Pruning: trimming or cutting parts that are not needed or that are injurious.

Pulverize: to reduce to a dustlike state.

Pupa: an insect in the stage of its life that comes just before the adult condition.

Purity (of seed): seeds are pure when they contain only one kind of seed and no foreign matter.

Ration: a fixed daily allowance of food for an animal.

Raupenleim: a patented sticky substance used to catch the cankerworm.

Resistant: a plant is resistant to disease when it can ward off attacks of the disease; for example, some varieties of the grape are resistant to the phylloxera.

Rotation (of crops): a well-arranged succession of different crops on the same land.

Scion: a shoot, sprout, or branch taken to graft or bud upon another plant.

Seed bed: the layer of earth in which seeds are sown.