Effects of Intercalated Long Days on Photoperiodic Induction and Development of Flowers and Fruits in Abelmoschus esculentus (L.) Moench.

Abstract

Summary Plants of Abelmoschus esculentus aged 10 days require a minimum of 4 consecutive SD cycles for the induction of flower buds (in all plants). Insertion of a single LD among them prevents floral induction. Two sub-threshold groups of 3 SD can be effectively summated provided that the number of long days intercalated between them does not exceed 4. Floral initiation was completely inhibited when single SD was alternated with single LD for a total of 60 days. Here again, it was shown that a minimum of 3 SD groups must be alternated repeatedly with single LD for successful initiation of flower buds in all plants while a minimum of 5 SD groups alternating repeatedly with single LD is required for the development of at least one flower bud per plant till anthesis. Likewise, the development of at least one fruit per plant required the alternation of single LD with groups of at least 5 SD cycles. Thereafter, the number and dry weights of fruits per plant as well as the 100 seed weights increased as the number of successive SD cycles alternated repeatedly with single LD was increased.