GB6000-1999

Tree seedling quality grading of major species for afforestation

主要造林树种苗木质量分级

GB 6000-1999 é uma norma nacional chinesa obrigatória vigente: Tree seedling quality grading of major species for afforestation. Setor: Alimentos. Foco: Segurança de produtos. Entrada em vigor: 1 de abr. de 2000.

A aplicabilidade depende do escopo do produto, da via de certificação, dos avisos da autoridade competente e das regras de transição. Solicite uma tradução ou verifique a fonte antes de usar este registro em uma decisão de conformidade.

Visão geral de conformidade

Esta visão geral está disponível por enquanto apenas em inglês.

Escopo e aplicabilidade

This standard applies to bare-root seedlings cultivated in open fields for afforestation purposes across major tree species in China. It is specifically designed for forestry engineers and nurseries dealing with seedlings, transplants, and grafted plants. The standard explicitly excludes container seedlings and those cultivated in greenhouses, focusing solely on open-field bare-root planting materials.

Requisitos técnicos

The standard establishes a two-tier grading system (Grade I and Grade II) for qualified seedlings, eliminating the previous unqualified category. Grading is determined by a combination of comprehensive control conditions, root system metrics, caliper (basal diameter), and seedling height. Key morphological and physiological indicators include root length, root width, and the number of first-degree lateral roots exceeding 5cm. The comprehensive control conditions mandate that seedlings must be free from quarantine pests, have straight stems, normal coloration, and be fully lignified. For long-term stored conifer seedlings, the standard introduces the Total Number of New Roots (TNR) as a vitality test indicator. Seedlings must meet the root system requirements first before being graded by caliper and height, with the caliper taking precedence if height and caliper fall into different grades.

Métodos de ensaio

Testing involves random sampling from a seedling lot, with sample sizes varying from 50 to 750 plants depending on the lot size. Measurements include: - Caliper: Measured with a vernier caliper at the basal stem, precise to 0.05cm. - Seedling height: Measured from the caliper point to the terminal bud base, precise to 1cm. - Root system: Length and width measured with a steel tape, precise to 1cm. - TNR test: 30 randomly sampled seedlings are potted in river sand under controlled environments (25°C day/16°C night) to count new root growth points after a specified period.

Perguntas frequentes

What products are regulated under GB 6000-1999?

GB 6000-1999 regulates bare-root tree seedlings of major species used for afforestation in China, including seedlings, transplants, cuttings, and grafted plants cultivated in open fields.

Are there any updates from the previous version of GB 6000?

Yes, this version replaces GB 6000-1985. Key updates include adding 19 new tree species, introducing root length and lateral root count as grading indicators, adopting a two-tier grading system (Grade I and II), and adding the TNR (Total Number of New Roots) test for stored conifer seedlings.

How does GB 6000-1999 handle seedlings that don't meet the grade?

The standard uses a two-tier system where only Grade I and Grade II are considered qualified. If a seedling's root system fails to meet the minimum requirements, it is automatically classified as unqualified, regardless of its caliper or height.

The summary above provides a high-level overview of GB 6000-1999. To ensure complete compliance for your forestry products entering the Chinese market, a precise and professional translation of the full technical specifications is essential. Purchase our high-quality English translation of GB 6000-1999 today to access all detailed parameters, grading tables, and testing procedures.

Indicações de aplicabilidade

Tipo: Produto
CCS: B61
ICS: 65.020.20
Órgão competente: National Forestry and Grassland Administration
Comitê técnico: National Technical Committee on Forestry and Grassland Seeds of Standardization Administration of China

Relações

Substitui:GB 6000-1985