Ginger Production in India and Other South Asian Countries
Ginger requires a warm and humid climate. The plant thrives well from sea level to an altitude of 1,500 m in the Himalayas, the optimum elevation being between 300 and 900 m. A well-distributed rainfall (150 to 300 cm) during the growing season and dry spells during land preparation as well as before harvest are required for large-scale cultivation of the crop. In areas receiving less rainfall, the crop needs regular irrigation.
Ginger can be grown in a wide range of well-drained soils of at least 30 cm depth, ranging from heavy laterite loams to clayey loam. Laterite loams containing not more than 30 percent sand or 20 percent clay and free from gravel have given higher yields. Panigrahi and Patro (1985) studied the performance of five ginger cultivars in three soil types in Orissa, India, and reported that in a sandy loam red soil, the cultivar Thingpuri gave the highest yield of 22 t/ha. Cho et al. (1987) recorded higher ginger yield in an alluvial plain area than in hilly or mountain foothill areas. Yield was high in soils having more than 1 m depth and with good drainage, and was negatively correlated with ploughing depth and soil moisture content. Liu and Gao (1987) studied the arsenic content in red soils and its effects on growth and yield of ginger. The total arsenic content varied between 76 and 1970 ppm. When arsenic was supplied to soils, the dry matter yield of ginger was decreased by 3.5 to 32 percent. Lee et al. (1990) reported that soils that were suppressive to rhizome rot had a higher clay content and lower pH than those conducive to the disease. The most favorable soil pH is 6.0 to 6.5. Hackett and Carolane (1982) reported that soil with uniform loamy texture is more suitable than other soil types. Sahu and Mitra (1992) got the highest yield in sandy loam soil having the minimum bulk density (1.20 g/cc), moderate acidic reaction (pH 5.7), and high organic matter (organic carbon 1.1 percent) and available potassium (351 kg/ha). The yield decreased with increase in soil clay content and decrease in pH.
Time of Planting
In south India, the crop is grown mainly as a monsoon crop from April-May to December but as an irrigated crop in north and central India. As a rain-fed crop, the first week of April is the best time of planting to get a higher yield under Kerala (India) conditions, registering a 200 percent increase in yield compared to planting in the first week of June. Considering the erratic behavior of southwestern monsoons, it is better to plant the crop as early as possible after the receipt of soaking rains. When June and July plantings were compared, planting in June recorded a higher yield and low incidence of soft rot. For irrigated ginger, the best time for planting is the middle of February. Sreekumar et al. (1981) at Ambalavayal (India) observed that the highest germination percentage was obtained with planting at the end of January or mid-February (average 80 percent).
Phogat and Pandey (1988) at Nainital (UP), India, noted that the highest values for all indices studied (plant height, number of leaves, number of tillers, rhizome length, rhizome width, number of rhizomes/plant, and yield of fresh rhizomes) were obtained by planting on March 15. The yields for 2 years were 253.4 and 226.3 quintals/ha with planting on March 15; planting on May 29 gave the lowest yields (119 and 101.6 quintals/ha).
From Orissa (India), Mohanty et al. (1990) reported that in trials on the effect of planting date on yield, planting on April 1 gave 29.67 t/ha, which declined to 4.2 t/ha when planting was on July 1. In Sri Lanka, where ginger is a homestead crop, planting starts immediately after the first rains in April or May.
Ginger Production in India and Other South Asian Countries: Seeds and Seed Rate
Spacing and Method of Planting
Spacing varies with soil fertility, cultivar, climate, and management practices. Earlier reports indicated that closer spacing gave better yield. Based on trials, planting of ginger is recommended on raised beds (in order to facilitate drainage) at a spacing of 20 X 20 cm or 25 X 25 cm and a depth of 4 to 5 cm with the viable bud facing upward. Pandey (1999) reported that among different spacings (40 X 20, 30 X 20, 40 X 30 and 50 X 20 cm) the highest yield was observed under closest spacing. Planting of irrigated ginger in raised beds (see Figure 5.2) gave the highest yield when compared to planting in ridges, furrows, and flat ground (KAU, 1993). The seed rhizome is placed 3.5 to 5.0 cm deep in a pit and soil is pressed over it followed by light irrigation. Mulching the beds twice with green leaves is important. In general, the planting depth varies with the size of the planting unit, soil type, and soil moisture content. Bolder seed rhizomes are planted deeper and smaller rhizome bits at shallow depths. The commonly adopted practice is to place the rhizome piece at 4 to 10 cm depth.
