Method of foliar feeding of fruit trees

Abstract

FIELD: horticulture.SUBSTANCE: method of foliar feeding of fruit trees includes spraying the fruit trees on the leaves with a working solution comprising calcium compounds selected from chloride, nitrate or calcium chelate with disodium salt of ethylenediaminetetraacetic acid, wherein, 25-40 days before the date of harvesting the fruit, spraying with a working solution comprising calcium compounds is alternated with spraying the fruit trees on the leaves with a working solution comprising potassium compounds selected from chloride, nitrate, sulphate, phosphate, hydrogen phosphate, potassium pyrophosphate. Each complete spraying cycle includes first treating fruit trees with a working solution comprising potassium compounds, followed 1-3 days later by spraying them with a working solution comprising calcium compounds, with the total number of such cycles per season being 3-6.EFFECT: increase in the calcium content of fruits when trees are grown on soils unfavourable for industrial horticulture and reduced development of subcutaneous spot disease on fruits.1 cl, 1 tbl, 4 ex

Description

[0001] The invention relates to agriculture, in particular to technologies for foliar feeding of fruit trees and shrubs using garden sprayers with potassium and calcium preparations, and can be used in modern industrial gardening.

[0002] The role of calcium in planning the nutrition of fruit trees is well known. Calcium is one of the most essential elements in plant nutrition, although in relative abundance it is significantly inferior to nitrogen, phosphorus, and potassium. It is absorbed not only by the roots but also by the leaves of plants. Calcium is involved in the construction and normal functioning of cell membranes, regulates their permeability, and is a component of the middle lamella of the cell wall.

[0003] Saturating fruits with calcium promotes full ripening of fruits with juicy, crispy pulp, uniform color, taste and aroma characteristic of a particular variety, forms strong and elastic integumentary tissues of the fruit, resistant to rot and mechanical stress, and significantly improves the shelf life of the fruit.

[0004] Calcium deficiency manifests itself as reduced growth and necrosis of shoot and root tips, i.e., in young plant parts characterized by high meristem activity. The effects of calcium deficiency on apple fruit have been studied most thoroughly. Low calcium concentrations in apples cause the development of many fruit diseases, including subcutaneous spot, vitreousness, decay, and increased damage by fungal rot. Of these diseases, subcutaneous spot is the most widespread and causes the greatest damage.

[0005] Subcutaneous spot on apples is classified as a "physiological disorder," meaning a fruit disease not caused by microbial, fungal, or other pests. Physiological disorders of fruit arise primarily due to the genetic characteristics of a particular variety and typically manifest during prolonged storage or immediately before harvesting in the orchard. They can also occur due to inadequate mineral nutrition, recurrent frosts, improper pruning in the orchard, failure to adhere to optimal harvesting times, improper storage conditions and methods, and other causes. Therefore, techniques and methods that prevent the development of such disorders are crucial.

[0006] Calcium deficiency causes similar damage to other fruits, such as cherries, apricots, peaches, plums, pears, and others. Most often, damage manifests itself in a significantly reduced shelf life, cracking, and increased damage from numerous fungal and viral pests.

[0007] Typically, all types of soil have sufficient calcium to support plant nutrition, but in some cases (on chalky soils), it can even be excessive, causing yellowing of tree leaves (chlorosis). However, even high calcium levels in the soil don't guarantee sufficient calcium in the fruit, so foliar feeding is necessary. Calcium is a difficult-to-transport nutrient, and when supplied solely from the soil, virtually no calcium reaches the fruit, being absorbed by growing leaves and branches. To increase calcium uptake during calcium feeding, so-called "spreaders" are added to a tank mix containing calcium compounds. These agents increase the spread of calcium preparations across the leaves and reduce their drift during treatments. Furthermore, very expensive chelated forms of calcium compounds are used for foliar application.

