WO2020168232A1

WO2020168232A1 - Thermal plant treatment method

Info

Publication number: WO2020168232A1
Application number: PCT/US2020/018351
Authority: WO
Inventors: Martin Fischer; Timothy Raymond Allen MATSON
Original assignee: Lazo Tpc Global, Inc. Dba Argothermal Systems
Priority date: 2019-02-14
Filing date: 2020-02-14
Publication date: 2020-08-20
Also published as: MX2021009693A

Abstract

A method of thermally treating plants to eliminate fungal infections of the plant includes generating and heating an air stream and applying the heated air stream to the target plant. The air stream is heated to a desired burn out temperature to destroy the hyphae of the fungus infecting the plant. The air stream is generated, heated, and applied by a thermal plant treatment (TPT) machine that is pulled through the field and applies the heated air to the crop as the TPT machine traverses the field.

Description

THERMAL PLANT TREATMENT METHOD

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of U.S. Provisional Application No. 62/805,685 filed February 14, 2019 for“THERMAL PLANT TREATMENT METHOD” by M. Fischer and T. R. A. Matson.

BACKGROUND

This disclosure relates to thermal treatment of plants. More specifically, this disclosure relates to thermal treatment of funguses on plants, such as Powdery Mildew and Septoria.

Powdery Mildew ( Erysiphe necator) is an important disease of grapes worldwide. Pesticides are expensive and resistance is always an issue. Many materials have been banned in various countries resulting in a continual search for alternatives to fungicides for powdery mildew control. Also, there are an extremely limited number of materials that can eradicate powdery mildew. In some conditions powdery mildew can reproduce in as little as five days.

Septoria ( Septoria ) is a genus of fungi that cause leaf spot diseases on vegetable crops such as tomatoes, potatoes, eggplant, soybeans, sugar beet, lettuces, and celery, among others. Septoria and septoria-like fungi cause spotting on leaves and fruit, leading to eventual destruction of crops or rendering the crop unmarketable. Commonly called “brown spot” or“blight,” these fungi are particularly destructive on crops grown in climates that include periods of cool and damp conditions. Once infections begin, it is very difficult to control with traditional chemical treatment solutions, many of which have been banned or are being banned by various countries.

SUMMARY

According to one aspect of the disclosure, a method of thermally treating a crop infected with a fungus to eradicate the fungal infection includes applying a series of heat treatments to the crop. Each one of the series of heat treatments includes generating an air stream with a blower of a thermal assembly of a thermal plant treatment machine; heating the air stream to a bum out temperature to thereby generate a heated air stream; traversing a field with the TPT machine; and ejecting the heated air stream from the TPT machine through a nozzle of the TPT machine and directing the heated air stream onto the target crop with the nozzle. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart illustrating a thermal treatment method.

FIG. 2 is an isometric view of a thermal plant treatment machine.

FIG. 3A is a plan view block diagram of a thermal plant treatment machine.

FIG. 3B is an elevation view block diagram of a thermal plant treatment machine.

DETAIFED DESCRIPTION

FIG. 1 is a flow chart illustrating thermal treatment method 10. In step 12, a fungal infestation, such as an infestation of powdery mildew or Septoria, is identified on a crop, such as a vine crop. The vine crop can be, for example, rows of grapes in a vineyard.

In step 14, a stream of heated air is generated. For example, the stream of heated air can be generated and blown by a thermal plant treatment (TPT) machine. As discussed in more detail below, the machine can include a thermal assembly configured to generate the stream of air, heat the stream of air to generate the heated air stream, and direct the heated air stream onto the target crop. The thermal assembly can include a blower configured to draw in and pressurize air. The blower can be of any suitable configuration for generating the air stream. For example, the blower can include a centrifugal fan. The air stream generated by the blower is ejected from the thermal assembly through a nozzle. The air stream can be ejected onto the target crop along any desired axis relative to the direction of travel of the TPT machine. In some examples, at least a portion of the heated air is ejected substantially horizontally relative to the ground surface. In some examples, at least a portion of the heated air is ejected substantially vertically relative to the ground surface.

