INFLUENCE OF INFLORESCENCE THINNING ON SEED QUALITY AND SEED YIELD OF BROCCOLI-CHINESE KALE HYBRID IN LOEI PROVINCE, THAILAND

The study investigated whether alternative thinning techniques applied to the central inflorescence affect seed yield and quality in seed production of the hybrid. Five thinning methods – reducing the central flower head size by either 50 or 75% at the either the full-grown stage or the stage when flower buds began to open; and inflorescence thinning combined with selection of plants with the 15 best flower stems – were compared with a no-thinning treatment. No significant differences were found in response to any inflorescence thinning treatment in terms of either pod length, pods per flower stem, seeds per pod, the weight of 1,000 seeds, seed germination percentage or speed of germination. On the other hand, although there were significant differences in the length of flower stem, the numbers of flower stems and seed yield per plant, no thinning treatment produced more or longer stems or yielded more seed than the control (unthinned) treatment. It is concluded that the best seed production techniques were either no thinning, or selecting the best inflorescences after a thinning treatment.