[0008] Currently known technology indicates that foliar feeding is the most effective method for increasing calcium content in fruits [1, 2, 3, 4]. Calcium fertilizers are applied immediately after fruit set in the garden, that is, in April-May, as it is known that the majority of calcium is absorbed by the fruit during ovary formation. Beginning with the "Walnut" fruit development phase, all subsequent foliar calcium applications are continued until harvest, at intervals of 7-14 days (see also [5, 6]).

[0009] The disadvantage of known methods of foliar feeding with calcium is their low efficiency (or lack thereof) when using various chemical preparations (fertilizers) due to the peculiarities of calcium absorption by vegetative and generative organs of fruit plantations, additional material costs due to the use of expensive chelated calcium fertilizers, which increase the cost of production [7, 8].

[0010] Let's list some factors that interfere with calcium absorption by fruits. These factors include:

[0011] - The presence in the soil of a large number of competing cations - potassium, sodium, magnesium, aluminum;

[0012] - The soil is too acidic;

[0013] - Ammonium salts have accumulated in the soil (when using ammonium nitrate);

[0014] - Lack of boron in the soil and during foliar feeding.

[0015] For example, an excess of potassium in the soil is a fairly common problem in modern horticulture, making it almost inevitable that apples will develop subcutaneous spot during storage. Carbonate soils, which are abundant throughout the Russian Federation and where orchards are still grown, also impede calcium absorption, as the carbonates are insoluble and cannot be absorbed by the trees. Varieties that require high levels of calcium, such as 'Hanni Crisp,' 'Golden Delicious,' 'Jonagold,' 'Ligol,' 'Pinova,' and 'Champion,' are susceptible to this condition throughout the country, despite the most meticulous care.

[0016] The technical result of the invention is an increase in the calcium content in fruits with foliar feeding, regardless of the soil type.

[0017] The problem is solved by the claimed method of foliar feeding of fruit trees, including spraying fruit trees on the leaves with a working solution containing calcium compounds selected from chloride, nitrate or chelate of calcium with disodium salt of ethylenediaminetetraacetic acid, wherein, 25-40 days before the date of harvesting the fruit, spraying with a working solution containing calcium compounds begins to alternate with spraying fruit trees on the leaves with a working solution containing potassium compounds selected from chloride, nitrate, sulfate, phosphate, hydrogen phosphate, potassium pyrophosphate, wherein each complete spraying cycle includes first treating the fruit trees with a working solution containing potassium compounds, which is followed after 1-3 days by spraying them with a working solution containing calcium compounds, and the total number of such cycles per season is 3-6.

[0018] The achieved technical result of increasing calcium absorption by fruits could not have been predicted based on the current state of the art, since calcium and potassium are competing ions in mineral nutrition, and the most expected result would have been the opposite of what was achieved. The applicants have not identified sources containing information on technical solutions identical to the present invention, with information on the influence of all the distinctive features of the invention on the achieved technical result, which allows us to conclude that it meets the criterion of "Novelty." The timing of the application of potassium-calcium nutrition cycles, the number of cycles, and the time interval between sprayings with potassium and calcium compounds were determined experimentally and are unknown from the technical literature. Based on the above, we believe that the claimed technical solution meets the criterion of "Inventive Step."

[0019] The simplicity and availability of the initial components and methods for their application, together with the obtained result, meets the criterion of “Industrial applicability”.

[0020] Fruit harvesting times are planned in advance and are usually determined by the fruit type, varietal characteristics, climatic conditions, and weather conditions in a given season, based on the desired harvest maturity of the fruit. The term "harvest maturity" in this technical solution implies that each pomological fruit variety has its own individual hardness limits in kg / cm. 2 , the content of dry soluble substances in mass % and the starch index in points, called the "Starch Iodine Test." Information on the optimal parameters for apple fruit maturity is presented on many resources, for example, on the resource [9].

[0021] Example 1.

