Productive features of New F1 Silkworm Hybrids Bombyx mori L.

The present research study was conducted in the Agricultural University – Plovdiv in the period 2020–2021. The following newly created F1 silkworm hybrids were tested: Vratsa 63xLine22 x Nig2xMerefa6; Nig2хMerefa6 х Vratsa 63хLine22. The industrial hybrid Super1 x Hesa2 was used as a control. The present research paper aimed at examining the values of the following important quantitative features of the new silkworm tetra-hybrids: fresh cocoon weight; shell weight; shell ratio; the good quality cocoons; the percentage of dry from raw cocoons. It was established that both new hybrids had higher values for the quantitative features compared to the used control variant. With relation to the fresh cocoon weight, the shell weight, the silkiness and the good quality cocoons, the hybrid Nig2хMerefa6 х Vratsa 63хLine22 had the highest indicators, followed by Vratsa 63хLine22 х Nig2хMerefa6, and Super1 х Hesa2 being last. It was concluded that both newly created hybrids could be recommended as appropriate for use into practice. [ABSTRACT FROM AUTHOR]