Effets des reprises de labour sur les tubercules de Cyperus rotundus L. en Nouvelle-Calédonie. II. Viabilité des morceaux de tubercules

Abstract

New Ploughing Effects on Cyperus rotundus L. in New Caledonia. II. Viability of Half-Tubers. In addition to stimulate vegetative growth of Cyperus rotundus by cutting off chains of tubers, the rotary hoe (Rotavator) is able to cut off pieces of tubers. Consequently, the objective of this trial, conducted in New Caledonia, is to study the development of halves of tubers cut lengthwise or widthwise. Forty eight days after planting, halves of tubers cut lengthwise or widthwise produce as many rhizomes, new tubers, sprouts as entire tubers. Because of reserves of nutrients reduced by 50%, halves of tubers cut lengthwise or widthwise produce less biomasses than entire tubers. Halves of tubers cut widthwise, by developing a bit more rapidly than halves of tubers cut lengthwise, seem to highlight the tuber's organogenesis. Finally, a tuber when is cut in half produce two viable pieces of tubers. Consequently, the use of sharp tools during new ploughing, as the rotary hoe, can increase directly the numbers of tubers in the soil. This result implies a reasonable use of tools during tillage or ploughing for a better control of C. rotundus.

Keywords

• Cyperus rotundus L.
• tubers
• Chains of tubers
• Vegetative growth
• Mechanical effects
• New Caledonia