Common Pest and Disease Control Methods for Roses

Roses

To succeed in growing roses, besides doing the basic care work well, pest and disease prevention is also crucial, because many insect eggs are invisible to the naked eye of gardening enthusiasts, and once a rose gets infected, it will not only affect its growth but also its ornamental value. So what are the control methods for rose pests and diseases?

I. Nettle Grubs (Slug Moth Caterpillars)

Mainly the larvae of the yellow nettle grub, brown-edged green nettle grub, beautiful brown nettle grub, mulberry brown nettle grub, and flat nettle grub, which feed heavily on leaves during hot seasons. Control method: Once discovered, immediately spray with 90% trichlorfon crystal at 800 times dilution, or 2.5% fenvalerate emulsifiable concentrate at 1500 times dilution.

II. Scale Insects

Mainly including white wax scale, Japanese wax scale, red wax scale, brown soft scale, cottony cushion scale, Chaff scale, snake-eye scale, etc. Their damage is characterized by piercing and sucking the sap of young rose stems and leaves, causing poor plant growth, mainly triggered by high temperature and humidity, poor ventilation, and insufficient light. Control method: During the peak hatching period of their nymphs, spray with 25% buprofezin wettable powder at 2000 times dilution.

III. Aphids

Mainly rose aphids and green peach aphids, etc. They pierce and suck the sap of young plant organs, damaging young stems, leaves, and flower buds, seriously affecting plant growth and flowering. Control method: Promptly spray with 10% imidacloprid wettable powder at 2000 times dilution.

IV. Rose Sawflies (Arge pagana)

Mostly at the larval stage, dozens or over a hundred gather in groups to cause damage, and in a short time can strip the young leaves of the plant completely, leaving only a few main veins, seriously harming the plant's normal growth. Control method: For a small number of potted plants, when they first appear, pick off the leaves where large numbers of larvae have gathered and crush them underfoot. If they appear in large numbers, spray with 75% phoxim emulsifiable concentrate at 4000 times dilution.

V. Carmine Spider Mites

Mainly including copper-green chafer, black velvet chafer, white-spotted flower chafer, small green flower chafer, etc. The adults often feed on new leaves, tender shoots, and flower buds, seriously affecting plant growth and flowering. Control method: Taking advantage of the adults' death-feigning behavior, shake them off in the evening and kill them. Taking advantage of the adults' phototaxis, use black light traps to lure and kill them. When adults are feeding and causing damage, spray with 50% malathion emulsifiable concentrate at 1000 times dilution.

VI. Stem Borers

Rose stem borers are the larvae of the rose stem sawfly, which bore holes in the stems, tunnel inside to feed, causing branches to break and upper parts to die. The larvae are white with a pale yellow head, about 15-17 mm long. Adults have wings, are black, with yellow on both sides of the abdomen. Pupae are vermilion red. Usually one generation occurs per year, causing damage from May to June, pupating inside the stems to overwinter. It is a relatively serious pest.

Editor's Tips:If you are a gardening enthusiast who frequently propagates roses, never use diseased branches as cuttings. We all know that bad genes will affect its entire life's growth. We hope that every gardening enthusiast's roses will not be infected by pests or diseases.

Common Pest and Disease Control for Roses

What are the common pests and diseases of roses? How to control them?

What are the common pests and diseases of roses? How to control them?

The main diseases of roses include powdery mildew, black spot disease, etc.; the main pests include aphids, scale insects, red spider mites, leaf roller caterpillars, longhorn beetles, sawflies, horntails, etc.

1) Control methods for powdery mildew

(1) Strengthen cultivation management by checking frequently. When diseased branches and leaves are found, immediately prune and burn them. Control watering, apply less nitrogen fertilizer, and prune carefully to give the inner canopy good ventilation and light.

(2) Chemical control: During the disease period, spray with 1000-2000 times dilution of triadimefon solution or 70% thiophanate-methyl at 1000-1500 times dilution. Before budding in early spring, spray with 3°-4° lime sulfur mixture. A 0.1%-0.2% wettable sulfur powder suspension can also be used for control. Normally spray once every 5-7 days, and when the disease is severe, spray once every 2-3

days. The method for making homemade sulfur powder suspension is: wrap sulfur powder in coarse cloth and rub it in clean water to make the sulfur powder suspension.

2) Control methods for black spot disease

(1) Choose and plant varieties with relatively strong disease resistance.

(2) Clear away dead branches and fallen leaves.

(3) Choose a ventilated and well-lit environment for cultivation, and strengthen fertilizer and water management.

(4) For chemical control, use 200-300 times dilution of Bordeaux mixture, spray every two weeks

once for prevention. Before sprouting, spray with 3°-5° lime sulfur mixture. When the disease occurs, spray with 70%

thiophanate-methyl at 1000 times dilution, or 75% chlorothalonil at 1000 times dilution, or 50% carbendazim at 800-**** times dilution, or 50% amobam solution. In early summer, spray 1% Bordeaux mixture once every 10

days.

3) Control methods for aphids: Check plants frequently, and when aphids are found, promptly kill them or pick off and destroy them. When the infestation is severe, spray with 40% omethoate at 1200 times dilution, or 90% trichlorfon crystal at 1000 times dilution, or menazon emulsion at 1500 times dilution, or 2.5% derris extract at 1000-1500 times dilution.

4) Control methods for scale insects

When scale insects first appear, remove them with a toothbrush or bamboo stick. In severely affected areas with major outbreaks, renew and prune to burn the infested branches, or change the cultivation location. During the nymph stage, spray with 40% omethoate at 1000-1500 times dilution, or 50% malathion emulsion at 800-1000 times dilution, or 50% phoxim at 1000-2000 times dilution; during the dormant period, spray with 3°-5° lime sulfur mixture, and pay attention to protecting and utilizing natural enemies such as the Australian ladybird beetle and large and small red ladybird beetles.

5) Control methods for red spider mites: First clear fallen leaves and weeds, or carry out nursery irrigation, to eliminate overwintering mite sources. During the occurrence period, spray with 0.2°-0.3° lime sulfur mixture or 40% dicofol emulsion at 2000 times dilution, or spray with 20% tetradifon at 800 times dilution.

6) Control methods for stem-boring pests: In combination with pruning, crush the eggs and kill newly hatched larvae at the egg-laying cracks, and promptly prune diseased and pest-damaged branches and infested tender shoots. During the larval hatching period, spray with 20% fenvalerate at 3000 times dilution, or 40% dimethoate at 2500 times dilution, and protect and utilize parasitic wasps.

7) Control methods for leaf roller caterpillars: Manually capture and kill the larvae, or spray with 40% omethoate at 2500 times dilution, or 90% trichlorfon crystal at 1000 times dilution.

For information on rose cultivation methods, please refer to: