The Agronomic Characteristics of the Yongcheonppong (Morus spp.) Appropriate for the Cold Region where the Freezing Injury Occured and Consideration on the Result of the Silkworm Rearing Affected by the Occured Frequency of the Freezing Injury

The Yongcheonppong was cultured in the form of a dense mulberry field coverd with polyethylene film and was tested in Suwon and Chunchon. The agronomic characteristic and some consideration on the result of the silkworm rearing were as follows. The Yongcheonppong was the medium budding variety and was longer in length of young shoots than the Kaeryangppong. The Yongcheonppong was higher in leaf yield in spring than the Kaeryangppong and was lower in leaf yield in autumn than the Kaeryangppong to the contrary. The Yongcheonppong was a little higher in the number of branches and was longer in the length of the branch than the Kaeryangppong and so was appropriate for rearing with mulberry shoots. Yongcheonppong was more resistant to twig blight and die-back and was a little susceptible to dwarf disease. As the Yongcheonppong was most resistant to the freezing injury, it was appropriate for the cold region and enabled the farmers to rear some amount of silkworms every year. In Chunchon, The Yongcheonppong increased by 11% in cocoon yield than the Kaeryangppong when the freezing injury occurred 1 year out of 2 years and produced about the same as the Kaeryangppong in cocoon yield when the freezing injury occurred 1 year out of 3 years.

凍害常習地 적응 뽕품종 “龍川뽕”의 재배학적 특성 및 凍害 發生頻度에 따른 蠶作狀況의 몇가지 考察

용천뽕을 수원지방에서 비닐피복 밀식재배법으로 관리한 경우의 재배학적 특성은 다음과 같으며 동해발생시의 육잠 성과의 몇가지 예를 고찰하였다. 1. 춘기 탈포기는 개량뽕보다 3일 빠르나 5개엽기는 동일한 중생뽕이고 춘잠기 수확 당시 신소장은 길다. 2. 용천뽕의 수량은 개량뽕보다 춘잠기에 많고 추잠기에는 적은 춘형이다. 3. 용천뽕은 개량뽕보다 가지수가 약간 많고 지조장도 길어서 가지뽕치기에 적합하다. 4. 용천뽕은 뽕나무 눈마름병과 줄기마름병에 약간 강하고 오갈병에 다소 약하다. 5. 용천뽕은 내동성이 극히 강하여 동해상습지에 적합하며, 연도간의 육잠규모를 안정적으로 유지할수 있는 경영상의 이점이 있다. 춘천지방에서의 육잠성과에 있어서 동해의 빈도가 2년 1회의 경우에는 용천뽕이 개량뽕보다 11%증수 효과가 있었으며, 3년 1회 빈도의 경우는 두 품종이 비슷하였다.