WO1999032419A1

WO1999032419A1 - Foliar feed

Info

Publication number: WO1999032419A1
Application number: PCT/NZ1998/000185
Authority: WO
Inventors: Alexander Leendert Frank Pons
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-12-23
Filing date: 1998-12-18
Publication date: 1999-07-01
Anticipated expiration: 2000-06-23
Also published as: EP1042255A1; ZA9811754B; AU1893299A

Abstract

A foliar feed which comprises two parts. The first part is an interactive calcium and a species specific foliar spray and the second part is a pH adjuster and buffering agent, a liquid fertiliser and at least one trace element. The two parts are maintained separate and are mixed with water prior to application as a foliar feed.

Description

Title

Foliar feed

Background to the invention Broadly the invention relates to an improved foliar feed incorporating a calcium

spray for arable and horticultural crops and in particular but not necessarily for fruit

trees.

Certain basic criteria can be applied to fruit to determine the quality of the fruit, in particular the colour and background colour, and on occasions, greasiness. Fruit,

that has to reach certain standards of quality, is however generally subjected to a more

stringent form of strict quality control parameters such as calcium level, starch pattern index, pressure and the concentration of sugar in the fruit which is usually measured by the Brix scale. These criteria are constantly changing and currently fruit is harvested with a specific calcium level, starch pattern index, pressure and concentration of sugar.

To achieve these criteria in the whole of the crop, a different approach is

required to what has been done historically, when only colour, background colour and

greasiness were the determining factors.

When quality is determined only by external parameters alone and not by both internal and external parameters, nutrition is far less critical. However because eating quality, crispness and keeping quality are much more closely observed, correct nutrition

of the fruit requires detailed attention.

SUBSTITUE SHEET (Rule 26) If properly fertilised, the soil can supply most of the nutrients required to produce a satisfactory crop of apples. However due to other conditions such as soil temperatures, micro-biological activity, moisture levels in the soil, and so forth, not all

the requirements are necessarily met in full and at the right time. To produce a top

quality crop of apples, some form of supplementary nutrition is highly desirable.

Fertilised irrigation can be of great assistance in producing a satisfactory crop, but it still relies on the root system to absorb the nutrients. The most direct way in which nutrients can be delivered to a tree is by placing the nutrients in the leaves where they are being most actively used in feeding the fruit and contributing to the quality of the

fruit. Foliar feeding is therefore a very important tool in helping to generate a better

quality product.

Foliar feeds have been promoted for many years and a measure of success in using foliar feeds to improve fruit quality and increase production has been achieved.

Many trials have been carried out, and it is generally considered that foliar feeds are

beneficial in most cases because they bypass the root system. Foliar feeds are of

particular advantage during the summer when high soil temperatures and often lack of moisture place the root system under pressure.

The use of calcium sprays and even phosphate sprays as foliar feeds have been advocated by many experts, with or without the addition of trace elements to enhance

background colour of the fruit. Such products have been found to be beneficial in a

SUBSTITUE SHEET (Rule 26) large number of cases and major improvements have been achieved in fruit quality and storage life of the fruit.

Known foliar feeds however are regarded as having three disadvantages. Firstly

they are generally not species specific , secondly they are generally expensive and

thirdly they do not have an adequate calcium component in an easily absorbable form. Consequently the use and application of foliar feeds is not as extensive as desirable.

Prior art United States Patent Specification 4297130 discloses a method of foliar feeding

by applying an aqueous spray of urea and formaldehyde to the foliage of the plant

during the flowering period.

US Patent specification 4443242 discloses another form of foliar feed and is concerned with an endeavour to improve the shelf life of foliar feeds by providing an aerosol container which is charged with a water in oil emulsion of foliar feed and an

aerosol propellant so the feed can be dispensed in small quantities without wastage.

US Patent specification 4304588 also relates to a foliar feed which consists of an aqueous solution of urea and monoethylol urea. The specification teaches that the acid nature of the plant substrate counteracts the alkaline buffering capacity of the plant

food to facilitate progressive condensation of the methylol urea.

