Factors Influencing Non-Uniform Flowering in Chrysanthemums and Insights toward Sustainable Management: A Review

Abstract

Chrysanthemum (Chrysanthemum morifolium) is an ornament crop that is widely grown in the world. Though of economic and aesthetic significance, uniform flowering continues to be a significant challenge with commercial cultivation regimes. The development of flower in chrysanthemum is controlled by a complex of photoperiodic, nutritional, environmental and genetic factors. Being a short-day plant, it needs continuous dark phases to trigger floral initiation that is mediated by phytochrome signal pathways and the main genes such as flowering locus T (FT), constans (CO), and suppressor overexpression constans 1 (SOC1). Night lighting may cause the disruption of these pathways and postponement flowering. Alteration of nutrient balance, especially high nitrogen, deficiency in phosphorus, potassium and micronutrients, shift the plant metabolism to vegetative growth at the cost of reproductive growth. Other environmental stress factors like heat, drought, salinity and pollution also reduce flowering through hormonal and oxidative impairments. The development of controlled-environment agriculture, precision cultivation, and genome editing offers promising methods of flowering stabilization. This review brings together existing information and the importance of integrative management approaches to sustainable production of chrysanthemums.