Weed control in raspberry and blackberry plantings using herbicides

Soil cultivation in raspberry and blackberry plantings covers a number of cultural practices in order to retain moisture, aeration, soil fertility and structure, control weeds and contribute to optimal growth, fertility and quality of raspberry and blackberry fruits. In intensive raspberry and blackberry production systems the principal weed control usually involves application of herbicides. Herbicides and mulching are employed in rows and interrow spacing respectively to keep down weeds. Generally, soil herbicides are persistent, less soluble and less mobile in soil, and thus their efficacy is longer. They are effective against weeds that emerge during the initial growing stages. However, the efficacy against ground shoots of perennial weed species was noted to lack. Foliar herbicides are applied during vegetation, usually in 10-20 cm high weeds. Total translocated herbicides of short persistence providing a broad spectrum of activity are among mostly used foliar herbicides, including some selective herbicides. During the 2007 vegetation season weed control was investigated using three herbicides: Casoron G (a.i. dichlobenil 67.5 g/kg) applied at the rate 60 (T1) and 80 kg/ha (T2), Galop (a.i. paraquat 200 g/l) applied at the rate 4.0 l/ha (T3) and Bonaca EC (a/o/fluroxypyr-meptyl 360 g/l) applied at the rate 0.8 (T4) and 1.0 l/ha (T5) in 10- and 7-year old raspberry plantings and 7- and 6-year old blackberry plantings. In the experiment EPPO standards were used for the randomized design in four replications. The size of the plots was 100x1 m (row region). A manual knapsack sprayer (Solo 425) with the Lumark 04-F11-nozzle and water application 300l/ha (Bonaca EC and Galop) was used. Casoron G granules were distributed using a depositor Uniroyal Chemical Casoron 6.75 GR. Efficacy was evaluated based on the number of plants per square m, and visually assessed according to the EWRC scale. The efficacy of the tested preparations with regard to the weed species registered ( Amaranthus retroflexus, Ambrosia artemisiifolia, Capsella bursa-pastoris, Chenopodium album, Ch. hybridum, Datura stramonium, Daucus carota, Erigeron canadensis, Hibiscus trionum, Lamium amplexicaule, L. purpureum, Polygonum lapathifolium, P. aviculare, Solanum nigrum, Sonchus asper, Stellaria media, Digitaria sanguinalis, Echinochloa crus-galli, Setaria glauca, Achillea millefolium, Cirsium arvense, Convolvulus arvensis, Plantago lanceolata, Taraxacum officinale, Tussilago farfara, Cynodon dactylon, Sorghum halepense) was as follows: annual broadleaf species: Bonaca EC (1 l/ha) is greater than Casoron G (80 kg/ha) is greater than Casoron G (60 kg/ha) is greater than Bonaca EC (0.8 l/ha) is greater than Galop (4 l/ha); perennial broadleaf species: Bonaca EC (1 l/ha) is greater than Bonaca EC (0.8 l/ha) s greater than Casoron G (80 kg/ha) is greater than Galop (4 l/ha) is greater than Casoron G (60 kg/ha); annual grass weeds: Casoron G (80 kg/ha) is greater than Casoron (60 kg/ha) is greater than Galop (4 l/ha); and perennial grass weeds: Casoron G (80 kg/ha) is greater than Casoron G (60 kg/ha) is less than Galop (4 l/ha). None of the combinations showed the efficacy against Cynodon dactylon and Sorghum halepense to be sufficiently high (greater than 95%). Casoron G (both application rates) efficacy against sorghum and wild foxglove was greater than 75 is greater than 95% and less than 75% respectively.