Spring disease prevention and control techniques for flowers, and what to know about introducing edible fungi

Spring, with its suitable temperature and humidity, is originally a season full of blooming flowers. But the signs of budding flowers are also transmitted to pests and diseases, and in spring various pests and diseases "arise with the season." Common spring flower pests and diseases mainly include powdery mildew, rust, black spot, leaf curl, chlorosis, as well as longhorn beetles, aphids, scale insects, scarab beetles, and others. The more serious types of damage include the following:

Damping-off

When the temperature is 20°C, newly sown flowers or trees, or those sown in late autumn, as well as some flowers prone to root rot, are highly susceptible to damping-off if the soil moisture is high.

Prevention and control methods: (1) Before sowing, apply 3 to 8 jin of 70% quintozene per mu to the soil and mix it evenly into the soil; (2) Control watering during the tender seedling stage and do not let the soil become too wet; (3) When diseased seedlings are first found, burn the diseased plants in a centralized manner, then drench the roots with a 1000-fold solution of 70% thiophanate-methyl wettable powder.

Rust

Rust is prone to infecting crabapple in large amounts after rain in April and May. Peony rust generally begins to develop in May, with irregular brown lesions appearing on the leaves and yellow-brown small granular objects forming on the underside of the leaves, while rose rust develops when rose buds are about to open, with yellow spots appearing on the upper surface of the leaves.

Prevention and control methods: (1) At the time of sprouting, promptly pick off and burn the yellow diseased buds that sprout first, thoroughly remove diseased plants and diseased residues, and eliminate the source of infection; (2) After sprouting, spray a 800-fold solution of 15% triadimefon wettable powder for control; (3) During the initial infection period, spray 15% triadimefon diluted with water at 700 to 1000 times.

Powdery mildew

It is commonly seen on flowers such as Impatiens, cineraria, dahlia, Chinese rose, and Hall crabapple, mainly occurring on the leaves, and also harming young stems, flowers, and fruits. When the disease first appears, multiple faded lesions first appear on the leaves, but there is no obvious margin around them, and later the small spots expand into large spots. As the disease progresses, the lesions become covered with white powder, the leaves shrink, affected flowers cannot bloom normally, and affected fruits stop developing. The occurrence period of this disease can extend from early spring through summer all the way to autumn.

Prevention and control methods: (1) Pay attention to ventilation and light transmission for the flowers; (2) Apply less nitrogen fertilizer and more phosphorus and potassium fertilizer; (3) When the disease first appears, remove diseased leaves as early as possible to prevent spread, or spray once with 15% triadimefon diluted with water at 700 to 1000 times.