Avaliação de diferentes materiais de cobertura e de um protetor físico, no estabelecimento de plantas de <i>Pinus taeda</i> L., por semeadura direta no campo.

Abstract

RESUMOEste trabalho teve como objetivo avaliar diferentes materiais de cobertura e o uso de protetor físico na implantação de povoamentos de Pinus taeda L. em semeadura direta no campo. Foram utilizados 3 materiais: vermiculita, acícula de pinus seca e picada, casca de arroz e sem-cobertura (testemunha), com e sem-protetor físico (copo plástico de 300 ml, sem fundo), com 5 repetições. A semeadura foi realizada na primeira quinzena do mês de maio de 1997, utilizando-se 3 sementes por ponto. Foram feitas analises de emergência aos 60 e 90 dias, sobrevivência aos 120, 180 e 210 dias e de densidade populacional aos 210 dias após a semeadura. A análise de variância e comparação de médias (Duncan 5%) possibilitaram concluir que: os materiais de cobertura vermiculita e acícula de pinus expressaram efeitos benéficos na emergência aos 60 dias, que é a fase mais crítica para o estabelecimento do povoamento de Pinus taeda; o protetor físico utilizado garantiu maior percentagem na emergência final, sobrevivência e densidade de plantas, demonstrando ser a semeadura direta uma forma, a mais, de regeneração.Palavras-chave: Semeadura direta, Pinus taeda, materiais de cobertura, protetor físico. ABSTRACTThis work has had as its objectives to evaluate different covering materials and physical protector's use in the forest population of Pinus taeda L. in direct sowing in the field. Three materials were used: vermiculit, dried and pricked pine needles, peel of rice and reference without covering, with and without physical protector (plastic cup of 300 ml, without botton), with five replications. The sowing was accomplished in the first half of May of 1997, being used three seeds per point. The evaluations done were: emergency at the 60 and 90 days, survival at the 120, 180 and 210 days and population density at the 210 days after sowing. The variance and averages analysis (Duncan 5%), has allowed to conclude that: the vermiculit and pine needles affected beneficially the number of plants emerged in the first 60 days, that is the most critical phase for the future of the forest population of Pinus taeda; the physical protector, provides the formation of a microenvironment, that guarantees larger percentage in the emergence, survival and initial density of

A cost–benefit evaluation of direct seeding with and without protector for two native tree species in a tropical rainforest

“…Protectors had different effects on plant establishment depending on the species. For Vochysia guatemalensis , they significantly improved it, in agreement with other studies that have also found enhanced plant germination (Mattei ; Mattei & Rosenthal ; Ceccon et al ) or survivorship in the first months after seeding (Serpa & Mattei ; Santos‐Júnior et al ) from the use of protectors. In contrast, we did not find any significant effects of the protectors on the establishment of Calophyllum brasiliense .…”

Semeadura direta de timbaúva (<i>Enterolobium contortisiliquum</i>), canafístula (<i>Peltophorum dubium</i>) e cedro (<i>Cedrela fissilis</i>) em campos abandonados.

“…A semeadura direta é um método alternativo e tem apresentado resultados promissores com espécies exóticas, especialmente do gênero Pinus (Mattei, 1993;1998;Brum et al 1999;Serpa, 1999, D'Arco e Mattei, 2000. Algumas tentativas foram realizadas com semeadura direta com espécies nativas (Mattei, 1995;Schneider, 1999;Alvino et al 2001;Mello, 2001;Krohn et al 2001), também produzindo resultados animadores.…”

Influence of physical protectors with different filters on the initial development of Peltophorum dubium (Spreng.) Taub seedlings

“…The weakness of seedlings in function to the soil compression resulted because of the less moisture observed as the principal factor of the cause of seedlings death. Serpa and Mattei (1999), observed a larger percentage of survival in plants of Pinus taeda, used for timber and cellulose originated in the interior the physical protectors. Besides, Santos-Junior et al (2004) observed an increment in the survival percentage of Tabebuia serratifolia, used for landscape and reforestation, while physical protector used for transparent plastic cups of 500 ml without bottom and buried 2 cm under the hole, was in relation to the absence of physical protector.…”

“…Different materials with different sizes, shapes and colors had been used as physical protectors by many researches (Barnett and Baker, 1991;Serpa and Mattei, 1999;Mattei et al, 2001;Klein, 2005;Klein et al, 2005;Ferreira et al, 2007). According to Carneiro (1995), those protectors must be light, non-toxic, hygroscopic and must recover all soil surface.…”