The air stream flows through a heating duct between the blower and the nozzle, where the air stream is heated to a desired bum out temperature. In some examples, the air is heated to a temperature of between about 230-degrees C and about 290-degrees C (between about 450-degrees F and about 550-degrees F). In some examples, the air is heated to a temperature of at least 260-degrees C (about 500-degrees F). In one example, the air is heated to a temperature of about 260-degrees C (about 500-degrees F). It is understood that the air temperature can be the temperature of the air within the heating duct, just prior to the air exiting the nozzle, at the exit of the nozzle, just after the air exits the nozzle, and/or when the heated air impinges on the target plant. The burn out temperature is configured to kill the hyphae of the fungus, such as powdery mildew or Septoria hyphae. The air stream can be heated in any suitable manner. In some examples, the heater is fuel-powered such that the heater receives fuel from a fuel tank, combusts the fuel, and produces a flame jet that extends into the heater duct to heat the air stream. For example, the heater can be an atmospheric burner. The air stream generated by the blower passes through the flame jet and picks up heat from the flame jet. While the air stream is described as passing through the flame jet, it is understood that the flame jet can be provided within its own enclosure to affect a heat exchange relationship between the enclosure and the air stream. In other examples, the heater is electrically- powered such that it receives energy from a power source, such as an electric generator. While the heater is described as heating the air stream at a location between the blower fan and the nozzle, it is understood that heater could alternatively be disposed upstream of the blower fan to heat the air prior to compression. In other examples, multiple heaters can be disposed at multiple locations, such as both upstream and downstream of the blower fan, to heat the air.

In step 16, the heated air is blown onto the infected crop. The TPT machine is traversed through the field at a desired speed to apply the heated air stream to the infected crop. In some examples, the TPT machine can be attached to and pulled by a tow vehicle, such as a tractor. The TPT machine traverses the field at a rate of about 1.5-8kph (about l-5mph). In some examples, the TPT machine traverses the field at a rate of 4.8kph (about 3mph). In some examples, the TPT machine is configured with multiple nozzles oriented in opposite lateral directions relative to the direction of travel. The TPT machine can thus direct heat to the crops on one side of two rows at the same time. The TPT machine can apply the heated air to both sides of the same row at different times. In some examples, the air around the crop is allowed to return to ambient temperature prior to applying the treatment on the other side of the row. In some example, the TPT machine is configured with multiple nozzles oriented vertically over multiple rows of the target crop. The nozzles can pass vertically over the multiple rows to apply the heated air simultaneously to the multiple rows. As such, the TPT machine can treat one or more than one row of crops in a single pass. In some examples, TPT machine does not need to pass adjacent a row of crops to treat that row.

In step 18, the treatment protocol described in steps 14 and 16 is repeated. The protocol is repeated to ensure burnout of the fungal hyphae infecting the target crop. The treatment protocol can be repeated according to a treatment schedule. In one example, steps 14 and 16 are repeated multiple times during a set time period. For example, steps 14 and 16 can be repeated three times within a one week period. The period between each heat treatment (with each heat treatment including steps 14 and 16) can be set or can vary. In one example, a first heat treatment can be applied on day one, a second heat treatment can be applied on day four, and a third heat treatment can be applied on day six. As such, the rest period between each heat treatment can be reduced as the number of heat treatments increases.

