Management of volunteer potato is difficult and requires an integrated approach. Soil fumigation is one tactic known to reduce population densities of certain weeds and may be a method to improve the management of volunteer potato. The effect of 1,3-dichloropropene (1,3-D) and metham sodium on potato tuber viability was tested in sealed glass jars at various doses, incubation temperatures, and times of exposure. Tuber viability data were fitted to a logistic model, and I 90 doses (90% suppression) were calculated for each combination of temperature and time of exposure. I 90 doses for 1,3-D ranged from 41 to 151 kg/ha and from 96 to over 480 kg/ha metham sodium. Both nondormant and dormant tubers were injured by exposure to metham sodium. Soil fumigation with 1,3-D and metham sodium has the potential to greatly reduce the number of viable potato tubers.

Isothiocyanates (ITCs) were evaluated as an alternative to methyl bromide (MeBr) for control of Palmer amaranth, large crabgrass, and yellow nutsedge; reduction of tuber density; and increase in marketable tomato yield in low density polyethylene (LDPE)-mulched tomato production. Allyl ITC was applied at 450, 600, and 750 kg ai ha−1; metham sodium (methyl ITC generator) was applied at 180, 270, and 360 kg ai ha−1; and MeBr plus chloropicrin (mixture of MeBr and chloropicrin at 67 : 33%, respectively) was applied at 390 kg ai ha−1. A nontreated weedy check was included for comparison. There was no injury to tomato plants following allyl ITC, metham sodium, or MeBr application. Allyl ITC at 750 kg ha−1 or metham sodium at 360 kg ha−1 controlled Palmer amaranth ≥ 79%, large crabgrass ≥ 76%, and yellow nutsedge ≥ 80% and was comparable to the weed control with MeBr. Highest rates of allyl ITC and metham sodium reduced yellow nutsedge tuber density (≤ 76 tubers m−2) comparable to the MeBr application. Total marketable tomato yield was ≥ 31.6 t ha−1 in plots treated with allyl ITC at 750 kg ha−1 or metham sodium at 360 kg ha−1. Marketable tomato yield from the highest rate of allyl ITC or metham sodium were similar to the yield (38.2 t ha−1) with MeBr treatment. Therefore, allyl ITC at 750 kg ha−1 and metham sodium at 360 kg ha−1 are effective alternatives to MeBr for Palmer amaranth, large crabgrass, and yellow nutsedge control in LDPE-mulched tomato.