Vol. 8, Issue 4 (2019)

Author(s):
Bikash Bhattarai, Soumen Maitra and Rocky Thokchom

Abstract:
An experiment was conducted to evaluate twenty different species of winter flowering ornamental annuals mostly used for landscaping purpose under different agro-climatic conditions in the Terai region of West Bengal, India, in respect of plant height, leaf chlorophyll content, earliness in flowering and biomass production both under open-field and polyhouse condition. The plant height at 15 days interval starting from 30 days after transplanting (DAT) was found greater in polyhouse condition than open-field cultivation. Petunia showed the maximum plant height (133.99cm) under polyhouse and minimum plant height was recorded in Daisy (26.08cm) at 75 DAT under open-field condition. Earliness in flower bud initiation (23.25DAT) was observed with Calendula officinalis under open-field condition and the delayed flowering was observed with Antirrhinum majus (74.67DAT) under protected condition. Candytuft took minimum time period to reach FBD from FBI (6.17days). Lupin required minimum time to bloom from FBD (1.50days) under polyhouse condition, whereas maximum time period requirement from blooming to wilting was observed in Helichrysum (21. 84days) in open-field condition. Maximum leaf chlorophyll content was found in Dimorphotheca (64.30 SPAD value) under open-field condition. Root: Shoot ratio on fresh weight basis was found higher in Phlox (0.523) under polyhouse and minimum was recorded from Ice Plant under open-field condition (0.016). Maximum and minimum Root: Shoot ratio on dry weight basis was obtained from Sweet Pea (0.335) and Ice Plant (0.019) respectively under open-field condition. Minimum shoot length was observed in Daisy (26.75cm) under both conditions and maximum was obtained from Antirrhinum (132.50cm) under polyhouse. Maximum and minimum root lengths were recorded with Calendula (28.25cm) under open-field condition and Sweet Pea (6.35cm) under polyhouse respectively. The present experiment gave the precise database of the comparative performance of twenty different winter annuals in respects of plant height, biomass production and the duration between the major stages of flowering from the preceding stage.