The effects of Kelpak growth regulator on the growth responses’ of three selected Fynbos species.

Abstract

The effects of liquid Kelpak® and Kelpak® Plantit® disk growth regulator on the growth responses of three selected fynbos species were evaluated in this study. The experiment was arranged using a block design, consisting of 270 plant samples. The experiment consisted of three fynbos species, Coleonema album, Erica verticillata and Leucospermum cordifolium. Each species was subjected to three treatments, the control with no applications, liquid Kelpak® and Kelpak® Plantit® disks (hereafter referred to as disks). The control consisted of 10 plants samples, for each of the three species, arranged is numerical order 1-10. The liquid Kelpak® consisted of 40 plant samples. These 40 plants were divided into 4 groups, containing 10 plants and each group having a different treatment with group 1; 300 ml, group 2; 200 ml, group 3; 100 ml and group 4; 50 ml. The disks consisted of 40 plant samples. These 40 plants were divided into 4 groups, containing 10 plants each and each group having a different treatment with group 1, 2 disks, group 2, 1 disk, group 3, ½ disk and group 4 ¼ disk. The objectives of this study were to assess the desired application of Kelpak® by analysing the physiological improvements or growth responses on of Coleonema album, Erica verticillata and Leucospermum cordifolium. Prior to planting, pre-trial measurements were recorded of each individual cutting. A standard ruler was used to measure the root length and shoot length of each plant, measurements were taken in millimetres. The weight of each plant was measured with a Radwag AS 220/C/2 analytical scale in grams. Plant growth, in terms of plant height was measured on a weekly basis. Plant height was measured with a standard ruler, from the surface of the medium to the tip of the tallest leaf. Watering during the trial period was conducted, using a hand held hose with a rosehead sprayer twice a week and during the third month of the trial once a week. Each container received an average of 250 ml of water. The final week of the trial final readings of the plants was conducted. Plants were carefully harvested and their roots were rinsed with tap water. A standard ruler was used to measure the root length and shoot length of each plant. The roots and shoots were then separated with a secateurs from each other. The fresh weight of each root and shoot weighed and recorded. The combined total weight in grams was captured. The roots and shoots were placed in a manila brown paper bag and placed in a laboratory oven at 55°C for 48 hours. The plants were then removed from the oven and the dry weight of each root and shoot weighed. The combined total was also recorded. The results indicated that liquid Kelpak® and Kelpak® Plantit® disk had an effect on the growth of fynbos species at different application rates. Liquid Kelpak® and Kelpak® Plantit® disks had significantly increased the shoot, root growth and total weight of plants in C. album grown in 15 cm pots over an 18 week period. The liquid Kelpak® indicated higher growth rates in the initial growing stages of C. album as the liquid was immediately available to the plant. The Kelpak ® Plantit® disks had better influence on the growth over a longer period as the disk dissolved at a slower rate which eventually became available to the plant. The liquid Kelpak® and Kelpak® Plantit® disks had significantly increased the dry root weight and post-harvest root length of E. verticillata grown in 15 cm pots over a period. The Kelpak® Plantit® disks indicated higher growth rates in the dry root weight of E. verticillata but both the liquid and the disk had a positive effect on the post-harvest root length. The results also indicated that the successful rooting of E. verticillata was attributed to rooting hormone Seradix 2 under greenhouse heating environment. Liquid Kelpak® and Kelpak® Plantit® disks had significantly increased the wet and dry shoot weights, dry root weights and post-harvest wet and dry total plant weights of L. cordifolium grown in 15 cm pots over the growth period. The Kelpak® Plantit® disks indicated higher growth rates in the dry shoot weights of L. cordifolium but both the liquid and the disk had a significant effect on the wet shoot weight. The liquid and the disks were also responsible for the improved dry root weight. The liquid application indicated the best post-harvest wet weight but the disks improved the post-harvest dry weights. It can therefore be confirmed that organic seaweed concentrates such as Kelpak® is effective on the growth development of L. cordifolium.