What are the latest planting methods for cilantro?

Cilantro can tolerate low temperatures of -1°C to 2°C, and its suitable growing temperature is 17°C to 20°C. Above 20°C it grows slowly, and at 30°C it stops growing. Cilantro has no strict requirements for soil, but soil with good structure, strong fertilizer and water retention capacity, and high organic matter content is beneficial for cilantro growth. Cilantro originated in the Mediterranean region of Europe. During the Western Han Dynasty in China (first century BC), Zhang Qian brought it back from the Western Regions. It is now cultivated in provinces and regions across China including Northeast China, Hebei, Henan, Shandong, Anhui, Jiangsu, Zhejiang, Jiangxi, Hunan, Guangdong, Guangxi, Shaanxi, Sichuan, Guizhou, Yunnan and Tibet.

Cilantro planting methods

1. Variety selection. Coriander has large-leaf varieties and small-leaf varieties. Large-leaf varieties have taller plants, larger leaves, fewer and shallower notches, a milder fragrance and higher yields; small-leaf varieties have shorter plants, smaller leaves, deeper notches, a stronger fragrance, cold tolerance and strong adaptability, but slightly lower yields. Generally, small-leaf varieties are mostly chosen for cultivation.

2. Open-field cultivation. Coriander can be cultivated in the open field in spring, autumn and winter. During the seedling stage, it should not be watered too much. When the seedlings grow to 10 cm, the plants grow vigorously, so they should be watered frequently to keep the soil surface moist. While watering, apply quick-acting nitrogen fertilizer 1 to 2 times. Pay attention to intertillage and appropriate thinning, and pull out weeds when thinning. In summer, appropriate shading is needed, and protection against heavy rain erosion is necessary. Drain promptly after rain to ensure uniform emergence.

3. Greenhouse cultivation. Generally direct sowing is done from September to October, and one irrigation of winter water is given before winter to help the seedlings overwinter. The greenhouse is covered in January, and no ventilation is needed from January to February. When the seedlings turn green again, carry out intertillage, loosening of the soil and weeding. When the seedlings reach 10 cm in height, the plants enter the vigorous growth period, and the greenhouse should be kept at 15°C to 25°C. Apply about 15 kg of ammonium sulfate per mu each time, 1 to 2 times, which can advance the harvest.

4. Land fertilization. Under normal circumstances, to plant cilantro (coriander), you should choose a plot with loose soil, rich organic matter and convenient irrigation and drainage. After the previous crop is harvested, turn the soil promptly to a depth of 15-20 cm, and let it weather and sun-dry for more than 2 weeks. Then broadcast 4000-5000 kg of decomposed high-quality farmyard manure and 10-15 kg of compound fertilizer per mu as base fertilizer. After plowing and harrowing, make beds with a surface width of 140-150 cm and a height of 20-25 cm, with the length determined by the length of the plot, and a ditch width of 30-40 cm, which also serves as a walkway. The bed surface requires fine, loose and level soil. If drilling is used, sowing furrows 4-5 cm wide and about 2 cm deep should also be opened on the bed surface at a row spacing of 8-10 cm, ready for sowing.

Pest and disease control of cilantro

1. Sclerotinia rot

① Practice crop rotation on diseased land, or disinfect the soil. Use 40% quintozene at 1 kg per 667 sq m, add 50 kg of fine soil, mix well and apply to the soil.

② Use disease-free seeds or dress seeds with chemicals.

③ After covering the greenhouse, spray 1000 times “Sclerotinia Clean” once, spray again after 10 days, spray a third time around the Beginning of Spring, and thereafter spray once every 7-9 days.

④ Ecological control: during the entire growth period, strengthen ventilation and reduce humidity to lessen the occurrence of the disease.

2. Leaf blight and spot blight

These two diseases occur in spots and patches, but once they occur, the condition spreads rapidly and causes relatively serious harm. They mainly damage leaves. After the leaves are infected, they turn yellow-brown, and when humidity is high the diseased parts rot. In severe cases, they infect downward along the leaf veins to the young stems and then to the heart leaves, causing serious yield reduction. Therefore, these two diseases must be especially controlled. These two diseases are new diseases in our region, possibly caused by seed-borne bacteria, so we adopt preventive measures focused on seed disinfection. The method is to soak the seeds in 500 times liquid of “Captan” or “Carbendazim” for 10-15 min, rinse clean and then sow. Next is to strengthen management. When humidity is too high in the early stage after covering the greenhouse, pay attention to ventilation and dehumidification. Once disease is found, spray promptly for control, using 600-800 times liquid of carbendazim, 600 times liquid of mancozeb, 800-1000 times liquid of 70% thiophanate-methyl, or 500 times liquid of chlorothalonil. Mixing two or more of these gives a better effect.

3. Root rot

It mostly occurs in low-lying, damp plots. After the cilantro root system is infected, the main root becomes yellow-brown or brown, soft and rotten, with no or almost no fibrous roots. When pulled by hand, the plant root system breaks. Above ground, the plant appears stunted, with yellow, withered leaves, losing its marketability. The control method is to avoid planting in low-lying land as much as possible, and humidity must not remain too high for a long time. Chemical control is mainly soil treatment. Carbendazim 1 kg can be mixed with 50 kg of soil and spread in the sowing furrows before sowing. In plots prone to the disease, a 300 times liquid of continuous-cropping agent can be irrigated in along with watering. Because root rot generally occurs in October before winter, control should be carried out before covering the greenhouse, mainly by irrigating the roots with 500 times liquid of “Previcur” or 600 times liquid of “Carbendazim”.

4. Powdery mildew

All above-ground parts of the coriander plant can be infected, but it mainly damages leaves, stems and flower stalks. It first appears on leaves near the ground, initially as white mold spots, which then expand on the mold spots into white powdery patches, occurring on both sides of the leaves; stem infection mostly occurs at the nodes. When conditions are suitable, the powdery material quickly covers the flowers and fruits, mostly spreading from the lower part of the plant upward. In the later stage, the hyphae turn from white to light brown, and many small black grains are produced on the diseased parts, namely the ascocarps of the pathogen.

[Control methods]

① Breed powdery mildew-resistant varieties and strengthen greenhouse temperature and humidity management.

② After harvest, promptly remove diseased residues to reduce overwintering sources of inoculum.

③ In the early stage of the disease, dusting or smoke methods can be used in the greenhouse. In the evening, dust 10% duobai dust at 1 kg per 667 sq m, or use 45% chlorothalonil smoke agent at 250 grams per 667 sq m, ignite with a smoldering fire and fumigate overnight

④ In the open field or greenhouse, you can use 1500-2000 times liquid of 30% triflumizole wettable powder, or 200-300 times liquid of 50% sulfur suspension concentrate, 150 times liquid of 2% wuyi mycin aqueous solution or 2% agricultural antibiotic 120 aqueous solution, 1500 times liquid of 15% triadimefon (paclobutrazol) wettable powder, 3000 times liquid of 25% diniconazole EC, 2000 times liquid of 15% triadimefon (paclobutrazol) wettable powder plus 4000 times liquid of 25% diniconazole EC, or 9000 times liquid of 40% flusilazole EC, once every 7-21 days, for 2-3 consecutive treatments. Stop using chemicals 7 days before harvest.