M.Sc.

China aster [Callistephus chinenesis (L.) Nees.] is one of the most important annual flower crops grown in India for cut flower as well as loose flower purposes. It ranks third next to chrysanthemum and marigold among the annual flowers and has gained popularity due to ease of cultivation, diversity of colours and good vase life. It is also used for bedding purpose in landscapes and as pot plants. In Kerala, the demand for annual flower crops is on the rise, however the cultivation is limited. China aster due to its hardy nature can be grown as a pure crop as well as intercrop in coconut gardens.

The investigation entitled ‘Evaluation of China aster [Callistephus chinenesis (L.) Nees.] for cultivation in tropical plains’ was conducted at the Department of Floriculture and Landscaping during 2018-2019 with an objective to evaluate the performance of China aster for cultivation in tropical plains. Ten varieties of China aster viz. Arka Kamini, Arka Shashank, Arka Archana, Phule Ganesh White, Phule Ganesh Violet, Phule Ganesh Pink, Phule Ganesh Purple, AAC-1, Local Pink and Mat White were evaluated for vegetative, floral and post harvest characters.

The varieties showed significant variation for vegetative characters. In all the varieties, leaf dentation was present and leaf shape was ovate for all varieties except Arka Shashank which had linear leaf shape. Stem colouration and leaf mid rib colouration were absent in varieties such as Arka Shashank, Arka Archana, Phule Ganesh White and Mat White and the rest of the six varieties showed the presence of purplish stem and mid rib colouration. The variety Phule Ganesh Pink was superior in plant height (68.86 cm) at 3 months after planting. The characters like plant spread (50.08 cm), number of leaves (56.48), number of primary branches (14.25) and stem girth (11.09 cm) were also highest in variety Phule Ganesh Pink. Leaf area was the highest in variety Phule Ganesh White (34.31 cm2). The variety Mat White was significantly inferior for all the vegetative characters observed.

Floral characters showed significant variation among the varieties. Powderpuff flower type was observed in Arka Shashank and all the other varieties had semi-double type flower. Days to bud initiation was minimum in variety Arka Shashank (44.40 days) and maximum in Phule Ganesh White (73.67 days). The same trend was observed for days to complete flower opening and days to 50 per cent flowering. The variety Local Pink had the highest duration of flowering (62.40 days) and variety Mat White (45.20 days) had the lowest duration of flowering. The variety Arka Shashank produced highest number of flowers per plant (20.20). The flower stalk length (21.13 cm), flower weight (6.94 g) and flower diameter (7.07 cm) were the highest in the variety Phule Ganesh Pink. The variety Phule Ganesh White was superior in terms of number of disc florets per head (251.00) whereas Phule Ganesh Pink had the highest number of ray florets per head (201.20). The flower yield per plant was highest in variety Phule Ganesh Pink (55.99 g). The variety Phule Ganesh White recorded the highest seed yield per flower (1.27 g) and seed germination (65.27 %).

Longest shelf life was observed in variety Phule Ganesh Pink (3.67 days) which was on par with Phule Ganesh White (3.33 days) and physiological loss of weight was recorded highest in Phule Ganesh White (35.70 %). The variety Phule Ganesh Pink had the longest vase life (13.93 days) and total water uptake was also maximum in variety Phule Ganesh Pink (20.27 ml). Anthocyanin content of flowers was recorded highest in the variety Phule Ganesh Violet (51.87 mg/g) followed by Arka Kamini (48.62 mg/g).

Dendrogram based on D2 statistics considering qualitative and quantitative characters indicated that high amount of variability is present among the varieties. Correlation and path analysis revealed that the characters such as number of primary branches (0.978), plant spread (0.894), leaf area (0.796) and flower weight (0.933) were having significant positive correlation with flower yield per plant with a direct effect of 0.150, 0.199, 0.281 and 0.498 respectively.

Ranking of varieties was done individually for loose flower and cut flower types. In ranking for loose flower types, variety Phule Ganesh Pink scored first position which was followed by Phule Ganesh White and Local Pink. When varieties were ranked for cut flower types, first position was scored by Phule Ganesh Pink while second position was shared by Phule Ganesh White, Phule Ganesh Purple and Local Pink. In overall ranking the variety Phule Ganesh Pink occupied first position followed by Phule Ganesh White and Local Pink and these can be recommended for commercial cultivation in tropical plains of Kerala during winter season.