CLIMATE IMPACT

ASSESSMENT for

Philippine Agriculture

(Rice and Corn)

MAY 2014 Number 05 / Volume 30

APRIL 2020

Number 04 / Volume 35

Impact Assessment and Applications Section (IAAS)

Climatology and Agrometeorology Division (CAD)

Philippine Atmospheric, Geophysical and Astronomical Services

Administration (PAGASA)

Department of Science and Technology

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P r e f a c e

The Impact Assessment and Applications Section

(IAAS) of Climatology and Agrometeorology Division (CAD) regularly issue this monthly/bulletin which will provide users such as food security managers, economic policy makers, agricultural statisticians and agricultural extension officials with qualitative information on the current and potential effects of climate and weather variability on rainfed crops, particularly rice and corn. This bulletin, entitled “Climate Impact Assessment for Agriculture in the Philippines”, represents a method for converting meteorological data into economic information that can be used as supplement to information from other available sources.

For example, an agricultural statistician or

economist involved in crop production and yield forecast problems can combine the assessment with analysis from area survey results, reports on the occurrence of pests and diseases, farmers’ reports and other data sources.

The impact assessments are based on agroclimatic

indices derived from historical rainfall data recorded for the period 1951 to the present. The indices, expressed in raw values percent of normals and percentile ranks, together with real time meteorological data (monthly rainfall, in percent of normal), percent of normal cumulative rainfall, as well as the occurrence of significant event such as typhoons, floods and droughts are the tools used in the assessment of crop performance. Crop reports from PAGASA field stations are also helpful.

The narrative impact assessment included in the

bulletin depicts the regional performance of upland, 1st lowland and 2nd lowland palay; and dry and wet season corn crops, depending on the period or the season. Tabulated values of normal rainfall and generalized monsoon and yield moisture indices are provided for ready reference. Spatial analysis of rainfall, percent of normal rainfall and the generalized monsoon indices in percentile ranks are also presented on maps to help users visualize any unusual weather occurring during the period. The generalized monsoon indices in particular, are drought indicators; hence, the tables (see Appendices) together with the threshold values can be used in assessing drought impact, if there are any. It also helps assess any probable crop failure.

It is hoped therefore that this bulletin would help provide the decision-makers, planners and economist with timely and reliable early warning/information on climatic impact including the potential for subsistence food shortfalls, thereby enabling them to plan alternate cropping, if possible, food assistance strategies/mitigation measures to reduce the adverse impact of climate and eventually improve disaster preparedness.

Impact assessment for other principal crops such as

sugarcane and coconut, for energy and for water resources management, are from time to time will be included in the forthcoming issues of this bulletin.

The IAAS of CAD will appreciate suggestions/comments from end-users and interested parties for the improvement of this bulletin.

Definition of Terms The Generalized Monsoon Index (GMI) helps determine

the performance of the rains during the season and serves as a good indicator of potential irrigation supplies. It is a tool used to assess rainfed crops.

The GMI for the southwest monsoon (GMIsw) in an area during June to September is defined as follows:

GMIsw = W6P6 + W7P7 + W8P8 + W9P9

The GMI for the northeast monsoon (GMIne) in an area

during October to January is defined as:

GMIne = W10P10 + W11P11 + W12P12 + W1P1

where: W = weight coefficient of monthly rainfall for the season; P = rainfall amount in the ith month

(i = 1 for January, 2 = for February, etc.)

The Yield Moisture Index (YMI) is a simple index that helps the users assess agroclimatic crop conditions during the crop season. The YMI for a particular crop is defined as follows:

n

YMI = [Pi Ki]

i where:

i = crop stage (1 = planting/transplanting, 2 = vegetative, 3 = flowering, 4 = maturity,

etc.) n = total no. of crop stages; P = rainfall during the ith crop stage; and K = appropriate crop coefficient for the ith crop stage.

Tentatively, the threshold values of categories of indices for interpretation being adopted for both YMI and GMI are as follows:

Percentile Rank Interpretation

> 80 Potential for flood damage

41 - 80 Near normal to above- normal crop condition

21 - 40 Moderate drought impact with reduced yield

11 - 20 Drought impact with major yield losses

< 10 Severe drought impact with crop failure and potential food shortages

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AGROCLIMATIC / CROP ASSESSMENT FOR FEBRUARY 2020

OVERVIEW

Harvesting of early-planted wet season corn has now started in some areas of the country.

Normal to above normal yield is expected in Surigao del Sur. While below normal yield is

anticipated in Casiguran, Tayabas, Infanta, Alabat, Daet, Catarman, Tacloban, and

Surigao del Norte. Sufficient moisture available during the month favors land preparation

and planting of dry season corn in Camarines Norte, Surigao del Norte and Surigao del

Sur. Due to inadequate rainfall in Infanta, Legaspi, Catanduanes and Catarman, planting

of dry season corn may be hampered. The standing, early-planted wet-season corn are

in good condition in Surigao del Sur. However, the same crops are suffering from moisture

stress in Casiguran, Tayabas, Infanta, Alabat, Daet, Catarman, Tacloban, and Surigao

del Norte.

