Abstract
This study was carried out to identify the optimum seeding dates for selecting a double-cropping system and to assess the effect of polyethylene film mulching on the yield of Proso millet. Seeds of the varieties Hwanggeumgijang and Ibaegchal were sown in Miryang on five different dates: 1st (May 25), 2nd (June 15), 3rd (June 25), 4th (July 5), and 5th (July 15), with and without polyvinyl mulching. The varieties have different characteristics, for example, Hwanggeumgijang is an early-maturing type and more sensitive to temperature, whereas Ibaegchal is a medium-maturing type and more sensitive to the duration for which it is exposed to sunlight. Late-sown Hwanggeumgijang had a short heading date from seeding and required a low accumulated temperature. It also had a shorter period of heading, a shorter culm length and a shorter diameter of stem. In contrast, it had had a higher number of ears $per\;m^2$ although similar ear length and similar 1000-grain weight. The yield potential of Hwanggeumgijang was found to decrease at a late seeding date. In particular, it significantly decreased at the seeding date of July 15. In the case of cultivation with polyvinyl mulching, the period of heading was shorter by 2-4 days and the yield potential was increased by approximately 12-32%. The length and diameter of culm in Ibaegchal were slowly decreased, but the length of ear, the 1000-grain weight and the yield potential were similar for all seeding dates (except July 15) and cultivation with and without mulching. When sown late, the length and diameter of the culm of Ibaegchal very rapidly decreased by the July 15 seeding date. The protein content of Ibaegchal was higher but the amlyose content of Ibaechal was lower compared to Hwanggeumgijang. At late seeding dates, the protein contents of the two varieties increased but the amylose contents were similar.
조생종인 황금기장은 온도에 민감하고 중만생종인 이백찰은 일장에 민감하여 남부지역에서 기장의 파종기에 따른 생육특성 및 수량 특성을 구명하기 위해 5월 25일부터 7월 15일까지 다섯번 파종한 결과가 다음과 같았다. 1. 조생종인 황금기장은 중만생 이백찰 보다 출수소요 일수가 짧고 적산온도가 낮았으며 파종기가 늦어짐에 따라 출수소요 일수는 단축된다. 2. 조생종인 황금 기장은 파종기가 늦어지면 줄기길이는 짧아지고 줄기의 두께는 얇아지나, 단위면적당 이삭수는 증가하고 이삭길이와 천립중은 거의 일정하였다. 3. 황금기장의 수량성은 파종기가 늦어짐에 따라 감소하고 7월 15일 이후에는 유의적 수준에서 감소한다. 4. 황금기장의 비닐 피복시 출수반응은 무피복에 비해 2~4일 빨랐는데 수량성이 12~32% 증수 하였다. 5. 이백찰은 파종시기가 늦어짐에 따라 경장과 경태는 완만하게 감소하다 7월 15일 이후에는 급격히 감소하였다. 6. 이백찰의 이삭길이, 천립중 및 수량성은 파종기 및 비닐피복 여부에 따라 특별한 차이가 없었으며 7월 15일 파종에서는 급격히 감소하였다. 7. 이백찰은 황금기장 보다 단백질 함량은 높았고 아밀로스 함량은 낮았으며 파종기가 늦어짐에 따라 두 품종의 단백질 함량은 증가하나 아밀로스 함량은 비슷하였다.
