REQUIREMENTS TO SESAME (SESAMUM INDICUM L.) CULTIVARS BREEDING FOR MECHANIZED HARVESTING

In 2004-2006, a cultivar trial was carried out with 22 Bulgarian sesame lines with indehiscent capsules, tested for 17 morphological and biological indexes such as components of seed production and suitability for mechanical harvesting. It was found that seed yield had a significant positive correlation only with the total number of capsules in a plant and duration of vegetation period. The indexes of stem height, lower and middle stem thickness, number, length and height of branches and capsules on them, related to the suitability of sesame plants for mechanical harvesting, did not correlate directly with the number of capsules per plant and did not affect the formation of seed yield. The higher the stem, the longer the branches, and the larger the number of empty capsules on the top and the total biomass of the plants, while the number of branches and height at first branch from soil surface decreased. This combination of stem indexes did not completely satisfy the requirements and parameters of the mechanized harvesting model without losses. Combining these contradictory requirements in the breeding of highly productive sesame cultivars with indehiscent capsules adapted to mechanize harvesting, can be achieved with reasonable compromise and balance by optimizing plant height and related indexes at the expense of increasing the number of branches and capsules on them.