Detailed Explanation of Key Technical Points for Growing Red Heart Pomelo

Red heart pomelo is different from ordinary pomelo; its flesh is red, and it was first discovered by people in Heping County. The red natural pigment contained in red heart pomelo is very beneficial to the human body, and its anti-cancer effect is very remarkable, especially for patients with heart disease and high blood pressure, for whom it has a very good dietary therapeutic effect.

Red Heart Pomelo Cultivation Techniques

1. Site selection. Choose unpolluted sloping land, with a slope of less than 20° for cultivation, and the soil should be neutral to slightly acidic.

2. Land preparation. Under dry field conditions, use a powder ridge machine for powder ridge land preparation, with a tillage depth of 50-90cm.

3. Grafting. Introduce excellent red heart pomelo scions, select local sour pomelo seedlings as rootstock, and adopt the single-bud cut grafting method.

4. Field planting. Dig holes and plant according to a spacing of 4.5m X 6.2m, at 420-500 plants/hectare, with each hole measuring 95cm X 95cm X 95cm in length, width and depth; apply 2-3 loads of farmyard manure, 25-50 kg of decomposed human and livestock manure, 200-300 grams of water-retaining agent and 0.5-1 kg of compound mixed medicinal fertilizer per hole, treat the roots of the cultivated red heart pomelo seedlings with soil attached in rooting water for 30 minutes, and let them dry naturally before use.

5. Seedling treatment. After successful grafting, apply dilute liquid fertilizer or manure water after 15-20 days, once a month, keep 1 strong new shoot of the scion and prune the rest, wipe off the sprouts growing from the rootstock at any time, and untie after 20-30 days to facilitate healing and growth of the graft union; pay attention to watering and irrigation to keep the soil or nutrient mud moist, and when the lignified part of the scion's new shoot stem is about 15 cm long, it can be taken out of the nursery for field planting.

Fertilization Techniques for Young Red Heart Pomelo Trees

For young trees, the main purpose is to cultivate each flush of branches and accelerate canopy growth. After planting, pomelo trees begin to grow new roots after 15-20 days, at which time decomposed human manure and urine should be applied as a top dressing. One-year-old trees have relatively weak root fertilizer tolerance, so the principle of “frequent application and application at each flush” should be adopted, 2-3 times a month, with the fertilizer concentration gradually increasing from dilute to concentrated, and each flush should be guaranteed 1-2 heavy fertilizer applications. 15-20 days before the pomelo flush, apply 5-10 jin of relatively concentrated human and livestock manure plus 0.1-0.2 jin of urea per plant, or use 1 jin of decomposed peanut plus 0.2 jin of urea for the flush, and then apply once more as a flush-strengthening fertilizer. Fertilization should use basin application or shallow ring trench application; winter fertilizer or heavier fertilizer should be applied deeply, with holes 60×30×30 cm in length, width and depth respectively, located vertically at the outer edge of the canopy. During the new shoot period, spray 0.4% urea + 0.5% magnesium sulfate solution to accelerate greening.

Pest and Disease Control to Protect Shoots and Fruit

1. Overwintering red spider mites: spray once in early February before spring shoots sprout, with Kemante diluted 2000 times with water, or in mid-March with Nisoran diluted 1000-1500 times with water.

2. Various diseases. From late February when young shoots are about 0.5 cm-5 cm until before flowering, no spraying during the flowering period; use copper-ammonium mixture, 1 jin of copper sulfate plus 5 jin of ammonium bicarbonate, wrap with plastic film for 24 hours, then add 1000 jin of water and spray the whole tree and the ground, or spray 1-2 times from when spring shoots are about 0.5 cm-5 cm until before flowering and in the early stage of young fruit after flower drop, using thiophanate diluted 500 times with water mixed with Jinggangmycin diluted 500 times with water, or carbendazim diluted 500 times with water and Jinggangmycin diluted 500 times with water, used alternately.

3. Other insects. For other insects, use dichlorvos diluted 1000 times with water. Timely control of spring shoot pests and diseases can promote robust spring shoots and lush branches and leaves; after flower drop, young fruit are less susceptible to disease in the early stage, and the fruit-setting rate is high.

Flower Thinning, Shoot Thinning and Pinching

1. Thinning flower branches. Adult fruiting trees or declining trees have many flowers, so some weak flower branches should be thinned. This is generally done from mid-to-late February to early March. In principle, follow the principle of removing weak ones and keeping strong ones, keep 4-5 flowers on each fruiting mother branch, and implement a reasonable combination of early, middle and late throughout the tree. After flower thinning, concentrate the tree's nutrients to meet the growth needs of the remaining flower buds, promote larger buds, better flower quality, and a higher fruit-setting rate after flowering.

2. Shoot thinning. Shoot thinning can improve ventilation and light penetration in the tree, reduce pest and disease damage, and is an effective measure to increase the fruit-setting rate. For shoot thinning, generally thin the denser parts at the top and outer periphery of the canopy, properly thin some of the higher vigorous shoots; tender spring shoots inside the canopy and short spring shoots on the outer periphery of the canopy are fruiting mother branches for the next year and generally should not be thinned. Spring shoot thinning can only be controlled within 5% of tender spring shoots and should not be too much. This helps increase leaf volume, produce more chlorophyll, improve the fruit-setting rate, and achieve high yield with more and high-quality fruit.

3. Pinching. Pinching can increase the fruit-setting rate, accumulate tree nutrients, reduce ineffective nutrient consumption, and produce more and better fruit. Pinching is generally carried out on vigorous shoots at the top of the canopy; pinch when young shoots are 5-7 cun long, leaving only 4-6 leaves.

Every step in growing red heart pomelo is very important. During planting, you must be careful and attentive, and in the later stage of planting you must do a good job in management to ensure the quality of the fruit. Red heart pomelo not only tastes good, but also has great effects, so with better planting, it will certainly bring everyone good returns.