A low-input sustainable agricultural system for the production of staked, fresh-market field tomatoes (Lycopersicon esculentum Mill.) is described. The system uses winter annual cover crops to fix N, recycle leftover nutrients, produce biomass, and prevent soil erosion throughout the winter and spring. Yields of tomato plants grown in hairy vetch (Vicia villosa Roth), crimson clover (Trifolium incarnatum L.), and rye (Secale cereale L.) plus hairy vetch mulches were higher than those grown in the conventional black polyethylene (BP) mulch system in 2 of 3 years. Fruit were heavier with the plant mulches than with BP mulch. Eight weeks after transplanting, N levels in tomato leaves were higher with plant than with BP mulch, although the plant mulch plots received only 50% of the N applied to the BP plots. The cover crops had no effect on populations of five phytoparasitic nematode species.

Fungi were isolated from soybean cyst nematode (SCN, Heterodera glycines) eggs collected in China, and 253 fungal isolates were assayed for production of compounds active against SCN and root-knot nematode (RKN, Meloidogyne incognita). Fungal isolates were grown for 3 and 7 days in potato dextrose broth (PDB), the culture broths were sterile-ltered to remove fungal biomass, and the ltrates were placed into 24-well plates to test for effects on egg hatch and juvenile motility. Meloidogyne incognita egg hatch ranged from 2 to 121% of hatch in PDB controls and H. glycines hatch from 15 to 224%. Activities of ltrates harvested after 3 and 7 days were signi cantly correlated. Only four isolates produced ltrates that signi cantly inhibited juvenile motility of SCN, RKN or both nematodes. This study identi ed fungal isolates capable of producing compounds active against these nematodes, and demonstrated that there was a low correlation in activity against SCN and RKN. The active fungal isolates are candidates for studies on identi cation of potential nematicides.

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A single compound with sex pheromone activity was isolated from the female soybean cyst nematode,Heterodera glycines, by a sequence of four high-performance liquid chromatographic steps and identified as vanillic acid by a combination of ultraviolet spectroscopy and chromatography. The structure was confirmed by gas chromatography-mass spectrometry. Both attractancy and coiling behavior in male soybean cyst nematode were elicited by authentic vanillic acid.

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