[tag=IN] ([lemma=all] [lemma=undergraduate])? [□]*
[tag=IN] ([lemma=all] [lemma=undergraduate])? [□ | □]*
[tag=IN] ([lemma=all] [lemma=undergraduate])? [□=□]*
If you discover iris borer damage early in the season , you can crush the insect while it is inside the leaf or remove the infested leaf . Various sizes of irregularly shaped , hard black sclerotia may be found inside the tan area of the stem . If you prune off the wilted shoot near the base and look at it in cross-section , you will see that the water conducting system inside the stem has turned brown . Apples stored near 33F may last as much as 10 times longer than apples stored at room temperature . An important result of PHC is that roses in healthy condition are less impacted by insects than plants under stress . Red lesions near the base of the stem eventually enlarge and girdle the stem , causing the upper portions of the plant to wilt and die . Aster yellows is vectored ( transmitted ) by insects called leafhoppers , and through grafting . Prevention through proper site selection , cultural management and good sanitation is by far the most important step in reducing the incidence and spread of disease . The fungus produces a large amount of cottony white , thread-like material called mycelium , which can grow up the stems of plants and also spread out across the soil to infect other plants . Control : Throughout the growing season , the infection can be reduced through sanitation and fungicide application . If environmental conditions are favorable for disease development , the fungus can spread through most of the root system within 7-10 days , causing death of the plant . Even a moderate event near downtown Los Angeles during business hours , or a great earthquake along the San Andreas Fault in southern California could lead to much more severe losses of life and property , dealing a devastating blow to the socioeconomic structure of the state of California . This disease , caused by bacteria present in the soil , infects plants through wounds or natural openings near the root crown of the plant . Because currants and gooseberries do not perform well under dry or waterlogged conditions , most soils will benefit from the addition of organic material such as shredded peat or compost before planting . If the bark temperature gets above freezing , water in the conductive tissue under the bark becomes liquid and begins to flow through the cells . They chew pinprick-sized holes and tunnel inside leaves as they continue down toward the rhizome . Branches that grow more vertically often break away from the tree under the weight of fruit . However , evidence indicates that some pear varieties may be self-fruitful under some conditions , and you might be able to get a small amount of fruit with only one tree .