What are the common flower diseases and insect pests?

Common diseases of flowers: cold in spring

1, damage

This is a non-communicable disease, which mainly occurs in some areas south of the Yangtze River and between Jianghuai and Jianghuai. By the end of March, the daytime temperature has reached above 20℃, and many people are eager to move their potted ornamental plants outdoors for conditioning and maintenance. At this time, there is often cold air going south, and there is a reversal weather of "late spring cold". The lowest temperature in the morning often drops below 4℃, which causes some new buds and leaves of tropical flowers to be "frozen to death".

Common plants such as Prynne, Milan, Jasmine, Clivia, Daifen Leaf, Giuttaro, upside-down Admiralty, arrowroot, Anthurium andraeanum and Poinsettia will seriously affect the normal growth of that spring.

Step 2: Solutions

Grasp the weather forecast of the local meteorological station in time, and in case of special weather of "late spring cold", a small number of potted plants that have been moved outdoors can be moved back to the greenhouse or indoors; If many potted plants are moved outdoors, they can be gathered together and covered with double plastic film.

In the Yangtze River valley and its northern area, outdoor activities are generally not allowed until Tomb-Sweeping Day or the end of the "final frost period". We can open the doors and windows, add electric fans and other measures to cool down, and then close the doors and windows at night to gradually adapt to the outdoor environment.

Common diseases of flowers: powdery mildew

1, damage

It mainly harms ornamental plants such as rose, crape myrtle, Mahonia, Euonymus japonicus, Polygonum, etc. It mainly harms leaves, petioles, pedicels, buds and shoots. The affected area is covered with a layer of white powder. In severe cases, leaves turn yellow, tender leaves curl, contract and thicken, buds die, deformed flowers appear, and tender branches bend and shorten.

Step 2: Solutions

Fumigation of sulfur powder In March, an electric fumigator was used in the shed, and sulfur powder was built in for sealing fumigation, which had good control effect.

Common diseases of flowers: anthracnose

1, damage

It mainly harms camellia, camellia, yemen iron, hydrangea, Clivia, evergreen, orchids, spider eggs, epiphyllum, rubber trees, cyclamen and so on. It mainly harms leaves, shoots and fruits. The focus is nearly round and grayish brown. In the later stage, the lesion turned gray, with obvious concentric wheel marks and small black spots.

Step 2: Solutions

We should improve the density of flowers in the whole pot, plant planting and row spacing, and improve ventilation conditions. When the potted soil is dry, water it properly to increase the resistance of plants.

At the initial stage of the disease, 500 times of 80% anthrax thiram wettable powder or 50% doxorubicin &; #8226; 800 times sulfur suspension, alternately sprayed once every 10 day, 2-3 times in a row.

Four common diseases of flowers: gray mold

1, damage

With the recovery of air, excessive humidity and poor ventilation, gray mold is still one of the main diseases of indoor flowers. Harm gerbera, rubber tree, chrysanthemum, cyclamen, poinsettia, geranium, Rieger begonia, green radish, dragon boat flower, hibiscus flower, Anthurium andraeanum and other potted flowers, especially the leaves and petals are seriously infected.

Step 2: Solutions

After March, it is necessary to strengthen ventilation and light transmission, reduce indoor air humidity, and prohibit spraying water on the leaves in the evening to prevent moisture from staying on the leaves for a long time.

For the plants at the early stage of the disease, 500 times of 65% zineb wettable powder or 50% carbendazim wettable powder at 1000 times can be sprayed alternately around noon, once every 10 day and continuously for 2-3 times.

Five Common Flower Diseases: Black Spot

1, damage

In March, due to poor indoor ventilation and high humidity, insect pests such as scale insects, aphids and whiteflies could not be completely eliminated, and sooty blotch still occurred on leaves and flowers of citrus, Milan, hibiscus, Michelia, Solanaceae, Ficus, Camellia, Bambusa, Rhododendron, Gardenia, Ilex, Fujian tea and other plants.

Step 2: Solutions

Strengthen indoor ventilation, timely kill aphids, scale insects, whiteflies and other insect vectors that induce sooty blotch.

A small number of leaves on individual plants are infected with coal pollution spots, and the coal pollution layer can be scrubbed with a wet cloth dipped in low-concentration washing powder water.

At the initial stage of onset, 50% A &；; #8226; Every 15 days, spray 500 times of sulfur suspension concentrate or 500 times of 75% Baijun wettable powder on the branches and leaves of diseased plants for 2-3 times continuously.

Common flower pests 6: scale insects

1, damage

Because of poor ventilation, insufficient light and high humidity, scale insects are still the main pests of potted ornamental plants in greenhouses.

Such as green scales on kumquat, gray scales on yew, manscales on hibiscus, chaff scales on Clivia, turtle scales and red scales on camellia, horny scales on holly, black helmet scales and oyster shields on cycads. The species of scale insects on each flower vary greatly.

2, prevention and control methods

Scale insects appearing on a few plants in this family can be dipped in 75% essence with cotton wool or wiped off with washing powder solution. For insect smaller scale insects, such as arrow moth, Bai Dun scale insects, etc. Scotch tape can be used to remove live insect carcasses.

Or spray with 25% chlorpyrifos wettable powder 2000 times, once every 15 days, twice in a row.

The seventh common pest in flowers: aphids

1, damage

With the increase of temperature and watering amount, the harm of aphids to indoor ornamental plants will be more serious. Aphids suck the juice of newly pumped branches and leaves, which will affect the normal growth of plants after spring.

2, prevention and control methods

For a small number of aphids on plants, tobacco powder, plant ash or slag ash can be sprinkled on the insect body and leaves, and after about 1-2 hours, most aphids can be killed by washing with clear water.

Common pests in flowers: whitefly

1, damage

It is mainly greenhouse whitefly, which harms chrysanthemum, hibiscus, rose, nasturtium, lantern flower and so on. Followed by whitefly, harm kumquat, golden bean, Eupatorium adenophorum, bergamot, rose, Prynne, Milan and so on. Their harmfulness cannot be underestimated.

2, prevention and control methods

In severe cases, 2000 times of 10% imidacloprid wettable powder or 2500 times of 25% chlorpyrifos wettable powder can be used.