SUBSTITUE SHEET (Rule 26) While it is apparent that foliar feeds are well known, prior to the present invention there has not been a foliar feed that incorporates both foliar feed and calcium in one product providing the desired degree of enhancement of quality to the fruit crop without detrimental side effects.

Object of the invention

It is therefore an object of this invention to provide an improved foliar feed and calcium spray which can be applied to arable and horticultural crops and in particular, but not exclusively to fruit trees to enhance the quality of the crop.

Disclosure of the invention

A foliar feed comprising a first part consisting of a mixture of urea and calcium chloride in water and a second part comprising a liquid fertiliser, at least one trace element and a pH adjusting and buffering agent wherein the two parts are maintained separate until prior to application when they are diluted with water to form a foliar

spray.

Preferably the pH adjusting and buffering agent is sodium bisulphate, potassium bisulphate or ammonium bisulphate.

Preferably all trace elements are utilised in the chelated form except for boron and molybdenum.

SUBSTITUE SHEET (Rule 26) Preferably the liquid fertiliser is one or more of mono potassium phosphate, calcium chloride, potassium phosphate, urea, calcium nitrate, potassium nitrate, potassium hydroxide, phosphoric acid, nitric acid, magnesium sulphate, magnesium nitrate or magnesium chloride.

Preferably fungicides and/or pesticides can be added to the foliar feed after the two parts have been combined.

Preferably the composition of the foliar feed reflects more or less the specific optimum nutrient levels in the leaves of the species for which the product is composed.

Detailed description of the invention

It is known that a calcium supplement is highly desirable as a foliar feed and this is normally applied by using calcium chloride or calcium nitrate. However calcium chloride is phytotoxic to the foliage of most crops so that leaf bum can readily occur at the usual application rates. Calcium nitrate is not phytotoxic to the foliage but is

phytotoxic to a large number of fruit causing russeting. Consequently the application

by a foliar feed of calcium supplements particularly by means of a spray usually results

in leaf bum especially when the buds and/or fruit are very immature. The risk of leaf bum is even higher if there are repeated applications of the calcium chloride and other calcium sprays. It is also known that despite this calcium chloride is the most

acceptable form of calcium application because it is not phytotoxic to most fruits.

Some other calcium sprays may be less phytotoxic to the leaves of the trees, but they are more phytotoxic to the fruit.

SUBSTITUE SHEET (Rule 26) The foliar feeds of the present invention are not based on solid fertiliser requirements of various crops, but are based on the optimum nutrient levels in the plants themselves.

In a highly desirable form, the foliar feed of the present invention comprises three key elements, these being a. A two part interactive calcium and general species specific foliar spray for supplementation of calcium and other nutrients to arable and horticultural crops. b. A pH adjuster and buffering agent which is typically sodium bisulphate, potassium bisulphate or ammonium bisulphate. c. The application of the mixed foliar feed by foliar application with the concentration of the feed adjusted to reflect the optimum nutritional levels for the crop.

The foliar feed is manufactured as follows:

Water soluble fertilisers such as one or more of the following; mono potassium phosphate, urea, calcium nitrate, potassium nitrate, potassium hydroxide, phosphoric acid, nitric acid, potassium sulphate, magnesium sulphate, magnesium nitrate, magnesium chloride and the like are dissolved in hot water in quantities that will result in chemical ratios which reflect the optimum relative quantities required for plant tissue of the crop to which the feed is to be applied.

SUBSTITUE SHEET (Rule 26) All trace elements are used in chelated form apart from boron which is used in the form of sodium borate and/or borax and molybdenum which is used as sodium molybdate or ammonium molybdate.

The raw materials for the macro nutrients are preferably singly or in

combination, mono potassium phosphate, urea, calcium nitrate, potassium nitrate,

potassium sulphate, magnesium sulphate, magnesium nitrate, magnesium chloride, potassium hydroxide, phosphoric acid, nitric acid or any other water soluble products as the case may be.

