General technical requirements for original stock archive of forest tree cultivar in Vietnam under TCVN 13701:2023

1. What is the original stock?

According to TCVN 13701:2023, the original stock is the first generation of a recognized variety or a rejuvenated variety obtained through multiplication from mature trees or parent plants. It includes seeds, tubers, roots, stems, branches, bud grafts, shoots, tissue culture plants, and seedlings.

The original stock is used for breeding materials or establishing variety gardens and seed orchards.

2. General technical requirements for maintaining seed orchards of forest tree cultivar in Vietnam

Seed orchards for forest tree cultivar must meet the following general requirements, according to TCVN 13701:2023:

+ Site selection: The location of the seed orchard must have suitable ecological conditions for the cultivated species.

+ Tree arrangement: Trees should be arranged in separate blocks, according to each variety, with a minimum of 10 trees per variety in the seed orchard.

+ Variety origin: Only recognized varieties should be used.

+ Pest and disease status: There should be no signs of pests or diseases.

+ Survival rate: A minimum of 90% survival rate is required (during the investment phase).

+ Variety name labels: Variety name labels should be placed at the beginning of each row, including the variety code, origin, and planting date.

+ Seed orchard records: Records should include the design plan, list of varieties, variety origin, planting date, number of trees, and care and fertilization logs.

3. Methods for determining criteria in seed orchards for forest tree cultivar in Vietnam

According to TCVN 13701:2023, the criteria for seed orchards of forest tree cultivar are determined using the following methods:

+ Average annual temperature (°C): Based on data from the nearest meteorological station to the planting site over a period of 3 years.

+ Average annual rainfall (mm): Based on data from the nearest meteorological station to the planting site over a period of 3 years.

+ Number of months with rainfall exceeding 100 mm: Based on data from the nearest meteorological station to the planting site over a period of 3 years.

+ Soil depth (cm): Select a representative location, dig a cross+section, and measure the soil depth directly using a ruler.

+ Mechanical composition: Determine based on soil fertility maps and existing data on the mechanical composition of the area, combined with direct field inspections in the seed orchard.

 In cases where the composition cannot be determined, soil samples should be collected for analysis using the following methods:

++ Soil sampling method according to TCVN 7538-2:2005 (ISO 10381 - 2:2002)

++ Determination of mechanical composition of soil according to TCVN 8567:2010.

+ Elevation above sea level (m): Use handheld GPS combined with topographic maps.

+ Slope (°): Use specialized slope measuring devices with an error not exceeding 1%, randomly measure at least 3 points in the orchard.

+ Tree arrangement design: observe and compare the design plan with the actual situation in the orchard.

+ Planting distance: Check the design plan and the actual situation in the orchard. Choose 3 rows and use a measuring tape to measure the planting distance between 4 consecutive trees in the middle row of each selected row.

+ Hole size: Measure directly using a measuring tape in the orchard.

+ Fertilization: Determine based on construction records, design plans, and field inspections in the orchard.

+ Care: Determine based on construction records, design plans, and field inspections in the orchard.

+ Duration of seed orchard maintenance: determined based on construction records, design plans, and field inspections in the orchard.

+ Variety origin: Determine based on construction records, design plans for the seed orchard, or use molecular indicators to assess the variety origin.

+ Pest and disease status: observe directly in the orchard.

+ Survival rate: Count the number of living trees and calculate the survival rate using the formula: survival rate = current number of trees / initial number of planted trees x 100%.

+ Variety name labels: observe directly in the orchard and determine based on construction and design records.

+ Seed orchard records: observe directly in the orchard, cross-check with the orchard records.

* Please note that TCVN 13701:2023 applies specifically to seed orchards of selected tree species such as Acacia hybrids, Eucalyptus hybrids, Casuarina, Melaleuca, and Michelia species, as well as recognized Macca species.

Best regards!

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