Prediction method for morbidity time of potato early blight and application of prediction method

Abstract

The invention relates to a method for predicting the morbidity time of potato early blight and application thereof, and belongs to the technical field of pest control. The invention provides a method for predicting outbreak time of potato early blight. The method comprises the following steps: (1) recording field meteorological data of potatoes, and calculating to obtain daily average temperature T and daily leaf wetting duration N; (2) determining a single-day potato early blight outbreak index Id according to the daily average temperature T and the daily leaf wetting duration N; and (3) calculating an accumulated potato early blight outbreak index Iacc according to the single-day potato early blight outbreak index Id, and when Iacc is greater than or equal to 35, determining potato field early blight outbreak. According to the method, meteorological conditions are quantified, and the attack time of potato early blight can be accurately predicted, so that the bactericide is accurately and timely applied for prevention and treatment, the formation and development of the early blight can be inhibited, the dosage and the use frequency of the bactericide can be effectively reduced, and the yield loss of potatoes is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of pest control, and in particular to a method for predicting the onset time of potato early blight and an application thereof. Background Art

[0002] Potatoes are the world's largest non-cereal crop and the fourth-largest food crop, after rice, wheat, and maize. Early blight is one of the most common foliar diseases in potato-growing areas worldwide. It is a fungal disease caused by Alternaria solani and is characterized by irregular, dark, concentric ring-shaped lesions, particularly on potato leaves, petioles, and tubers. Without effective control measures, early blight can rapidly intensify, leading to reduced potato yields. In recent years, the rapid growth of early blight has become an unavoidable problem. High temperatures and low rainfall in summer have contributed to the increase in early blight. Early blight can occur anywhere potatoes are grown, but its severity varies from year to year, depending primarily on weather conditions (primarily temperature and humidity), potato variety, and other factors. Effective crop management through the accurate and timely application of fungicides can inhibit the development and progression of early blight.

[0003] In most potato-growing regions, growers typically apply fungicides early in the early stages of early blight based on past experience, without considering climatic and environmental factors. Accurately predicting the onset and recurrence of early blight could effectively reduce the amount and frequency of fungicide applications, minimizing potato yield losses. Currently, there is a lack of effective methods for quantitatively predicting the onset of early blight based on meteorological conditions.

[0004] Based on this, the present invention is proposed. Summary of the Invention

[0005] The present invention aims to provide a method for predicting the onset time of potato early blight and its application, so as to solve the problem in the prior art that the onset time of potato early blight cannot be accurately predicted, resulting in excessive use of fungicides and reduced potato production.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for predicting the outbreak time of potato early blight, comprising the following steps:

[0008] (1) Record the temperature of the potato field and calculate the daily average temperature T; record the relative humidity of the potato field and calculate the daily wet leaf duration N;

[0009] (2) Determine the single-day potato early blight outbreak index I based on the daily average temperature T and daily wet leaf duration N obtained in step (1) d ;

[0010] (3) According to the single-day potato early blight outbreak index I d The cumulative potato early blight outbreak index I was calculated acc , when I acc When the temperature is ≥35, an outbreak of early blight in potato fields is determined;

[0011] The daily wet leaf duration N in step (1) is calculated as the sum of the durations during which the relative humidity in the potato field is greater than 90% within 24 hours.

[0012] Preferably, the daily average temperature T and the daily wet leaf duration N in step (1) are both integers.

