Detailed Explanation of Garlic Growth Characteristics and Management Strategies in April

Growth during this period involves both vegetative growth and reproductive growth advancing together. In the early stage, rapid vegetative growth predominates. The garlic plant's growth volume has ample space, growth accelerates, and the vegetative growth of garlic is fully developed. The number of leaves, leaf assimilation area, and root number reach their maximum values for the entire life cycle. After mid-month, scape growth predominates, and the bulb is in the early stage of expansion. By the end of this period, the total root number can reach 120-150 roots, and the depth of penetration into the soil can reach 40-50 cm. All leaves of the plant have formed.

During this period, the growth volume of all plant parts is at its greatest. Sufficient water and fertilizer are needed to lay the material foundation for high yield and quality. This period is also when the demand for fertilizer and water is most urgent, and there are 2 periods of maximum fertilizer efficiency. That is, the vigorous vegetative growth stage (early April) is the period of maximum nitrogen fertilizer efficiency. Nitrogen fertilizer applied during this period has the highest fertilizer efficiency in the entire life cycle. Nitrogen deficiency during this period has the greatest impact on yield, and the earlier the nitrogen deficiency, the greater the impact on yield. The scape elongation stage (late April) is the period of maximum potassium fertilizer efficiency. Research shows that garlic's response to potassium fertilizer is that potassium deficiency in the late growth stage has a great impact on yield, and the later the deficiency, the greater the impact. At the same time, according to reports, there is a significant positive correlation between the maximum leaf width, pseudostem diameter (leaf sheath) and the weight of garlic scapes and bulbs. To achieve high yields of garlic bulbs and scapes, it is necessary to cultivate plants with thick and strong leaf sheaths and broad leaves. This period is also the peak period for garlic diseases and pests.

The following management measures should be carried out in production:

Apply heavy seedling-promoting fertilizer

In early April, combined with watering, apply a heavy topdressing mainly of nitrogen and sulfur to improve soil fertilizer supply and accelerate the enhancement of root fertilizer absorption capacity, meeting the nutrient requirements for vigorous garlic growth. Apply 70-80 jin of 40% nitrogen-sulfur fertilizer per mu, which can be broadcast or applied with irrigation water. At the same time, application has proven that nitrogen-sulfur fertilizer is more effective than urea during this period.

Prevent root maggots and garlic mites

In early April, garlic maggot larvae have already begun to cause damage. Combined with watering, apply pesticide irrigation to control root maggots and simultaneously control garlic mites and nematodes. Effective pesticides are phoxim and its mixtures, or chlorpyrifos mixed with qimanding applied with irrigation water. This kills both maggots and mites with good results. The use of highly toxic and high-residue pesticides is prohibited, so as to ensure the food safety of garlic scapes and bulbs from the source.

Prevent excessive growth and promote thick and strong growth:

As temperature rises and fertilizer and water are adequately supplied, garlic plant growth rate significantly accelerates, making excessive growth very likely, causing garlic plants to become taller and leaf sheaths to become thinner. At this time, promptly spray garlic nutrient solution plus garlic leaf sheath thickening agent to coordinate the relationship between vegetative growth and product organ growth, and suppress excessive vegetative growth. This achieves the plant type requirements for high-yield garlic, accomplishes the management goals of thick and strong leaf sheaths and wider leaves, and lays the material foundation for full bulb enlargement.

Strengthen control of white rot

Garlic white rot mostly fully manifests and breaks out into disaster 3-5 days after Qingming watering. According to research, to reduce the occurrence and damage of white rot, the optimal control period should be spraying fungicide once 2-3 days after watering to enhance plant disease resistance and inhibit pathogen activity, achieving twice the result with half the effort. According to experiments, the relatively effective pesticide for controlling garlic white rot is Baifujing (author's compound formula) at 90 grams per mu, followed by iprodione at 100-150 grams per mu.

Control leaf blight well

Garlic leaf blight is the main disease damaging garlic leaves. The occurrence period is from mid-April to early May, and the peak period is during the most vigorous growth period of garlic (late April). In the field, garlic leaf blight mainly has 4 types of manifestation, all of which form dry spots on the leaf surface. Control pesticides include Baifujing, iprodione, etc., but Baifujing has better results. Pesticide control should begin in mid-April, and must be applied once before watering with bulb-expanding fertilizer. After that, apply 2-3 times consecutively depending on weather conditions.

Apply bulb-expanding fertilizer well

In late April (mostly around "Grain Rain"), apply 30-40 jin of 30% (14-0-16) sulfur-containing high-potassium water-dispersible compound fertilizer with irrigation water to accelerate bulb expansion. At this time, the root system has gradually begun to age. In production, the starting point should be to nourish and protect the roots, strictly preventing root damage from affecting yield. The time of watering and fertilizing must not be later than 5 days before starting to harvest garlic scapes.