What Causes a Cactus to Lean?
Both indoor and outdoor cacti can suffer from leaning. A cactus that has been growing upright but is now leaning indicate that your plant is stressed…
Disease control is a slightly different situation than pest control, but aggressive intervention isn't always the answer. Plant diseases, especially fungal diseases, are very often the result of factors you can actually control:
Proper placement. Site plants so they get plenty of air circulation around them to prevent fungal spores from attaching to leaf surfaces. Planting too close to the house or crowding plants will set the stage for fungal invasion.
Good landscape sanitation. If you have a plant that's prone to fungal disease, be sure to remove and discard fallen leaves from the base of the plant on a regular basis to prevent the spread of the disease. More importantly, take steps to prevent the onset of fungus. Once a fungal disease arrives, it's likely to stick around for a while.
Practice prevention. To prevent fungus, water the bases of plants rather than the leaves, unless of course you're trying to control aphids. Apply fresh mulch now and then throughout the growing season to prevent spores from bouncing back onto leaf surfaces. And use horticultural oils, baking soda solutions — perhaps even milk — to prevent fungal diseases from attacking plants in the first place.
Finally, the most important thing you can do to prevent pests and disease problems is to give your plants optimum growing conditions — the particular type of light, water and soil that each plant needs. And maintaining healthy soil is important too.
"Make no mistake, healthy plants are far more able to withstand attack by pests and diseases than unhealthy ones are," Paul says. "So don't skimp on the compost it can do more to maintain healthy soil and produce healthy plants than most people realize."
Asocochyta blight, bacterial blight, root rot, damping off, downy and powdery mildew, fusarium wilt, and various viruses are some of the pea plant diseases that may afflict pea plants.
Asocochyta blight is composed of a trio of fungi, Ascochyta pisi, Phoma medicaginis var. pinodella (A. pinodella), and Mycosphaerella pinodes (A. pinodes), which survive through the winter months in plant debris or are introduced during planting season on infected pea seeds. Wind and rain transmit spores onto healthy plants.
Although symptoms may vary depending upon the fungus causing the infection, generally Asocochyta blight appears as a blackened stem, yellow foliage with brown blotches and bud drop. Both pods and seeds may be afflicted, and severe infections kill off seedlings.
To control Asocochyta blight remove and destroy diseased plants as soon as symptoms appear. There are no resistant fungicides available, so preventative measures such as crop rotation with non-susceptible crops on a yearly basis, and planting of disease free seed are recommended.
Similar to the Asocochyta blight, bacterial blight is another disease in pea plants that survives winter in infected surface plant refuse and in infected seed. Most commonly caused by the bacteria Pseudomonas syringae, bacterial blight may also be caused by other bacterium. Again, water, either rain splash, overhead watering or pet or human activity in a wet garden, spread the bacteria afflicting pea plants, often those that are already damaged by such things as frost.
At first bacterial blight looks like shiny, dark green water spots on the leaf surfaces and then these irregularly shaped spots become papery, brown to translucent with the center lighter in hue. If allowed to continue, the disease will spot all of the plant, including its pods and cause bud and young pod drop.
To fight bacterial blight, plant commercially grown, disease free seeds and do not use those from other plants, even if they appear to be healthy. Remove all debris in the fall and rotate crops yearly. Also, water plants at the base of the plants, and do not work around them when leaves are wet to prevent the spread of this disease in pea plants.
Root rot and Damping off
Caused by a number of fungi, root rot and damping off are other common pea problems exacerbated by cool, wet soil. Seeds become soft and rotted while seedlings fail due to sunken stem lesions. Older seedlings develop root rot when peas are planted in overly wet soil.
Root rot fungi makes foliage yellowed, stunted, wilted or just plain dead looking. Should you be so inclined to look, roots will be brown, black or red with the outer layer of root peeling off. On occasion, lesions may appear.
To prevent these fungal conditions, purchase commercially grown, disease free seeds and/or those pre-treated with fungicide. Again, rotate crops and be sure to plant in well draining soil with proper spacing. Do not over water.
Downy and Powdery mildew
Downy mildew and powdery mildew are also fungi that are spread via spores, although cool, moist conditions foster spore dispersal in downy mildew, while absence of rain does so in powdery mildew.
Fungicide application may be helpful as well as crop rotation. Remove debris at the end of the growing season and purchase disease free seeds.
Fusarium wilt is a soil-borne fungus, which may also be found in old plant debris as well as the soil. Wilting is one of the first signs of this disease, slowly progressing to faded, yellowing foliage and stunted growth. Eventually most plants succumb to this fungal pathogen and die.
Though fungicides are available that may alleviate the issue, the best way to control its spread is by preventing infection in your crops. This can be achieved through regular rotation of crops and sterilization of the soil through solarization.
Pesticides and Integrated Pest Management in the Home Garden
Traditionally, home gardeners would use pesticides to manage pests in their gardens and keep the landscape healthy. Commercial growers have used Integrated Pest Management for many years. More and more amateur and home gardeners are now using home, lawn, and garden integrated pest management techniques. It is a management method that seeks to limit or suppress pest populations by using various compatible tactics.
Integrated pest management tactics minimize potential harmful effects on the environment and human health. There is still a place for synthetic, natural, and organic pesticides, but generally, only as a last resort. A crucial part of IPM is scouting for common diseases, mite pests, and beneficials.
Preferred pest management tactics include encouraging beneficial insects into the garden, biological control, planting cover crops, and monitoring insect pests.