How to control Botrytis cinerea of cucumber

Botrytis cinerea is one of the most susceptible diseases of cucumber, especially cucumber in greenhouse. Botrytis cinerea is easy to spread in the weather of low temperature and insufficient cumulative time of light. Botrytis cinerea directly harms young cucumbers, leaves and stems, and then plants die in a large area. The following are the symptoms, incidence regularity and control measures of cucumber gray mold:

Grey mold cucumber

Symptoms: Botrytis cinerea bacteria mostly invade from failed female flowers, causing petals to rot, and grow a grayish brown mildew layer, and then expand to young melons, resulting in waterlogged navel, young flowers rapidly soften, atrophy, rot, surface dense mildew layer. When the larger cucumber is susceptible, the infected place first turns yellow and produces gray mold, then the mildew layer changes to light gray, and the infected cucumber stops growing, rotting or falling off. Botrytis cinerea in leaves is generally caused by shedding rotten flowers or broken melons attached to the leaf surface, forming a large spot with a near round or irregular shape between 20 and 50 mm in diameter, with obvious edges and a small amount of gray mold attached to the surface of the spot. When the rotten melon or rotten flower is attached to the cucumber stem, it will also cause the rot of the plant stem, and in serious cases, it can also cause the melon node on the stem to rot and break the vine, and finally the plant will die.

Incidence regularity: the peak period of Botrytis cinerea infection and rotten melon is the cucumber fruiting period, the optimum temperature is 18-23 ℃, the highest is 30-32 ℃, and the lowest is 4 ℃. When the humidity in the greenhouse exceeds 85%, the dew time of cucumber leaves lasts for a long time, and Botrytis cinerea is particularly easy to occur. Botrytis cinerea adheres to infected cucumbers or plants with hyphae or conidia and sclerotia, or overwinters in soil. The conidia of overwintering Botrytis cinerea spread with airflow, agricultural operation and irrigation.

Grey mold cucumber

Prevention and control measures:

The main results are as follows: 1. The cultivation methods of high border and drip irrigation were adopted in greenhouse and greenhouse to properly control watering for cucumber in early growth stage and after disease, release air timely and late, reduce humidity, reduce the time of dew on the roof and leaf surface and spit water at leaf edge. Clean the dust on the shed surface and enhance the light.

2. The diseased flowers, melons and leaves should be removed and buried deeply in the early stage of the disease after the cucumber harvest.

3. Chemical control. Greenhouses and greenhouses can use 300 grams of 10% Sukeling smoke per mu, 1 kg of 5% Garenon dust per mu, once every 9 minutes for 11 days, and 2-3 times in a row. At the initial stage of the disease, 50% Nongliling water dispersant should be diluted 1000 times, 40% Shijiale suspension should be diluted 800 times, 50% Kaiser water dispersible granules should be diluted 1500 times, 50% ash should be diluted 1000 times, 50% Sukeling wettable powder should be diluted 800 times, 50% propofoin wettable powder should be diluted 1500 times, etc. spray cucumber plants once every 7-10 days. 2-3 times in a row. When dipping flowers, add 200 times dilution of Xerox, 1000 times dilution of Nongliling, 800times of promethazine and 800times of Sukeling.