Mohanty and Sarma (1978) reported that best growth and the highest rhizome yield (23.4 t/ha) was obtained with Ceresan wet-treated rhizomes, planted in raised beds, with farmyard manure (FYM) at 25 t/ha + N, P2O5, and K2O at 75, 50, and 50 kg/ha, respectively, and mulched with green leaves at 15 t/ha at planting followed by two mulches using 7.5 t/ha at 45 and 90 days after planting.
Kin et al. (1998) reported that narrow ridge cultivation reduced the ginger rot disease effectively by 78.1 percent compared with unridged plots.
Ginger Production in India and Other South Asian Countries: Shade
Nutrient Uptake and Removal
The growth of ginger can be classified into three distinct periods: a phase of active vegetative growth (90 to 120 days after planting), a phase of slow vegetative growth (120 to 180 days after planting), and a phase of senescence (180 days to harvest). The pattern of rhizome development also followed the same trend except that the development of rhizome continued up to harvest. According to Johnson, the total uptake of N, P, and K progressively increased with advancing periods of crop growth, and the uptake by the leaf and pseudostem progressively increased up to 180 days after planting and decreased thereafter. However, the uptake by rhizome steadily increased till harvest. He also standardized the period between 90 and 120 days after planting as the ideal time for leaf analysis and recommended the 5th to 12th leaves for foliar diagnosis.
Organic Matter
In olden days, ginger was cultivated in freshly cleared forest soils and as such there was no need to apply fertilizers. But the situation has changed and now it has become impossible to realize a satisfactory yield without an adequate supply of fertilizers together with a heavy dose of organic matter. Sadanandan and Iyer (1986) observed that organic amendments such as neem cake and Pongamia cake reduced the incidence of rhizome rot and improved the yield in ginger. Cho et al. (1987) opined that the ginger yield was positively correlated with the soil organic matter content. In Kerala, the major ginger-producing state of India, the recommended dose of organic matter is 25 to 30 t/ha of FYM and 30 t/ha of green leaves as mulch applied in three splits, 15 t at the time of planting and 7.5 t each at 60 days and 120 days after planting (KAU, 1993).
In a field trial on alfisol, application of 45 t/ha of FYM and 600 kg KCl/ha resulted in the highest yield of rhizome with acceptable quality in terms of fiber content. Khandar and Nigam (1996) reported that the rhizome yield of ginger increased with an increased ratio of FYM application (33 t/ha) compared to 22 t/ha. Plant height was greater with FYM. Chengat (1997) studied the effect of organic manure and Azospirillum on the growth and yield of ginger in Kerala (Figure 5.7). Application of FYM at the rate of 48 t/ha resulted in the highest returns and benefit-cost ratio (2.32), giving an additional profit of 32.04 percent over control. Sadananandan et al. (1998) reported that among six organic fertilizers (FYM, neem cake, brasicca cake, groundnut cake, and gingelly cake), groundnutcake gave the highest soil organic matter. Neem cake gave the highest benefit-cost ratio followed by groundnut cake.
Ginger Production in India and Other South Asian Countries: Nutrient Requirements
Secondary and Micronutrients
Since ginger is cultivated with high doses of organic manure and green leaf mulch, an additional supply of secondary and micronutrients is not usually required. However, Roy et al. (1992), West Bengal, India, had observed that in local cultivars of ginger, the highest yield of 48.8 t/ha was obtained with a combination of 0.3 percent zinc, 0.2 percent iron, and 0.2 percent boron. Wang et al. (1993) reported that zinc affects protein synthesis and RNA metabolism leading to amino acid accumulation under zinc deficiency Srinivasan et al. (2003) carried out a study on zinc nutrition of ginger. They found that zinc deficiency exists in 49 percent of soil samples analyzed from various ginger-growing regions of India. Their study indicated that zinc application at 5 kg/ha increased the rhizome yield significantly. The culture model they developed indicated that 6 kg/ha zinc is the best for maximizing the yield.
