ABSTRACT Palm trees are propagated almost exclusively by seeds and each species germinates under a certain temperature range. In this sense, the two-way thermogradient plate may be used to determine temperature limits for germination and seed response to temperature. The objective was to define the alternating temperature regime promoting higher and faster seed germination of Carpentaria acuminata and Phoenix canariensis palms using a two-way thermogradient plate. This equipment allowed 64 combinations of alternating and constant temperatures, ranging from 6.97 to 36.42 ºC for C. acuminata, and 7.96 to 35.94 ºC for P. canariensis. Seeds were sown in Petri dishes (25 x 9 cm) containing 1% water agar. Linear regressions were estimated to determine cardinal temperatures. After 50 days, non-germinated seeds were transferred from the two-way thermogradient plate to a germination chamber at 30 °C. The temperature regime promoting highest seed germination percentage of C. acuminata was 30.45/33.00 °C (day/night), with minimum, optimum, and maximum temperatures of 9.13, 28.53, and 36.33 °C, respectively. For seed germination of P. canariensis, the most appropriate temperature regime was 29.77/17.93 °C (day/night), with minimum, optimum, and maximum temperatures of 9.53, 28.03, and 35.43 °C, respectively.

RESUMO A conservação da Amazônia é uma preocupação global, apoiada pela ratificação do Bonn Challenge e do Acordo de Paris pelo governo brasileiro e pelas regulamentações nacionais de proteção e restauração da vegetação. O Amazonas é o maior e menos desmatado estado da Amazônia brasileira (<3%). Realizamos um levantamento do estado atual e potencial da produção de sementes e mudas no Amazonas, indicando os principais obstáculos e gargalos onde investimentos futuros podem ajudar a alcançar o compromisso da restauração ecológica em larga escala. Visitamos os 35 produtores de sementes ou mudas de espécies nativas oficialmente registrados, e entrevistamos seus proprietários ou responsáveis técnicos, utilizando um questionário com perguntas abertas e fechadas. Os empreendimentos eram predominantemente privados, familiares, com pequena produção (10.001 - 100.000 mudas por ano) e concentrados na região metropolitana de Manaus. Detectamos outros 54 viveiros não oficialmente registrados. A produção anual (2018) foi de quase quatro toneladas de sementes e quase dez milhões de mudas. Segundo os proprietários, esta produção poderia aumentar de cinco a sete vezes com a infraestrutura existente. A produção foi focada principalmente em espécies para produção alimentar (48% sementes, 74% mudas), enquanto apenas 35% de sementes e 8% de mudas foram destinadas para restauração ecológica. Os principais gargalos citados pelos produtores foram baixa demanda por espécies nativas, alto custo de transporte e excessiva burocracia. Para alcançar restauração em larga escala, recomendamos o cumprimento de políticas de proteção e restauração da vegetação e uma reestruturação do setor de sementes e mudas em uma abordagem ascendente (bottom-up).

ABSTRACT Conservation of the Amazon rainforest is a global concern and is supported by the Brazilian government’s ratification of the Bonn Challenge and Paris Agreement and the introduction of national regulations on vegetation protection and restoration. Amazonas is the largest and least deforested of the states occupied by the Brazilian Amazon (< 3%). We carried out a survey on the current state and growth potential of seed and seedling production in Amazonas state, pointing out constraints where future investment can promote the achievement of large-scale restoration commitments. We visited the 35 officially registered seed producers or nurseries working with native seeds and interviewed their owners or managers using open and closed questions. Enterprises were mainly privately-owned family businesses with small production (10,001 - 100,000 seedlings per year) and concentrated in the metropolitan area of the state capital Manaus. We uncovered a further 54 non-officially registered nurseries. Annual production (2018) was almost four tons of seeds and nearly ten million seedlings. According to the owners, production could be increased five to seven times with existing infrastructure. Production is focused foremost on species for food production (48% seeds, 74% seedlings), while ecological restoration only makes up 35% of seed and 8% of seedling use. Major bottlenecks cited by the producers were low demand for native tree species, high transportation costs and excessive bureaucracy. To achieve large-scale restoration, we recommend enforcement of national policies for vegetation protection and restoration, and a restructuring of the seed and seedling sector with a bottom-up approach.