[0013] Preferably, the single-day potato early blight outbreak index I in step (2) is d The determination method is as follows:

[0014] When 7≤T≤17, 0≤N≤6, I d =0; when 7≤T≤17, 7≤N≤15, I d =1; when 7≤T≤17, 16≤N≤20, I d =2; when 7≤T≤17, N≥21, I d =3;

[0015] When 18≤T≤20, 0≤N≤3, I d =0; when 18≤T≤20, 4≤N≤8, I d =1; when 18≤T≤20, 9≤N≤15, I d =2; when 18≤T≤20, 16≤N≤22, I d =3; when 18≤T≤20, N≥23, I d =4;

[0016] When 21≤T≤25, 0≤N≤2, I d =0; when 21≤T≤25, 3≤N≤5, I d =1; when 21≤T≤25, 6≤N≤12, I d =2; when 21≤T≤25, 13≤N≤20, I d =3; when 21≤T≤25, N≥21, I d =4;

[0017] When 26≤T≤29, 0≤N≤3, I d =0; when 26≤T≤29, 4≤N≤8, I d =1; when 26≤T≤29, 9≤N≤15, I d =2; when 26≤T≤29, 16≤N≤22, I d=3; when 26≤T≤29, N≥23, I d =4.

[0018] In the present invention, the cumulative potato early blight outbreak index I in step (3) is acc The calculation formula is as follows:

[0019]

[0020] In the formula, n represents the total number of days recorded, i represents the number of days recorded, and I di A single-day potato early blight outbreak index representing the number of recording days.

[0021] The present invention provides application of the prediction method in preventing and controlling potato early blight.

[0022] The present invention provides a method for predicting the recurrence time of potato early blight after prevention and control, comprising the following steps:

[0023] (1) When the cumulative potato early blight outbreak index I acc When the temperature is ≥35, it is determined that early blight has broken out in the potato field, and fungicides are immediately used for prevention and control. After prevention and control, the temperature of the potato field is recorded to calculate the daily average temperature T, the rainfall in the potato field is recorded to calculate the daily total rainfall P, and the relative humidity in the potato field is recorded to calculate the daily wet leaf duration N.

[0024] (2) Based on the daily average temperature T, daily rainfall P, and daily wet leaf duration N obtained in step (1), the average temperature T for 5 days is calculated using a 5-day sliding window. avg , total rainfall P t Total wet leaf time N t ;

[0025] (3) The average temperature T obtained according to step (2) avg , total rainfall P t Total wet leaf time N t Determine the potato early blight recurrence index R on a single day d ;

[0026] (4) According to the single-day potato early blight recurrence index R d The cumulative potato early blight recurrence index R was calculated acc , when R acc When the temperature is ≥9, it is determined that early blight has recurred in the potato field;

[0027] The daily wet leaf duration N in step (1) is calculated as the sum of the durations during which the relative humidity in the potato field is greater than 90% within 24 hours;

[0028] The cumulative potato early blight outbreak index I in step (1)acc is the cumulative potato early blight outbreak index I obtained according to the prediction method acc .

[0029] Preferably, the daily average temperature T, daily rainfall total P and daily wet leaf duration N in step (1) are all integers;

[0030] The average temperature T in step (3) avg , total rainfall P t Total wet leaf time N t All are integers.

[0031] Preferably, the single-day potato early blight recurrence index R in step (3) is d The determination method is as follows:

[0032] When T avg <22, N t <60, P t <25, R d =0; when T avg ≥22, N t <60, P t <25, R d =0;

[0033] When T avg <22, N t ≥60, P t <25, R d =1; when T avg <22, N t <60, P t ≥25, R d =1; when T avg <22, N t ≥60, P t ≥25, R d =1;

[0034] When T avg ≥22, N t ≥60, P t <25, R d =2; when T avg ≥22, N t <60, P t ≥25, R d =2;

[0035] When T avg ≥22, N t ≥60, P t ≥25, R d =3.

[0036] Preferably, the cumulative potato early blight recurrence index R in step (4) is acc The calculation formula is as follows:

[0037]

[0038] In the formula, n represents the total number of days recorded, i represents the number of days recorded, and R di The potato early blight recurrence index for a single day represents the number of recording days.

[0039] The present invention provides application of the prediction method in preventing and controlling potato early blight.

