How to prevent the growth of summer vegetable seedlings?

The main reasons for the excessive growth of seedlings are lack of light and high temperature, especially at night when the temperature is too high and respiratory consumption is too much. In addition, too much nitrogen fertilizer and water, too dense sowing, untimely seedling transfer and so on are also easy to cause seedling overgrowth.

First, the reasons for the growth of summer vegetable seedlings?

① is most likely to overgrow and cause serious damage from emergence to cotyledon expansion, which is mainly due to over-dense sowing and not removing the mulch in time after emergence, which makes the seedlings overcrowded.

② did not cool down in time after emergence, and it was easy to make the Hypocotyl of seedlings elongate excessively.

③ cotyledons expand to the 2-3 leaf stage, the seedlings are too late, or because the temperature is too high and the seedlings are not planted in time (moving the seedlings into the bowl), the seedlings are overcrowded and overgrown.

Due to the continuous overcast and rain, the soil and air humidity in the seedling bed was too high, the nitrogen fertilizer in the nutrient soil was too high, and the seedlings could not be ventilated and light in time, and the seedlings which were dilute and crowded could not be drained in time in the management of ④ pseudo-planting.

2. Methods to prevent seedlings from overgrowing

The sowing density of ① should not be too high to avoid seedling crowding after emergence. For example, eggplant fruits and vegetables generally need 2-3 square meters of sowing bed and 15-25 grams of seeds per mu of field. At the same time, about 30% of the seedlings will be removed in time after emergence.

② seedlings in time. False planting and colonization. After emergence, eggplant fruits should be planted for 2-3 times, and pseudo-planting should be carried out when the seedlings are "two leaves with one heart". The density of pseudo-planting should be controlled at 120-130 plants / square meter.

③ strengthens ventilation and light transmission, and controls temperature and humidity. Ventilation and light transmission, reducing temperature and humidity, strengthening low temperature training and controlling the excessive growth of seedlings should be carried out after seedling unearthed, before pseudo-planting, after pseudo-planting and before planting.

④ carries out fertilizer and water management reasonably. In the preparation of nutritious soil, we should pay attention to the amount of phosphorus and potassium fertilizer and control the amount of nitrogen fertilizer. Moisture and topdressing should be strictly controlled in the seedbed, and nitrogen fertilizer should not be applied when topdressing is needed.

⑤ drained the seedlings in time. About 20 days before eggplant and melon colonization, the seedlings are often overcrowded. At this time, the seedlings should be moved properly to separate the large and small seedlings and expand the living space of a single plant.

⑥ medicament control is futile. Once the seedlings grow, in addition to the above-mentioned measures, 0.2% Bordeaux solution (equal volume) can be sprayed, or 2000-2500 times of 50% brucine can be sprayed.