Control techniques of diseases and insect pests of marigold

Marigold has fewer diseases and insect pests, mainly standing blight, black spot, powdery mildew, stinging moth, shell insects and other diseases and insect pests. In the process of prevention and control, we should adhere to the principle of prevention first, prevention is more important than treatment, and timely prevention and control. Let's take a look at the pest control techniques of marigold.

Black spot disease

[incidence characteristics] Black spot mainly affected leaves, petioles and tender shoots. At the beginning of the disease, purple-brown to brown spots appeared on the front, and after enlargement, most of them were round or amorphous dark-brown spots.

[control methods] carbendazim, thiophanate methyl, daconine and other drugs can be sprayed.

Powdery mildew

[disease characteristics] powdery mildew invaded tender leaves, white powdery substance appeared on both sides, and the early symptoms were not obvious. five days after the appearance of 3Murray in the powdery mildew layer, the leaves showed water stains, gradually lost green and turned yellow, and caused leaves to fall off in case of severe injury.

[control methods] carbendazim and triadimefon were sprayed during the onset period, but the effect of Guoguang Inna was the best.

Leaf blight

[characteristics of the disease] most of the leaves were invaded by the tip or margin of the leaves, which were small yellow spots at first, and then rapidly expanded into irregular spots. The withered area of the seriously damaged whole leaf reached 2 × 3 of the whole leaf, chlorosis and yellowing of the diseased part, brown dry and shedding.

[prevention and treatment methods] Comprehensive prevention and treatment should be taken when the disease occurs, and fungicides such as carbendazim and methyl topiramate should be sprayed.

Spodoptera litura

[harmful characteristics] the larvae of Spodoptera litura, Plutella xylostella, Spodoptera litura, Plutella xylostella and Spodoptera litura ate a lot of leaves in high temperature season.

[control methods] as soon as it is found, it should be sprayed with 90% trichlorfon crystal 800x solution or 2.5% fenvalerate EC 1500 times solution.

Shell worm

[harm characteristics] there are mainly white wheel scale, Japanese tortoise wax scale, red wax scale, brown soft wax scale, blow cotton scale, bran shield scale, snake eye scale and so on, which is characterized by sucking the juice of young stems and young leaves of marigold, resulting in poor plant growth. it is mainly induced by high temperature and humidity, poor ventilation and poor light.

[control method] during the peak incubation period of nymphs, 2000 times of 25% prolactin wettable powder can be sprayed.

Aphids

[damage characteristics] are mainly marigold aphids, peach aphids, etc., they absorb the sap of young organs of plants, harm tender stems, young leaves, buds and so on, and seriously affect the growth and flowering of plants.

[control method] 2000 times of imidacloprid wettable powder was sprayed in time.

Rosa trifoliata

[harm characteristics] mostly in the larval stage, dozens or more than a hundred clusters do harm, which can eat up the young leaves of the plant in a short time, leaving only a few main leaf veins, seriously endangering the normal growth of the plant.

[control methods] A small number of potted plants can pick leaves with a large number of larvae and trample to death when they first appear. It appears in large quantities and can be sprayed with 4000 times of phoxim EC.

Cinnabar spider mite

[hazard characteristics] it can occur for 10 to 15 generations a year. Adult mites, young mites and nymph mites are concentrated on the back of the leaves, and the eggs are mostly laid on both sides of the veins of the dorsal leaves or under the gathered filaments. Each female mite can lay 50 to 150 eggs, and the maximum time is 500. the time to complete the first generation is only 10 to 13 days at 23 ℃ to 25 ℃, and about 7 to 8 days at 28 ℃. The high temperature and drought season is rampant, which often leads to a large number of dense white spots on the front of the leaves and yellowing even withered spots on the back of the leaves.

[prevention and control method] once found, spray with 2000 times of 25% Baileba wettable powder in time.

Beetle

[harmful characteristics] mainly copper green beetles, black velvet beetles, white star beetles, small blue and white beetles, etc., often use adults to eat new leaves, shoots and buds, seriously affecting plant growth and flowering.

[control methods] make use of the false death of adults to vibrate and kill in the evening. Make use of the phototaxis of adults, trap and kill with black light. When adults feed, spray with 1000 times 50% malathion EC.