REGION I (Ilocos Region) Due to the insufficiency of moisture, any farming activity related to planting rice and corn may not be done in any part of the region during the month. CAR (Cordillera Autonomous Region) As of this month, moisture deficiency is still prevalent across the region, that is why, any farming activity related to planting rice and corn are hindered. REGION II (Cagayan Valley) Dry and sunny weather is experienced all over the region. This is favorable for sun-drying and other rice stocking activities of post-harvested late planted lowland 2nd palay. REGION III (Central Luzon) Harvesting of early-planted, wet- season corn had just begun in Aurora province. Yield is expected to be below normal in Casiguran due to the moisture stress experienced by crops during the critical stage of growth. REGION IV-A (CALABARZON) Harvesting of early-planted, wet-season corn had just started over Quezon Province; yield is expected to be below normal since the crops suffered from moisture deficiency during the vegetative stage. The inadequacy of rainfall in Infanta hinders the land preparation and planting of dry season corn during the month.

REGION IV-B (MIMAROPA)

The dry and sunny weather during the month favors sun-drying and other stocking activities of post-harvested late-planted lowland 2nd palay across the region. REGION V (Bicol Region)

Harvesting of early-planted, wet season corn had just begun in Camarines Norte; below normal yield is anticipated due to the insufficiency of moisture during the vegetating stage. For the same reason, planting of corn in Legaspi and Catanduanes may be hampered. Meanwhile, adequate rainfall received in Daet favors land preparation and planting of dry season corn over the area. REGION VI (Western Visayas)

Sun drying and other rice stocking activities for the post-harvested lowland 2nd palay continues. REGION VII (Central Visayas) Dry and sunny weather prevailed in Mactan during the month, allowing for sun-drying and other rice stocking activities of post-harvested, late-planted lowland 2nd palay.

REGION VIII (Eastern Visayas)

Harvesting of early-planted, wet season corn has commenced in Catarman and Tacloban. Below normal yield is expected this season because crops were subjected to moisture stress during the vegetating stage. Likewise, land preparation and planting of dry-season corn may be hampered due to the minimal rainfall in Catarman during the month.

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REGION IX (Zamboanga Peninsula)

During the month, insufficient moisture available across the region hinders any farming activity related to planting rice and corn. REGION X (Northern Mindanao)

Farming activities related to planting rice and corn are hindered by the insufficient amount of rainfall received during the month.

REGION XI (Davao Region)

Farming activities related to planting rice and corn are hindered by the insufficient amount of rainfall received during the month.

REGION XII (SOCCSKSARGEN)

Farming activities related to planting rice and corn are hindered by the insufficient amount of rainfall received during the month.

REGION XIII (CARAGA Region)

Harvesting of early-planted wet season corn had just begun across the region. Normal to above normal yield may be expected in Surigao del Sur, while in Surigao del Norte, below normal yield may be anticipated because crops suffered from moisture deficiency during the critical stage of growth and development. On the other hand, the sufficient moisture available during the month favors land preparation and planting of dry season corn across the region. ARMM (Autonomous Region of Muslim Mindanao) Land preparation of dry season corn is hindered by the minimal amount of rainfall received during the month.

For Particulars, please contact:

THELMA A. CINCO, Impact Assessment and Applications Section (IAAS)

Climatology and Agrometeorology Division (CAD), PAGASA-DOST

Telefax No.: 434-58-82/ telacebes@yahoo.com

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TABLE 1.0 CUMULATIVE YIELD MOISTURE INDICES FOR EARLY

PLANTED WET SEASON CORN in millimeters and percentile rank.

(February 2020 – April 2020)

STATIONS FEBRUARY MARCH APRIL

YMI %RANK YMI %RANK YMI %RANK

Region III (Central Luzon)

Baler 56 33 117 10 262 10

Casiguran 101 50 226 28 302 20

Region IV-A (CALABARZON)

Alabat 148 82 199 58 258 62

Ambulong 18 80 23 53 25 27

Infanta 185 72 252 38 350 33

Tayabas 123 83 154 57 249 63

Region V (Bicol Reg.)