Biofertilizers
Ginger responds well to the application of biofertilizers. Studies conducted by Vilasini (1996) indicated that soil solarized for 30 days and incorporated with Trichoderma (125 g/m2) and amended with neem cake (500 g/m2) could control the disease effectively and increase the yield considerably. Sharma et al. (1997) found that inoculation with Glomus mosseae at the spore stage (10 X 102)/g soil gave taller ginger plants, with higher yield (46.5 g per pot) and greater number of tillers per plant than other treatments under the subtropical conditions of Himachal Pradesh, India. Soil application of Gigaspora margarita (2.5 g per rhizome) at the time of planting increased plant height, number of leaves and tillers, root weight, and yield of ginger, which is similar to that of pine needle organic amendment and seed treatment with Trichoderma harzianum.
Treating rhizomes of cv. Mahi with Azetobacter and Azospirillum followed by application of N at 50 kg/ha produced a higher green ginger yield of 20.34 t/ha against an uninoculated field (receiving 75 kg N/ha), which yielded 17.44 t/ha.
Ginger Production in India and Other South Asian Countries: Mulching
Soil Solarization
Solarization had a profound promotive effect on ginger growth by suppressing the weed population, and the effect lasted until harvest. Even though solarization substantially reduced weed population, its effect was less on sledges. Bulbostylis barbata, Cynadon dactylon, and Cyperus rotundus survived the solarization. Vilasini (1996) observed that soil solarization for 30 days combined with Trichoderma application could control the rhizome rot disease and increase the yield.
An increased growth response of ginger plants was observed as a result of solarization. Growth parameters such as height, number of leaves/plant, number of tillers, number of roots, leaf length, leaf breadth, and fresh weight of shoots and rhizomes were influenced by solarization. A significant increase in yield was obtained through solarization. Trichoderma incorporated + neem cake amended + 30 days solarized treatment gave the highest yield/plant (623.23 g) and also per plot (10,159.57 g), which was 53.6 percent more than that of control. The availability of N, P, and K was improved by solarization. The initial cost of solarization is comparatively high. An amount of Rs. 52,500 is required for solarizing ore ha of a ginger field. An additional profit generated from this technique was Rs. 40,136/ha/yr for 30 days solarization.
Water Management
Ginger is grown both as a rain-fed and irrigated crop. Korla and Tiwari (1999) at Solan, Himachal Pradesh, India, observed that significant effects of rain-fed and irrigated conditions were observed on pseudostem length, tillers per plant, leaf length, leaf breadth, and yield per plot. Significant genotypic differences were observed for pseudostem length, rhizome length, rhizome breadth, and yield per plant. In general, the commercial cultivar Himgiri performed well and was consistent under both environments for most of the characters. The performance of SC 646 was similar to Himgiri for tillers/plant, leaves/plant, leaf length, leaf breadth, rhizome length, rhizome breadth, yield of individual plants, and total yield/plot. Plessis and Anderson (1986) found that overhead sprinkling of water raised the yield of ginger from 36.4 to 45.2 t/ha.
Ginger Production in India and Other South Asian Countries: Intercropping and Rotation
Growth Regulators
Das and Nair (1976) studied the effect of urea at 2 percent and/or planofix containing NAA at 200 or 400 ppm applied to five ginger cultivars in June. The crop was harvested in the following February. The production of dry ginger was highest in the cv. Maran, followed by Sierra Leone, China, Thinladium, and Rio de Janeiro. The best treatment was urea + planofix at 200 ppm.