[0022] The proposed method was implemented during the 2021-2022 season at a farm in the Republic of Crimea on soil oversaturated with potassium compounds, which is known to prevent the fruit from fully absorbing calcium compounds—the key element protecting fruit from the development of subcutaneous spot. A 7-year-old plot of an intensive apple orchard with drip irrigation was selected for the study. The pomological variety "Golden Delicious" was grown there, a variety highly susceptible to subcutaneous spot. Two plots of 0.5 hectares each were studied, the second serving as a control.

[0023] Fruit trees began blooming on April 15th, and petals began to fall on April 22nd. In plots one and two, calcium-based fertilizers (calcium chloride) were applied at a concentration of 1.5% by weight, at a rate of 850 liters of working solution per hectare, using foliar application, beginning on April 24th (the end of flowering). In plot one, potassium fertilizers were applied as a foliar fertilizer two days before each application of calcium.

[0024] In both areas, during foliar feeding with calcium preparations, boron compounds and the Izagri Stick spreader were used in a tank mixture throughout the season at a rate of 250 grams per 1000 liters of working solution.

[0025] In addition to the above treatments, we carried out regular fertilizing with phosphorus, nitrogen and magnesium fertilizers on both plots, protective measures against fungal, bacterial and other infections, against harmful insects, as well as fertilizing with microelements and watering in accordance with the agrotechnical support plan for the garden and weather conditions.

[0026] As a result, 10 additional fertilizations of plantings with calcium compounds were carried out on two plots each.

[0027] According to the tables on the optimal degree of maturity for the Golden Delicious variety [9], for this variety the firmness should be within the range of 7.0 - 7.5 kg / cm, the starch content 5-6 points on a 10-point scale and the content of dry soluble substances 14.0 - 14.5 wt.%. The fruits in two plots should have reached these values ​​by September 20.

[0028] Thirty days before harvest, on August 20, the first plot was treated with potassium dihydrogen phosphate two days before each calcium treatment at a rate of approximately 4.0 kg per hectare. The rate of the working solution during the potassium treatment was 800 liters per hectare. A total of four cycles of these double treatments were carried out. In the control plot, calcium spraying continued as before.

[0029] One and a half weeks before harvesting, the plantings were treated with the fungicide "Geoks", after which the apples began to be harvested on September 21 and placed in the refrigerator for long-term storage, and their mineral composition was also determined.

[0030] In the first section, the mineral composition of the fruits was, in mg per 100 grams of fresh fruits:

[0031] Nitrogen - 51;

[0032] Boron - 0.21;

[0033] Potassium - 133;

[0034] Calcium - 7.7;

[0035] Magnesium - 6.6;

[0036] Phosphorus - 14.4;

[0037] In the second (control) section, the mineral composition of the fruits was, in mg per 100 grams of fresh fruits:

[0038] Nitrogen - 56;

[0039] Boron - 0.22;

[0040] Potassium - 115;

[0041] Calcium - 3.9;

[0042] Magnesium - 8.6;

[0043] Phosphorus - 12.5.

[0044] After fruit collection, the percentage of fruits with initial signs of subcutaneous spot was randomly determined. In the first plot, this percentage was 0.12, while in the second (control) plot, it was 8.54.

[0045] Thus, compliance with the stated conditions allows you to significantly saturate the fruits with calcium and reduce the percentage of damage to apples grown even in soil oversaturated with potassium.

[0046] Example 2.

[0047] The proposed method was implemented during the 2022-2023 season at a farm in the Saratov region on soil oversaturated with calcium carbonate compounds, which is known to impede the fruit's full absorption of calcium compounds. A 5-year-old plot of an intensive apple orchard with drip irrigation was selected for the study. The pomological variety "Hanny Crisp" was grown there, a variety highly susceptible to subcutaneous spot. Two plots of 1.0 hectares each were studied, the second serving as a control.

[0048] Fruit trees began to bloom on April 27, petals began to fall on May 9, and in the first and second sections, they began to feed with calcium preparations (calcium nitrate) at a concentration of 2.0 mass.% in the amount of 750 liters of working solution per 1 hectare on the leaf, starting from May 12 (the end of flowering).