Daet 117 62 198 47 305 50

Legaspi 88 42 318 57 374 42

Masbate 62 65 134 60 144 50

Virac 24 15 221 60 276 50

Region VIII (Eastern Visayas) Catarman 173 60 326 50 368 38

Catbalogan 73 43 202 47 233 37

Tacloban 151 57 262 45 350 43

Region XIII (CARAGA)

Butuan 56 52 143 50 201 48

Hinatuan 195 25 509 20 733 23

Surigao 275 58 406 30 591 33

ARMM (Autonomous Region of Muslim

Mindanao)

Cotabato 26 25 93 32 112 15

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TABLE 2.0 YIELD MOISTURE INDICES FOR DRY SEASON CORN

in millimeters and percentile rank. (April 2020 – June 2020)

STATIONS APRIL MAY JUNE

YMI %RANK YMI %RANK YMI %RANK

Region IV-A (CALABARZON)

Infanta 85 45

Region V (Bicol Reg.)

Daet 93 72

Legaspi 49 23

Virac 126 83

Region VIII (Eastern Visayas)

Catarman 36 25

Region XIII (CARAGA)

Hinatuan 250 67

Surigao 160 70

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TABLE 3.0 DECADAL AND CUMULATIVE DECADAL RAINFALL

For the month of APRIL 2020

[actual values (in mm) and percent of normal]

REGION DECADE ACTUAL

MAR.

% Normal

of Actual

CUMULATIVE

FEB.-MAR.

% Normal

Cumulative

R01

Ilocos Region

10 10 105 40 57

11 1 9 41 76

12 21 105 62 66

CAR

CAR

10 8 53 77 78

11 1 8 78 83

12 14 64 92 75

R02

Cagayan Valley

10 8 23 232 80

11 2 6 234 83

12 29 96 262 76

R03

Central Luzon

10 21 62 147 79

11 2 7 148 81

12 21 68 170 72

R04-A

CALABARZON

10 13 38 277 84

11 2 8 280 81

12 11 39 291 74

R04-B

MIMAROPA

10 2 20 52 74

11 1 10 53 64

12 5 22 58 65

NCR

NCR

10 4 37 85 133

11 1 11 86 122

12 13 83 100 106

R05

Bicol Region

10 12 25 396 56

11 2 6 398 52

12 22 63 421 50

R06

Western Visayas

10 6 35 129 92

11 1 6 130 88

12 2 6 132 88

R07

Central Visayas

10 2 14 299 129

11 1 6 300 127

12 11 45 310 124

R08

Eastern Visayas

10 15 34 648 86

11 1 4 649 82

12 54 123 703 79

R09

Zamboanga Peninsula

10 0 0 159 46

11 1 3 160 50

12 6 21 165 47

R10

Northern Mindanao

10 5 17 217 62

11 1 3 218 65

12 6 17 224 66

R11

Davao Region

10 52 112 493 79

11 2 4 495 94

12 18 33 514 88

R12

SOCCSKSARGEN

10 5 22 146 48

11 1 3 147 62

12 4 13 151 59

CARAGA

10 54 82 899 79

11 4 5 902 82

12 60 94 962 80

ARMM

10 1 3 130 53

11 1 3 131 60

12 4 14 135 59

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A. Decade 1 – APRIL 01-10, 2020

B. Decade 2 – APRIL 11-20, 2020

B. Decade 2 – JULY 11-20, 2018

C. Decade 3 – APRIL 21-30, 2020

FIG 1.0 TEN DAYS ACTUAL RAINFALL DISTRIBUTION IN THE PHILIPPINES for the month of APRIL 2020

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A. Normal Rainfall (mm)

C. Percent of Normal Rainfall ( % )

B. Actual Rainfall (mm)

FIG 2.0 RAINFALL IN THE PHILIPPINES for the month of APRIL 2020

2020

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Fig. 3.0 Comparison of normal rainfall and potential evapotranspiration with

the actual monthly rainfall at Laoag, Basco, Baguio, Aparri,

Dagupan, and Tuguegarao.

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Baguio

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AparriB

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Dagupan

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Tuguegarao

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Fig. 3a. Comparison of normal rainfall and potential evapotranspiration

with the actual monthly rainfall at Iba, Ambulong, Muñoz, Port Area,

Calapan, and Science Garden.

0100200300400500600700800900

10001100120013001400150016001700

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Iba

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Ambulong

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Muñoz

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Port Area

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Calapan

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S. Garden

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Fig. 3b. Comparison of normal rainfall and potential evapotranspiration

with the actual monthly rainfall at Daet, Casiguran, Infanta,

Legaspi, Alabat, and Puerto Princesa.

0100200300400500600700800900

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Daet

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Casiguran

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Infanta

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Alabat

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Fig. 3c. Comparison of normal rainfall and potential evapotranspiration with

the actual monthly rainfall at Cuyo, Masbate, Mactan, Tacloban,

Catarman and Dumaguete.

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Cuyo

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Masbate

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Tacloban

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Catarman

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Dumaguete

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Davao

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Gen. Santos

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Zamboanga

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Cag. de Oro

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Dipolog

Fig. 3d. Comparison of normal rainfall and potential evapotranspiration with the

actual monthly rainfall at Davao, General Santos, Zamboanga, Cagayan

de Oro, and Dipolog.