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L. Setyobudi

2013

Crop Loss/Kehilangan Hasil

• A grower takes a particular pest control action to prevent an anticipated crop loss– Generally one cannot recoup losses

– This implies a certain predictive capability• Generally based on the experience of the farmer

• Grower's predictive capability is often limited

– Risk and uncertainty• Uncertainty

• Risk

• Pest management program is to turn an uncertainty into a measurable risk

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Nature of crop loss• Direct loss (the crop product

itself is affected)– The loss can be one of

quality, quantity or both

– Loss is generally proportional to pest population density at low densities, approaches an upper limit (often 100%) as pest population increases

– The loss function can often be linearized with the "multiple hit" transformation (Plot ln(1.0/(1.0 - L0SS)) versus pest population where LOSS is expressed as a proportion, 0.0 to 1.0)4/24/2013 3LSB AEIPM

• Indirect loss (the pest attacks plant parts other than the crop product)– Photosynthetic area removed

– Diversion of photosynthate

– Net assimilation reduced• Reduction in photosynthetic rate

• Respiration rate increased

• Water balance upset

– The yield response to pest population density can take various shapes• May get no measurable yield loss at

low pest population densities

• Some cases of yield enhancement at low levels of pest damage

• Yields may drop to zero with increasing pest populations or may approach some yield level below the level attainable in the absence of pests

– Multiple pests can interact synergistically to reduce yields or can interfere with one another

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The crop loss or yield functions can change with crop development

• Different stages of crop development

• The yield (quality and quantity) at harvest can be affected both by brief episodes of pest damage and by the cumulative effects over the season

• The crop loss or yield functions also vary with cultivars with different levels of pest resistance

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• The crop loss and yield functions can also be affected by factors in the physical environment (temperature, rainfall, cultural practices, etc.)

• Crop loss and yield functions can be used to evaluate the effects of pest control measures that abruptly change pest populations (pesticides, sanitation measures, etc.)

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• Consider first the

population

dynamics

(momentum)

• Use the projected

controlled and

uncontrolled pest

populations to

predict the crop

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Kehilangan Hasil

• Kehilangan hasil adalah Fungsi dari:

– Tanaman (Jenis dan Pola Pertumbuhan)

– Tingkat Kerusakan dan saat terjadinya kerusakan

–Waktu terjadinya kerusakan

–Harga Produk

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Map Produksi

POTENTIAL / THEORITICAL YIELD

ATTAINABLE YIELD

ECONOMIC YIELD

ACTUAL YIELD

YIELD/CROP LOSS

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Definitions and Nomenclature

• Various terms such as crop, production, yield, pest, stress, crop loss, and yield loss, will be used while discussing crop losses. It is important to understand these terms at the beginning of the course. For a definition of each term, click each of the words below:

• Crop - A population of plants grown to provide food, fiber, medicine, seed, fuel or other products.

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• Production: The amount harvested in a country or region in one year

• Yield: The measurable produce of economic value from a crop. This may be evaluated in terms of quantity and/or quality. Yields are stated in SystèmeInternational d’unités derived units such as kg/ha or t/ha. Several reference points for yield levels such as theoretical yield potential, attainable yield, actual yield, economic yield, and primitive yield can be recognized (Figure 1).

• Theoretical yield potential: The yield obtained when crops are grown under optimal environmental conditions using all available production and pest control technologies to maximize yield (Figure 1).

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Yield levels as reference points for crop loss assessment (modified from Zadoks 1990 and Oerke et al. 1994)

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• Attainable yield: The site-specific yield obtained when crops are grown using current cultivation and plant protection practices at the farm level (Figure 1).

• Actual yield• Economic yield In many instances, economic yield is

somewhere between the actual and the attainable yield. It is the yield level that optimizes the input/output ratio involving production costs vs. financial return (Figure 1). In crop protection terms, it refers to the yield, using crop protection practices in the most cost effective manner.

• Primitive yield: The yield of local varieties in subsistence agriculture or yield obtained without the use of crop protection practices (no protection scenario) (Figure 1).

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Yield levels as reference points for crop loss assessment (modified from Zadoks 1990 and Oerke et al. 1994)

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To predict a crop loss a reference yield is necessary

Theoretical Yield Calculated by plant physiologists

Approached in plant breeding programs

Attainable Yield

Yield with all stresses on crop (constraints) removed

Limited by the genes of a crop in a particular environment

Approached in small, experimental plots

Actual Yield

Economic Yield

Depends on market value of crop and cost of production

May be above or below actual yield

Occurs where the profit is maximized

Primitive Yield Little or no inputs

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Yield categories and delineation of yield gaps 1 and 2

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Three main research tasks that relate to improving crop yields

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A gradient of biotechnologies ranging from the more simple (near bottom) to the more complex (top)

Source: Jones 1990.

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Approaches & Objectives to define production constraints and ensure future profits through crop

protection

APPROACH TARGETS

CURRENT PRACTICES

Actual Yield

IDENTIFICATION/QUANTIFICATION CROP LOSSES

Attainable Yield

COST ANALYSIS

Economic Yield

LARGE SCALE ADAPTATION NEW CONTROL PRACTICES

Future Profits

Farm Surveys/enquiries

Field experiments/surveys

Market surveys

Field Demonstration /

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Components of Yield Gaps (Adopted from De Datta, 1981)

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Rice Yield Gap in Indonesia

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Quality vs Quantity on Perishable vsDurable

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Simulasi Penilaian Kehilangan Hasil

• Kelompok Pests dan pengaruhnya terhadap kehilangan hasil tanaman (Boote et al. 1983)1. Stand reducers

2. Photosyntenthic rate reducers

3. Leaf senescence accelerators

4. Light stillers

5. Assimilate sappers

6. Tissue consumers

7. Turgor reducers

• Pengaruh toxin seringkali sangat sulit untuk diukur dan dikategorikan

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REFERENCES

• Teng, P. S. 1987. (Edit) Crop Loss Assessment and Pest Management. APS Press. 270 pp.

• Chiarappa, L. 1971. (Edit). Crop Loss Assessment Methods. FAO Manual on the evaluation and prevention of losses by pests, disease and weeds. FAO-CAB.

• Berbagai sumber di Internet dengan key word: Crop Loss Assessment Methods, dll.

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ASSIGNMENT # 2

1. Buat proposal/TOR penelitian Crop Loss assessment profile pada komoditas yang menjadi pilihan saudara. Format: Ringkasan, A. Latar Belakang, B. Rasional, C. Tujuan, D. Manfaat, E. Output, F. Mekanisme danRancangan, G. Jadual Pelaksanaan, H. Indikator Kinerja.

2. Belajar apakah saudara hari ini.

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