[0049] For foliar feeding with calcium preparations, boron compounds and Silvet Gold spreader were used in a tank mixture throughout the season at a rate of 280 grams per 1000 liters of working solution.

[0050] Feeding the plants with nitrogen compounds began in early spring by applying nitrogen fertilizers under the roots, then continued feeding through fertigation by drip irrigation.

[0051] In addition to the above treatments, we carried out regular fertilizing with phosphorus and magnesium fertilizers in both areas, protective measures against fungal, bacterial, and other infections, against harmful insects, as well as fertilizing with microelements and watering in accordance with the agrotechnical support plan for the garden and weather conditions.

[0052] As a result, a total of 8 fertilizations of the plantings with calcium compounds were carried out on each of the two sites.

[0053] According to the tables on the optimal degree of maturity for the variety "Hanny Crisp" [9], the firmness of this variety should be within the range of 9.5 - 10.0 kg / cm, the starch content of 6-8 points on a 10-point scale and the content of dry soluble substances of 14.0 - 14.6 wt.%. The fruits in two plots should have reached these values ​​​​by September 10. 25 days before this, three days before each calcium treatment, the plantings were treated with potassium sulfate at a rate of about 5.0 kg per 1 ha. The consumption of the working solution during potassium treatment was 1000 liters per 1 ha. A total of 3 cycles of such double treatments were carried out. In the control plot, calcium spraying was continued as before.

[0054] Ten days before harvesting, the plantings were treated with the fungicide "Geoks", after which the apples began to be harvested on September 11 and were placed in the refrigerator for long-term storage, and their mineral composition was also determined.

[0055] In the first section, the mineral composition of the fruits was, in mg per 100 grams of fresh fruits:

[0056] Nitrogen - 56;

[0057] Boron - 0.24;

[0058] Potassium - 135;

[0059] Calcium - 8.0;

[0060] Magnesium - 7.2;

[0061] Phosphorus - 10.1;

[0062] In the second (control) section, the mineral composition of the fruits was, in mg per 100 grams of fresh fruits:

[0063] Nitrogen - 57;

[0064] Boron - 0.27;

[0065] Potassium - 112;

[0066] Calcium - 3.8;

[0067] Magnesium - 5.6;

[0068] Phosphorus - 11.1.

[0069] After fruit collection, the percentage of fruits with initial signs of subcutaneous spot was randomly determined. In the first plot, this percentage was 1.1, while in the second (control) plot, it was 10.2.

[0070] Thus, compliance with the stated conditions allows you to significantly saturate the fruits with calcium and reduce the percentage of damage to apples grown even on highly carbonate soil.

[0071] Example 3.

[0072] The proposed method was implemented during the 2021-2022 season at a farm in the Krasnodar Territory on soil oversaturated with calcium carbonate compounds, which were unavailable for tree roots to absorb. A 12-year-old plot of a conventional apple orchard with drip irrigation was selected for the study. The pomological variety "Jonagold" was grown there, a variety highly susceptible to subcutaneous spot. Two plots of 0.8 hectares each were studied, the latter plot serving as a control.

[0073] Fruit trees began to bloom on April 18, petals began to fall on April 25, and in the first and second sections, they began to fertilize with calcium preparations (calcium chloride) at a concentration of 2.0 mass.% in the amount of 1000 liters of working solution per 1 hectare on the leaf, starting from April 27 (the end of flowering).

[0074] In both areas, during foliar feeding with calcium preparations, boron compounds and the Silvet 408 spreader were used in a tank mixture throughout the season in the amount of 320 grams per 1000 liters of working solution.

[0075] Feeding the plantings with nitrogen compounds began in the early spring period by applying nitrogen fertilizers under the roots, then they continued feeding through fertigation by drip irrigation, but in the first two areas, feeding continued for 85 days from the end of flowering until July 19.