Application of Ethrel (Ethephon: 2-chloroethane phosphonic acid) three times at 200 ppm as a foliar spray starting from day 70 after planting at an interval of 15 days increased vegetative growth in ginger, whereas Cycocel had no significant effect on vegetative growth. Foliar application of 2 percent urea + 400 ppm planofix reduced the fiber content in cultivars Maran, China, and Tinladium. Ravishankar and Muthuswamy (1984) reported that ginger plants treated with 2-chloroethyltrimethyl ammonium chloride (CCC) have only negligible endogenous gibberellins. CCC at 180 and 200 ppm improved auxin and cytokinin levels in the rhizomes. Furutani and Nagao (1986) were of the opinion that the rhizome yield in ginger increased with diaminozide and decreased with GA3 and Ethephon. Application of Ethrel at 50 to 400 ppm, 2 months after planting and twice at 20-day intervals recorded higher yield of rhizomes (25 t/ha) over untreated controls. Futurani et al. (1985) noted a higher ginger rhizome yield with the application of ethephon 750 ppm combined with a preplant soaking in hot water at 51°C for 10 minutes. The treatment increased the shoot number by 122 percent and yield by 38 percent. Nair and Das (1982) reported a higher oleoresin content with the application of 2 percent urea and 400 ppm Planofix. Chatterjee et al. (1992) reported that a maximum plant height (84.6 cm), the number of tillers/plant (7), the number of leaves/plant (66.7), and rhizome yield/plant (268 g) were with the 2 percent urea + 20 mg NAA/1 treatment combination. The highest leaf N content at 160 days after planting was obtained with the one percent urea + 20 mg NAA/1 treatment combination. The highest leaf P and K content at 160 days after planting was obtained with one percent urea treatment.
Organic Farming of Ginger
Organic farming is an approach to sustainable agriculture aiming to create an integrated, ecofriendly and economically sustainable production system. This integrated system includes the protection of soil fertility through the application of organic matter and fostering the soil biological activity. Nutrients are applied through relatively insoluble nutrient sources (organics), maintenance of the nitrogen source through the raising of leguminous crops, recycling organic residues, and disease and insect pest control through crop rotation, use of natural predators, biopesticides, and resistant varieties as well as by maintaining diversity in crop plants.
The approaches to the organic cultivation of ginger involve the following aspects.
1. Nutritional management through:
• The application of FYM, oil cakes, vermi-compost, and bio-fertilizers
• Raising leguminous cover and intercrops
• Use of permitted fertilizers such as powdered rock phosphate and sulfate of potash
2. Insect — pest management through:
• Cultural practices
• Mechanical (manual) collection and removal of root grubs, beetles, and others
• Use of biopesticides such as neem products, extracts of Lantana, and incorporation of Trichoderma in the soil
• Use of bioagents such as Bacillus thuringiensis strain kurusakthy, into the borehole of pseudostems to kill the larvae of the stem borer; Trichoderma, for control of other soilborne pathogens
3. Use of tolerant varieties
4. Disease management through practices such as crop rotation and adjusting planting time
5. Adoption of proper cultural practices such as providing drainage, shade, and timely removal of affected plants etc.
Ginger Production in India and Other South Asian Countries: Maturity and Harvest
Postharvest Handling
Bhuyan et al. (1990) conducted thin-layer drying experiments on the cv. Siliguri in order to study its drying characteristics. The quality of dried ginger was also evaluated by determining its volatile oil and oleoresin contents. A small-capacity tray dryer was designed and built and its performance tested. The heat utilization factor, coefficient of performance, overall thermal efficiency, and uniformity of drying of sliced ginger on each of the trays were determined. The dryer performed satisfactorily. The air temperature of 60°C was found suitable for drying ginger slices.
Ali et al. (1991) at Udaipur, India, developed an abrasive, brush-type, ginger-peeling machine. The machine consists of two continuous vertical abrasive belts with a 32-gauge steel wire brush. The brush wires are 2 cm high and spaced at 1.9 cm intervals and the peeling zone is 135 cm long and 30 cm wide. The machine was found to operate satisfactorily with a peeling efficiency of about 85 percent and a capacity of 200 kg/h.
The influence of various postharvest treatments like scraping, slicing, blanching, boiling, coating, and their combinations on the yield and quality of dry ginger and storage life was studied. Slicing the ginger rhizomes before drying is preferred over conventional drying since it reduces the time for drying and the product obtained has good color and comparable quality.
