Proper drought and disease prevention management during the garlic scape development period

The garlic scape development period is the reproductive growth stage of garlic, mainly including the flower bud differentiation stage and the scape elongation stage. The differentiation of flower buds and bulbils is a critical period in garlic growth and development, and smooth differentiation helps increase yield. The scape elongation stage refers to the period from when the scape begins to elongate until the scape is harvested after the tail-flicking stage, about 30 days. During the garlic scape development period, flower bud differentiation requires temperatures below 10°C; the scape elongation stage requires an optimal temperature of 12°C-18°C. If the temperature is too low, the scape elongates slowly, affecting yield; if the temperature is too high, the scape elongates quickly, the fiber content increases, and quality deteriorates. Garlic is a light-loving vegetable; before bolting it needs a temperature of 15°C-19°C and a long photoperiod of more than 13 hours per day to pass through the light stage and promote bolting and flowering. During the scape elongation stage, the plants grow most vigorously and have a high water demand, requiring a relative soil humidity of 70%-80%; before harvest, 60%-70% is more suitable and favorable for harvesting. In mid-April, the province-wide average temperature was 14.5°C, 0.8°C higher than usual. The province-wide average precipitation was 8.6 mm, more than 10% lower than usual. In most areas, light and temperature were relatively suitable, and soil moisture was adequate, which was favorable for scape elongation. According to current meteorological conditions, the following measures should be taken in production:

1. Strengthen field fertilizer and water management. During the scape elongation stage, the plants grow vigorously and require significantly more fertilizer and water. In field management, heavy fertilizer and heavy watering should be used to promote rapid scape growth. Generally, water every 5-6 days, and apply fertilizer with every two waterings. Fertilizers should mainly be potassium sulfate or compound fertilizer, and thoroughly decomposed dry manure. The last chemical fertilizer application should be more than 30 days before the scape harvest period. Watering should be stopped 3-4 days before harvest to let the plants wilt slightly, so as to prevent the scapes from being too brittle and easily broken.

2. Harvest at the right time. If harvested too early, the scapes are short and small, with low yield and poor quality; if harvested too late, the scape quality is poor, and nutrients are also consumed, affecting bulb expansion. The scapes should be harvested promptly when the tails flick out, when the bracts are white, or when they turn yellow, while also taking care to protect the leaves to ensure photosynthetic capacity in the later stage and increase bulb yield.

3. For garlic grown with plastic film mulching or in arched sheds, during the scape elongation stage, watering should be done frequently according to seedling condition and soil moisture to keep the field moist. Around the time the bracts emerge, the plastic film can be removed and field weeds thoroughly cleared. Stop irrigation 3-5 days before pulling the scapes to facilitate harvest. Immediately after harvest, topdress and water to prevent premature aging of the plants and promote bulb expansion.

4. For fields with excessive humidity, attention should be paid to timely drainage to prevent leaves and scapes from being damaged by diseases such as leaf blight. At the same time, take care not to apply nitrogen fertilizer alone; increase the application of complete fertilizers containing nitrogen, phosphorus, and potassium to cultivate robust plants and enhance their resistance.