The sodium bisulphate is added in strengths which generate the required pH as

may be required for any particular crop under consideration.

The required urea is dissolved in hot water with further hot water added to dilute to the required strength. Calcium chloride is then added to make the required strength which may vary from crop to crop.

After preparation, the two parts of the foliar feed are maintained separate until required. This prevents the insoluble or saturating components of either part from precipitating out of solution as is prone to happen when the two parts are stored pre- mixed. The two parts are usually mixed in a sprayer tank (or a holding container) which would usually be at least half filled with water to ensure adequate chemical

dilution occurs as the chemicals are added. The concentrate is then added to the spray

tank whilst agitating the liquid. The sprayer (or holding container) is then filled with

SUBSTITUE SHEET (Rule 26) water to the level required to achieve the desired chemical concentrations. As the mixture is not left to sit before use there is no or very little precipitation and the mixture is thus a clear solution.

The interaction between the foliar feed and the calcium spray reduces the phytotoxicity to the foliage of the calcium chloride while the foliar feed component

enhances the uptake of nutrients and the plant and crop health.

Other chemicals may be added to the sprayer or holding container if fungicides and/or pesticides are required.

By combining the urea with calcium chloride in one container and then adding

that to the diluted foliar feed of the water soluble fertilisers in the other container, the phytotoxicity of the calcium chloride is reduced whilst the uptake of the calcium is enhanced. Consequently it is possible to use calcium chloride at much higher concentrations than has previously been possible and the spray of the present invention is thus more effective than known foliar feeds which can only be used at considerably

lower concentrations.

In addition, the nutritional values of the foliage is improved as is the health and performance capability. The resulting improvement in the calcium levels in the crop

results in an improvement in quality, storability, appearance and palatability of the crop.

SUBSTITUE SHEET (Rule 26) This process can be applied to virtually all arable and horticultural crops, including particularly tomatoes, apples, pears with adjustments for crop or location specific concentrations.

The materials can also be used as a russet preventer as well as enhancing both

the colour and fruit quality.

Results of experimentations

The spray made in accordance with the present invention was trialed at an orchard with a long history of using all manner of foliar feeds. The first variety of apple

to be harvested was Cox's orange and analysis indicated that the level of calcium in the

fruit were higher than they had been in the past. In addition the fruit was firmer and

sweeter and the orchardist was able to harvest the fruit in one pick instead of two or three. Similar treatment with the foliar spray of the instant invention also resulted in Gala and Royal Gala apples having a better colour and the apples retained their firmness longer on the trees. The Braebum apples were superior to those previously grown and the Fuji apples did not develop the late russet which plagues this variety in

the test district. In addition the bud development was markedly better, the leave size

increased and the leaves looked shinier and greener. The better bud development resulted in a better fruit development in the following year.

There was little or no leaf bum even after eighteen applications of full strength

sprays. The only moderate leaf bum occurred in two trees that were under stress from other causes.

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SUBSTITUE SHEET (Rule 26) While the test was in progress, the test area experienced the severest drought in more than 50 years and high day temperatures were followed by high night temperatures. Even so the blossom on the treated trees was much stronger than in previous years which helped to achieve a better fruit size in all varieties and the colour

of the fruit was extremely good. While many orchards in the test district had to

abandon part of their Standard Gala and Royal Gala crops due to poor starch patterns, the orchard under test was able to hold off for an extra week for the final pick of Standard Gala apples until the colour was brighter, without loosing quality and firmness. At the end of the fourth week of harvest of the Standard Gala, the S.P.I, was

still only 3.45, while the pressure was still > 7.5. The colour was 45 %. Minimum

requirements were S.P.I. <4.5, pressure >7 and colour >20%. The lower the S.P.I, at

the end of the season the better.

