Screening ginger (Zingiber officinale Rosc.) genotypes under different growing conditions and for value addition

Abstract

Ginger is an important commercial spice crop grown in India for culinary and medicinal purposes. The present study entitled “Screening ginger (Zingiber officinale Rosc.) genotypes under different growing conditions and for value addition” was taken up at College of Horticulture, Vellanikkara during 2015-18 to evaluate the performance of ginger genotypes with respect to yield and quality, growth under different growing conditions, quality of different maturity stages and to identify types suitable for different value added products. A total of fourteen somaclones developed through indirect organogenesis and indirect embryogenesis were selected for the study. Genotypes exhibited wide variability in plant characters, yield characters and quality attributes. Plant height was maximum in the somaclone SE 86102 (107.35 cm) at 6 months growth stage. Number of tillers was maximum in CHP118 (20.33) at 6 months stage. Number of leaves per shoot was found higher in CHP 118 (28.67) and in SE 86 26. Leaf area was the highest in CHP 118 at 4 months stage and C8632 at 6 months stage. Among the physiological parameters recorded, photosynthetic and transpiration rates were the highest in CHP 118 and SE 86 42. Number of primary and secondary rhizomes was maximum in SE 8626, CHP 118 and C8632 (>30 t/ha). Weight of primary and secondary rhizomes was highest in SE 8626 and SE 8642. Fresh yield was highest in SE 8626, CHP 118, SE 8642 & C 8632. Driage (23%) and dry yield (7.9t/ha) were the highest in SE 8626. The quality attributes such as volatile oil, oleoresin and crude fiber contents varied significantly among the genotypes. The highest content of volatile oil (3.62%) was recorded in CHP 118. Oleoresin content (>6%) was maximum in Rio-de- Jenairo. Fibre content increased with age of rhizomes recording lowest values (< 2.5%) in SE 86 83, C 86 26 and SE 86 42. Highest content of Gingerol (1.48 %) and Shogoal (0.16%) was recorded in Rio –de- Janeiro and CHP 282 respectively. Among the genotypes evaluated under different growing conditions, variability in plant height was observed. During the growth stages, all the genotypes exhibited higher plant height under rain shelter condition, whereas at 6 months stage plants were taller in open field. Number of tillers and leaves were significantly higher in open condition. Tiller number ranged from 14 to 17 under open field and 6 to 7 in rain shelter. Leaf area was the highest at 5 months growth stage which later decreased. Among the two growing conditions, the highest leaf area was observed in open condition in SE 8640 and SEHP 9. Generally, somaclones grown in open condition recorded higher yield and SEHP 9, SE 8081 and SE 8640 were identified as higher yielders. But in SE 86 40, the yield was on par both in open and rain shelter conditions indicating its suitability for growing under rain shelter condition. Driage did not differ significantly between the two growing conditions. Driage and dry yield were higher in SE 86 81 and SEHP 9. Higher values for photosynthetic rate, transpiration rate and stomatal conductance were recorded in open field. Among the two growing conditions, quality parameters were higher in rainshelter cultivation though not significant. SE 8640 recorded the highest volatile oil content under both growing conditions (open field -4.45 % and rain shelter -4.67 %). All genotypes except SE 8640 recorded an oleoresin content of more than 5 %. Fibre content increased with maturity recording maximum values at 7 months stage. Lower fibre content was recorded under rain shelter condition. Among the somaclones, SE 8681 and SE 86131 recorded lower values for fiber content at 5 months stage. Elite varieties satisfying the requirements for specific end products are the need of the hour to capitalize on the processing front. Biochemical parameters such as moisture content, TSS, titratable acidity, pH and colour were recorded for analyzing the storage stability of the products viz., candy, flakes and powder. The somaclones SE 8683, C 8626 and SE 8642 were found to be the best for candy preparation based on its overall consumer acceptability and storage stability. SE 8683, C 8626 and SE 8642 were found suitable for flakes preparation and SE 8683, C 8626, SE 8642 and C8632 for making quality ginger powder.