Weed management effect on vegetative growth and flowering parameters of chrysanthemum

摘要

Chrysanthemum (Chrysanthemum morifolium Ramat.) is one of the most widely cultivated herbaceous perennial plants belonging to family Asteraceae and commonly known as 'Autumn Queen' or 'Queen of East'. Chrysanthemum produces showy flowers with different flower colour, shape and plant height, that can be used as pot plants for beautifying indoors and outdoors, as cut flowers for making bouquets and base decoration, as loose flower for making garlands, worshipping purpose and for garden decoration (Arora 2013). It contributes largely to the floriculture industry by virtue of its yield potential, colour variation and long life. In the North-Indian plains, the commercial growers propagate chrysanthemum plants through terminal stem cuttings at the end ofJune that can be extended up to the end of July, i.e. Kharif season. After transplanting in July and August, the terminal rooted cuttings have a very slow growth rate initially as they take long time to get established in the field (Singh 2006). The early emergence and faster growth of weeds causes severe competition with crops for light, moisture, space and nutrients, resulting in yield losses up to 50-100% (Rao et al. 2007, Mehta et al. 2010, Meena et al. 2013). Use of pre-emergence herbicide can be aviable option for controlling weeds right from the emergence of crop (Shivasankar and Subramaniam 2011). Chrysanthemum is the most appropriate crop to concentrate on the development of successful weed control strategy to encourage crop growth and flowering that would be greatest benefit to the flower industry as a whole. Chemical weed control is an effective method and an alternative to old practices of manual weeding as manual weeding is costlier and has become impracticable due to non-availability oflabourers during the critical period of weed competition. Though use of pre-emergence herbicide, immediately after transplanting of very tender rooted cuttings, can give good control of weeds, but may retard growth and development ofthe delicate seedlings. Keeping all these in view, the present experiment was conducted to enhance the vegetative growth and flower yield with better weed control, using different combinations of herbicides.