[0040] The present invention has the following technical effects and advantages:

[0041] The method of the present invention quantifies meteorological conditions and can accurately predict the onset time of potato early blight, thereby accurately and timely applying fungicides for efficient crop management and prevention, inhibiting the formation and development of early blight, effectively reducing the amount and frequency of fungicide use, and reducing potato yield losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A flowchart of the method for predicting the outbreak time of potato early blight;

[0043] Figure 2 This is a flow chart of the method for predicting the recurrence time of potato early blight;

[0044] Figure 3 This is a meteorological data chart for the potato plantation area from June to August. DETAILED DESCRIPTION

[0045] The present invention provides a method for predicting the outbreak time of potato early blight, comprising the following steps:

[0046] (1) Record the temperature of the potato field and calculate the daily average temperature T; record the relative humidity of the potato field and calculate the daily wet leaf duration N;

[0047] (2) Determine the single-day potato early blight outbreak index I based on the daily average temperature T and daily wet leaf duration N obtained in step (1) d ;

[0048] (3) According to the single-day potato early blight outbreak index I d The cumulative potato early blight outbreak index I was calculated acc , when I acc When the temperature is ≥35, an outbreak of early blight in potato fields is determined;

[0049] The daily wet leaf duration N in step (1) is calculated as the sum of the durations during which the relative humidity in the potato field is greater than 90% within 24 hours.

[0050] In the present invention, the daily average temperature T and the daily wet leaf duration N in step (1) are both integers.

[0051] In the present invention, the single-day potato early blight outbreak index I in step (2) is d The determination method is as follows:

[0052] When 7≤T≤17, 0≤N≤6, I d =0; when 7≤T≤17, 7≤N≤15, I d =1; when 7≤T≤17, 16≤N≤20, I d =2; when 7≤T≤17, N≥21, I d =3;

[0053] When 18≤T≤20, 0≤N≤3, I d =0; when 18≤T≤20, 4≤N≤8, I d =1; when 18≤T≤20, 9≤N≤15, I d =2; when 18≤T≤20, 16≤N≤22, I d =3; when 18≤T≤20, N≥23, I d =4;

[0054] When 21≤T≤25, 0≤N≤2, I d =0; when 21≤T≤25, 3≤N≤5, I d =1; when 21≤T≤25, 6≤N≤12, I d =2; when 21≤T≤25, 13≤N≤20, I d =3; when 21≤T≤25, N≥21, I d =4;

[0055] When 26≤T≤29, 0≤N≤3, I d =0; when 26≤T≤29, 4≤N≤8, I d =1; when 26≤T≤29, 9≤N≤15, I d =2; when 26≤T≤29, 16≤N≤22, I d =3; when 26≤T≤29, N≥23, I d =4.

[0056] In the present invention, the cumulative potato early blight outbreak index I in step (3) is acc The calculation formula is as follows:

[0057]

[0058] In the formula, n represents the total number of days recorded, i represents the number of days recorded, and I di A single-day potato early blight outbreak index representing the number of recording days.

[0059] The present invention provides application of the prediction method in preventing and controlling potato early blight.

[0060] The present invention provides a method for predicting the recurrence time of potato early blight after prevention and control, comprising the following steps:

[0061] (1) When the cumulative potato early blight outbreak index I acc When the temperature is ≥35, it is determined that early blight has broken out in the potato field, and fungicides are immediately used for prevention and control. After prevention and control, the temperature of the potato field is recorded to calculate the daily average temperature T, the rainfall in the potato field is recorded to calculate the daily total rainfall P, and the relative humidity in the potato field is recorded to calculate the daily wet leaf duration N.

