Effects of Nitrogen and Phosphorus on the Growth of Microorganisms Associated with Apple Replant Disease and on Apple Seedlings Grown in Soil Infested with these Microorganisms*

Abstract

The growth of fungi causing apple replant disease (ARD) was inhibited by the addition of N and P to the growing medium. The population of bacteria antagonistic to ARD‐causing fungi was significantly increased in the growing medium supplemented with N 400 P 400 mg/l or greater. The application of nitrogen alone or in combination with phosphorus to soil infested with fungi or bacteria that cause apple replant disease significantly increased seedling height. The addition of P alone to these infested soils did not have any effect on seedling height. Significant increases in seedling height occurred with N applications when seedlings were grown in soil to which bacteria that are antagonistic to fungi causing ARD had been added. These results suggest that the application of N, with or without P, to apple replant soils may suppress the growth of ARD‐causing fungi or bacteria and promote the growth of antagonistic bacteria.

Comprehensive Analysis of the Influence of Fulvic Acid from Paper Mill Effluent on Soil Properties, Soil Microbiome, and Growth of Malus hupehensis Rehd. Seedlings under Replant Conditions

“…3− for specific adsorption sites on the solid surface to reduce the adsorption of soil P. 28 In addition, PFA can form soil humic matter clay mineral complexes, thereby reducing P fixation. Since P is an important influencing and limiting factor in ARD control, 36 it is speculated that PFA may activate the soil P in the long-term process, thus alleviating the ARD to a certain extent.…”

Evaluation of monoammonium phosphate and bacterial strains to increase tree growth and fruit yield in apple replant problem soil

“…Increased initial root length is a known consequence of high P supply to wild cherry (Neilsen et al, 1990b). Neilsen et al (1989) also demonstrated that P likely increased initial diameter growth and the first 2 years of yield of McIntosh and Delicious apple trees irrigated with wastewater high in P. Increase in tree growth and fruit set by the application of monoammonium phosphate could also be because of its deleterious effect on replant causing fungi or bacteria and promotion of antagonistic bacteria in soil (Utkhede and Smith, 1991;Utkhede and Li, 1989b). Neilsen et al (1989) also demonstrated that P likely increased initial diameter growth and the first 2 years of yield of McIntosh and Delicious apple trees irrigated with wastewater high in P. Increase in tree growth and fruit set by the application of monoammonium phosphate could also be because of its deleterious effect on replant causing fungi or bacteria and promotion of antagonistic bacteria in soil (Utkhede and Smith, 1991;Utkhede and Li, 1989b).…”

“…Application of high rates of P in the year of planting increased the number of flower clusters and fruit set in sub-sequent years (Neilsen et al, 1990a). Recently it was shown that application of N, with or without P, to apple-replant-problem-soils suppresses the growth of replant-disease causing fungi or bacteria and promotes growth of antagonistic bacteria in soil (Utkhede and Smith, 1991). Fertilization of replant soil with monoammonium phosphate (llN:55P:0K) reversed the stunting effect caused by replant-causing bacterial isolates under greenhouse conditions (Utkhede and Li, 1989b).…”

Effect of Emerging Soil Chemical Amendments on the Replant Soil Environment and Growth of Malus hupehensis Rehd. Seedlings

“…Moharana et al found that phosphate fertilizer can improve the soil environment and increase soil enzyme activity. The application of a certain amount of phosphate fertilizer in orchards can effectively control the occurrence of apple replant disease or reduce the degree of damage that it induces . Hao and Xiao showed that adding superphosphate to replant soil can promote the growth of medicinal materials and alleviate replanting obstacles.…”

“…The application of a certain amount of phosphate fertilizer in orchards can effectively control the occurrence of apple replant disease or reduce the degree of damage that it induces. 12 Hao and Xiao 13 showed that adding superphosphate to replant soil can promote the growth of medicinal materials and alleviate replanting obstacles. The application of quicklime has been shown to improve the stability of soil aggregates 14 and reduce the occurrence of soilborne diseases of strawberries grown in greenhouse conditions.…”