In an earlier test which commenced at the end of the blossom stage, Cox's

Orange, Fuji and Pacific Rose apples, all of which are very susceptible to russet, were

sprayed at five day intervals with the equivalent of a full strength calcium chloride

spray. No leaf bum occurred and no russet was detected on the fruit in any of the six

trial blocks. Trials have also been carried out with up to double doses of the instant composition and the only trees which developed leaf bum were trees under stress from other causes such as compaction, phytophthora etc. Pear trees were also sprayed with the foliar feed and they did not show any adverse effects, even when sprayed at 25

degrees C. Pear trees are generally not sprayed with calcium compounds as their leaves

are excessively sensitive to calcium sprays.

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SUBSTITUE SHEET (Rule 26) It is known that calcium and phosphate play an important role in fruit quality. By modifying the phosphate, potassium and nitrogen rates in the foliar feed to be in line

with the phosphate, potassium and nitrogen levels in the leaves, and with help of the buffering agent, phosphate is not only taken up better but is also more effective. This applies to the leaves as well as the fruit. The calcium chloride assists the leaves in making better use of the moisture available and provides spectacular results,

particularly from orchards which do not have irrigation.

Trace elements, in particular zinc, often have difficulty at being absorbed into the trees in sufficient qualities and in a form which is useable to the leaves. For this reason the instant foliar spray has all the trace elements other than boron and molybdenum in chelate form. The trace elements utilised in the instant foliar spray are, among others, zinc which is very important to get good leaf size and healthy growth

and copper which plays an important part with the phosphate and nitrogen in better bud

development for the following year. The healthier and bigger the buds, the healthier and

the bigger the fruit will be that develops from those buds.

Molybdenum plays an important role in the manufacture of proteins for the skin

of the fruit. This helps to give the skin added elasticity which results in less risk of

splitting at the stem end and gives the colour an almost three dimensional appearance. When combined with calcium chloride, this helps the formation of a protective layer

over the apple without it becoming greasy and that will assist to reduce late russet in varieties which are sensitive to this.

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SUBSTITUE SHEET (Rule 26) Experiments have been done by combining the foliar feed of this invention with various fungicides and insecticides and to date the foliar feed has been totally compatible although it is considered it is preferable not to use the feed in combination with oils and hormone sprays.

It has also been found that the earlier the foliar spray of the present invention is applied the better and trials to date not caused any russet or leaf burn, even straight after the blossom stage. Varieties prone to calcium deficiency should be sprayed every week to ten days, starting as early as possible, and continuing till harvest. Others should at least receive ten sprays at regular intervals. If late russet is a problem the frequency of application should be increased closer to harvest to keep a regular cover on the fruit.

Having read the foregoing disclosure it will be apparent to those skilled in the art that various changes and amendments can be made to the foliar feed and yet still come within the general concept. All such changes and amendments are intended to be included in the scope of the present invention.

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SUBSTITUE SHEET (Rule 26)

Claims

1. A foliar feed comprising a first part consisting of a mixture of urea and calcium chloride in water and a second part comprising a liquid fertiliser, at least one trace element and a pH adjusting and buffering agent wherein the two parts are maintained separate until prior to application when they are diluted with water to form a foliar spray.

2. The foliar feed of claim 1, wherein the pH adjusting and buffering agent is sodium bisulphate, potassium bisulphate or ammonium bisulphate.

3. The foliar feed of claim 1 wherein all trace elements are utilised in the chelated form except for boron and molybdenum.

4. The foliar feed of claim 1 wherein the liquid fertiliser is one or more of mono potassium phosphate, urea, calcium nitrate, potassium nitrate, potassium hydroxide, phosphoric acid or nitric acid, potassium sulphate, magnesium sulphate, magnesium nitrate, magnesium chloride and calcium chloride.

5. The foliar feed of claim 1, including fungicides and/or pesticides which are added to the foliar feed after the two parts have been combined.

6. The foliar feed of claim 1 wherein the composition is adjusted to the specific optimum nutrient levels in the leaves of the species for which the product is composed.

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SUBSTITUE SHEET (Rule 26)