Effects of a Root Barrier and Localized Fertilizer Application on Root Growth of Young Peach (Prunus persica) Trees

摘要

The response of 2-year-old peach trees to localized application of fertilizer and a physical barrier in soil was measured in greenhouse studies. Pots had a split root design so that the root system was partitioned at the junction with the stem. Half the pot was not treated and the other half received one of four treatments at one location, 43 to 46 cm from the root collar: 1) soil volume restricted with polypropylene nonwoven fabric (FAB); 2) fertilizer alone (PER, 8N-5.2P-26.6K); 3) FAB+FER; and 4)untreated control (UTC). Minirhizotrons were used to measure root growth over time at four distances from the root collar in each pot half. In FER and FAB+FER, fertilizer was applied once each wk until 16 wk after planting (WAP) when root growth was evident at the treatment location. Then all treatments were fertilized daily from 17 to 19 WAP at the same root location. At 17 WAP, the number of new roots increased significantly in soil that received FER and FAB+FER compared with FAB and UTC. Root growthwas enhanced to a lesser extent in soil not receiving FER or FAB+FER on the treated side (i.e. near the treated soil). Root growth on the untreated pot half did not change in response to fertilization or fabric. Thus, weekly localized applications of lowrates of fertilizer enhanced the peach tree capacity to respond to daily localized applications of fertilizer. However, the greatest number of roots grew at 43 to 46 cm from the root collar where localized FAB+FER was applied. This treatment also resulted in the most rapid response of shoot growth to daily fertilization. This differential root and shoot response to fertilization and a root barrier may affect efforts to control peach tree size with root restriction and other orchard floor management practices.