What are the 6 Best Kiwi Fertilizers?

What is a kiwi?

Kiwi (Actinidia) is a climbing plant that produces vine-like shoots, similar to grapevines. The use of kiwi fertilizer is crucial for enhancing kiwifruit yield and fruit mineral composition, with potassium being particularly important. However, while nutrient application generally boosts yields, excessive or imbalanced fertilization can have detrimental effects on plant health and productivity.

Kiwi is a dioecious species, meaning there are distinct male and female plants. Only the female kiwi plants produce fruit, but a sufficient number of male plants is necessary for effective pollination and optimal fruit production. Actinidia species are perennial, exhibiting vigorous growth with climbing and sometimes strangling tendencies. The plants produce unisexual flowers, with female plants bearing pistiliferous flowers and male plants bearing staminiferous flowers. The resulting fruit is berries that vary in shape and color, ranging from bright green to red and often covered in fine, stiff hairs.

Kiwifruit is highly nutritious, containing more Vitamin C than oranges and possessing the ability to neutralize free radicals, making it an excellent dietary supplement. Historically, kiwifruit has been used to treat various health disorders such as digestive issues, rheumatism, and dyspepsia, and it has gained global popularity for its potential health benefits. Among deciduous fruit plants, kiwifruit is particularly susceptible to iron chlorosis. Additionally, kiwi plants require 600 to 800 hours of chilling to ensure adequate production. Proper fertilization involves watering the base of the plant one to two days before applying fertilizer or manure, as fertilization significantly impacts the yield and quality of kiwifruit.

Kiwifruit is generally categorized into three types

1. Actinidia deliciosa

Female kiwi varieties produce green pulp fruits with hairy skin and require 600 to 800 chill hours.

2. Actinidia chinensis

Yellow pulp kiwi varieties need fewer chill hours (300-400), can grow in warmer areas, and are less sensitive to calcareous soils.

3. Actinidia arguta

Its production volume is lower compared to the previous two groups.

Major Kiwi Fertilizers

When kiwi is fertilized, it will produce large, robust plants that bear many blossoms.  Although they may survive in neutral soil, kiwi plants prefer slightly acidic soil. In the following years, rates may move up or down based on vine vigor.

One of the primary elements influencing kiwifruit quality and output is fertilization. Therefore, to ensure high production levels and the preservation of fruit quality, appropriate cultural practices—including fertilization—should be investigated.

Larger fruit sizes and higher yields are encouraged by timely manuring. Pruning kiwi plants on time also guarantees robust plants with lots of blooms.

The main fertilizers are listed as follows:

Mycorrhiza

Because of its extremely shallow root system, kiwis are particularly vulnerable to waterlogging. The growth of new roots is inhibited by low oxygen levels.

By expanding the area of contact between the soil and the root, mycorrhiza improves nutrient uptake, increases the plant’s resistance to active limestone, and promotes the formation of pathogen-free roots.

Apply 100 g per vine tree for a 5-year plant annually. And increase the dose by 10-15% for each year-old plant.

Compost / FYM

Apply 30 kg of farmyard manure around the root zone of 6-year-old kiwi plants and lightly mix it with the soil to prevent it from blowing away and to ensure it reaches the roots. Water the plant adequately after applying the manure, either on the same day or the next. The use of organic amendments enhances the calcium, phosphorus, potassium, and iron content of the kiwifruits.

Nitrogen (N)

Nitrogen is crucial for the mineral nutrition of kiwifruit. Ammonium nitrate and urea are suggested nitrogen sources, applied twice a year: in May/June and one month later. Researchers found that high nitrogen levels can accelerate fruit softening during storage and increase the incidence of botrytis storage rot at harvest. Additionally, excessive nitrogen can lead to decreased fruit yield.

Apply 200 grams of urea per plant annually for 6-year-old kiwi plants, splitting the dose into two equal parts as mentioned above.

Phosphorus (P)

Phosphorus plays a vital role in kiwi farming by promoting strong root development and enhancing the plant’s ability to absorb other essential nutrients. It is crucial during the early stages of plant growth, aiding in the establishment of healthy root systems which support vigorous vine growth. Phosphorus also contributes to improved flowering and fruit sets, ensuring better yields. Additionally, it helps in energy transfer within the plant, influencing metabolic processes that are essential for growth and fruit development. Adequate phosphorus levels are essential for producing high-quality, nutrient-rich kiwifruit and overall plant health.

Use DAP as a phosphorus source and apply 100 grams per plant for 6-year-old kiwi plants per year.

Potassium (K)

The highest rate of potassium application resulted in the highest level of marketable fruit yield. Apply potassium at the end of March and again three months later. It is recommended to use 200-250 grams of K2O per plant for 6-7-year-old kiwi plants to achieve high productivity.

Calcium (Ca)

Calcium is a crucial nutrient for maintaining and enhancing fruit quality in kiwifruit. To ensure an adequate supply of calcium, apply it through calcium nitrate, which is an effective source for plant uptake and improves overall fruit firmness and storage life.

Calcium is primarily transported through the xylem, but as the fruit matures, the xylem becomes less functional. Therefore, it’s best to apply calcium at the onset of fruit to ensure proper absorption of calcium by the fruit.

Apply calcium nitrate 100 g per tree for 6-year-old trees per year to increase the storage life of kiwi fruit.

How to Apply Kiwi Fertilizers?

At least a day or two before applying any food, water the area. Apply granular fertilizer in the recommended amount around the vines’ root zone. Gently scratching it in will prevent it from blowing away and improve the food’s absorption by the roots. To release the nutrients from the dry meal, add a lot of water. Blend any kind of liquid fertilizer as per the instructions on the container. To avoid scorching the foliage, the fertilizer is sprinkled only on the root zone.  Using a garden sprayer set to the recommended rate according to the instructions, combine the measured liquid.

The ideal time of day to fertilize is in the morning. Don’t forget to hydrate the plant food to prevent the burning of the roots when they start to absorb nutrients. Granular fertilizers should be equally distributed around the plant’s base, keeping the trunk out of the way.

FAQs

Q1. How to tell if Kiwi is ripe?

Here is the indicator that confirms kiwi is ripe:

• Color

Ripe kiwis typically have brown, fuzzy skin that feels slightly wrinkled.

• Apply gentle pressure

Gently squeeze the kiwi, a ripe kiwi will yield slightly to pressure but not be too soft or mushy. The skin should be slightly under your fingers.

• Smell

Smell the kiwi near the stem end; a ripe kiwi will have a sweet, fragrant aroma.

Q2. How often should I water kiwi plants?

Kiwi plants require constant irrigation in order to thrive.  Aim to keep the soil’s moisture content consistent without making it extremely damp. Young kiwi plants usually need more frequent irrigation during periods of heat or drought. As the plants get older, give them water while considering the local climate and the state of their current root systems. It’s time to water if the top inch of soil feels dry. Check the soil’s moisture content on a regular basis. Your kiwi plants need enough water to grow well and bear fruit in a healthful manner.

Q4. How to ripen kiwi?

The best way to speed up the ripening of kiwis is to store them in a paper or resealable bag alongside an apple or a ripe banana. Ethylene gas is released by bananas and apples to speed up ripening. While allowing air to pass through, the paper bag aids in trapping the gas. Plastic bags should not be used since they can retain moisture and cause fruit to get moldy. However, even with this procedure, it may require one to two days. Placing the kiwi in a bright position will allow the warmth to hasten the ripening process.