The potato cyst nematode (Globodera rostochiensis cv. Woll) is responsible for large yield losses in the potato crop, and opportunities for reducing the attack of these plant nematode species are, therefore, important. This study has been devoted to the testing of the in vitro effects on the potato cyst nematode of eight glucosinolates [prop-2-enyl-, but-3-enyl-, (R)-4-methylsulfinylbut-3-enyl-, benzyl-, phenethyl-, 4-hydroxybenzyl-, (2S)-2-hydroxybut-3-enyl-, and (2R)-2-hydroxy-2-phenylethylglucosinolate] as well as the effects of the products of this myrosinase-catalyzed hydrolysis. The glucosinolates were used at three concentrations, 0.05, 0.3, and 1.0 mg/mL, in the presence or absence of the enzyme myrosinase. The effects of the compounds on the mortality were monitored every 8 h for a 72 h period. No effects were found for any of the intact glucosinolates. However, when active myrosinase was included with 1 mg/mL phenethylglucosinolate at pH 6.5, 100% mortality was observed within just 16 h. A similar effect was achieved at the same concentration of benzyl- and prop-2-enylglucosinolates in the myrosinase-containing solutions, although longer exposures were required (24 and 40 h, respectively). The main aglucone products released from the glucosinolates with pronounced effects on the nematodes were shown to be the corresponding isothiocyanates. The results suggest that mixtures of these specific glucosinolates and active myrosinase or autolysis of plant materials containing these enzymes and glucosinolates might be used to control the potato cyst nematode in the soil.

Plants of the family Brassicaceae are receiving increased attention within the policy of reducing pesticides towards a more friendly agricultural system. The effect of these plants has been attributed to glucosinolates and to their hydrolysis derivatives, particularly the isothiocyanates. Potatoes, the largest cultivated horticultural crop, is susceptible to the nematode Globodera rostochiensis which is controlled by the use of synthetic compounds, with subsequent environmental impact. The search for alternative control methods prompted this study in which is reported the effect of several concentrations (0.05, 0.3 and 1.0 mg/ml) of 2-phenylethyl glucosinolate on the mortality of juveniles of G. rostochiensis. The study was conducted over a period of 72 h with evaluations at every 8 h. The results showed no effect with the pure glucosinolate, whilst a 100% mortality occurred within 8 h for 2-phenylethyl glucosinolate (1 mg/ml) with added myrosinase (25%).