수단그라스계 잡종(雜種)인 Pioneer988의 수량(收量)과 잡초억제(雜草抑制) 및 조단백질함량(粗蛋白質含量)에 대한 파종량(播種量)과 제초제(除草劑)의 효과(效果)를 구명(究明)하기 위하여 파종량은 ha당(當) 25kg와 50kg으로 처리하였으며 제초처리(除草處理)는 인력제초(人力除草), alachlor 처리, simazine 처리 및 alachlor와 simazine을 복합(複合)처리하였고 대조구로 잡초(雜草) 효임구(效任區)를 두었다. 수량(收量)은 파종량에 의해 영향을 받지 않았으나 잡초 방임구에서는 고파종량(高播種量)이 높은 수량(收量)을 보여주었으며, 제초처리 간에는 alachlor+simazine복합처리구가 가장 높은 수량을 보여주었으나 인력제초구(人力除草區)와 simazine처리 간에 유의성은 없었다. 잡초수량(雜草收量)은 파종량에 의해 영향을 받지 않았으나 잡초구에서만은 고파종량(高播種量)이 잡초수량을 낮추는 경향이 있었고, 제초처리 중에는 alachlor+simazine복합처리가 가장 낮은 잡초수량을 보였다. 1회 수확시(收穫時) 초장(草長)은 인력제초구(人力除草區)가 제초제처리구보다 높았으나 3회 평균치(平均値)에서는 alacholor+simazine복합처리구가 가장 높았고 잡초구(雜草區)가 가장 낮았다. 파종량은 초장(草長)에 영향을 미치지 못하였다. ha당(當) 주수(株數)는 고파종량구(高播種量區)에서 많았으나 주당(株當) 분얼경수(分蘖莖數)는 저파종량구(低播種量區)에서 많았으며 제초처리구 간에는 주수(株數)와 분얼경수(分蘖莖數)에 유의하가 없었고 잡초구에서만 낮은 수치를 보였다. 사초(飼草)의 단백질함량(蛋白質含量)은 파종량(播種量)에 의해 영향을 받지 않았으며 simazine처리와 alachlor+simazine 복합처러가 인력제초(人力除草)나 alachlor 처리보다 조단백질함량(粗蛋白質含量)을 높여주었다. 이상의 결과(結果)를 종합하면 청예용(靑刈用) 수단그라스계 잡종(雜種)을 산파(散播)할 경우에 파종량은 ha당(當) 25kg이 적당하다고 할 수 있으며 잡초제거는 반드시 실시하되 alachlor와 simazine을 복합처리하는 것이 가장 제초효과가 좋았고 높은 수량과 아울러 높은 조단백질함량(粗蛋白質含量)을 얻을 수 있다고 하겠다.
This experiment was carried out to find the effect of seeding rates and herbicides on the weed control, yield and crude protein of sorghum-sudangrass hybrid (Sorghum bicolor (L.) Moench). The variety used in the present study was Pioneer 988. Two different seeding rates were 25 kg/ha and 50 kg/ha and five weed control treatments were weedy check, hand weeded check, alachlor, alachlor+simazine, and simazine of preemergence application. The results of this study are summarized as follows: 1. Forage yield was not influenced by seeding rates. There was no significant difference between forage yield from 25 kg/ha and from 50 kg/ha of seeding rates. But weedy plots showed higher yield from the high seeding rate. Alachlor+simazine treatment showed the greatest yield among the weed control treatments. But there was no difference among the hand weeded treatment, simazine treatment, and alachlor+simazine treatment. 2. Seeding rates did not affect weed yield, but weedy plots showed the tendancy toward higher weed yield from the low seeding rate. Alachlor+simazing preemergence application showed the most effective weed control. But there was no significant difference in weed yield among the treatments of the hand weeded, alachlor+simazine and simazine. The weed yield in alachlor treatment was significantly higher than other three treatments. 3. The height of plant was shortest on the weedy plots and the longest height was obtained from the alachlor+simazine application. But in the first harvest the height was reduced by herbicides. Seeding rates did not affect the plant height. But the height was slightly taller under the low seeding rate than under the high seeding rate. 4. The percent crude protein of the forage did not affected by two seeding rates. Simazine treatments increased the percent crude protein and total crude protein yield. Simazine and alachlor+simazine application showed the significantly higher percent crude protein than hand weeded and alachlor treatments. Simazine increased the percent crude protein without reduction of forage yield. 5. Whereas the number of original stand was greater in the high seeding rate, the number of tillers per stand was higher in the low seeding rate. Weed reduced the number of stands and tillers. There was no significant indifference among the weed control treatments. It is concluded from above results that when sorghum-sudangrass hybrids are broadcasted for forage, 25 kg/ha rate of seeding is appropriate and alachlor+simazine treatment is most effective on weed control, maximum forage yield, and high percent crude protein.
