MSc

Kiriyath (Andrographis paniculata (Burm.f.) Wall. ex Nees., an important
medicinal plant belonging to the family Acanthaceae, is known as “King of Bitters” and is traded
in high volume and prioritized by State Medicinal Plant Board, Kerala. In medicinal plant
cultivation, both yield and quality of produce are important. Variations in environmental
conditions have great influence on production of active principles, and it is necessary to identify
optimum growing conditions to grow cultivars with high yield potential. The present study was
taken up in the Department of Agronomy, College of Horticulture,Vellanikkara to study the
effect of variations in growing conditions, time of planting and mulching on yield, quality and
weed dynamics of Andrographis paniculata. The trial was laid out in Randomized Block Design,
replicated thrice. The treatments consisted of two growing conditions viz., open and 50 per cent
shade, four dates of planting viz., 15th May, 15th June, 15th July and 15th August, and three
mulching practices, viz., no mulching, paddy straw mulching and black polythene mulching.
Growing condition, planting date and mulching significantly influenced the plant height,
number of branches and biomass yield of Andrographis paniculata. The highest biomass yield of
10.02 t ha-1 was observed under 50 per cent shade, May planting (12.87 t ha-1) and mulching with
black polythene (12.25 t ha-1). Higher biomass yield was observed in the treatment combination
of 15th May planting under shade with black polythene mulching (15.67 t ha-1) as brought out by
analysis of interaction effects. It was on par with June planting with black polythene mulch under
shaded condition (14.33 tha-1).
Among different soil chemical properties studied, available K content of soil alone was
significantly influenced by different treatments and was found higher in open condition (168.40
kg ha-1), August planting (176.58 kg ha-1) and with paddy straw mulching (188.08 kg ha-1).
Physiological, chemical and biochemical parameters were also significantly influenced
by growing condition, planting date and mulching. Total chlorophyll content at the time of
harvest was higher under shade (2.23 mg g-1), May planting (2.22 mg g-1) and with paddy straw
mulching (2.08 mg g-1). Higher andrographolide content was recorded under 50 per cent shade
(1.05%), August planting (1.04%) and with paddy straw mulching (1.05%). Analysis of
interaction effects revealed that treatment combination of July planting under shade with paddy
straw mulching recorded higher andrographolide content (1.17%) and was on par with August
planting with paddy straw mulching under shade (1.14%). Crop planted in June recorded
significantly higher CGR at different growth stages. CGR was also found higher under black
polythene mulch at different growth periods. Relative growth rate between 30 to 60 DAP was
higher under open condition, June planting and under no mulch condition.
Soil temperature was higher under open, and with black polythene mulching whereas soil
moisture was higher under shade, and with black polythene mulching throughout the crop period.
Weed density and dry weight were significantly influenced by the treatments. Lower
weed dry weight was observed in August planting (at 30 DAP), and July planting (at 60 DAP).
Black polythene mulching was the best treatment when weed control was considered, followed
by paddy straw mulching. Highest weed control efficiency was recorded in July planting with
black polythene mulch under open condition (99%), and July planting with paddy straw mulch
under shade recorded lowest weed index (12.56%).
Maximum temperature, forenoon and afternoon relative humidity and solar radiation
were negatively correlated with plant height, number of branches, days to first flowering,
biomass yield and andrographolide content. Minimum temperature exhibited positive correlation
with plant height, number of branches, and biomass yield at flowering stage. Rainfall had
negative correlation with biomass yield initially, later on positive correlation was observed.
A higher B: C ratio of 3.53 was obtained with May planting along with black polythene
mulching under shaded condition. From this experiment it can be concluded that planting of
Andrographis paniculata in May - June under 50 per cent shade with black polythene mulch can
be recommended for high yield, quality and profit. It is a suitable crop for growing in
homesteads or as an intercrop in plantation crops.