Importance of Fall Fertility in Apples and Pears
The best time to apply post-harvest fall fertilizer is right after harvest. The tree has just been through harvest and a tough growing season and needs to be replenished for the winter. Also, typically after harvesting, for most varieties, there is still an opportunity to get some irrigation cycles on to incorporate the fertilizer into the soil. Post-harvest is also when root activity is at its largest, so the proper amount of water and nutrition can really set up the crop nicely for next year.
Looking at Image 1 (above), you can see that at post-harvest during root growth, many nutrients are required.
Importance of Nutrition
Table 2. Tree fruit demand for primary macronutrients per ton of fruit harvested.
|0.9 – 2.1
|0.2 – 0.4
|2.0 – 3.9
|0.10 – 0.22
|Cheng and Raba 2009; Palmer and Dryden 2006; Sallato, 2021.
|1.3 – 2.7
|Silva and Rodriguez 1995
Throughout our growing area, many of our soils have high pH as well as high salts, it’s recommended a light rate of humic or fulvic acid to help delineate any issues around high soluble salts. Balancing the ratios of key elements is also crucial in addition to addressing nutrient deficiencies. Post-harvest fertilization plays a vital role in preparing for the upcoming crop season. This period is favorable for nutrient uptake since the trees remain active, allowing roots to absorb the applied nutrients. These absorbed nutrients serve as reserves for the following growing season.
The nutrition applied in the fall has a crucial impact on the tree and fruit in the upcoming year. Horticultural practices also play a key role in setting up next year’s crop. These storage nutrients are essential for sustaining growth during stressful periods, dormancy, and the initiation of growth in the spring. It is important to find the right balance of nutrients to promote both vegetative and reproductive growth for consistent and quality fruit production. Through effective fertilizer management, the goal is to produce healthy trees with moderate vigor and high-quality fruit. Getting fertilizer applied and watered in quickly, will help achieve better nutrient uptake.
Benjamin Sullivan // Tech Nutrition Agronomist
The above has some info extracted from an article by Dean Rainham, Horticultural Consultant at AgFirst firstname.lastname@example.org. Also, information was supplied by Dr. Deepak Mathur, Ph.D. Senior Technical Manager (International) Agrichem Australia.
Weinbaum, S.A., I. Klein, F.E. Broadbent, W.C. Micke and T.T. Muraoka. 1984. Effects of time of nitrogen application and soil texture on the availability of isotopically labeled fertilizer nitrogen to reproductive and vegetative growth of mature almond trees. J. Am. Soc. Hortic. Sci. 109:339–343.
Neilsen D. and G. Neilsen 2008. Managing Nutrition for High Density Apple and Sweet Cherries. USHA Convention.