[0062] (2) Based on the daily average temperature T, daily rainfall P, and daily wet leaf duration N obtained in step (1), the average temperature T for 5 days is calculated using a 5-day sliding window. avg , total rainfall P t Total wet leaf time N t ;

[0063] (3) The average temperature T obtained according to step (2) avg , total rainfall P t Total wet leaf time N t Determine the potato early blight recurrence index R on a single day d ;

[0064] (4) According to the single-day potato early blight recurrence index R d The cumulative potato early blight recurrence index R was calculated acc , when R acc When the temperature is ≥9, it is determined that early blight has recurred in the potato field;

[0065] The daily wet leaf duration N in step (1) is calculated as the sum of the durations during which the relative humidity in the potato field is greater than 90% within 24 hours;

[0066] The cumulative potato early blight outbreak index I in step (1) acc The cumulative potato early blight outbreak index I obtained by the prediction method is acc .

[0067] In the present invention, the daily average temperature T, daily rainfall total P and daily wet leaf duration N in step (1) are all integers;

[0068] The average temperature T in step (3) avg , total rainfall P t Total wet leaf time N t All are integers.

[0069] In the present invention, the single-day potato early blight recurrence index R in step (3) is d The determination method is as follows:

[0070] When T avg <22, N t <60, P t <25, R d =0; when T avg ≥22, N t <60, P t <25, R d =0;

[0071] When T avg <22, N t ≥60, P t <25, R d =1; when T avg <22, N t <60, P t ≥25, R d =1; when T avg <22, N t ≥60, P t When ≥25, R d =1;

[0072] When T avg ≥22, N t ≥60, P t <25, R d =2; when T avg ≥22, N t <60, P t ≥25, R d =2;

[0073] When T avg ≥22, N t ≥60, P t When ≥25, R d =3.

[0074] In the present invention, the cumulative potato early blight recurrence index R in step (4) is acc The calculation formula is as follows:

[0075]

[0076] In the formula, n represents the total number of days recorded, i represents the number of days recorded, and R di The potato early blight recurrence index for a single day represents the number of recording days.

[0077] The present invention provides application of the prediction method in preventing and controlling potato early blight.

[0078] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0079] Example

[0080] Experimental location: The potato planting area of ​​my country's second largest potato planting and processing enterprise in Chabei Management District, Zhangbei District, Hebei Province, with sandy loam soil.

[0081] Experimental variety: "Xueyu No. 1", susceptible to potato early blight.

[0082] A portable weather station at a height of 1m was placed in the potato plantation to continuously observe and record the temperature, rainfall, and relative humidity data for 24 hours every day from June to August, and the daily wet leaf duration was calculated. The results are as follows: Figure 3 As shown in the figure, the red line represents temperature, the blue line represents daily rainfall, the green line represents relative humidity, and the gray part represents daily wet leaf duration. The horizontal axis in the figure represents the number of recorded days, the vertical axis on the left represents temperature (℃) or rainfall (mm), and the vertical axis on the right represents relative humidity (%) or wet leaf duration (h).

[0083] 1. Prediction method for potato early blight outbreak time

[0084] The process of the potato early blight outbreak prediction method is as follows Figure 1 As shown, the details are as follows;

[0085] (1) Starting from June 1st, the daily average temperature T is calculated based on the 24-hour temperature data and the daily wet leaf duration N is calculated based on the 24-hour relative humidity data. Figure 3 As shown;

[0086] The daily wet leaf duration N was calculated as the sum of the durations during which the relative humidity in the potato field was greater than 90% within 24 hours.

[0087] (2) Determine the single-day potato early blight outbreak index I based on the daily average temperature T and the daily wet leaf duration N d ;

[0088] Single-day potato early blight outbreak index I d The determination method is as follows:

[0089] When 7≤T≤17, 0≤N≤6, I d =0; when 7≤T≤17, 7≤N≤15, I d =1; when 7≤T≤17, 16≤N≤20, I d =2; when 7≤T≤17, N≥21, I d =3;

[0090] When 18≤T≤20, 0≤N≤3, I d =0; when 18≤T≤20, 4≤N≤8, I d =1; when 18≤T≤20, 9≤N≤15, I d =2; when 18≤T≤20, 16≤N≤22, I d =3; when 18≤T≤20, N≥23, I d =4;

