Effect of Photoperiod, Temperature and Thinning Chemicals on Production of Begonia × hiemalisotsch.
Date Issued
2007
Date
2007
Author(s)
Kao, Ho-Hui
Abstract
Begonia × hiemalis Fotsch is one of the popular flowering potted plants in Taiwan during fall and winter, the production generally beginning in late summer and early fall, and sales during fall and winter. One of the aims of this study is investigate the application of lamp for day-extension lighting or night interruption (NI), to create a long day environment, in order to inhibit reproductive growth. Another aim is investigate the opportunity temperature of Begonia × hiemalis Fotsch cultivars in Taiwan and the effect of temperature on growth. This study also investigate the effect of plant growth regulators (PGRs)— ethephon and NAA on growth and flowering of Begonia × hiemalis Fotsch. To evaluate the practicability of using PGRs for flowering control, and try to solve the problem of flowering plantlets.or lighting treatment, plants of ‘Netja Dark’ were treated by tungsten lamp to investigate the effect of lighting treatment on flowering and growth. Treatments included day-extension lighting to 12-, 14-, and 16-h daylength; 2- or 4- h lighting in the middle of night; and 4-h lighting in the mid or in the terminal of night. Of total leaves number was significantly increase from 15.7 up to 19.4, by day-extension lighting treatment to 14-h daylength, and leaves no. of lateral shoots was also up to 9.1 from 5.6. Number of lateral shoots and dry weight were increase, too. Results of day-extension lighting to 12-h and 16-h were similar to 14-h daylength, which also enhance vegetative growth. 2- or 4-h lighting in the middle of night increased no. of total leaves, lateral shoot leaves, lateral shoots, and dry weight of plants, as well as day-extension lighting. Day-extension treatments couldn’t inhibit flowering efficiently; days to flowering were same with the untreated control. Plants treated by NI, would be inhibited significantly in plant height, and delay in flowering. Numbers of node counted at first flower were increased by 4-h lighting in the middle of night. 4-h lighting in the middle and in the terminal of night, both decrease the days to first flower, from 65 days to 31 days.or temperature experiences, roots of ‘Netja Dark’ cuttings development completely, and had most root no. and longest roots under 30/25℃. Under 25/20℃ was similar to 30/25℃, however, cuttings grew weakly and slowly at 20/15℃and 15/13℃. Plantlets of ’Netja Dark’ grew fast at 30/25℃, it coasted only 43.2 days to first flower; the second is 30/25℃ to 50.7 days; significantly laggard at 20/15 and 15/13℃ to 77.3 and 89.3 days. Besides, plants flowering at 30/25 and25/20℃ were identical, but not identical at 20/15 and 15/13℃. Nnmbers of flower, petal and total leaves were decreased with the drop of temperature, especially in 20/15℃and 15/13℃. They had more flowers, leaves, and decreased days to flowering, but flower diameter reduced about 10 mm at 30/25℃. In the growth chamber, plantlets of ‘Netja Dark’ grew better at 28/22℃ than 30/25℃ on plant height, no. of flowers and flower buds, total fresh and dry weight, and no. of later shoots (>3 nodes). The quality and maintainability were significant better at 28/22℃. Plantlets of ‘Barcos’ grew fast to flowering at 30/25℃ and 25/20℃.or plant growth regulators experiences, plant of ‘Clara’ treated with ethephon 400、800、1600 and 3200 mg•L-1 lead to flower abscission one week after treatments. Ethephon sprayed on all plants which flower bud small than 1.5 cm, 400 and 800 mg•L-1 let the days to first flower increase about 18 to 23 days, effectively delay flowering. Treatment of ethephon 1600 and 3200 mg•L-1 made continuous flower abscission. After ethephon treatments, number of nodes, leaves and inflorescence of plants were increased. Although internodes got shorter, leaf area became smaller, and inflorescences looked thinner, but didn’t affect plant quality. Treated with NAA didn’t make flower abscission, but delay flowering on plants which biggest flower buds less than 0.5 cm for 9 days at NAA 10 mg•L-1.lowering plantlets of ‘Netja Dark’ were sprayed ethephon 400、800、1200、1600 mg•L-1once, or twice of ethephon 400、800、1200 mg•L-1. All ethephon treatments did flowering delay but flower abscission and newly flowering not identical. In all treatments, plantlets sprayed with ethephon 400 or 800 mg•L-1 once were best than the others, those treatments could delay flowering slightly and get to 100% flowering percentage on plant height and no. of flowers. Therefore, base on our achievements, it would be more investigated to the application of ethephon on flowering plantlets.
Subjects
Begonia × hiemalis
Photoperiod
Temperatur
Type
thesis
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