Assessment of variability and performance of new landraces of small cardamom ( Elettaria cardamomum Maton)

Even though fourteen improved varieties of small cardamom have been released in India so far, many of the farmers in the traditional cardamom tracts still use farmer selected landraces as planting material and hence the importance of landraces is not questionable. Four new landraces of small cardamom identified from Idukki district of Kerala State of India namely Pulari, Pappalu, Kalarikkal Bold and Arjun were evaluated along with Njallani Green Gold (popular landrace) and ICRI-2 (improved variety released by Indian Cardamom Research Institute) for growth, yield and quality characters. Eight growth characters, eight yield characters and eleven quality characters were analyzed for the purpose and all of them except two yield characters showed statistically significant variation indicating the occurrence of significant genotypic difference between these landraces. A comparative analysis of overall performance of the four landraces was also carried out and the results showed that Pappalu, Kalarikkal Bold and Pulari performed significantly superior to Njallani Green Gold and ICRI-2, the controls. Pappalu showed 132.22 per cent increase in yield over Njallani Green Gold and 158.02 per cent over ICRI-2. The cumulative performance indices of all the new landraces were worked out and the landrace Pappalu had the highest performance index of 30.06 followed by Kalarikkal Bold (27.45), Arjun (25.57) and Pulari (24.14). All the four new landraces have been found to be superior to ICRI-2 while Pappalu, Kalarikkal Bold and Pulari showed superiority over Njallani


Introduction
Small cardamom, often referred to as the 'queen of spices' is the commercial product obtained from the zingiberaceous, perennial, rhizomatous plant Elettaria cardamomum Maton. It is grown extensively in the Western Ghat region of South India at an elevation of 800-1300 m as an under crop in forest lands. It is also grown on plantation scale in countries like Guatemala, Sri Lanka, Papua New Guinea, El Salvador, Vietnam, Laos, Cambodia and Tanzania. Cardamom is native to the moist evergreen forests of Western Ghats of South India (Ravindran, 2002). It is cultivated in India in an area of 69,770 ha, out of which Kerala occupies 60 per cent, Karnataka 30 per cent and Tamil Nadu 10 per cent. Cardamom production in India during 2014-15 was 18,000 MT (Spices Board, 2015).
Even though fourteen improved and location specific varieties of small cardamom have been developed and made available to farmers of India by various research institutes working on the crop, many farmers still depend on promising landraces for cultivation (Radhakrishnan and Mohanan, 2012). Being a crop that is mainly propagated clonally using suckers, screening of such landraces so as to select promising genotypes from them has immense potential in crop improvement of cardamom. Recently, progressive farmers from the Cardamom Hill Reserve (CHR) of Idukki district of Kerala have identified and come out with four new landraces namely Pulari, Pappalu, Kalarikkal Bold and Arjun. The present study has been carried out to characterize and evaluate the variability and performance of the four new landraces of cardamom in comparison with the released variety ICRI-2 and the most popular landrace Njallani Green Gold with regard to growth, yield and quality characters.

Materials and methods
The study was carried out on participatory mode in planter's field in the CHR of Idukki district, during 2010-2016. The planter's field is located at an altitude of 1,068 m above MSL at 9 o 53' N latitude and 77 o 09' E longitude. The location enjoys humid tropical climate with a well distributed rainfall of 2700 mm per annum. The soil is forest loam with a pH of 5-6. Populations of the landraces namely Pulari, Pappalu, Kalarikkal Bold, Arjun and control varieties such as Njallani Green Gold and ICRI-2 were planted in randomized block design (RBD) with four replications and eighteen plants per plot at a spacing of 3 m x 3 m in 2010. The populations were raised from suckers propagated vegetatively to avoid heterogeneity due to segregation. Recommended package of practices of Spices Board, India was followed for cultivation. Data on twenty seven characters including eight growth characters such as tiller number, tiller height, leaves per tiller, leaf length, leaf breadth, leaf area, number of vegetative buds and number of bearing tillers; eight yield characters such as panicles per clump, panicle length, racemes per panicle, capsules per raceme, seeds per capsule, internodal length, fresh seed weight and dry seed weight; and eleven quality characters such as fresh husk weight, dry husk weight, 100 fresh capsule weight, fresh yield per plant, dry yield per plant, volatile oil content, oleoresin content, moisture content, percentage of 7 mm and above sized capsules, recovery percentage and seed:husk ratio were recorded and analyzed statistically. The variation between the landraces in the case of each character and also from the control genotypes was estimated by calculating range, mean, standard deviation, standard error and coefficient of variation. Analysis of variance (ANOVA) was carried out to test the significance of variation between the landraces in comparison with the control genotypes. Test of significance was done with reference to standard F table (Fisher and Yates, 1963). Critical difference was calculated to find out the significance of variation between any two observations. Comparative performance of the cardamom genotypes was analyzed based on performance index calculated as per Amaravenmathy and Srinivasan (2003).

