Key Stages For Fertilization In Fruit Production

Four of the critical stages of high nutrient demand for fruit trees are pollination, early development, mid to late season, and late season/postharvest. During these times, growers should be sure to maintain healthy fertilization levels.

Some tips for nutrient management during each stage of fruit production:

Stage 1: Pollination

Fertilizing for fruit set actually starts the season before during bud development. This year, you’ll feed the buds from the prior season for good fruit set for this season. Fertilization during bud development is important because you can always thin fruit off, but you can’t create blossoms and fruit set if you don’t have it at the beginning. Boron is critical during pollination and early fruit set. Many growers apply a foliar boron spray, particularly during early bloom. Foliar applications are the most efficient method of uptake, and a foliar spray applies nutrient right where it needs to be – on the buds themselves. The buds are a small target, so growers don’t need to apply much. In most cases, only a pound or two of boron per acre per season would be needed.

Fase2 growth nutrients during this phase will stimulate growth in perennial crops such as orchards and vineyards. Fase2 promotes fruit set and bud retention and is intended for foliar applications.

Stage 2: Early Development

Early development is largely about nitrogen and phosphorus, applied to produce a good canopy and for the energy to get and hold fruit set. Overall, fertilizer rates will be based on what’s appropriate for the age of the tree and the results of a soil test.

Stage 3: Mid To Late Season

Calcium and potassium are the nutrients to monitor mid- to late-season. While every variety will need more potassium during this time, calcium is especially important for Honeycrisp apples.

Foliar applications are the way to fine tune a crop, fill in certain growth stages, or deal with a dry period of little water uptake – but start with the soil to get the right balance. As trees will also be setting buds for next season during this phase, micronutrients can be important to apply at this time.

Stage 4: Late Season/Post Harvest

Some of the very early season apple varieties and all types of cherries will have a fair bit of growing to do, even into the late season. For these, maintaining insecticide and fungicide applications, even after harvest, will maintain leaves as long as possible and give trees more energy going into winter. Some growers have also been looking into late-season nitrogen as a way to improve spring flush and vigor.

Throughout the entire growing season, Pro-Germinator and Sure-K are two main nutrition products that support a balanced fertilizer program. Pro-Germinator is primarily used as a soil application, but it can also be applied as a foliar nutrient. It provides season-long phosphorus availability. Sure-K provides potassium for foliar or fertigation applications, which allows flexible use depending on crop or variety. For those varieties that need additional calcium, Liberate Ca from AgroLiquid can be tank mixed with many other products for efficient source of calcium applications.

2 thoughts on “Key Stages For Fertilization In Fruit Production

  1. Do strawberries also need fertilizer as you have stated in the above article?
    Do you have other recommendations for strawberries?

    1. Strawberries do indeed need fertilizer for optimal growth and yield. However, the levels of nutrients and the timing when a strawberry requires them is different from a fruit tree. There are distinct growth stages, such as bloom and fruit set, with both crops and in a general sense they both need the same nutrients for each stage. Still, when that occurs each season and how much each need are different. Also, there are two types of strawberries grown here in the US. One type is most commonly called “June bearing” or essentially these plants produce for only about 1 month each year. The other type is “ever-bearing” or the strawberries can be harvested for several consecutive months. With the first type, most of their fertilizer needs to be applied early in the spring to achieve a strong plant early in the season and then after harvests are complete a second period of growth occurs for the plants to set runners for the next season. With the ever-bearing, they require more constant feeding all season as they continue to grow and set fruit. Early season growth comes primarily from nitrogen applications (High NRG-N and/or N-Response). Phosphorus (Pro-Germinator) and micro-nutrients will be key components at the time of bloom and early fruit set. Lastly potassium (Sure-K or Kalibrate) and calcium (Liberate Ca) are key nutrients for berry development and maintaining firm berries at harvest. With the June bearing varieties, much of the fertility can be applied before the plants break dormancy in the spring. Additional nutrients can be applied with irrigation water or in diluted sprays over the top of the plants during the growing season. The quantity of nutrients you will need to apply will be based on your soil levels, yield goals and the type of berries you are growing.

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