How to cultivate safflower for high yield? Detailed explanation of key planting techniques
Saffloweris an annual or biennial herbaceous plant of the Asteraceae family. Its flowers are used as medicine; they are pungent, bitter and slightly warm in nature, and have the effects of activating blood and resolving stasis, and unblocking meridians and relieving pain. Safflower has strong adaptability and prefers a mild, dry climate with ample sunlight; it has a certain tolerance to drought and cold, fears high temperature and high humidity, and has low requirements for water, fertilizer and soil conditions. Its cultivation and management techniques are as follows:
I. Site selection and land preparation
It is best to choose sandy loam with high terrain, dryness, medium fertility and good drainage for planting; planting on clay, low-lying, waterlogged and overly fertile land makes it prone to disease. Avoid continuous cropping; suitable preceding crops are peanut, soybean and wheat. During land preparation, apply about 2500 kg of compost per mu, plus 15 kg of superphosphate, then plow and harrow level. In areas with abundant water, it is advisable to plant on raised beds.
II. Propagation method
Propagate by seed. In the north, spring sowing is mostly used; sowing can be done after the soil thaws in mid to late March, and no later than early April, otherwise the growth vigor is weak and pests and diseases are severe. In the south, autumn sowing is mostly used, and late September to early October is the best time to sow. Sowing too early makes the seedlings grow excessively, the roots crack, and the following year the stems bolt early, the plants are tall and the yield is low. Sowing too late results in uneven emergence or overly small seedlings that are difficult to overwinter. Either drilling or hole sowing can be used. Row spacing 30 cm, plant spacing 15 cm, sowing depth 3-6 cm, and after sowing cover with soil and press firm. The seeding rate is 2.5-3 kg per mu.
III. Field management
1. Thinning: thin to a plant spacing of about 15 cm, remove diseased, weak, and overly large or overly small seedlings, and keep medium-sized vigorous seedlings.
2. Cold protection: for autumn-sown safflower, in late December firm the soil on both sides of the seedlings. Before the ground freezes, water once with winter water to keep the field moist and prevent it from drying and cracking, so that the soil and roots are in close contact, which helps safe overwintering.
3. Drainage and irrigation: safflower prefers dryness, but before emergence, during the overwintering period, the budding stage and the flowering stage, the soil needs to be kept moist, especially before flowering and during the flowering stage. If drought occurs, irrigate early. After mid-May, if rainfall increases and temperature rises, dig ditches promptly to drain water so as to reduce disease occurrence.
4. Topdressing: during the safflower growing period, whether fertilizer is sufficient at the bud stage greatly affects yield. If the early fertilizer is too sufficient, it will promote excessive vegetative growth of safflower and make it easy to break; if the rows close and shade too early, poor ventilation increases pests and diseases and affects later growth. Therefore, topdressing is carried out in two applications. The first is before and after final thinning, with a light application to promote seedlings. The second is at the bud-bearing stage, with one heavy application; generally use 1500-2000 kg of manure per mu, mixed with 5 kg of ammonium sulfate, to promote more and larger buds. If the base fertilizer is sufficient and the seedlings are growing well, the first topdressing may be omitted.
5. Hilling and earthing up around the roots: after safflower bolts, most of the upper branches are prone to lodging, so hilling and earthing up around the roots should be carried out in early May.
6. Topping: after safflower bolts, pinch off the terminal buds to promote more branching and increase the number of flower buds.
IV. Pest and disease control
1. Anthracnose: mainly damages stems, flower branches and leaves, causing purplish-red and brown comb-shaped or oblong lesions, so that the plants cannot form buds or the buds droop and cannot open, and the plants wither and die. The disease is severe from May to June. Control methods: choose disease-resistant varieties; generally spiny safflower is more disease-resistant than spineless safflower; choose plots with high terrain, dryness and good drainage, plant on raised beds, and avoid continuous cropping; from late April begin spraying 1:1:100 Bordeaux mixture or 65% wettable zineb 500-fold solution or 50% wettable thiram 1000-fold solution, once every 7-10 days, for several consecutive applications.
2. Fusarium wilt: mainly manifested as the main root turning black and rotting, the pith of the stem turning brown, the stem appearing fibrous, sometimes with orange-red sticky exudate visible, and finally the aboveground part wilting and drying up. It begins to occur in early May and is severe in the rainy season. Control methods: rotate with gramineous crops; pull out diseased plants and disinfect the diseased holes with lime; select disease-free plants for seed production; after harvest clear the garden and burn diseased and residual plants in a centralized manner.
3. Black spot and ring rot: mainly damage the leaves. Nearly round brown lesions appear on the diseased parts, with small black dots on them; ring rot lesions are larger than black spot lesions and have concentric rings. Damage occurs from May to the harvest period. Control methods: rotate with gramineous crops; before and at the early stage of disease, spray 1:1:100 Bordeaux mixture or 65% wettable zineb 500-fold solution, once every 7 days, for several consecutive sprays.
4. Sclerotinia rot: mainly manifested as yellowing leaf color and withered branches, with black mouse-dropping-like sclerotia appearing at the roots or in the stem pith. It occurs from May to June. Control methods are the same as for Fusarium wilt.
5. Safflower fruit fly: also called bud maggot or boring worm. At the bud stage, adults lay eggs in the buds, and the larvae bore and feed inside, causing rotten buds, so that they cannot flower or do not flower completely, greatly affecting yield. Control methods: at the stage when buds show white, spray 40% dimethoate emulsion 1000-fold solution, or 90% trichlorfon 800-fold solution, and spray once more after a week; clear the garden and dispose of residual plants; avoid intercropping or relay intercropping with Atractylodes macrocephala, cornflower, etc.