Nematode extermination in place using heat blankets

• US 7,469,500 B2
• Filed: 12/20/2005
• Issued: 12/30/2008
• Est. Priority Date: 01/05/2005
• Status: Expired due to Fees

• Current Assignee: Reginald B. Lovelace
• Original Assignee: Reginald B. Lovelace
• Inventors: Lovelace, Reginald B.
• Primary Examiner(s): Ark; Darren W
• Application Number:
  US11/312,325
• Publication Number:
  US 20060242900A1
• Time in Patent Office: 1,106 Days
• Field of Search: 431/24, 431/321, 47/14.2, 219/483, 219/486
• US Class Current: 43/132.1
• CPC Class Codes: A01M 17/00 Apparatus for the destruction of vermin in soil or in foodstuffs injecting fertilisers into the roots of trees A01G29/00
• CPC Class Codes: A01M 19/00 Apparatus for the destruction of noxious animals, other than insects, by hot water, steam, hot air, or electricity electric traps A01M23/38

Abstract

A system and method for nematode extermination in lawns using an array of insulated heat blankets (2) placed on the lawn, and energized in a controlled sequence to raise the soil temperature to an effective degree and depth to exterminate nematodes. An electric current controller such as a programmable logic controller (PLC) activates a first subset of the blankets (2) until they reach an upper setpoint temperature, then maintains the blanket temperature within a desired range with reduced current while activating additional blankets. The heat penetrates the soil over a period of about 20 to 50 hours to raise the temperature to at least about 52° C. (125° F.) at a sufficient depth such as at least 12 cm (4.7 inches) to kill at least most nematodes.

Claims

1. A method for nematode extermination in soil, comprising:

providing a plurality of electric heat blankets, each blanket comprising an upper surface, a lower surface, and a thermal insulating layer on the upper surface of the respective heat blanket;

providing an electric power circuit connected to each blanket for energizing the respective blanket;

providing a temperature sensor in, on, or below each blanket that measures the temperature of the respective blanket;

providing an electric current control device that receives the temperature of each blanket from the respective sensor and controls the power circuits to reach a desired temperature range in a first subset of the blankets up to a total available current load, then reduces the current provided to the first subset of the blankets to maintain the desired temperature range in the first subset of blankets while similarly controlling additional of the plurality of blankets until each of the plurality of blankets has been maintained within a desired temperature range for a desired period of time;

placing the heat blankets on a surface area of soil; and

energizing each heat blanket to achieve a first temperature range of approximately 150°

C. (300°

F.) to 200°

C. (392°

F.) for a first period of time of approximately 20 to 50 hours in each heat blanket in order to obtain a second temperature of at least 52°

C. (125°

F.) at a given soil depth of at least 12 cm (4.7 inches) for a second period of time that is effective for killing at least most nematodes in the soil under each heat blanket.

2. A method for nematode extermination in soil, comprising:

providing a plurality of electric heat blankets, each blanket comprising an upper surface, a lower surface, and a thermal insulating layer on the upper surface of the respective heat blanket;

providing an electric power circuit connected to each blanket for energizing the respective blanket;

providing a temperature sensor in, on, or below each blanket that measures the temperature of the respective blanket;

providing an electric current control device that receives the temperature of each blanket from the respective sensor and controls the power circuits to reach a desired temperature range in a first subset of the blankets up to a total available current load, then reduces the current provided to the first subset of the blankets to maintain the desired temperature range in the first subset of blankets while similarly controlling a second subset of the plurality of blankets until each of the plurality of blankets has been maintained within a desired temperature range for a desired period of time;

placing the heat blankets on a surface area of soil;

energizing each heat blanket to achieve a first temperature range of approximately 150°

C. (300°

F.) to 200°

C. (392°

F.) for a first period of time of approximately 20 to 50 hours in each heat blanket in order to obtain a second temperature of at least 52°

C. (125°

F.) at a given soil depth of at least 12 cm (4.7 inches) for a second period of time that is effective for killing at least most nematodes in the soil under each heat blanket;

defining the first subset of heat blankets comprising at least one blanket, the first subset of heat blankets comprising a total power load up to, but not exceeding, the total available current load;

energizing the first subset of heat blankets to reach the first temperature range in the first subset of heat blankets;

maintaining the first temperature range in the first subset of heat blankets with reduced current;

energizing the second subset of heat blankets within the total available current load while the maintaining step is in progress; and

further maintaining each blanket of the first and second subsets within the first temperature range until each blanket of the first and second subsets has been maintained in the first temperature range for the first period of time.