Treating Garlic Seed Cloves with Negative Temperatures Increases the Productivity of Noble Garlic in the Brazilian Semi-Arid Region

Abstract

The treatment with low temperatures, for a certain period, stimulates the accumulation of phytohormones in garlic seed cloves, which influence the growth and development of the plants. Thus, this work aimed to evaluate the effects of garlic seed cloves under negative temperatures for different periods on the development and productivity of noble garlic cultivated in the Brazilian semi-arid region. Two experiments were carried out and analyzed separately in the municipalities of Mossoró and São Miguel, RN, Brazil, in which three temperature ranges (−5 to −3 °C, −2 to 0 °C and 1 to 3 °C) and three periods (50, 55, and 60 days) were tested. Low-temperature conditioning of the garlic seed cloves was carried out in a temperature-controlled freezer. Relative humidity during treatment ranged from 60 to 70%. Seed cloves submitted to temperatures below zero provided the differentiation of cloves, even in unfavorable edaphoclimatic conditions for cultivating noble garlic. Seed cloves conditioned with negative temperatures increased the productivity of garlic grown in Mossoró, but with a lower average yield than garlic produced in São Miguel. Garlic seed cloves treated at negative temperatures in São Miguel provided garlic productivity equivalent to the yield of garlic grown in the states of the southern region. In addition, it produced class 6 and 7 bulbs, which have greater commercial value and acceptance by consumers. The results demonstrated the potential of garlic seed cloves treated with temperatures below zero to increase the production of noble garlic in the semi-arid region of the country.