HORTICULTURAL TECHNIQUES TO IMPROVE CELOSIA-PLUMOSA GROWTH FOR CUT FLOWERS

Celosia plumosa is a quantitative short-day plant in which a long phot operiod of 16 h markedly delayed flowering. Increasing the temperature regime from 17/12 degrees C to 27/22 degrees C (day/night) enhanced p lant growth and flower stem and inflorescence length, and shortened th e time to flower appearance. Pinching the seedlings increased the numb er of newer stems per plant, but under continuous short-day conditions their growth was retarded. Pinching the seedlings and maintaining the m first for 3 weeks under non-inductive long-days to increase their ve getative growth, and then exposing them to inductive short days, incre ased the number of marketable flowering stems of suitable length. This suggested procedure of pinching followed by a long-day/short-day phot operiod also resulted in desirable inflorescence length with infloresc ences born on stems of sufficient diameter and strength to significant ly improve flower quality.