Study of variability
To analyze the variation between the landraces the data were subjected to statistical analysis and the results are presented in Table 1. Among the 27 growth, yield and quality characters studied, 25 characters showed statistically significant variation between the landraces and controls indicating the presence of variability between them so as to maintaining their genetic identity. Among the growth characters taken for the study significant variations were observed among the landraces and controls in terms of tiller number, tiller height, leaf length, leaf breadth, leaf area, number of vegetative buds and number of bearing tillers. Among the yield characters studied dry yield per plant was found to be the most variable. Significant variation was shown by panicles per clump, panicle length, racemes per panicle, seeds per capsule and fresh yield per plant, but capsules per raceme and internodal length were found to show only nonsignificant statistical variation. Among the quality characters studied seed: husk ratio was the most variable. Other parameters that were found to be significantly variable among the landraces and controls were 7 mm and above sized capsules, dry husk weight, percentage of oleoresin, 100 capsule weight, dry seed weight, percentage of moisture content, percentage of volatile oil, seed weight fresh, recovery percentage and husk weight fresh.
Study of variability between the genotypes in terms of the variation of the above characters indicated that among the growth characters the highest coefficient of variation was shown by number of vegetative buds (65.84%) followed by number of bearing tillers (20.18%) and the lowest coefficient of variation by tiller number (2.71%). Leaf area showed a coefficient of variation of 17.61 per cent, tiller height showed a coefficient of variation of 16.01 per cent, in leaves per tiller it was 7.54 per cent, 6.56 per cent in the case of leaf length and 6.00 per cent in the case of leaf breadth. Among the yield characters the highest coefficient of variation was shown by dry yield per plant (36.36%) followed by fresh yield per plant (32.22%) The above analysis of the four landraces of cardamom in comparison with two standard checks showed that Arjun produced higher number of tiller per clump when compared to ICRI-2, but not with Njallani Green Gold, the standard check. Tiller height in Pulari, Pappalu, Kalarikkal Bold and Arjun was found to be higher when compared to the controls. Leaves per tiller, leaf length and leaf breadth were higher in Pulari and Pappalu. Leaf area was higher in all the four landraces when compared to ICRI-2. Number of vegetative buds was higher in Pappalu and Kalarikkal Bold when compared to ICRI-2. Number of bearing tillers was higher in Pappalu, Kalarikkal Bold and Arjun when compared with Njallani Green Gold. Panicles per clump were higher in Pappalu, Kalarikkal Bold and Arjun when compared to both the controls. Panicle length was higher in all the four selected landraces when compared to both the checks. Only Pappalu produced higher number of racemes per panicle when compared to Njallani Green Gold and ICRI-2. Capsules per racemes were higher in all the four landraces when compared to ICRI-2. Seeds per capsule were higher in all the four landraces compared to both the checks. Only Arjun showed higher fresh seed weight when compared with ICRI-2. Only Pulari showed higher dry seed weight when compared with Njallani Green Gold. Fresh husk weight, 100 capsule weight and dry husk weight were higher in all the four landraces when compared with standard checks. Fresh yield per plant was higher in Pulari, Pappalu and Kalarikkal Bold when compared with both the checks while Arjun showed higher fresh yield per plant than ICRI-2. Dry yield per plant was higher in all the four selected landraces when compared to the standard checks. Percentage of volatile oil was higher in Kalarikkal Bold when compared to Njallani Green Gold but was on par with ICRI-2. Percentage of oleoresin was higher in Pulari, Pappalu and Arjun when compared with both the controls. Percentage of moisture content, percentage of 7 mm and above sized capsules and recovery percentage were higher in all the selected landraces when compared to the Njallani Green Gold and ICRI-2. Seed: husk ratio was higher in Arjun when compared to Njallani Green Gold and ICRI-2 and in Pulari it was higher when compared with ICRI-2 only.

Study of yield performance
Comparative yield performance of Pulari, Pappalu, Kalarikkal Bold, Arjun, Njallani Green Gold and ICRI-2 is provided in Table 2 and it shows that Pappalu and Kalarikkal Bold offer better performance over the controls. Pappalu showed 132.22 per cent increase of yield over Njallani Green Gold and 158.02 per cent over ICRI-2. Kalarikkal Bold showed 86.66 per cent increase of yield over Njallani Green Gold and 107.40 per cent over ICRI-2.

Evaluation of performance index
Study of comparative performance of the landraces in comparison with the controls revealed that Pappulu (30.06) showed the highest cumulative  (Table 3).
In the case of the controls, cumulative performance index was 27.11 in the case of Njallani Green Gold and 24.11 in the case of ICRI-2. From the above data, it can be seen that in terms of the agronomic characters studied, Pappalu showed the best performance followed by Kalarikkal Bold, Njallani Green Gold, Arjun, Pulari and ICRI-2. Performance assessment of several cardamom genotypes was carried out by earlier workers and they have succeeded in selecting certain promising selections and hybrids (Korikanthimath et al., 1997;Kuruvilla et al., 2006). Performance assessment of fourteen cardamom genotypes was carried out by Radhakrishnan et al. (2005) and it resulted in the selection of certain promising genotypes and hybrids. Hrideek et al. (2015) have studied the variability of some other landraces of cardamom so as to select the best performers. By analyzing all the facts the present findings indicate the potential of using the genotypes like Pappalu, Kalarikkal Bold and Pulari for further breeding programmes as parental material so that varieties with significantly superior characters could be developed.