Causes of yellowing pumpkin
There are several reasons why pumpkin leaves turn yellow. More often yellowed foliage and ovaries are the result of improper care when grown. However, in some cases this is a sign of disease and pest attack. Let's take it in order.
Causes of yellowing pumpkin
If agricultural technology for cultivating a vegetable is observed, problems rarely arise: the leaves are usually green, which is a confirmation of the photosynthesis occurring in them, and the vegetable itself gives a good harvest.
If the leaves and ovaries of the pumpkin turn yellow and dry - this is a signal of improper care.
A sharp temperature drop, prolonged heat and prolonged cold snap equally affect the development of the plant, causing him severe stress. It does not matter in which direction the mode deviation occurred.
Unsuitable weather is one of the main reasons why pumpkin leaves turn yellow.
- With the onset of cold weather, pumpkin foliage freezes, its edges dry, and the plates themselves turn yellow. The vegetable stops nutrition, stops growth, the ovaries do not appear at all, or the resulting ones do not form into fruits, but crumble.
- When increased to 32 ° or more, pollination does not occur, the inflorescences dry and fall.
Seeds are sown after the threat of frost has passed and the soil is warmed up to a temperature of at least 12 ° C, optimally 15-18 ° C.
Compliance with agricultural techniques when planting pumpkins is a condition for the proper development of a vegetable crop.
The basic rules include:
- presowing treatment of seeds;
- regular harvesting of weeds;
- disinfection of soil and equipment;
- autumn digging of ridges;
- changing planting locations and choosing the right predecessors in accordance with crop rotation recommendations.
In the process of caring for a planted pumpkin, gardeners often exceed the norm and frequency of watering.
Irrigation must be suitable for weather conditions:
- plentiful watering is required only when the hot period occurs, while the plant is irrigated in the evening under the root, and during the period of solar activity, make sure that water does not fall on the foliage, a suitable water temperature of 20-27 ° C;
- in cooler climatic regions, watering is reduced to a minimum, resorting to it only when the soil dries.
Lack of nutrition and an excess of minerals
Poor care can kill a plant
Due to the lack of some elements important for the development of pumpkins, the leaves dry and fall off.
For full growth, the following components are required:
Make up for the lack of nutrition with regular top dressing. Minimum fertilizer application:
- after planting seedlings in open soil or when appearing on seedlings, planted by the seed method, 3-4 leaves;
- at the flowering stage;
- with the beginning of fruiting.
The opposite cause of ovary falling and foliage drying is an excess of nutrients due to frequent top dressing.
A hint to reduce fertilizer application is unnecessarily massive pumpkin lashes and dense green mass. Most often, gardeners are faced with an excess of nitrogen.
- Root rot becomes the cause of yellowing of the leaves, its causative agent is a fungus that affects the root system and disrupts metabolic processes;
- Chlorosis - leads to a quick, uncharacteristic thickening and yellowing of foliage due to impaired photosynthesis, appears due to a lack of potassium and sulfur with simultaneous sharp changes in temperature;
- Powdery mildew and its false appearance, peronosporosis - fungal diseases, manifested in the form of white deposits (spore compounds) under which foliage changes color;
- Anthracosis - leads to yellowness and subsequent decay of the foliage, reaching the root neck, causes malnutrition, which causes the death of the culture.
Methods of struggle
Vegetable culture is treated with chemical and folk remedies:
- in the fight against chlorosis, with a lack of potassium, make wood ash (200 g per 10 liters of water) and potash fertilizer complexes (20-25 g / m²);
- against downy mildew (peronosporosis), plants are treated with Bordeaux liquid with a concentration of 1%, urea (10 granules per 10 liters of water) or Strobi, Kuproksat, Oksikhom;
- when signs of powdery mildew appear, they use fungicides - Karatan, Topaz, Fitosporin and spraying with solutions based on whey, which is diluted in water (1:10);
- Pre-sowing soaking of seeds in copper salts (solution with a concentration of 0.5%) or in the combination of iron with boron (solution with a concentration of 0.25%) helps to fight root rot; in case of damage to the plant, the upper soil layer is removed from the root neck and sprinkled with fresh soil and watered with an ash solution (200 g per 10 l of water), the root neck is additionally sprayed with Fundazol with a concentration of 1%;
- for the treatment of pumpkin for anthracosis, treatments are carried out with Bordeaux liquid with a concentration of 1% or 90% copper chloride.
Pests may cause yellowing of leaves
- Spider mite - settles on the lower side of the leaf plate, wrapping it in cobwebs, feeds on plant juice through punctures in the tissues, as a result of which the leaves become covered with specks, acquire a yellow color and dry, after a mass attack the ovaries fall and the fruits stop developing;
- Sprout fly - special damage is not caused by adult adults, but from a larva that penetrates into the stem and feeds on plant juice and soft tissues;
- Aphids - colonize the stems and lower leaf layer in colonies, suck out plant juice, primarily affect inflorescences, shoots and ovaries, and prevent the fruits from developing.
Methods of struggle
Pest control is also carried out with chemical preparations and alternative methods:
- regular weeding is carried out against the spider mite and plants insect repellent, such as calendula, are planted,
- from a sprout fly, plantings are sprayed with ammonia or hydrogen peroxide (1 tsp per 1 liter of water);
- in the fight against melon aphids, foliar supplements are used with phosphorus and potassium (20 g of superphosphate, 10 g of potassium chloride per 10 l of water), as well as by spraying with infusions (50 g of tobacco, 10 g of laundry soap per 10 l of water, 400 g of ash, 50 g of laundry soap per 10 l of water, 100 g of onion per 10 l of water).
A complex measure against pests is the treatment of plantings with insecticides, for example, Biotlin in solution with a concentration of 5 ml per 10 l of water.
As already mentioned, if the leaves of the pumpkin turn yellow, it means that the rules of care were violated or the vegetable became ill.
Eliminating the problem is always difficult, in addition there is a risk of crop loss, therefore, it is best to carry out preventive measures.
Preventive measures are aimed at creating conditions under which the risk of diseases and pests is minimized.
- removal of vegetable residues from the garden, in which pathogens, fungi and insect larvae can persist for the winter and subsequently become active;
- changing the place of planting pumpkins, returning to their original place only after 3-4 years;
- sowing seeds and seedlings in dry sunny weather in moistened land;
- regular loosening of row-spacing, which reduces the evaporation of moisture and reduces the number of irrigation, increases the penetration of air currents to the roots;
- pinching the stems, leaving up to 4 ovaries, forming a bush in 2 stems, which supports proper nutrition of the entire plant.
Chemical and folk remedies
- carry out pre-sowing treatment of seeds, make it permissible by soaking before planting in a weak solution of potassium permanganate;
- twice during the growing season, plantings are sprayed with Bordeaux liquid to prevent the appearance of fungal infections;
- choose pest resistant varieties;
- increase the immunity of plants by introducing fertilizer complexes and organics;
- sprayed plantings with infusions to repel pests (with garlic, onions, wood ash, tobacco);
- when the primary sign of damage appears, they are treated with fungicidal and insecticidal agents.