GB/T 29376-2026Technical code of practice for the propagation of virus-free potato pre-basic seed (English PDF)

4.1 Environmental Requirements

4.1.1 The location should be in a cool climate, free from pollution sources, and with good natural isolation.

4.1.2 It should be located away from potato fields and there should be no other solanaceous plants or plants that easily attract aphids nearby.

4.1.3 The water source shall meet the requirements for production irrigation and the water quality shall meet the requirements of GB 5084.

4.2 Infrastructure Requirements

4.2.1 It should have functions of temperature control, humidity control, ventilation, rain protection, and insect prevention, with good lighting conditions. The mesh size of the insect-proof mesh should preferably be 0.247mm. (60 mesh).

4.2.2 A buffer zone should be built at the entrance and disinfection facilities should be set up to facilitate disinfection.

4.3 Disinfection Requirements

4.3.1 Internal facilities should be disinfected regularly. Greenhouses can be disinfected by sulfur fumigation, spraying with an 800-fold dilution of 50% carbendazim wettable powder, or 0.05% [unspecified agent]. Sodium hypochlorite can be used for disinfection. For wire mesh greenhouses, a 50% carbendazim wettable powder solution diluted 800 times can be sprayed.

4.3.2 Tools should be disinfected with 75% ethanol or 0.05%~0.1% sodium hypochlorite solution, and rinsed with clean water 2 to 3 times after disinfection.

4.3.3 Staff should wear clean work clothes, wash their hands with soap before work, and should not smoke during work.

5.Propagation Procedure for Virus-Free Potato Seed Culture The potato virus-free primary seed breeding program is divided into a substrate primary seed breeding program and an aeroponic primary seed breeding program. The sequence includes 8 stages, while the aeroponic original seed breeding program includes 7 stages. Among these, the entire substrate original seed breeding program details the prevention of diseases, pests, and weeds. The pest and disease control steps (see 6.7) are detailed in the entire aeroponic original seed breeding process, further outlining the pest and disease control steps (see 7.6). The flowchart is shown in Figure 1. As shown. Figure

6.1 Preparation of the seedbed

6.1.1 The size and form of the seedbed can be determined according to the size of the greenhouse or net house.

6.1.2 Seedbeds should be isolated from the ground.

6.1.3 Treat the seedbed with fungicides and insecticides, and record the name of the agent, the application time, and the dosage.

6.2 Preparation of the substrate Spread a layer of sterilized substrate such as vermiculite, perlite, or coconut coir on the seedbed, about 10cm thick; mix in NPK compound fertilizer per square meter. (15-15-15) 40g~50g; water thoroughly, and when the moisture content reaches 70%~90%, prepare to plant the seedlings.

6.3 Seedling hardening The containers containing the virus-free seedlings were moved from the culture room to a greenhouse or netted room, and hardened off for 5 to 10 days under natural light and a temperature of 18°C to 25°C. Use shade netting to provide shade under strong sunlight.

6.4 Transplanting

6.4.1 Remove the virus-free seedlings, wash off the culture medium, trim some of the old roots, and insert them into the seedbed substrate, ensuring full contact between the roots and the substrate, leaving two leaves exposed. Three top leaves, spray water promptly.

6.4.2 Plant.200 to 300 cuttings per square meter.

6.5 Seedling Management

6.5.1 After transplanting virus-free seedlings, they should be covered with plastic film and shade netting.

6.5.2 Before the seedlings take root, under natural light conditions, the temperature should be controlled at 12°C~25°C and the relative humidity should be maintained at 95%~100%.

6.5.3 After the seedlings have developed new roots, gradually remove the shade netting, maintaining a substrate moisture content of 60%-70%. Depending on the plant growth, spray with water or nutrients. Liquid, proper ventilation.

6.5.4 Thirty days after transplanting, 0.2% potassium dihydrogen phosphate solution and 0.2% urea solution can be sprayed alternately, and the fertilization time and fertilizer type should be recorded. And the amount of fertilizer applied.

6.6 Management during the tuber formation stage When the stolons begin to swell, the temperature should be maintained at 16°C~25°C, and the substrate moisture content should be maintained at 65%~75%.

6.7 Pest and Weed Control

6.7.1 Pest and disease control should be carried out throughout the production process, and the time, name of the pesticide, and dosage of each application should be recorded.

6.7.2 Conduct regular inspections throughout the entire growth period and promptly remove diseased and miscellaneous plants.

