Allelopathic Influence of Sorghum Aqueous Extracts and Sorghum Powder on Germination Indices and Seedling Vigor of Hybrid Corn and Jungle Rice

ABSTRACT: Allelopathy has become a paramount tool for controlling weeds in crop plants without deteriorating the environment. Allelopathic effects of sorghum aqueous extracts and sorghum powder on a single cross maize (Zea mays L.) hybrid “HC-8080” and a summer weed, jungle rice (Echinochloa colona L.) were assessed in the research laboratory of Agronomy, Faculty of Agriculture, Gomal University, Dera Ismail Khan, KPK, Pakistan. The treatments included: T1: control (untreated check), T2: sorghum aqueous extract at a rate of 5 mL kg-1 soil, T3: sorghum aqueous extract at a rate of 10 mL kg-1 soil, T4: sorghum aqueous extract at a rate of 15 mL kg-1 soil, T5: sorghum powder at a rate of 5 g kg-1 soil, T6: sorghum powder at a rate of 10 g kg-1 soil and T7: sorghum powder at a rate of 15 g kg-1 soil. The results unveiled that sorghum aqueous extract at a rate of 15 mL kg-1 soil was the most deleterious treatment which reduced the germination percentage (GP) in maize and E. colona by 23.57% and 47.03%, germination index (GI) by 22.30% and 42.14%, root length by 32.25% and 62.54% and shoot length by 23.22% and 62.76%, respectively over control. Similarly, 15 g kg-1 soil sorghum powder reduced the same parameters respectively by 18.85% and 41.09%, 15% and 33.53%, 9.3% and 54.69% and 15.88% and 45.34% in maize and E. colona, respectively and stood better than other powder treatments. Therefore it is concluded that sorghum extracts and powder can both be used to control weeds efficiently but their deleterious effect on the corresponding crop should also be an important consideration.

摘要：化感作用（Allelopathy）已成为在不破坏生态环境的前提下防控作物田间杂草的关键手段。本研究于巴基斯坦开伯尔-普赫图赫瓦省（KPK）德拉伊斯梅尔汗市戈马尔大学农学院农学实验室开展，探究了高粱水浸提液（sorghum aqueous extracts）与高粱粉末（sorghum powder）对单交玉米（Zea mays L.）品种‘HC-8080’以及夏季杂草光头稗（Echinochloa colona L.）的化感效应。试验共设置7组处理：T1为未处理对照组；T2为施加5 mL·kg⁻¹土壤的高粱水浸提液处理；T3为施加10 mL·kg⁻¹土壤的高粱水浸提液处理；T4为施加15 mL·kg⁻¹土壤的高粱水浸提液处理；T5为施加5 g·kg⁻¹土壤的高粱粉末处理；T6为施加10 g·kg⁻¹土壤的高粱粉末处理；T7为施加15 g·kg⁻¹土壤的高粱粉末处理。研究结果显示，相较于对照组，施加15 mL·kg⁻¹土壤的高粱水浸提液处理对玉米与光头稗的化感抑制效果最强，可使二者的发芽率（Germination Percentage, GP）分别降低23.57%与47.03%，发芽指数（Germination Index, GI）分别降低22.30%与42.14%，根长分别降低32.25%与62.54%，苗高分别降低23.22%与62.76%。同理，施加15 g·kg⁻¹土壤的高粱粉末处理可使玉米与光头稗的上述指标分别降低18.85%与41.09%、15.00%与33.53%、9.30%与54.69%、15.88%与45.34%，且其抑制效果优于其余粉末处理组。综上，高粱水浸提液与高粱粉末均可高效防控杂草，但在实际应用中也需兼顾其对目标作物的负面影响。