Use of activated carbon to protect tomato against metribuzin

Abstract

Summary Protection of tomato (Lycopersicon esculentum Mill., cv. UC 134) against metribuzin was increased by placing a small quantity of activated carbon near each seed position before pre‐emergent application of the herbicide. The most protective location of the carbon was the surface of the soil, immediately above the seed. In this location, 0.10 g of activated carbon protected tomatoes from the phytotoxic effects of 0.700 kg metribuzin ha−1 whereas, without the activated carbon, 0.175 kg metribuzin ha−1 killed both tomato and blackberry nightshade (Solanum nigrum L.). Placing plastic discs in this location did not reduce the phytotoxicity; however, a barrier that prevented lateral invasion by the herbicide, of the zone of soil through which the plumule emerged, partially protected the plains from 0.350 kg metribuzin ha−1, showing that metribuzin entered the plants in substantial quantities via the plumule as well as the roots. This result suggests that activated carbon maintained a lower metribuzin concentration in the plumule/root zone than the bulk concentration. It also explains way the soil surface was the most protective carbon location. These findings provide the basis for extending the use of preemergent herbicides to situations in which previously they could not be used safely or economically.

Enhanced Pesticide Sorption by Soils Containing Particulate Matter from Crop Residue Burns

“…They attributed the observation to the presence of ash charcoals (including BC) in the soils receiving the regular burning of cane trash, although no direct evidence of pesticide sorption by ashes was presented. Toth et al (24) ascribed the observed reduction in the phytotoxicity of diuron applied over the ash of recently burned kangaroo grass to the diuron sorption by the ash. Another study using a soil-plus-charcoal (commercial) sorbent indicated that the presence of the charcoal not only enhanced pesticide sorption but also altered the sorptive characteristics of the soil by reversing the effect of pH on sorption, changing sorption isotherm from Freundlich type on the soil to Langmuir type on the soil-plus-charcoal, and reaching maximum sorption at relatively low equilibrium concentrations in solution (25).…”

Soil Detoxication by the Means of Activated Carbon in Breeding Process

“…The positive impact of activated carbon application for protection of various crops from the affects pesticides and herbicides has been discovered and studied in the world's leading research enterprises. [2][3][4][5][6][7][8][9][10][11][12][13][14].…”

Potential use of activated carbon as a protectant against pre‐emergence herbicides in direct‐seeded processing tomatoes

“…If the carbon is located in a small patch (approximately 2 cm in diameter) above the tomato seed, protection is still achieved, and less carbon is required (Toth et al, 1987), Activated carbon can reduce the phytotoxic effect of herbicides, metribuzin in particular, on tomatoes (Elmore & Woods, 1980;Lange, 1981;Romanowski, 1982;Toth et al, 1987), Toth et al, (1987) suggested that the activated carbon maintained a lower metribuzin concentration in the shoot/root zone than in the remainder of the soil volume.…”

“…In previous experiments metribuzin gave unsatisfactory pre-emergence control of 5, nigrum (Morgan et al, unpublished data). Furthermore, the benefits of alternative herbicides for use in a monoculture situation are numerous, Toth et al (1987) showed that the best location for the carbon was on the soil surface immediately above the tomato seed. The positioning of activated carbon relative to the seed is important, and as our results from a similar experiment complement those of Toth et al, (1987), these data too are presented in this paper (Experiment 2), The experiments reported here also examined the influence of watering method on the effectiveness of carbon protection, the amount of activated carbon required in a field situation, and whether the results obtained in a loamy sand soil are applicable to other soil types.…”

“…Furthermore, the benefits of alternative herbicides for use in a monoculture situation are numerous, Toth et al (1987) showed that the best location for the carbon was on the soil surface immediately above the tomato seed. The positioning of activated carbon relative to the seed is important, and as our results from a similar experiment complement those of Toth et al, (1987), these data too are presented in this paper (Experiment 2), The experiments reported here also examined the influence of watering method on the effectiveness of carbon protection, the amount of activated carbon required in a field situation, and whether the results obtained in a loamy sand soil are applicable to other soil types. In addition, we considered that the potential use of activated carbon in conjunction with existing herbicides warranted an attempt to find a practical means of applying the activated carbon in the field until such time as equipment now under development (Toth etal., 1987) becomes available.…”