Efficacy, uptake and distribution of different herbicides in the water hyacinth

Experiment conducted in the glasshouse with water hyacinth plants in pots revealed that 3h.after spraying parquet or 2.4-D at recommendeb herbicida rates, 43 to 53, of the herbicide is found in the plants and the rest is present in the water culture Out of the total [¹⁴Clparaquat applied,38,9,8·8. 32 and 0.9% was found in the leaf blads. petioles, underwater foliage and roots respectively. The corresponding values for [¹⁴C]2, 4-D were 320. 94. 13 and 0.2% As the time interval after spraying increased, a greater accumulation of herbicide in the under-water parts was evident A net loss of 14 and 60%. of the applied 2,4-D was recorded 1 and 2 weeks after spraying respectively the rate of paraquat loss from the plant water system was similar to 2,4-D. Absorption of [¹⁴C]2,4-D from the culture solution by the roots and the floats of the water hyacinth was. evident Translocation of root-absorbed 2, 4-D into the meristematic folrar parts was dernonstrated If the substrates was treated with 2,4-D.a minimal concentration of 1 p. p. m. was required for water hyacinth death In another experiment glyphosite at 2 to 6 kg a 1 ha and 2.4-D.amine at 0–75 2.25 kg a ha gave complete control of water hyacinth Asulam was found to be unsatis factory even at 6 kg a.1 ha the highest rate tried.