ISHS Acta Horticulturae 635: XXVI International Horticultural Congress: Managing Soil-Borne Pathogens: A Sound Rhizosphere to Improve Productivity in Intensive Horticultural Systems
INTERACTION OF PRE-PLANT TREATMENTS, FERTILIZER APPLICATION TIME AND METHOD, AND CULTIVAR ON PERFORMANCE OF APPLES IN A REPLANT SITE |
| Author: | C.R. Rom |
| Keywords: | Malus, methyl bromide, fertigation, foliar nutrient content, fruit yield |
| Abstract:
In order to optimize performance of a high density apple orchard on a replant site, a study of cultivar, pre-plant soil treatments, and fertilizer application methods was established in Arkansas (USA, 35o 40' N, 94oW) on a moderately drained silt-loam soil. Pre-plant treatments of 1) an untreated check, 2) winter solarization (covered with 1.5mil black polyethylene), and 3) winter solarization plus soil fumigation with methyl-bromide (plus 2% chloropicrin) at 668kg/ha were applied the fall prior to tree planting. The winter solarization plastic remained in place for 5 months prior to planting 2 apple cvs. on M.26; 1) ‘Jonee’, and 2) ‘Smoothee’. Six annual fertilizer treatments were applied following planting: 1) no fertilizer, 2) spring top-dress application, 3) fall top dress, 4) split spring/fall top-dress, 5) spring fertigation, 6) fall fertigation. After 9 seasons and 8 years harvest, ‘Smoothee’ had greater yields (totally and annually) than ‘Jonee’ but similar production efficiency. Trees in fumigated plots had wider canopies and larger trunk cross-sectional area, had greater yields (44%) and average fruit size than those from untreated controls after 9 seasons. Yields of trees in solarized plots were intermediate to the fumigated and control trees although not statistically different than controls. Fertilized trees had more and larger fruit than unfertilized controls. There was no significant difference between spring and fall fertilizer applications for yield. Tree size and corresponding yield in spring fertigated plots was less than other fertilizer treatments. Spring fertigated trees had high levels of foliar Mn and showed symptoms of Mn-toxicity induced bark necrosis beginning in the second season. There was no consistent interaction of the treatments for most variables measured and the main effects accounted for the majority of experimental variation. | |
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