Abstract: Disclosed embodiments concern a process for controlling plant pests, such as insects, nematodes, fungi, weeds, and combinations thereof, with specific embodiments being particularly useful for weed suppression. One disclosed embodiment comprises providing a plant, or a portion thereof, selected from the family Brassicaceae, particularly from the genera Brassica and Sinapis, and even more particularly from the genus Sinapis. Plant material is applied to soil prior to crop planting, simultaneously with crop planting, or subsequent to emergence of desired plants. The method may further comprise processing plant material. For example, with reference to Sinapis alba processing can include crushing the plants to obtain seed meal, which can be applied as obtained, or can be in other useful forms, such as pellets. Alternatively, effective glucosinolates may be extracted from plant material, either with or without first pressing the plant material.