Radha et al. (1993) in Rajasthan, India, developed a small, manually operated ginger-peeling machine for application at the level of the individual farmer. It operates on the principle of abrasive peeling. The performance of the machine was evaluated in terms of peeling efficiency and ginger meat loss. At full-capacity operation, the machine had a peeling efficiency of 71 percent with 1.3 percent losses.
Mukherjee et al. (1995) evaluated the feasibility of a combination process involving gamma irradiation, packing in closed PE bags, and biological control of fungi causing storage rot as a means of extending the shelf-life of fresh ginger rhizomes at ambient temperature (25 to 30°C). Storage in closed PE bags reduced weight loss but increased sprouting and rooting, which could be prevented by gamma irradiation at 60 Gy (unit of absorbed dose of radiation). Rotting caused by Sclerotium (Corticium rolfsii) was, however, a major cause of spoilage during extended storage. Four isolates of Trichoderma sp. isolated from sclerotia of C. rolfsii infecting ginger rhizomes, one of Gliocladium virens, and four isolates of fluorescent Pseudomonas were tested, of which one isolate ofTrichoderma was found highly effective in suppressing the growth of C. rolfsii. The efficacy of the antagonist was demonstrated under simulated market conditions using artificially inoculated rhizomes. The recommended procedure consists of dipping washed, air-dried rhizomes in Trichoderma suspension (108 spores/mL), air-drying, and packing in 250-gauge LDPE bags followed by irradiation at 60 Gy. Rhizomes thus treated remained in good marketable condition for up to 2 months at ambient temperature without sprouting or significant loss of quality and <5 percent weight loss. An in vitro bioassay system was developed to demonstrate the efficacy of the antagonist to protect the cut surface of sliced rhizomes inoculated with the pathogen. The method could be used for rapid screening of antagonists.
Storage
Because ginger rhizomes are bulky and perishable, the storage of the seed rhizome for 3 to 4 months from harvesting to next planting season is faced with many problems, such as rotting, sprouting, rooting, and shriveling, which can result in huge losses. Therefore, adopting an efficient storage technique in ginger will go a long way in minimizing the storage loss of the valuable planting material.
Trials conducted in Kerala showed that storing ginger in 200-gauge thick polythene covers of size 35 X 25 cm with 125 punch holes (each hole with 4 mm diameter) was an effective method (Jayachandran et al., 1992). In Kerala, traditionally, ginger seed rhizome is stored with the leaves of Glycosmis pentaphylla in wooden pole racks or sleeves and kept under shade. The rhizomes are also stored in pits dug under shade, the floor of which is lined with sand or sawdust (KAU, 1993).
Rai and Hossain (1998), Orissa, India, reported that there are three traditional methods of seed rhizome storage: storage in soil pits, storage in a dry, shady place, and storage in the field involving delayed harvesting. The first method is the best for small-scale growers, but it is expensive and laborious for large-scale growers. Storage in a dry, shady place is economical for the larger growers, but there is a problem of rhizome drying. Storage in the field by delayed harvesting is not to be encouraged as it harbors rhizome rot — causing fungi and bacteria as well as insect pests such as scales and mealy bugs.
Research on agronomy, nutrition management, and various other aspects of production technology has not been carried out in other ginger-producing countries such as Sri Lanka, Nepal, Bhutan, and Bangladesh. The research information comes mainly from the studies carried out in India. Ginger is a minor crop in other countries, and most of the production aspects are applicable to other south Asian countries as well. The constraints faced by ginger growers in these countries are also the same. Solutions are not yet available for the most severe constraints such as the rhizome rot and bacterial wilt. In spite of the advancements in productivity, the gap between the average yield (15-20 t/ha) and potential yield (40-50 t/ha) is wide, and the potential yield of ginger in India and other producing countries such as China is still wider. A great deal of work has to go into the production physiology of ginger to narrow this gap, to increase the productivity, and to make ginger production more economical and remunerative.
E. V. Nybe and N. Mini Raj “Ginger Production in India and Other South Asian Countries” (2005)