Sign up for email alerts of new Fluid Journal issues!
Fluid Journal : Fluid Journal 2005-2007
Apple Orchards Respond To Boron Fertigation Drs. G. Neilsen, D. Neilsen, E. Hogue, Mr. L. Herbert Canadian studies show increase in leaf and fruit boron concentrations. Spring 2006 FLUID JOURNAL Page 1 Summary: Leaf concentrations of boron (B) were effectively increased via foliar application. Foliar B applications ameliorated deficiency systems associated with 'blossom blast' in thespring and fruit corking and cracking at harvest. Fertigated B was mobile within the soil and it was relatively easy to increase leaf and fruit B concentrations via fertigation of modest rates of 0.34 g per tree. The ready response of tissue B concentrations to fertigated B suggests caution is required to select moderate B application rates in order to avoid toxicity when fertigating B. There were minor differences in leaf B concentrations among 'Gala,' 'Fuji,' 'Fiesta,' and 'Spartan' apple cultivars during the field trails. Nevertheless, in general, all cultivars responded similarly to B treatments, including non-application or application via foliar spray or fertigation. An experimental high-density apple block (674 trees/A) on M.9 rootstock was planted in 1992 and maintained until 1996 as a randomized, replicated split-plot experiment with five nitrogen (N) potassium (K) fertigation treatments, each with subplots containing four apple cultivars ('Gala,' 'Fuji,' 'Fiesta,' and 'Spartan'). Management of B nutrition varied throughout the experiment, ranging from no application (1992-93) to foliar applications (1994) to fertigation of 0.34 g B per tree during the growing season (1995-96). Deficient concentrations of B were measured in leaves, and 'blossom-blast' B deficiency symptoms were observed within two years when applications of B were absent. Foliar application of B increased leaf B concentrations and ameliorated B deficiency symptoms. Boron fertigation readily increased root zone soil solution B concentrations and increased leaf B concentrations to values within the sufficient optimum range for apples. Generally, cultivars responded similarly to B treatments although, relative to other cultivars, 'Spartan' and 'Fuji' had higher concentrations of B in leaves In the fruit-growing region of the Pacific Northwest of North America, fertigation induced problems on sandy soils have included rapid soil acidification leading to nutrient imbalances such as K deficiency. This has stimulated the development of adaptive strategies to minimize soil Figure 1. Effect of various B treatments on leaf B concentration for four cultivars from 1992 to 1996 (dotted line shows 20 ppm deficiency threshold).
Fluid Journal 2002-2004
Fluid Journal 2008-2009