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[tag=TO] | [lemma=a] □ □
[tag=TO] | [lemma=test] □ □
Trees grafted to dwarfing rootstocks require only 3 to 4 years to begin bearing fruit , while standard-sized trees may require eight years or more . For this reason , we strongly endorse a series of projects over the next few years to test the suitability of SAR interferometry for volcano monitoring and to determine requirements for future satellite missions , partly or wholly dedicated to volcano monitoring . Remote-sensing techniques allow crucial data to be collected for eruption forecasting , while minimizing the hazard to scientific investigators . If a geranium planting is of particularly high value and rust has been a problem in previous years , fungicides may be applied to prevent infection .