Detailed Explanation of Field Cultivation Techniques for Witloof Chicory

(1) Variety selection. At present, China's witloof chicory varieties are relatively backward compared with those from abroad. Domestic varieties are few and cheap, so when not cultivating for high quality, domestic varieties can be chosen. Foreign varieties are expensive and numerous, but each variety has different characteristics. If it is a new variety, it must be successfully trial-planted before large-scale planting.

(2) Seed preparation. The thousand-grain weight of chicory seeds is 1.2-1.5 grams. The germination rate of witloof white chicory seeds should be above 80%. For direct seeding, use 150 grams of seed; for seedling raising, use 30 grams. Under general conditions, chicory seeds remain viable for about 8 years.

(3) Land preparation, fertilization and bed making. Cultivating ideal root stocks is the key to obtaining high yield and high quality. It is advisable to choose loam or sandy loam with a deep plow layer. According to the condition of the land, apply 45000-75000 kg of decomposed organic fertilizer and 750 kg of slow-release compound fertilizer per hectare. After fertilization, level the land and make high beds 80 cm wide (furrow to furrow) running north-south, with a bed height of about 15 cm. Note that decomposed organic fertilizer should be applied; otherwise, white grubs are likely to occur and damage the roots. In plots where white grubs occur severely, avoid planting as much as possible or take control measures.

(4) Sowing. Chicory is suitable for direct seeding; raising seedlings and transplanting easily forms crooked roots or branched roots. However, direct seeding greatly increases the amount of seed used; otherwise, missing plants and broken rows easily occur. Crooked roots and forked roots have little effect on the yield and quality of witloof production, but they are not easy to handle during witloof cultivation. The choice can be made according to the source of the seeds. Plug tray seedling raising can be used. Determine the germination rate in advance, and determine the amount of seed according to the germination rate and the field seedling density. For direct seeding in the field, sow at 3-5 times the amount of seed used for seedling raising. Either drill sowing in furrows or dibbling in holes is acceptable. Cover with soil 0.5-1.0 cm (similar to cabbage sowing). After compacting, water immediately, and seedlings will emerge in 3-4 days.

(5) Sowing and seedling raising period. The Beijing area is suitable for autumn cultivation; spring cultivation tends to bolt and cannot form good root stocks. For direct seeding, sow around July 10; for seedling raising, it can be 2-3 days earlier. The sowing period coincides with Beijing's muggiest and hottest season, so management must be strengthened after sowing, especially water management. Watering not only provides moisture but also improves the field microclimate. Watering should be done according to weather conditions. When the weather is hot and the sun is blazing, one watering per day is appropriate; supplemental water by sprinkler irrigation is even better. After the seedlings emerge completely and the roots have grown downward, watering can be relaxed somewhat.

(6) Transplanting and seedling retention density. For seedling-raised cultivation, transplanting can be done in early August. On high beds 80 cm wide, plant two rows in a wide-narrow row pattern, with a row spacing of 30 cm on the ridge and a plant spacing of 15 cm. Keep 150000 plants per hectare. For direct seeding, after two thinnings, select the superior and remove the inferior, keeping the same number of plants as above.

(7) Management after final thinning. Early stage: in early August the weather is still relatively hot, so water management should still be strengthened. During this period, nitrogen fertilizer can be applied twice to promote plant growth. Middle stage: in September, with ample sunlight and suitable climate, chicory is in its period of vigorous growth, with both aboveground and underground parts growing vigorously. Watering should preferably keep the soil moist. Apply compound fertilizer once in the middle stage, at 300-450 kg per hectare, and carry out furrow cultivation. Each watering should be thorough. Late stage: in October the weather gradually turns cool. By early October, roots and leaves have basically formed, and watering should be controlled. Apart from watering 1-2 times in early October, do not water in mid-to-late October. Spray potassium dihydrogen phosphate on the leaves twice to promote the movement of nutrients to the roots, increase the dry matter in the roots and reduce moisture, so as to benefit the next stage of storage and witloof cultivation.

(8) Root stock harvest. In the Beijing area, root stocks can be harvested at the end of October and the beginning of November. When harvesting root stocks, use a shovel and try to dig out all the roots; do not leave broken roots in the soil (roots left in the soil will sprout the next year and become difficult-to-remove weeds). Place the plants together with roots neatly by bed, let them dry in the sun for 2-3 days according to weather conditions, and then stack them in the field in round piles like stacking Chinese cabbage, with roots inside and leaves outside. In this way, they can be left in the field for a longer time, leaving time to sort the root stocks. Note that the roots must absolutely not suffer freezing injury; roots that have suffered freezing injury will rot during witloof cultivation. When sorting, cut the leaves with a knife, leaving 4-6 cm above the upper part of the root. If left too long, they easily rot during storage; if left too short, it is easy to damage the growing point and no commercial bud clusters can be formed. Remove the outer yellow leaves and rotten leaves by hand, and store in a warehouse or cellar at 0-1°C. Carry out witloof chicory cultivation in stages and batches. Combined with root storage, the supply period of chicory can be greatly extended. A standard chicory root should be straight, without forked roots, 3-5 cm in diameter, and about 99-127 grams in weight. Roots thicker than 5 cm easily form side buds.