Diseases of PerillaLeaf spotLeaf spot usually occurs from June to harvest, harming the growth of perilla. Initially, small brown or dark brown spots of different sizes and shapes appear on the leaf surface, and then develop into large round or polygonal spots, generally with a diameter of 0.2-2.5 cm. The spots are not obvious on purple leaves, but are more obvious on green leaves. After drying, holes are often formed. In severe cases, the spots merge and the leaves fall off. Prevention and treatment methodsWhen selecting seeds, choose from disease-free plants. Pay attention to soil drainage and avoid over-planting. Starting from the early stage of the disease, spray with 800 times diluted 80% wettable mancozeb, or 1:1:200 Bordeaux mixture. Spray 2-3 times every 7 days. However, spraying should be stopped half a month before harvest to ensure that the medicinal materials are free of pesticides. Pests of PerillaRed SpiderIt is most likely to occur during the dry months of June to August when the humidity is high. Adult red spider mites are small, usually orange-red, sometimes yellow. Red spider mites gather on the back of the leaves to suck sap. Initially, yellow-white spots appear on the leaves, and later larger yellow-brown spots can be seen on the leaves. As the spots expand, the entire leaf turns yellow and falls off. Prevention and treatment methodsDuring the outbreak period, spray with 2000 times diluted 40% dimethoate emulsion as early as possible. However, it is required to stop spraying pesticides half a month before harvest to ensure that no residual poison remains on the medicinal materials. Spodoptera exiguaFrom July to September, the larvae harm the growth of perilla, and the leaves will be bitten into holes. The mature larvae will pupate in thin silk cocoons on the plants. Prevention and treatment methodsSpray with 1000 times diluted 90% crystalline trichlorfon. |
<<: Zephyranthes pests and control methods
>>: Gladiolus (Gladiolus) Pests and Control Methods
1. Light exposure time When caring for it, you mu...
1. The difference of leaves The leaflets of black...
The general requirement for the soil for succulen...
Why does the orchid not bloom after being divided...
When is the right time to prune lilacs? Lilac pru...
Flower language of forsythia Forsythia is the cit...
How to shape rose bonsai There are three main way...
Bougainvillea is a vine-like shrub that can climb...
Okra seed planting time Okra likes to grow in a w...
1. How many cypress trees should be planted in th...
Jade tree blossoms (photo) First, planting materi...
There are fewer insect pests during the growing s...
Activated carbon as fertilizer Activated carbon i...
environment It likes a warm, dry, well-lit enviro...
Rain orchid Zephyranthes often bloom suddenly aft...