[0076] In addition to the above treatments, we carried out regular fertilizing with phosphorus and magnesium fertilizers in all three areas, protective measures against fungal, bacterial, and other infections, against harmful insects, as well as fertilizing with microelements and watering in accordance with the agrotechnical support plan for the garden and weather conditions.

[0077] As a result, a total of 12 fertilizations of plantings with calcium compounds were carried out in two areas.

[0078] According to the tables on the optimal degree of maturity for the ‘Goden Rush’ variety [9], the firmness of this variety should be within the range of 7.5-8.0 kg / cm, the starch content 4-5 points on a 10-point scale and the content of dry soluble substances 13.7 - 14.5 wt.%. The fruits in all three plots should have reached these values ​​by September 16-17. At the same time, in the first plot, 40 days before this date, foliar feeding with calcium began to alternate with foliar feeding with potassium. In this plot, one day before each calcium treatment, the plantings were treated with potassium nitrate at a rate of about 3.5 kg per 1 ha. The consumption of the working solution during potassium treatment was 650 liters per 1 ha. A total of 6 cycles of such double treatments were carried out. In the control plot, calcium spraying continued as before.

[0079] On September 18, they began to collect apples and put them in the refrigerator for long-term storage, and their mineral composition was also determined.

[0080] In the first section, the mineral composition of the fruits was, in mg per 100 grams of fresh fruits:

[0081] Nitrogen - 57;

[0082] Boron - 0.41;

[0083] Potassium - 129;

[0084] Calcium - 8.1;

[0085] Magnesium - 10.0;

[0086] Phosphorus - 13.4;

[0087] In the second (control) section, the mineral composition of the fruits was, in mg per 100 grams of fresh fruits:

[0088] Nitrogen - 69;

[0089] Boron - 0.13;

[0090] Potassium - 112;

[0091] Calcium - 3.9;

[0092] Magnesium - 6.8;

[0093] Phosphorus - 12.5.

[0094] After fruit collection, the percentage of fruits with initial signs of subcutaneous spot was randomly determined. In the first plot, this percentage was 0.6, while in the second (control) plot, it was 6.2.

[0095] Thus, compliance with the stated conditions allows you to significantly saturate the fruits with calcium and reduce the percentage of damage to apples grown even on highly carbonate soil.

[0096] Example 4.

[0097] The proposed method was implemented during the 2022-2023 season at a farm in the Krasnodar Territory on soil oversaturated with calcium carbonate compounds, which were inaccessible to tree roots. A 7-year-old plot of a conventional apple orchard with drip irrigation was selected for the study. The pomological variety "Champion" was grown there. This pomological variety is highly susceptible to subcutaneous spot. A total of two plots of 1.0 hectares were selected, the latter serving as a control. Flowering of the fruit trees began on April 16, petals began to fall on April 23, and calcium preparations (calcium nitrate) at a concentration of 2.0 wt.% in the amount of 1000 liters of working solution per 1 hectare on the leaves, starting on April 27 (the end of flowering).

[0098] In both areas, during foliar feeding with calcium preparations, boron compounds and the Gladius spreader were used in a tank mixture throughout the season at a rate of 300 grams per 1000 liters of working solution.

[0099] Feeding of plantings in both areas with nitrogen compounds began in the early spring by applying nitrogen fertilizers under the roots, then feeding continued through fertigation by drip irrigation until July 24.

[0100] In addition to the above treatments, we carried out regular fertilizing with phosphorus and magnesium fertilizers in all six areas, protective measures against fungal, bacterial, and other infections, against harmful insects, as well as fertilizing with microelements and watering in accordance with the agrotechnical support plan for the garden and weather conditions.

[0101] As a result, a total of 14 foliar feedings of plantings with calcium compounds were carried out in both areas.

