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[tag=DT | □=□]
[tag=DT | □ & □]
In general , these insects do not kill the plant , but may stunt or kill parts , affect flowering , or cause aesthetic damage . By this we mean that , within a given pixel , the position of radar scatterers has not changed to any significant degree , but the ensemble of scatterers ( i.e ., the entire ground surface within that pixel , as well as some adjacent ones ) has moved up , down , or sideways in some correlated fashion . As discussed in more detail below , to measure surface displacement to this precision requires a relatively accurate a priori estimate of topography in the region and information on the position and orientation of the antennas during each image acquisition . Planting healthy clumps in new locations where the soil is well drained usually prevents further trouble . This disease can appear at any time of the growing season , but is most common in cloudy , rainy weather . Some grasses are semi-evergreen and hold their color into the winter , such as blue oat grass . One method of control is to hang a very strongly scented bar of soap in each tree in summer . Although pear trees are generally susceptible to a number of disease and insect problems , the fact that they are relatively uncommon in the Minnesota landscape often prevents these problems from becoming severe for home gardeners . Since the quantity on the left is determined entirely by the phases of the interferograms and the orbit geometries , the line-of-sight component of the displacement is measurable for each point in the scene . Grafting describes any of a number of techniques in which a section of a stem with leaf buds is inserted into the stock of a tree . Remove individual flowers as they fade by cutting them off behind the stem swelling at the base of each bloom . In addition , some of the most dangerous volcanoes are those with very long repose intervals that can lull inhabitants and volcanologists alike into a false sense of security . " These 4 to 5 scaffold branches should begin about 30 inches from the ground ( 40 inches if turf will be located beneath the branches and need to be mowed ) , should be spaced as equally around the trunk as possible and should be spaced vertically at least 6 inches from one another . Apple and pear trees require a site in full sun , so choose a spot where the sun shines directly for at least 8 hours each day . Closer planting will make training and management of the trees difficult , and the trees may shade each other so that fruit quality is harmed . These leaves tend to be more severely infected than leaves affected later in the growing season . Remember some rose cultivars and species are more resistant to disease . Equally essential for control of this disease is manipulating the environmental conditions that contribute to the growth and sporulation of the fungus . In addition , remove any weak new growth . When purchasing an apple or pear tree , you should know both the scion and the rootstock you ’ re getting . Remove any branches lower than 30 inches . The paint will reflect the heat of the sun just as the white plastic tree guards do . With the right conditions , any dead plant tissue can release thousands of Botrytis spores . Some apple varieties produce strongly vertical growth and need more training ; others tend to produce branches that are naturally well-angled . These structures may be unsightly but effective .