A cultivation study of the growth parameters and flowering Initiation of Streptocarus formosus for the flowering potlant Production industry

Abstract

The purpose for this study was to investigate whether Streptocarpus formosus was suitable for cultivation in hydroponics and to determine whether different solution temperatures in the root zone of the plants would have an effect on the vegetative growth, semi-dormancy and inflorescence formation of the plant. The experiment was conducted over a period of 8 weeks. Fifty plants were cultivated from one initial mother plant obtained from Kirstenbosch National Botanical Garden, Cape Town. All the plants were planted in Leca, a soilless inert growth medium, held suspended in a deep water hydroponic system with identical concentrations of nutrient solution. Five treatments were evaluated with 10 sample replicates. Treatments were made up of 5 different temperatures, namely: 18 degrees Celsius (TEMP1), 22 degrees Celsius (TEMP2)' 26 degrees Celsius (TEMP3) which was used as the control, 30 degrees Celsius (TEMP4), 34 degrees Celsius (TEMP5). Leaf and root lengths; number of leaves, abscission layers, flower buds and flowers; and wet weight were all measured pre-and postharvest. Chapter 2 reviewed the commercial potential of Streptocarpus formosus as a flowering potted plant. It was found that S. formosus has economic importance not only as a potted indoor house plant but also for use outdoors and possibly could be considered for the cut flower market. It can also make significant contributions to the breeding development of further Streptocarpus hybrids. In chapter 3 it was seen that the various treatments had significant effects in terms of plant vegetative growth, leaf formation and root development. Treatment WT1 showed the highest individual mean value for vegetative growth, leaf formation and root development. The lowest individual mean value for vegetative growth, leaf formation and root development. was observed in treatment WT5. Overall treatments with a lower temperature regime had better vegetative growth, leaf formation and root development, that being WT1-WT2, while the higher temperature regimes WT3-WT4 showed sub-optimal root growth and the highest, WT5 resulted in negative values. . In chapter 4 it was seen that the various treatments had significant effects in terms of semidormancy in the plant abscission layer formation and inflorescence development. Treatment WT1 showed the highest individual mean value for inflorescence development. The lowest individual mean value for inflorescence development was observed in treatment WT5. All the treatments showed an optimal result for overcoming the formation of abscission layers. Chapter 5 investigated a detailed protocol for production and cultivation of Streptocarpus formosus as a commercial flowering pot plant for both indoors and outdoors where it could also be used as a bedding plant and even as a cut flower for the vase. Overall this study has found that S. formosus is suitable for cultivation as a flowering pot plant and that while root zone heating will overcome the eco-dormancy period in cultivation it will have limited positive effects of the vegetative growth, and no positive effects on inflorescence formation during this eco-dormancy period. This research has shown that the lowest temperature treatment had the most advantageous result on the vegetative growth of the plant.