Cucumber viral disease is highly damaging, what medicine is good for control?

Viral disease is one of the most common diseases during cucumber growth. It can cause leaves to turn yellow and wither, lead to cucumbers failing to set fruit, affect yield, and in severe cases can kill the entire plant. Therefore, when planting cucumbers, this disease must be controlled. So what are the harms of cucumber viral disease? What medicine is good to spray?

Harms of cucumber viral disease:

Mosaic viral disease: It is a systemic infection, and the virus can reach any part except the growing point. When infected at the seedling stage, the cotyledons turn yellow and wither, and the young leaves show a mosaic pattern of alternating dark green and light green, while the affected leaves show varying degrees of shrinkage and deformity. When infected at the mature plant stage, the new leaves show a mosaic pattern of alternating yellow and green, the diseased leaves are small and shrunken, and the leaves become thicker; in severe cases, the leaves curl backward; the internodes of the stem shorten, the stem becomes deformed, and in severe cases the leaves of the diseased plant wither; the fruit shows a mottled pattern of alternating dark green and light green, the surface is uneven, and the fruit is deformed. Severely diseased plants have clustered small leaves, fail to set fruit, and shrink and die.

Green mottle-type viral disease: The new leaves produce small yellow spots, which later become light yellow markings, and the green parts form uneven raised tumor-like growths. The leaves become smaller, causing plant stunting, and the leaves are mottled and distorted (Figure 1-75). The fruit bears dark green spots and raised tumor-like growths, and is mostly deformed fruit.

Cucumber viral disease also occurs severely when there are many weeds, nearby diseased crops, high temperature, water shortage, fertilizer shortage, extensive management, and many aphids. In Zhejiang and the middle and lower reaches of the Yangtze River, the peak disease periods are from April to June and from September to November. The green mottle-type viral disease can be seed-borne and can also overwinter in the soil, becoming the primary infection source for the disease the following year. It undergoes multiple secondary infections through wind and rain and farming operations, and aphids do not transmit the virus. Storms, plants colliding with each other, friction between branches and leaves, or root damage during cultivation can all easily cause virus infection. The disease is severe when the temperature is high in the field or greenhouse.

What medicine is good to spray?

1. Treat seedlings with weak virus vaccine N14 and satellite virus S52 to improve plant immunity and also control tobacco mosaic virus and cucumber mosaic virus. The weak virus vaccine can also be diluted 100 times, with a small amount of emery added, and sprayed with a pressure spray gun at 2-3 kg per sq m.

2. Spray once before and once after transplanting with 24% mixed fatty acid copper aqueous solution at 700-800 times dilution or 10% mixed fatty acid emulsion at 100 times dilution, which can induce cucumber disease tolerance and increase yield; soybean milk, milk, and other high-protein substances diluted 100 times with clear water can also be sprayed to weaken the virus infection ability and inactivate the viral disease. 27% high lipid film emulsion at 200 times dilution can also be used, once every 7 days, for 2-3 consecutive times.

From before disease onset to the early stage of disease, the following agents can be used for control: 2% ningnanmycin aqueous solution at 200-400 times dilution; 4% pyrimidine moroxydine aqueous solution at 200-300 times dilution; 20% morpholine guanidine hydrochloride • copper acetate wettable powder at 500-700 times dilution; 7.5% bacterial poison • moroxydine aqueous solution at 500-700 times dilution; 2.1% alkanol • copper sulfate wettable powder at 500-700 times dilution; 25% copper succinate • moroxydine wettable powder at 600-800 times dilution; 3.85% triazole • copper • zinc aqueous emulsion at 600-800 times dilution; 1.5% copper sulfate • alkyl • alkanol aqueous emulsion at 1000 times dilution; 3.95% diazole nucleoside • copper • alkanol • zinc aqueous solution at 500-800 times dilution; 5% bacterial poison clear aqueous solution at 300-500 times dilution; 31% moroxydine • triazole nucleoside soluble powder at 800 times dilution; 25% moroxydine • zinc sulfate soluble powder at 500-700 times dilution; 3% triazole nucleoside aqueous solution at 600-800 times dilution; 1.05% nitrogen glycoside • copper sulfate aqueous solution at 300-500 times dilution; 20% morpholine guanidine hydrochloride wettable powder at 400-600 times dilution; spray with water, and spray once every 7-10 days depending on disease severity. Spray once each after transplanting, at the early fruit stage, and at the full fruit stage.