In former days a vegetable grower would plant many times more seed than the plants he needed, to ensure a stand even if the seed quality were poorer than expected. Any excess seedlings were thinned out by hand, and the crop was harvested by hand, involving several harvests, with no concern for uniform maturity. Today the situation is different. Labor is expensive and becoming more so. The trend is toward mechanization, which requires precision planting or planting to a stand, with a once-over harvest. Only high-quality seed will do the job.