MSc

The study entitled ―Physiological and phenological responses of cardamom (Elettaria cardamomum Maton.) as influenced by varying altitudes. This was carried out to evaluate the physiological changes that occur in the physiology and phenology of cardamom (Elettaria cardamomum (L.) Maton.) growing at different altitudinal locations in Idukki district of Kerala.

The objective of the experiment was to study the physiological changes that occur in the physiology and phenology of small cardamom (Elettaria cardamomum Maton.) and to find out the optimum altitudes at which the cardamom plant can perform with maximum efficiency. The study was conducted at BL Ram Cardamom Hill Reserve near Pooppara of Idukki District of Kerala.

Njallani (Green Gold) variety of small cardamom plants of 6 to 8 years age at three different locations: BL Ram (1246 MSL), Killippara (1312 MSL & 1402 MSL) and Koluthamppara (1524 MSL & 1603 MSL) were selected. The study was conducted during the period of October 2020 to March 2021. The biometric parameters measured were plant height, number of tillers per plant, number of leaves per tiller, number of panicles per tiller and number of berries per panicle. Physiological parameters like photosynthetic rate, transpiration rate, stomatal conductance and water use efficiency were analysed by using portable photosynthetic system (CIRAS-3 SW). Portable minimum maximum thermometer was set at each location to record daily temperatures.
The treatments had significant effect on the plant canopy development. Plants at lower altitude tend to produce taller tillers compared to other treatments. Similarly the number of tillers were also higher at lower altitude, T1 (1200-1300 m above MSL). At the same time more number of leaves were produced by the plants grown at higher altitude T5 (1600-1700 m above MSL). This may be due to the difference in solar interception at different treatment locations. Plants at lower altitude tends to grow more taller to get more sunlight. Similarly the number of panicles produced and


number of capsules produced per panicle were also higher at lower altitude and it showed a decreasing trend as altitude increased.

Physiological parameters like photosynthetic rate, transpiration rate, stomatal conductance, specific leaf area, water use efficiency were analysed to study the trend in variation in the physiological performance of the plant. Small cardamom plants growing at higher altitudes had higher photosynthetic rate, transpiration rate, stomatal conductance and specific leaf area. The plants grown at higher altitude were more physiologically active compared with the treatments at lower altitudes. Small cardamom plants at T5 (1600 MSL) showed higher photosynthetic rate (3.771µmol CO2 m-2 s -1), transpiration rate (29.007 mmol H2O m-2 s -1), stomatal conductance (1504.00 mmol H2O m-2 s -1 ), specific leaf area (167.843 cm2g-1 ) and water use efficiency (15.37 kg m-3). T5(1600MSL) had the highest protein content, followed by T4 (1500 MSL) and the lowest was recorded for T1 (1200 MSL). The nutrient status in soil were also analysed. Highest nitrogen and phosphorus content were recorded for lower altitudes. The potassium content was higher at T2 (1300m above MSL).
Similarly the NPK status in leaf canopy at both upper leaves and lower leaves were also analysed and highest nitrogen content was observed in T2 (1300 MSL) in the upper canopy. Phosphorous content was the highest in T3 (1400 MSL) in lower canopy. The potassium content was highest at T3 (1400 MSL) in both upper and lower canopies.

Phenological study conducted in small cardamom has shown that maximum number of bunches was produced in T2(1300 MSL) and T4(1500MSL) had the minimum number of bunches produced per panicle. Both T1 (1200 MSL) and T5(1600MSL) had the highest number of spikelets per panicle and T3(1400MSL) and T4 (1500 MSL) had the lowest no. of spikelets per panicle. Number of berries per panicle was highest at T5(1600MSL).
It is therefore concluded that, significant variation in physiological, biochemical and yield components was there among treatments. Small cardamom plants grown at higher altitude shows higher physiological activity such as


photosynthetic rate, transpiration rate, stomatal conductance and specific leaf area compared with those at lower altitudes whereas plants at lower altitudes are more biologically active viz. plant height, number of tillers, number of panicles, number of capsules thus the overall yield is balanced.