Dry‐Matter Production, Allocation and Nutritive Value of Forage Chicory Cultivars as a Function of Nitrogen

Abstract

AbstractForage chicory cultivars vary in origin and morphology and may respond differently to nutrient inputs because of photosynthate allocation and resource acquisition. Understanding nitrogen (N) influences on chicory seedling development and allocation of photosynthates among plant parts is important in terms of stand establishment, plant persistence, herbage production and nutritive value. We conducted experiments in the glasshouse to determine if amount (0, 50 and 100 mg N kg−1 soil) and source (ammonium nitrate or urea) of exogenous N influenced leaf dry‐matter (DM) production, N nitrate (NO3) and total non‐structural carbohydrate (TNC) allocation among roots and shoots in the chicory cultivars Forage Feast, Lacerta or Grasslands Puna. Herbage DM productivity and the ratio of energy (TNC) : protein varied among cultivars because of differential photosynthate allocation between shoots and roots, and occurred later in the growth interval when N was applied. Forage Feast, compared with the other cultivars, produced the largest roots and greatest herbage DM without added N. Leaf appearance rate in Lacerta and Grasslands Puna increased with increasing N. Instantaneous growth rates of Grasslands Puna and Lacerta at 100 N were three times that of 0 N plants. Nitrate concentrations were very high in young seedlings of all three cultivars before applying N. The findings help define application practices for these cultivars and N management practices for optimal leaf production in establishing forage chicory plants.