ha-1), T3= FYM (5 t.ha-1) + VC (2 t ha-1), T4= FYM (5 t.ha-1) + PSB, T5= VC (2 t.ha-1) + PSB, T6= FYM (5 t.ha-1) + VC (2 t.ha-1) + PSB, T7= Control, T8= RDF through inorganic fertilizers (50:25:25 kg.ha-1 as N, P2O5, and K2O). The use of organic manures and PSB significantly (P&lt;0.05) increased the rhizome yield and soil-available macronutrients in V. jatamansi due to the release of nutrients from the decomposition of organic manures. The addition of T6 resulted in a maximum canopy height (18.28 cm), plant fresh biomass (16.42 t.ha-1), dry biomass (3.19 t.ha-1), rhizome fresh weight (3.16 t.ha-1), and dry weight (1.16 t.ha-1), as well as highest organic carbon content (0.75%), nitrogen (221 kg.ha-1), phosphorus (46.70 kg.ha-1), and potassium (201 kg.ha-1). Applying FYM, vermicompost, and PSB combination would be a promising strategy for growing V. jatamansi.

Evaluation of ginger genotypes for commercial cultivation in Mizoram and future prospects

A study was carried out for three years (2019, 2020 &amp; 2021) in the experimental field at ICAR Research Complex for NEH Region, Mizoram Centre, Kolasib, Mizoram to check the performances of seven ginger genotypes viz., Gurubathani, Bold Nadia, Bhaise, John's ginger, PGS 121, PGS 95 and PGS 102 against Local ginger cv Thingria and their economic feasibility for commercialization in Mizoram, India. Out of seven genotypes when compared with Local ginger cv Thingria, five genotypes have out yielded Local cultivar in the range of 21.25 to 45.45% with Bhaise having 45.45% higher rhizome yield than Local ginger. On the other hand, Bold Nadia possesses a combination of good quality traits. The highest B:C ratio was obtained in Bhaise (2.08) followed by PGS 102 (1.99), Gorubathani (1.95) and Bold Nadia (1.87). The highest cost of cultivation was contributed by labour cost which was 53.40% of total cost of cultivation. The four genotypes viz., Bold Nadia, Bhaise, PGS 102 and Gorubathani can be selected as potential genotypes possessing optimum combination of all traits. Based on economic analysis, these genotypes can be considered for commercial purposes under Mizoram condition. Different production systems such as intercropping, pro-tray technology, and bulb extraction method may increase the overall income of farmers. Farmers need to venture the possibilities of value addition in ginger on commercial basis. Government intervention is required for creating marketing infrastructures, initiating youth-centered schemes, occasional skill training and developing farmer-friendly policies to protect them from market risks and exploitation. Ginger has been an important horticultural crop and widely marketed spice crop of Mizoram, a potential enterprise contributing to state economy

Growth and rhizome yield of Ginger (Zingiber officinale) using plantlets with various heights as planting materials

Growth and rhizome yield of Ginger (Zingiber officinale) using plantlets with various heights as planting materials

Control of Bacterial Wilt (Ralstonia solanacearum) and Reduction of Ginger Yield Loss through Integrated Management Methods in Southwestern Ethiopia

Background: Bacterial wilt incited by Ralstonia solanacearum is the most important disease affecting ginger production in southwestern Ethiopia. The unavailability of disease-free planting materials, resistant cultivars, and effective chemical compounds are the key constraints in managing the disease. Objective: The study was initiated to determine the effect of integrated management methods on bacterial wilt disease and yield loss of ginger through combining hot water, bio-fumigation, soil-solarization and chemical pesticides. Methods: A total of seven treatment combinations comprising hot water, bio-fumigation, soil-solarization, Mancozeb, and bleaching powder were tested in a randomized complete block design in three replications. Data on disease incidence, growth, yield, and yield components were recorded from randomly selected plants. Results: The use of Mancozeb for seed socking and soil drenching combined with bio-fumigation and soil-solarization reduced the incidence of bacterial wilt by 63.3% and enhanced the rhizome yield by 66.8%. Rhizome and soil treatment using bleaching powder along with soil bio-fumigation also reduced the disease incidence by 38.9% and increased ginger yield by 61.5%. It also provided the highest (6678.7%) marginal rate of return of any treatment combination tested in the experiment. Disease incidence was highly significantly and inversely (r= -0.98**) correlated with rhizome yield. The regression slope estimated that 83.4% of ginger yield loss was associated with bacterial wilt disease. Conclusion: A combined application of Mancozeb, bio-fumigation and soil-solarization can be used to control ginger bacterial wilt. Alternatively, bleaching powder for rhizome and soil treatment in conjunction with bio-fumigation can be employed as an integrated management system against the disease.