In one specific example, 15 rows in a Chardonnay vineyard were heavily infested with powdery mildew. This infestation was due to the fact that an application for powdery mildew had been missed which shows how critical timing is in the control of this disease. The 15 rows were divided into three replications of heat treatment and three replications of traditional chemical treatment to attempt to eradicate the present mildew infection. The chemical rows were treated with RNA Fruit Wash at 24 fl oz Mettle 125 ME at 5 fl oz in a spray volume of 117 gallons per acre on day one. The TPT machine had two blowers that directed heat to the vines on opposing sides of two rows at a time. The heat treatment was applied at 260-degrees C (500-degrees F) while the rig was traveling 4.8kph (3 mph). The thermal treatments were applied on day two, repeated on day five, and again on day seven. Evaluations of severity of mildew post treatment were conducted on days eight and nine. Ten grape clusters were tagged in each replication for evaluation after the treatments. All berries were removed from each cluster separately and counted. Diseased berries were noted, and percent severity was calculated. A t-test was applied to the data to determine if there were significant differences in control between the heat treatments and the traditional fruit wash treatment. Based on the t-test, the heat treatment (1% severity) provided significantly better control/eradication of powdery mildew than the fruit wash/Mettle treatment (9.4% severity). Powdery mildew can also be controlled throughout the season by alternating heat treatments with the use of fungicides. Post Treatment infection levels: Thermal 1.04 %; Fruit Wash + Mettle 9.35 %. At the 95% level of confidence: Confidence limits 8.304 ± 4.142.

Method 10 provides significant advantages. Heat treatments are more effective at eliminating fungal infections, such as of powdery mildew and Septoria, than chemicals alone. Heat treating fungal infections is more cost effective, as propane fuel costs can cost about 12x less per acre when compared to chemical washes. In addition, heat treatment leaves no chemical residue on the crop, as no chemicals are applied. Because no chemicals are applied, chemical run off and other environmental hazards are eliminated. FIG. 2 is an isometric view of TPT machine 20. TPT machine 20 includes frame 22; wheels 24; fuel tank 26; and thermal assemblies 28a, 28b. Each thermal assembly 28a, 28b includes blower 30, heater duct 32, heater 34, and nozzle 36. Wheels 24 are attached to frame 22. Fuel tank 26 is supported on frame 22 and provides fuel to heaters 34 for combustion. Thermal assemblies 28a, 28b are mounted on frame 22 and are configured to generate an air stream, heat the air stream to generate a heated air stream, and direct the heated air stream onto a target crop. It is understood that, in some examples, components of thermal assemblies 28a, 28b can be distributed throughout TPT machine 20 and/or combined for each thermal assembly 28a, 28b. For example, a single blower 30 can be configured to provide air for each nozzle 36, such that thermal assemblies 28a, 28b include a common blower 30. In some examples, TPT machine 20 can include a common blower 30, common heater duct 32, and common heater 34 for each of the laterally facing sets of nozzles 36.

For each thermal assembly 28a, 28b, blower 30 includes a fan configured to draw air into the blower housing, compress the air to generate the air stream, and eject the air into heater duct 32. Each thermal assembly 20 is configured to generate exit air speeds of 10km/hr-250km hr. The fan can be any suitable fan for generating the air stream, such as a centrifugal impeller.

Heater duct 32 extends between and directs the air stream from blower 30 to nozzle 36. Heater 34 is mounted to heater duct 32 and is configured to heat the air stream to generate the heated air stream. In some examples, heater 34 is fuel-powered such that heater 34 receives fuel from fuel tank 26, combusts the fuel, and produces a flame jet that extends into heater duct 32 to heat the air stream. For example, the heater can be an atmospheric burner. The air stream generated by blower 30 passes through the flame jet and picks up heat from the flame jet. While the air stream is described as passing through the flame jet, it is understood that the flame jet can be provided within its own enclosure to effect a heat exchange relationship between the enclosure and the air stream.

The heated air stream is blown out of thermal assemblies 28a, 28b through respective nozzles 36. Each nozzle 36 includes a plurality of openings configured to direct the heated air stream at differing vectors. The differing vectors ensure that the heated air stream is directed onto the target crop in an even manner, thereby ensuring that the full plant receives the desired heat treatment. For example, a subset of the openings in each nozzle 36 can direct the heated air along a vector oriented upwards through a horizontal plane, a subset of the openings can direct the heated air along a vector oriented along the horizontal plane, and a subset of the openings can direct the heated air along a vector oriented downward through the horizontal plane.

