Some types of vernalized garlic show tendency to secondary bulb growth, which can be influenced by nitrogen, potassium and mulching, but there are few studies about the subject. The experiment was carried out in a typical Hapludox, medium texture soil in Campinas, São Paulo State, Brazil. The experimental design was in randomized blocks, 4 x 4 x 2 factorial scheme with four rates of N (0; 50; 100 and 150 kg ha-1), four rates of K(2)0 (0; 50; 100 and 150 kg ha-1), two management systems (with and without mulching) and three replications. The useful area of each plot was 1.5 m².and planting (May, 1999 and 2000) was done in 0.20 x 0.10 m plots. After harvest (October, 1999 and 2000) and a hardening period (50 days), the bulbs were evaluated for weight, lateral shoot growth and other defects, total yield and commercial production. Nitrogen and potassium rates and mulching influenced independently the garlic characteristics, varying in function of each evaluation. The nitrogen fertilizations increased the lateral shoot growth and potassium reduced this problem in both years. Most of the bulbs were classified as small in 1999 and as medium size in 2000. Mulching decreased yields in all classes and reduced total and commercial yield and did not affect other defects. The estimated maximum total yield was 3,922 and 8,689 kg ha-1 N with 74 and 107 kg ha-1 N in 1999 and 2000, respectively. The commercial yield (3,563 kg ha-1) was obtained with 68 kg ha-1 N in 1999. There was no response to N rates in 2000. The estimated maximum commercial yield was obtained with 94.5 kg ha-1 K2O ha-1 in 1999. There was a linear response to rates of potassium in 2000.
fertilization; nutrition; Allium sativum; lateral shoot growth