[0091] When 21≤T≤25, 0≤N≤2, I d =0; when 21≤T≤25, 3≤N≤5, I d =1; when 21≤T≤25, 6≤N≤12, I d =2; when 21≤T≤25, 13≤N≤20, I d =3; when 21≤T≤25, N≥21, I d =4;

[0092] When 26≤T≤29, 0≤N≤3, I d =0; when 26≤T≤29, 4≤N≤8, I d =1; when 26≤T≤29, 9≤N≤15, I d =2; when 26≤T≤29, 16≤N≤22, I d =3; when 26≤T≤29, N≥23, I d =4.

[0093] (3) According to the single-day potato early blight outbreak index I d The cumulative potato early blight outbreak index I was calculated acc , when I acc When the temperature is ≥35, an outbreak of early blight in potato fields is determined;

[0094] Cumulative potato early blight outbreak index I acc The calculation formula is as follows:

[0095]

[0096] In the formula, n represents the total number of days recorded, i represents the number of days recorded, and I diSingle-day potato early blight outbreak index representing the number of recording days;

[0097] The calculation starts from June 1 and the cumulative potato early blight outbreak index I is calculated on July 21. acc When the value is equal to 35, it reaches the threshold value, confirming the outbreak of potato early blight and requiring immediate use of fungicides for prevention and control.

[0098] 1.2 Verification Experiment

[0099] Through field observation of potato leaves, 100 potato plants were randomly selected, the total number of leaves and the number of diseased leaves on each plant were recorded, the diseased leaf rate was calculated, and the diseased leaf rate was used as an indicator to judge the incidence of potato early blight.

[0100] The calculation formula for the diseased leaf rate is as follows:

[0101] Diseased leaf rate (%) = (number of diseased leaves / total number of investigated leaves) × 100%;

[0102] The criteria for determining potato early blight are:

[0103] When the diseased leaf rate is below 5%, the potato can be considered to be in the early stage of disease or basically not diseased;

[0104] When the diseased leaf rate is 5% to 10%, the disease is mild;

[0105] When the diseased leaf rate is 10% to 20%, it is considered moderate disease;

[0106] When the diseased leaf rate exceeds 20%, it means the disease is more serious.

[0107] On July 21, the diseased leaf rate of potato plants was measured and the results showed that the diseased leaf rate was between 5% and 10%, which was a mild disease. It was confirmed that potato early blight had broken out, which was the same as the predicted result of the outbreak time of potato early blight.

[0108] 2. Prediction method for potato early blight recurrence time

[0109] The process of the potato early blight recurrence prediction method is as follows Figure 2 As shown, the details are as follows:

[0110] (1) According to “1. Prediction method of potato early blight outbreak time”, the cumulative potato early blight outbreak index I on July 21 is accIf the value is ≥35, an early blight outbreak in the potato field is confirmed, and the potato field should be immediately treated with a 20% tolfenpyrad + 12.5% ​​diphenylether conazole suspension concentrate and a 4% diphenylether conazole + 40% chlorothalonil suspension concentrate at a dose of 1 L / ha. Starting from July 21, the daily average temperature T is calculated based on the 24-hour temperature data and the daily total rainfall P is calculated based on the 24-hour rainfall data and the daily wet leaf duration N is calculated based on the 24-hour relative humidity data and the daily average temperature T is calculated based on the 24-hour rainfall data and the daily average rainfall duration N is calculated based on the daily average humidity data.

[0111] The daily wet leaf duration N was calculated as the sum of the durations during which the relative humidity in the potato field was greater than 90% within 24 hours.