FIG. 3A is a plan schematic block diagram of TPT machine 20'. FIG. 3B is an elevation schematic block diagram of TPT machine 20'. FIGS. 3A and 3B will be discussed together. TPT machine 20' is disposed in a field to treat target crops TC that are planted in rows R1-R6. TPT machine 20' can treat each of rows R1-R6 simultaneously. TPT machine 20' is substantially similar to TPT machine 20 (FIG. 2) and is configured to perform one or more steps of method 10 (FIG. 1).

Frame 22', wheels 24', and thermal assemblies 28' of TPT machine 20' are shown. Wheels 24' support TPT machine 20' relative to the ground surface. Frame 22' supports other components of TPT machine 20'. In the example shown, frame 22' can include a generally-laterally extending boom supporting at least a portion of each thermal assembly 28'. Thermal assemblies 28' can be substantially similar to thermal assemblies 28a, 28b (FIG. 2). Thermal assemblies 28' are configured to apply heated air onto the target crops TC. Each thermal assembly 28' includes one or more nozzles for directing heated air onto the target crops TC. In some examples, each thermal assembly 28' includes a blower, heater, and nozzle, similar to blower 30 (FIG. 2), heater 34 (FIG. 2), and nozzles 36 (FIG. 2). Thermal assemblies 28' can include nozzles configured to direct the air in one or more relative directions, similar to nozzles 36'.

During operation, TPT machine 20' traverses the field generally in direction D. As shown, TPT machine 20' can provide heat treatment to multiple ones of rows R of plants simultaneously. Nozzles pass over each row R and direct the heated air HA onto the target crop TC. TPT machine 20' can apply the heated air to multiple rows of target crop TC simultaneously and does not have to pass adjacent a row to treat that row. TPT machine 20' can be self-propelled and/or be configured to be towed by an agricultural implement, such as a tractor.

While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

CLAIMS:

1. A method of thermally treating a crop infected with a fungus to eradicate the fungal infection, the method comprising:

applying a series of heat treatments to the crop, wherein each one of the series of heat treatments comprises:

generating an air stream with a blower of a thermal plant treatment machine;

heating the air stream to a burn out temperature to thereby generate a heated air stream;

traversing a field with the TPT machine; and ejecting the heated air stream from the TPT machine through a nozzle of the TPT machine and directing the heated air stream onto the target crop with the nozzle.

2. The method of claim 1, wherein the burn out temperature is at least 500- degrees F.

3. The method of claim 1, wherein the TPT machine is traversed through the field at between l-5mph, inclusive.

4. The method of claim 3, wherein the TPT machine is traversed through the field at about 3mph.

5. The method of claim 1, wherein applying the series of heat treatments is performed during a time period occurring between fruit set and harvest.

6. The method of claim 1, wherein applying the series of heat treatments further includes:

applying a first heat treatment to the target crop;

applying a second heat treatment to the target crop after a first rest period; and

applying a third heat treatment to the target crop after a second rest period.

7. The method of claim 6, wherein the first rest period is longer than the second rest period.

8. The method of claim 7, wherein the first rest period is greater than 48- hours and the second rest period is greater than 24-hours.

9. The method of claim 1, wherein the step of ejecting the heated air stream from the TPT machine through the nozzle of the TPT machine and directing the heated air stream onto the target crop with the nozzle includes: directing at least a portion of the air stream toward a ground surface as a portion of the nozzle passes over the target crop.

10. The method of claim 9, wherein the step of directing at least a portion of the air stream towards the ground surface includes directing the portion of the air stream generally vertically.

11. The method of claim 1, wherein the step of ejecting the heated air stream from the TPT machine through the nozzle of the TPT machine and directing the heated air stream onto the target crop with the nozzle includes:

directing at least a portion of the air stream generally horizontally as a portion of the nozzle passes over the target crop.