Abstract
The present study comprised a series of eight experiments carried out in order to develop a package of technology for the production of high quality carrot seed. All the experiments were conducted at the USDA-Alliums Field Laboratory, Horticulture Farm, Bangladesh Agricultural University, Mymensingh during August 2005 to July 2008. The study was set to find out the optimum age and spacing of steckling, extent of root cutting, steckling vernalization, growing conditions, doses of phosphorus and boron, umbel keeping for the high quality carrot seed production. The varietal experiment showed that Brasilia (Agroflora) gave the best seed yield than the rest three varieties viz. Prima (Agroflora), New Kuroda and TS Kuroda. The spacing experiment demonstrated the superiority of 25cmx25cm spacing for planting of stecklings over 30cmx30cm, 30cmx25cm and 25cmx20cm. The extent of root cutting experiment revealed that 75-day old roots were better than 65 and 85-day old roots, and cutting of lower 1⁄2 part of root was better than the cutting of 4 and the control (no root cut). The experiment on phosphorus and boron fertilization demonstrated that the application of 30kg P and 0.6kg B/ha were optimal for the production of carrot seed. The experiment on the growing condition showed that the poly tunnel with shade providing net was better for quality seed production of carrot over the polythene as well as the open fied conditions. The low temperature steckling treatment demonstrated that 8°C showed better performance over the ambient and 4°C temperature for 30 days. The umbel keeping experiment revealed that the primary and the secondary umbels gave the highest seed yield. From the findings of the seven previous experiments, three packages were selected on the basis of performance that are package-I (75-day old steckling, 50% root cut, 25cmx25cm spacing, steckling vernalization at 8°C, keeping primary and secondary umbels, application of 30kg P and 0.6kg B/ha and ploy tunnel with shade providing net growing condition); package-II (85-day old steckling, 25% root cut, 30cmx25cm spacing, steckling vernalization at 4°C, no umbel cut, application of 25kg P and 0.4kg B/ha and ploy tunnel with white polythene growing condition); and package-III (65-day old steckling, no root cut, 25cmx20cm spacing, steckling vernalization at ambient temperature, no umbel cut, no additional P and B fertilizer use, open field growing condition). Finally, the packages were tested on Brasilia (Agroflora) and New Kuroda carrot varieties which resulted in 898 and 868kg/ha seed yield, respectively, package- I gave the best performance over the package-II, III as well as control method (no treatment. were applied, only 75-day old roots were uprooted and planted in the bed at 30cmx25cm spacing).