[0102] According to the tables on the optimal degree of maturity for the Champion variety [9], the firmness of this variety should be within 6.5-7.0 kg / cm, the starch content 5-6 points on a 10-point scale and the content of dry soluble substances 12.5-13.0 wt.%. The fruits in all three plots should have reached these values ​​by September 29-30. 30 days before the planned harvest date, in the first plot, 40 days before this date, foliar feeding with calcium was alternated with foliar feeding with potassium. In this plot, before each calcium treatment, two days before it, the plantings were treated with potassium pyrophosphate at a rate of about 1.5 kg per 1 ha. The consumption of the working solution during potassium treatment was 600 liters per 1 ha. A total of 5 cycles of such double treatments were carried out. In the control plot, calcium spraying continued as before.

[0103] On October 1st, we began to collect apples and put them in the refrigerator for long-term storage, and their mineral composition was also determined.

[0104] In the first section, the mineral composition of the fruits was, in mg per 100 grams of fresh fruits:

[0105] Nitrogen - 42;

[0106] Boron - 0.34;

[0107] Potassium - 127;

[0108] Calcium - 7.5;

[0109] Magnesium - 8.6;

[0110] Phosphorus - 9.9.

[0111] In the second (control) section, the mineral composition of the fruits was, in mg per 100 grams of fresh fruits:

[0112] Nitrogen - 47;

[0113] Boron - 0.35;

[0114] Potassium - 106;

[0115] Calcium - 4.1;

[0116] Magnesium - 6.6;

[0117] Phosphorus - 9.9.

[0118] After fruit collection, the percentage of fruits with initial signs of subcutaneous spot was randomly determined. In the first plot, this percentage was 0.6; in the second (control) plot, it was 4.9.

[0119] This example also demonstrates not only the effectiveness of the claimed method in increasing the calcium saturation of fruits on carbonate soils and reducing the number of apple fruits affected by subcutaneous spot, which are genetically prone to such damage.

[0120] Examples of foliar feeding using the stated method for other fruit trees are presented in Table 1. Comparative fruit samples were fed only with calcium compounds.

[0121]

[0122] The presented Examples 1-8 show that the claimed method of foliar feeding of fruit plantations increases the calcium content in fruits when cultivating various types of trees of various pomological varieties, even on soils that are unfavorable in terms of calcium nutrition, and minimizes the development of the disease subcutaneous spot on apple fruits.

[0123] The proposed method is industrially applicable and allows to increase the efficiency of fruit cultivation and reduce their losses from physiological damage.

[0124] Sources of information taken into account:

[0125] 1. de Freitas ST, Mitcham EI 3. Factors Involved in Fruit Calcium Deficiency Disorders / / Horticultural reviews. - 2012. - T. 40. - P. 107-146.

[0126] 2. de Freitas ST, do Amarante CVT., Mitcham EJ Mechanisms regulating apple cultivar susceptibility to bitter pit / / Scientia Horticulturae. - 2015. - T. 186. -C. 54-60.

[0127] 3. Jemeric T. et al. Bitter pit in apples: pre-and postharvest factors: A review / / Spanish Journal of Agricultural Research. - 2016. - T. 14. - No. 4. - C. 08-01.

[0128] 4. Gudkovsky V.A. System for reducing losses and maintaining the quality of fruits and grapes during storage - Michurinsk, 1990. - 119 p.

[0129] 5. Ryabtseva T.V., Kalinnikova N.G., Fruit growing. - T. 19. - 2007.- p. 74-78.

[0130] 6. Blankenship SM, Dole JM 1-Methylcyclopropene: a review / / Postharvest biology and technology. - 2003. - T. 28. - No. 1. - pp. 1-2 5.

[0131] 7. Internet resource at the link: https: / / pr-agro.ru / catalog / helatem-edta-ca-10 /

[0132] 8. Internet resource at the link:

[0133] https: / / plantators.com / shop / dobavki / kalcziya-xelat-edta-10-100gr /

[0134] 9. Internet resource at the link:

[0135] https: / / freshforma.ru / technology / semnaya-stepen-zrelosti.html

Images