Search Results
Abstract
S-ethyl dipropylthiocarbamate (EPTC), a,a,a-trifluoro-2,6-dinitroN,N-dipro-pyl-p-toluidine (trifluralin) and 2-chloro-2’,6’-diethyl-N-(methoxymethyl) acetanilide (alachlor) at 4.5 and 9 kg/ha provided control of goosegrass (Eleusine indica (L.) Geartn), large crabgrass (Digitaria sanguinalis (L.) Scop), redroot pigweed (Amaranthus retroflexus (L.)) and common lambsqualters (Chenopodium album (L.)) in three different planting media of container-grown English ivy (Hedera helix L. cv. Shamrock) and azalea (Rhododendron obtusum Planck, cv. Hino Crimson). 2,6-Dichlorobenzonitrile (dichlobenil) provided control of all the previously mentioned weeds as well as common cockle bur (Xanthium pennsylvanicum Wallr.) and tall morningglory (Ipomea purpurea (L.) Roth). The three planting media utilized in the study varied in ratios of peat, sand and soil. EPTC resulted in equal injury to azaleas in all three soil mixes. Dichlobenil at 9 kg/ha injured English ivy in all three soil mixes with the greatest degree of injury being recorded in the planting medium containing the least amount of peat.
Abstract
Newly transplanted cabbage (Brassica oleracea L. var. capitata L. f. alba DC. cv. Market Prize) was treated with alachlor [2 chloro-2′, 6′-diethyl-N-(methoxymethyl)acetanilide] at rates of 0, 3.4, and 6.7 kg/ha in 4 tests at 2 locations during 1971, 1972, and 1976. Both rates provided control of all predominant weeds, except ivyleaf morningglory, [Ipomoea hederacea (L.) Jacq.]. Decreased crop vigor usually occurred with the high rate of alachlor. Cabbage samples from the 1976 tests contained alachlor residues below 0.01 ppm, the low detectable limit. Residue levels in soil samples from plots that received 3.4 kg/ha decreased from 0.72 to to 0.07 ppm at one location and 0.72 to 0.08 ppm at the other location during the 10 and 11 weeks of the experiment. Residues in soils from the 6.7 kg/ha plots decreased from 1.58 to 0.10 ppm and 1.89 to 0.22 ppm for each location, respectively.
Abstract
Field studies were conducted at 2 sites to evaluate preplant activated charcoal root dips in reducing herbicide injury to newly planted strawberries (Fragaria × ananassa), In 1981, growth of charcoal treated ‘Prelude’, following application of 0.28 kg/ha terbacil (on 0.5% organic matter, Orangeburg loamy sand), was equal to control plants. Charcoal root dips did not prevent injury from 0.56 and 1.11 kg/ha of terbacil on this soil. In 1982, on Orangeburg loamy sand (0.3% organic matter), injury to ‘Apollo’ by diphenamid (4.5 kg/ha) or napropamide (4.5 kg/ha) applications immediately after planting was reduced by charcoal treatment. On the same soil, alachlor (3.4 kg/ha) or metolachlor (2.2 kg/ha) caused equal amounts of injury with or without charcoal root dips. Some crop protection from terbacil at 0.28 kg/ha was achieved with charcoal; however, none was observed with the 0.42 kg/ha rate.
Abstract
Hexazinone was applied as a soil drench to 1-year-old rooted hardwood cuttings of highbush (Vaccinium corymbosum L.) and rabbiteye (V. ashei Reade) blueberries in a series of greenhouse experiments. No differences in susceptibility to hexazinone were detected among 10 highbush and 3 rabbiteye cultivars growing in a fine sand soil. Two highbush and 2 rabbiteye cultivars were assayed for hexazinone tolerance in low, medium, and high organic matter soil which contained 1.3%, 3.5%, and 49.5% organic matter, respectively. Hexazinone at 1 or 2 kg/ha had no inhibitory effect on blueberry growth in the high organic matter soil, inhibited growth slightly on the medium organic matter soil and caused severe injury in the low organic matter soil. At rates of 4 and 8 kg/ha, injury was severe on the medium and low organic matter soils but very slight on the high organic matter soil.
Abstract
Single and multiple applications of 2,4-D to American ginseng (Panax quinquefolium L.) with fully expanded leaves during a 3-year period caused no visible injury to foliage or roots. During the final 2 years of the study, percent plant survival was greater with two applications per year than with one, and percent gain in root weight decreased with increased rate of application of the herbicide. Also, terminal weight of roots decreased with increased number of years of herbicide application. Treated plants did not differ from nontreated plants in percent survival, final root weight, or percent gain in root weight. Herbicide residue was not detected (<0.02 ppm) in roots from plants that received multiple applications of the three highest 2,4-D dosages: 0.56, 1.12, or 2.24 kg·ha−1 a.i. Foliar residues were detected in plants treated once or twice per year for 3 years with 0.56 or 1.12 kg·ha−1 a.i. 2,4-D. Chemical name used: (2,4-dichlorophenoxy)acetic acid (2,4-D).
Conservation tillage is an effective sustainable production system for vegetables. No-till planters and transplanters and strip-till cultivation equipment are presently available for most vegetables. Lack of weed management tools (herbicides, cultivators, etc.) continues to be the cultural practice that limits adaptability of some vegetables to conservation tillage systems. Nitrogen management can be critical when grass winter cover crops are used as a surface residue. Advantages of using conservation tillage include soil and water conservation, improved soil chemical properties, reduction in irrigation requirements, reduced labor requirements, and greater nutrient recycling. However, disadvantages may include lower soil temperatures, which can affect maturity date; higher chemical input (desiccants and post-emergence herbicides); potential pest carryover in residues; and enhancement of some diseases.
Abstract
Azide as NaN3 or KN3 impregnated on clay granules gave excellent control of yellow nutsedge (Cypetus esculentus L.) compared to methyl isothiocyanate combined with chlorinated C3 hydrocarbons (Vorlex) or a non-hand weeded control. Nematode control was obtained with all treatments. Significant yield responses from the use of azide were obtained with all crops.