6.7.3 Remove weeds from inside and outside the greenhouse or net house in a timely manner.

6.7.4 After the seedlings have recovered from transplant shock, implement pest and disease control measures based on the occurrence of pests and diseases. Apply fungicide and insecticide once a week.

6.8 Harvest

6.8.1 Stop watering 10 to 15 days before harvest.

6.8.2 Harvest at the appropriate time.

6.9 Post-harvest commercial processing

6.9.1 Remove defective potatoes, plant debris, withered leaves, and other impurities.

6.9.2 Grading and packaging are carried out according to different specifications such as 3g~5g, 5g~10g, 10g~20g, and over 20g per grain, with tags attached to both the inside and outside of the packaging. Labels should be attached or affixed, and the labels should comply with the requirements of GB 20464, indicating the variety name, specifications, number of grains, harvest date, place of origin, etc.

6.9.3 The storage management of original seed culture shall comply with the provisions of GB/T 29379.

7.1 Atomized cultivation facilities

7.1.1 Includes cultivation troughs, water pumps, filters, atomizing devices, infusion pipelines, automatic timing units, and storage tanks, etc. (Schematic diagram of atomized cultivation facilities) See Figure 2. Figure

7.3 Planting

7.3.1 Determine the planting time based on local climate conditions.

7.3.2 Transplant the virus-free seedlings when they reach a height of 10cm to 15cm.

7.3.3 Before transplanting, cover the cultivation trough with a black film and cover the cover with a light-blocking material.

7.3.4 Spacing between rows and plants for virus-free seedlings. 15cm×10cm for early-maturing varieties and 20cm×15cm for mid-to-late-maturing varieties.

7.3.5 Plant the prepared virus-free seedlings into the planting holes of the cover plate and fix them in place, leaving 2 to 3 top leaves exposed.

7.4 Aeroponics Management

7.4.1 Nutrient solution Maintain the nutrient solution conductivity (EC) value between 1500 µs·cm^-1 and 3500 µs·cm^-1, and control the pH value between

7.4.2 Spraying time Spray for 30 seconds every 5 minutes within 7-10 days after planting; after the plant's root system has developed, spray for 30 seconds every 5-25 minutes during high temperatures and sunny days. Spray for 40 seconds, then stop spraying for the rest of the time; at night and on rainy days, spray for 20 seconds during the 6-35 minute period, then stop spraying for the rest of the time.

7.4.3 Temperature and Humidity Management The optimal temperature for seedlings is 10°C~15°C, the optimal temperature for the vegetative growth stage is 20°C~28°C, and the optimal temperature for tuber formation is 15°C~ 22°C. Nutrient solution temperature controlled between 16°C and 20°C. Relative humidity controlled between 55% and 70%.

7.5 Plant Management About 20 days after transplanting the virus-free seedlings, remove the leaves from the bottom 2 to 5 stem nodes of the plant and move the main stem down into the culture trough.

7.6 Pest and Disease Control

7.6.1 Before planting, spray the entire pipeline, storage tank, and cultivation trough with a 0.05%~0.1% sodium hypochlorite solution for disinfection. After disinfection, rinse with clean water. Rinse 2 to 3 times.

7.6.2 Spray fungicide and insecticide every 7-10 days after transplanting. Rotate fungicide and insecticide for early blight and late blight. The agent should not be used twice consecutively.

7.6.3 Thirty days after transplanting, add 10,000 times dilution of 72.2% cymoxanil hydrochloride to the nutrient solution to prevent root fungal diseases.

7.6.4 Before each nutrient solution change, clean the tank, add a small amount of clean water and 5mg/L calcium hypochlorite for spray disinfection, and continue for 1 hour.

7.6.5 Record the time, name, and dosage of each drug application.

7.7 Harvest Harvest in batches when the tubers weigh >=3g.

7.8 Post-harvest commercial processing

7.8.1 After rinsing the newly harvested primary seed with clean water, soak it in 0.5% carbendazim wettable powder for 10 seconds, then remove and place it at a temperature of 15°C~20°C. The wood was treated with corkation for 10 days at a relative humidity of 90%~95% or spread out to dry under diffused light for 7~10 days.

7.8.2 Grading and packaging are carried out according to different specifications such as single grain weight of less than 1g, 1g~3g, 3g~5g, 5g~10g, 10g~20g, and more than 20g. Packaging. Labels should be attached or affixed to both the inside and outside of the packaging. The labels should comply with GB 20464 requirements and indicate the variety name, specifications, number of grains, and harvest date. Dates, place of origin, etc.

7.8.3 The storage management of original seed culture shall comply with the provisions of GB/T 29379.