Effect On The Growth And Development Of Several Plant Growth Retardants For Potted Freesias

Freesia hybrida, a species of Freesia genus in Iridaceae family, has been known as one often cut flower crops worldwide and valued for its colorful and scented flowers. However,the application of freesia was limited for its soft stem and centralized flowering season.Up to date, few research and application of potted freesias were reported in our country. Itwill helpful to perform studies and development some technology on the potted freesias,which will be further extend the application of freesia in Shanghai and others in China.One of Freesia hybrida cultivars with yellow flowers was used to study the effect on thegrowth and development of some plant growth retardants for potted freesias in this presentpaper. Five plant growth retardants with different concentrations, different treated timesand different treated methods were selected. The growth and development of pottedfreesias was evaluated synthetically by some indices about the plant vegetative growth andflowering, and the appropriate plant growth retardant and treatment method weresuggested.The main results were shown as following:(1) The effect on the plant height. The inhibition on the plant height of potted freesias wasobserved in the treated plants by these plant growth retardants. For treatment of dippedbulbs, a more significant inhibition was present in the treatment by PP333, Topflor andCCC than that by Pix. However, some phytotoxicity was observed in treated plants byTopflor. For treatment of drenched soil, the inhibition effect by Topflor was moreobvious that by PP333. The plant height of potted freesias was also inhibited by treatedby foliage spray, and more obvious effects were shown in the treated plants by PP333 and Topflor. In general, it seems suitable to use PP333and Topflor with appropriateconcentrations in terms of the aim of stuntedness.(2) The effect on the foliage width. The different effects on the foliage width of pottedfreesias were observed among various plant growth retardants and different treatedmethods. For treatment of drenched soil, the foliage width was raised by treated withPP333and Topflor, while no significant different was observed in the treatment by CCCand Pix. For treatment of drenched soil, the foliage width was significantly raised bytreated with and Topflor compared with control. No significant effect was observed bytreated by foliage spray.(3) The effect on the numbers of tiller. The different effects the numbers of tiller of pottedfreesias were observed among various plant growth retardants. More tillers wereobserved after treated by PP333, Pix and B9and CCC with longer treatment time,however, no obvious effect was observed in treated plants by Topflor. For the numbersof foliage, it increased by treated with PP333and decreased by treated with Topflor, andno obvious difference in others.(4) The effect on the flowering characters. In general, no obvious effect on the flowercharacters was observed. No adverse effect on flower color, flower type, the earlyflowering season, flower size and the numbers of inflorescence and florets wasobserved by treated with various plant growth retardants. However, the height of theinflorescence was inhibted.(5) In conclusion, the comprehensive effect of PP333and Topflor were positive for pottedfreesias, even though more suitable concentration and treatment time should beoptimized in future. Meanwhile, it's better to use the treatment methods by dippedbulbs and drenched soil than that by foliage spray.