Regulation of apical dominance through pinching and its effect on vegetative growth and floral yield in African marigold (Tagetes erecta L.)

Abstract

Marigold (Tagetes erecta L.) is a widely cultivated ornamental crop valued for its bright and attractive flowers, which hold significant importance in decoration, religious rituals, and the floriculture trade. Pinching, a cultural practice involving the removal of the terminal bud, is an effective method for modifying plant growth, improving branching, and enhancing flower production. This review compiles existing research on the role of pinching in influencing vegetative development, flowering behavior, floral quality, and overall yield in African marigold. Pinching disrupts apical dominance, promotes axillary bud outgrowth, increases branching, and redirects assimilates towards lateral shoots, ultimately improving flower production. Pinching significantly improves flower yield plant-1 and hectare-1, with notable gains in total flower count and yield quality. However, unpinched plants exhibit larger individual flowers with prolonged longevity. Seasonal timing, cultivar differences, and environmental conditions modulate pinching outcomes. The integration of pinching with cultivar-specific and seasonal management practices offers a low-cost, effective agronomic strategy for optimizing marigold productivity and market value.