Sugarcane Field Residue and Bagasse Allelopathic Impact on Vegetable Seed Germination

The chemical interaction between plants, which is referred to as allelopathy, may result in the inhibition of plant growth and development. The objective of this research was to determine the allelopathic impact of sugarcane (Saccharum officinarum) var. ‘HoCP 96-540’ field residue and sugarcane bagasse extracts on the germination of three vegetable crops. Tomato (Solanum lycopersicum L.), Chinese kale (Brassica oleracea L. var. alboglabra Bailey), and cucumber (Cucumis sativus L.) seeds were treated with 4 extract concentrations (0, 16.7, 33.3, and 66.7 g/L) from either sugarcane field residue or sugarcane bagasse extracts. Germination of the tomato, Chinese kale, and cucumber seeds decreased as concentration of sugarcane field residue extracts increased. At the highest residue concentration (66.7 g/L), germination decreased by 44%, 82%, and 88% for tomato, Chinese kale, and cucumber, respectively. These results would indicate that sugarcane field residue would not be a suitable natural mulch or soil amendment for local vegetable production, especially where the vegetables were direct-seeded. If evaluated correctly, the sugarcane field residue may be an effective natural mulch for perennial ornamental plants in landscape applications, serving as a physical and chemical barrier to germinating and emerging weed species. Sugarcane bagasse extracts did not inhibit Chinese kale and cucumber germination, and only inhibited tomato germination by 13% at the greatest concentration (66.7 g/L) in 1 experiment. As the first documented bioassay implicating bagasse as allelopathic active, further research should investigate the subject using higher concentrations, and additional sugarcane and tomato varieties. Except for the one instance with tomato germination, it appears that sugarcane bagasse has potential as a natural mulch for vegetable production, although the mulch would only be a physical barrier to weed establishment and not a allelopathic chemical barrier. Future research should determine the allelopathic active compounds in sugarcane field residue and if the concentration of allelopathic chemicals vary by sugarcane variety.