High-tunnel Organic Ginger: Response to Propagation Material, Fertilizer, and Prepropagation Rhizome Storage

Ginger (Zingiber officinale, Roscoe) is a tropical rhizome crop typically grown from rhizome pieces, but can also be produced from seedlings. No information is available on how the seedling method compares with the rhizome piece method in organic ginger culture. In addition, information on the growing of organic ginger in the mid-Atlantic region is lacking. Some of the challenges include limited knowledge of rhizome storage, types of propagation materials for planting in the field or high tunnel, and acceptable organic fertilizers that will not increase the excess P currently polluting the Chesapeake Bay watershed. The objective of this study was to assess plant development, soil nutrients, and economic feasibility of organic ginger derived from different storage conditions and planting materials when grown in different nutrient sources in a high tunnel. Three types of plant material (single-shoot transplant seedlings derived from 36.5–40.0 g/rhizome, multishoot transplant seedlings derived from 60–120 g/rhizome, and rhizome seeds of 60–120 g) and three fertilizers types [cotton seed meal, 6N–0.9P–0.8K (0.18 kg⋅m–2), plus AZOMITE (1 kg⋅m–2); Nature Safe, 13N–0P–0K (0.07 kg⋅m–2); and Phytamin All Purpose Liquid fertilizer, 4N–1.3P–3.3K (0.26 L⋅m–2)] were used in 2018. In 2019 and 2020, three types of plant material and two fertilizer types at modified rates from the 2018 study, plus two storage containers (pans and flats), were tested. In general, the rhizome storage container did not affect plant height, leaf soil plant analysis development (SPAD) index, and rhizome yield, and its effect on tillers was none or mixed. Fertilizer type had mixed effects on plant height and tiller number, and no effect on the leaf SPAD index. Rhizome yields in 2019 and 2020 were unaffected by fertilizer, but Nature Safe produced a greater benefit-to-cost ratio (BCR) and profitability index (PI) than Phytamin. Soil P was generally less in Nature Safe–fertilized soil than in Phytamin-fertilized soil. Multishoot seedlings produced the greatest rhizome yield, BCR, PI, and tallest plants, and had some of the highest tiller numbers. These findings show that it would be more profitable to use multishoot seedlings as planting material in high tunnels compared with single-shoot seedlings and rhizome seeds. Furthermore, the lower P levels in the Nature Safe–fertilized soils compared with the Phytamin soils, and greater PI suggest that using Nature Safe will be a better choice than Phytamin for growing organic ginger.

Effects of Slow-Release Fertilizer on Lotus Rhizome Yield and Starch Quality under Different Fertilization Periods

Slow-release fertilizer is an environmentally friendly fertilizer that is widely used in crop cultivation instead of traditional nitrogen fertilizer. However, the optimal application time of slow-release fertilizer and its effect on starch accumulation and rhizome quality of lotus remains unclear. In this study, two slow-release fertilizer applications (sulfur-coated compound fertilizer, SCU, and resin-coated urea, RCU) were fertilized under three fertilization periods (the erect leaf stage, SCU1 and RCU1; the erect leaf completely covering the water stage, SCU2 and RCU2; and the swelling stage of lotus rhizomes, SCU3 and RCU3) to study the effects of different application periods. Compared with CK (0 kg∙ha-1 nitrogen fertilizer), leaf relative chlorophyll content (SPAD) and net photosynthetic rate (Pn) remained at higher levels under SCU1 and RCU1. Further studies showed that SCU1 and RCU1 increased yield, amylose content, amylopectin and total starch, and the number of starch particles in lotus, and also significantly reduced peak viscosity, final viscosity and setback viscosity of lotus rhizome starch. To account for these changes, we measured the activity of key enzymes in starch synthesis and the relative expression levels of related genes. Through analysis, we found that these parameters increased significantly under SCU and RCU treatment, especially under SCU1 and RCU1 treatment. The results of this study showed that the one-time application at the erect leaf stage (SCU1 and RCU1) could improve the physicochemical properties of starch by regulating the key enzymes and related genes of starch synthesis, thus improving the nutritional quality of lotus rhizome. These results provide a technical choice for the one-time application of slow-release fertilizer in lotus rhizome production and cultivation.