How to Treat Diseases of Xiaomila Peppers? A Detailed Guide to Prevention and Control Methods

Xiaomila pepper is actually the facing-heaven pepper (chaotianjiao); when immature it is pale green, when ripe it is orange-yellow, and dried Xiaomila peppers are red with orange-yellow streaks, while those that are bright red are not of this variety. Although peppers are very refreshing to eat, a pepper plant from sprouting to fruiting must endure many storms and diseases, so what diseases affect Xiaomila peppers? And how should they be prevented and controlled?

I. Diseases of Xiaomila Peppers and Their Prevention and Control

The common diseases of Xiaomila peppers include damping-off, root rot, bacterial wilt, viral disease, Phytophthora blight, powdery mildew, anthracnose and others. Different treatments must be used according to the different disease symptoms; when disease occurs, identify the symptoms early and apply the right remedy.

Damping-off in Xiaomila peppers mainly infects seedlings at the cotyledon stage or before the true leaves have unfolded. After the seedlings emerge, water-soaked lesions appear on the stem base near the ground, gradually turning yellow, constricting and becoming sunken; the leaves do not wilt before the seedling collapses, and it can easily be pulled loose from the lesion by a gentle tug with the hand. When moist, a white cottony mold layer can be seen on the diseased part. The control method is to use “Miao Ying Chun” at 3000 times dilution (5ml/15 kg) + 72.2% propamocarb hydrochloride at 1500 times dilution (10ml/15 kg) + 70% imidacloprid at 5000 times dilution (3 g/15 kg), applied as a root drench or spray.

The symptoms of root rot are that the cortex of the stem base and roots of diseased plants turns brown to dark brown and becomes wet-rotten; when touched by hand, the cortex of the diseased roots falls off or peels away, exposing the dark xylem. Generally the plants are stunted and short. In the early stage of the disease, agents such as sodium dichloroisocyanurate, chlorothalonil, thiram, or difenoconazole can be chosen for control.

The symptoms of bacterial wilt in Xiaomila peppers are that the leaves gradually turn yellow from the bottom upward and drop off in large numbers, or the cortex of the stem base where it contacts the ground becomes water-soaked and rots, while the stems and leaves above ground quickly wilt. The control method is to use “Miao Ying Chun” at 3000 times dilution (5ml/15 kg) + 72.2% agricultural streptomycin sulfate at 3000 times dilution (5ml/15 kg), applied as a root drench 7 days after the seedlings are transplanted.

The common symptoms of viral disease include mosaic wrinkling or brown necrosis, systemic necrotic streaks, and mottled patches of alternating dark green and light green on the fruit. Generally, 20% moroxydine + copper acetate at 750 times dilution (20 g/15 kg) + 70% imidacloprid at 5000 times dilution (3 g/15 kg) + Leili 2000 (1000 times dilution) or Jikeshan at 600 times dilution is chosen for spraying.

When Phytophthora blight occurs, drainage work should be done promptly. Treatments such as Meibang 58% metalaxyl + mancozeb at 600 times dilution (25 g/15 kg), Sapa 25% metalaxyl + cymoxanil at 600 times dilution (25 g/15 kg), and Kelasi 65% polyoxin and other agents can be used. The disease occurs at the seedling stage, mature stage and fruiting stage, generally with brown constriction at the stem base.

Powdery mildew mainly occurs on the leaves. In the early stage, round white powdery spots appear on the upper or lower surface, gradually expanding and joining into large powdery patches; later the entire leaf is covered with white powder, ultimately causing a large number of leaves to drop. Generally, chlorothalonil, hexaconazole or pyraclostrobin is used for control.

The consequence of anthracnose is a large amount of leaf drop and rotten fruit. Shilan 30% difenoconazole (5 g/15 kg), 45% prochloraz at 2000 times dilution (7.5ml/15 kg), and Meibang 50% thiophanate-methyl suspension concentrate at 600 times dilution (25ml/15 kg) can be used for control.

Compared with drug treatment, early prevention is more important. When choosing Xiaomila pepper varieties, choose varieties with strong disease resistance, and before sowing, disinfect the seeds as much as possible.