[0112] (2) Based on the daily average temperature T, daily rainfall P, and daily wet leaf duration N obtained after July 21, the average temperature T for 5 days is calculated using a 5-day sliding window. avg , the total rainfall for 5 days P t and the total wet leaf duration N for 5 days t ;

[0113] (3) According to the calculated average temperature T avg , total rainfall P t Total wet leaf time N t Determine the potato early blight recurrence index R on a single day d ;

[0114] Single-day potato early blight recurrence index R d The determination method is as follows:

[0115] When T avg <22, N t <60, P t <25, R d =0; when T avg ≥22, N t <60, P t <25, R d =0;

[0116] When T avg <22, N t ≥60, P t <25, R d =1; when T avg <22, N t <60, P t ≥25, R d =1; when T avg <22, N t ≥60, P t ≥25, R d =1;

[0117] When Tavg ≥22, N t ≥60, P t <25, R d =2; when T avg ≥22, N t <60, P t When ≥25, R d =2;

[0118] When T avg ≥22, N t ≥60, P t When ≥25, R d =3.

[0119] (4) According to the single-day potato early blight recurrence index R d The cumulative potato early blight recurrence index R was calculated acc , when R acc When the temperature is ≥9, it is determined that early blight has recurred in the potato field;

[0120] Cumulative potato early blight recurrence index R acc The calculation formula is as follows:

[0121]

[0122] In the formula, n represents the total number of days recorded, i represents the number of days recorded, and R di The potato early blight recurrence index for a single day represents the number of recording days;

[0123] The cumulative potato early blight recurrence index R was calculated starting from the fifth day after control on July 21. acc , we learned that on August 17, the cumulative potato early blight recurrence index R acc When the value is equal to 9, it reaches the threshold value, which indicates the recurrence of potato early blight and requires immediate use of fungicides for prevention and control.

[0124] 2.1 Verification Experiment

[0125] The verification method is the same as that in “1.2 Verification Experiment”.

[0126] On August 17, the diseased leaf rate of potato plants was measured and the results showed that the diseased leaf rate was between 10% and 20%, which was a moderate disease. It was determined that potato early blight had recurred, which was consistent with the predicted result of potato early blight recurrence time.

[0127] As can be seen from the above embodiments, the present invention provides a method for predicting the outbreak time of potato early blight, comprising the following steps: (1) recording potato field meteorological data to calculate the daily average temperature T and the daily wet leaf duration N; (2) determining the single-day potato early blight outbreak index I according to the daily average temperature T and the daily wet leaf duration N. d; (3) According to the single-day potato early blight outbreak index I d The cumulative potato early blight outbreak index I was calculated acc , when I acc When the RH is ≥35, an outbreak of early blight in the potato field is determined. The method of the present invention quantifies meteorological conditions and can accurately predict the onset time of potato early blight, thereby accurately and timely applying fungicides for efficient crop management, inhibiting the formation and development of early blight, effectively reducing the amount and frequency of fungicide use, and reducing potato yield losses.

[0128] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for predicting the outbreak time of potato early blight, characterized in that: The steps include: (1) Record the temperature of the potato field and calculate the daily average temperature T; record the relative humidity of the potato field and calculate the daily wet leaf duration N; (2) Determine the single-day potato early blight outbreak index I based on the daily average temperature T and daily wet leaf duration N obtained in step (1) d ; (3) According to the single-day potato early blight outbreak index I d The cumulative potato early blight outbreak index I was calculated acc , when I acc When the temperature is ≥35, an outbreak of early blight in potato fields is determined; The daily wet leaf duration N in step (1) is calculated as the sum of the durations during which the relative humidity in the potato field is greater than 90% within 24 hours.

2. The prediction method according to claim 1, characterized in that The daily average temperature T and the daily wet leaf duration N in step (1) are both integers.

