Detailed Explanation of Eggplant Grafting Techniques, with Operation Process

AbstractRootstock introduction: Ping eggplant rootstock, prickly eggplant rootstock, and Torubamu rootstock have relatively high disease resistance and grafting survival rates. Scion selection: Nongyou long eggplant, Hangzhou red eggplant, Xi'an green eggplant, etc. Grafting seedling cultivation: sow the rootstock first, then the scion. Cleft grafting: when the rootstock grows to 6-7 true leaves and the scion grows to 5-6 true leaves, grafting can be carried out. Splice grafting: the size of the rootstock and scion is the same as for cleft grafting.

I. Rootstock Introduction

1. Ping eggplant rootstock

(1) Also called red eggplant and scarlet eggplant, it is mainly resistant to fusarium wilt and moderately resistant to bacterial wilt, with a control effect of up to 80%. Its seeds germinate easily, and the grafting survival rate is relatively high.

(2) Generally, when using Ping eggplant as rootstock, it needs to be sown 7 days earlier than the scion. The main soil-borne disease is bacterial wilt. Generally, in plots with severe disease, this variety is not suitable for use as rootstock.

2. Prickly eggplant rootstock

(1) Highly resistant to verticillium wilt, with a control effect above 93%. It is currently a commonly used rootstock variety in the north. Its seeds germinate easily; after soaking for 24 hours, they will all germinate in about 10 days.

(2) Prickly eggplant is relatively tolerant to low temperatures and is more suitable for grafted cultivation in greenhouses in autumn and winter. When using prickly eggplant as rootstock, it should be sown about 5-20 days earlier than the scion.

3. Torubamu rootstock

(1) It can achieve a high level of resistance or immunity to 4 soil-borne diseases: verticillium wilt, bacterial wilt, fusarium wilt, and root-knot nematode disease. The seeds need to be pregerminated. When soaking the seeds, gibberellin can be used at a concentration of 100-200 mg per kilogram, then soak for 24 hours.

(2) Then rinse clean with clear water, put into a small cloth bag for pregermination. For pregermination and sowing, it should be 25 days earlier than the scion; if soaking and direct sowing, it needs to be 35 days earlier.

II. Scion Selection

1. For the above rootstocks, the compatibility as scion is relatively strong. Generally, 7-10 days after grafting, the wound will heal. Rootstocks do not have very strict requirements for the scion.

2. For example, in some provinces, E'qie No. 1, 8819 line eggplant, Nongyou long eggplant, etc. for autumn-winter crops, as well as Suqi eggplant, Hangzhou red eggplant, etc. for winter-spring crops, and Xi'an green eggplant, Luoyang green eggplant, and 9318 purple long eggplant, etc., can all be used as scions.

III. Grafting Seedling Cultivation

1. Generally, in the sowing period, sow the rootstock first, then the scion. For autumn-winter crops, the rootstock is sown in mid-July; for winter-spring crops, the rootstock is sown in early to mid-September; and for early-maturing greenhouse cultivation, the rootstock is sown around January.

2. When soaking and pregerminating scion seeds, use warm water at 55°C for soaking, or soak with a 500-fold solution of 50% carbendazim for 2 hours. For the scion seedling bed soil, choose field soil that has not been planted with Solanaceae crops, or use soilless seedling cultivation.

IV. Cleft Grafting

1. When the rootstock grows to 6-7 true leaves and the scion grows to 5-6 true leaves, grafting can be carried out.

2. During grafting, select rootstock and scion with similar stem thickness to pair. Above the 2 true leaves of the rootstock, use a blade to cut horizontally to remove the upper part, then make a vertical cut 1-1.5 cm deep in the middle of the stem cross-section.

3. Take the scion seedling and keep 2-3 true leaves. After cutting horizontally, remove the lower end, then carefully cut it into a wedge shape. The length of the slanted surface should be the same as the rootstock cut. Then insert the scion into the rootstock cut. After aligning, secure it firmly with a fixing clip and place it on the seedling bed.

V. Splice Grafting

1. The size of the rootstock and scion is the same as for cleft grafting. First keep 2 true leaves on the rootstock, then remove the upper part, and cut it into a 30° angled surface with a length of 1-1.5 cm.

2. Take the scion, then keep 2-3 true leaves, cut horizontally to remove the lower end, and also cut it into a slanted surface of the same size as the rootstock. Align and press the two closely together, then secure firmly with a fixing clip.

VI. Management of Grafted Seedlings

1. Heat preservation. After grafting, the suitable temperature for wound healing is about 25°C, so the seedling bed greenhouse should be controlled at 24-26°C during the day for 3-5 days, generally not exceeding 28°C; at night it should be maintained at 20-22°C, and must not be lower than 16°C.

2. During this period, a small arch shed can be set up inside the greenhouse for heat preservation. In hot weather, cooling measures should be taken. Cooling can be achieved by building shade and ventilation. After waiting 3-5 days, begin ventilation, then gradually lower the temperature.

3. Moisture retention is crucial to the success of grafting. Generally, within 3-5 days, the humidity inside the small arch shed should be maintained at 90%-95%. After 4-5 days, ventilation is needed to lower the temperature and humidity, while also maintaining relative humidity between 85%-90%.

4. If shading is needed, paper quilts, straw curtains, etc. can be used to cover the small arch shed. No shading is needed on cloudy days. Within 3-4 days after grafting, full shading is required.

5. On the 4th day, begin giving light in the morning and evening and shading at noon. Later, gradually remove the covering. When the temperature is too low, light can be provided appropriately earlier, which helps raise the temperature and promote wound healing; at noon when the temperature is high, shading should be carried out.

6. After about 10-15 days, when the graft union has completely healed, remove the fixing clips and resume routine management. Generally, the rootstock of grafted seedlings often grows side shoots, which need to be removed promptly on sunny mornings to prevent pathogens from the soil surface from infecting through the wound.

VII. Planting Time

Grafted eggplant seedlings in arch sheds can be planted in late March; grafted eggplant seedlings in autumn greenhouses can be planted in mid-September; grafted eggplant seedlings in winter-spring greenhouses can be planted in mid-December.