3. The prediction method according to claim 1, wherein: The single-day potato early blight outbreak index I in step (2) d The determination method is as follows: When 7≤T≤17, 0≤N≤6, I d =0; when 7≤T≤17, 7≤N≤15, I d =1; when 7≤T≤17, 16≤N≤20, I d =2; when 7≤T≤17, N≥21, I d =3; When 18≤T≤20, 0≤N≤3, I d =0; when 18≤T≤20, 4≤N≤8, I d =1; when 18≤T≤20, 9≤N≤15, I d =2; when 18≤T≤20, 16≤N≤22, I d =3; when 18≤T≤20, N≥23, I d =4; When 21≤T≤25, 0≤N≤2, I d =0; when 21≤T≤25, 3≤N≤5, I d =1; when 21≤T≤25, 6≤N≤12, I d =2; when 21≤T≤25, 13≤N≤20, I d =3; when 21≤T≤25, N≥21, I d =4; When 26≤T≤29, 0≤N≤3, I d =0; when 26≤T≤29, 4≤N≤8, I d =1; when 26≤T≤29, 9≤N≤15, I d =2; when 26≤T≤29, 16≤N≤22, I d =3; when 26≤T≤29, N≥23, I d =4.

4. The prediction method according to claim 1, wherein: The cumulative potato early blight outbreak index I in step (3) acc The calculation formula is as follows: In the formula, n represents the total number of days recorded, i represents the number of days recorded, and I di A single-day potato early blight outbreak index representing the number of recording days.

5. Use of the prediction method according to any one of claims 1 to 4 in preventing and controlling potato early blight.

6. A method for predicting the recurrence time of potato early blight after prevention and treatment, characterized in that: The steps include: (1) When the cumulative potato early blight outbreak index I acc When the temperature is ≥35, it is determined that early blight has broken out in the potato field, and fungicides are immediately used for prevention and control. After prevention and control, the temperature of the potato field is recorded to calculate the daily average temperature T, the rainfall in the potato field is recorded to calculate the daily total rainfall P, and the relative humidity in the potato field is recorded to calculate the daily wet leaf duration N. (2) Based on the daily average temperature T, daily rainfall P, and daily wet leaf duration N obtained in step (1), the average temperature T for 5 days is calculated using a 5-day sliding window. avg , total rainfall P t Total wet leaf time N t ; (3) The average temperature T obtained according to step (2) avg , total rainfall P t Total wet leaf time N t Determine the potato early blight recurrence index R on a single day d ; (4) According to the single-day potato early blight recurrence index R d The cumulative potato early blight recurrence index R was calculated acc , when R acc When the temperature is ≥9, it is determined that early blight has recurred in the potato field; The daily wet leaf duration N in step (1) is calculated as the sum of the durations during which the relative humidity in the potato field is greater than 90% within 24 hours; The cumulative potato early blight outbreak index I in step (1) acc The cumulative potato early blight outbreak index I obtained by the prediction method according to any one of claims 1 to 4 acc .

7. The prediction method according to claim 6, characterized in that The daily average temperature T, daily rainfall total P and daily wet leaf duration N in step (1) are all integers; The average temperature T in step (3) avg , total rainfall P t Total wet leaf time N t All are integers.

8. The prediction method according to claim 6, characterized in that The single-day potato early blight recurrence index R in step (3) d The determination method is as follows: When T avg <22, N t <60, P t <25, R d =0; when T avg ≥22, N t <60, P t <25, R d =0; When T avg <22, N t ≥60, P t <25, R d =1; when T avg <22, N t <60, P t When ≥25, R d =1; when T avg <22, N t ≥60, P t When ≥25, R d =1; When T avg ≥22, N t ≥60, P t <25, R d =2; when T avg ≥22, N t <60, P t When ≥25, R d =2; When T avg ≥22, N t ≥60, P t When ≥25, R d =3.

9. The prediction method according to claim 6, characterized in that The cumulative potato early blight recurrence index R in step (4) acc The calculation formula is as follows: In the formula, n represents the total number of days recorded, i represents the number of days recorded, and R di The potato early blight recurrence index for a single day represents the number of recording days.

10. Use of the prediction method according to any one of claims 6 to 9 in preventing and controlling potato early blight.

Images