Concepts of IPM

5th lessonHagus Tarno

Trends in expenditure on crop protection products (based on trade prices) from 1960 to 2000 (Data from CountyNatWest WoodMac, 1992, FAO 2002).

Estimation of the effect of crop protection on the yield of the eight principal food and cash crops, 1988-1990 (After Oerke et al., 1993).

Concepts of Pest Management

• Understanding the agricultural ecosystem• Planning the agricultural ecosystem• Cost/Benefit and Benefit/Risk• Tolerance of Pest Damage• Leave of Pest Residue• Timing of Treatments• Public Understanding and Acceptance

Understanding the agricultural ecosystem

• Ecosystems are self-sufficient habitats where living organisms and the non living environment interact to exchange energy and matter in continuing cycle

• Agricultural ecosystem contain less diversity of animal and plant species than natural ecosystem such as forest

• Agroecosystem is intensively manipulated by man subjected to sudden alterations such as treatments with pesticides

• Agroecosystem can be more susceptible to pest damage and catastrophic outbreaks, because of the lack of diversity in species of plants, species of insects and the sudden alterations imposed by weather and man

Planning the agricultural ecosystem

• It`s unfortunate that one would try to grow a crop where that crop cannot be successfully grown.

• In insect pest management applied agroecosystem planning should anticipate pest problems and ways to avoid them

Cost/Benefit and Benefit/Risk

• Cost/Benefit– In most agricultural pest control activities, benefits

usually are not known, they are usually not measured and costs of prevention become costs of production.

• Benefit/Risk– The use of insecticides when they are not needed

is contrary to the pest management philosophy.

Tolerance of Pest Damage

• Quantitative studies of the degree of damage versus reduction in crop yield are urgently needed.– EIL – ET– GEP

Tanspot (Drechslera tritici-repentis) in wheat: Disease-loss relationship calculated from the sum of leafspots on the upper three leaves and yield loss (Data from Wolf, 1991).

Practical use of disease prediction, dependent on crop specific tolerance of infection.

Schematic description of the decision model ”IPM wheat model“ for an optimum control of wheat diseases by minimized input of fungicides (Modified after Ver-reet, 1995).

Decision scheme for threshold-oriented control of wheat diseases according to the IPM wheat model in Germany (Modified after Verreet and Klink, 2000).

Decision scheme for threshold-oriented control of barley diseases according to the IPM barley model in Germany (Data after Appel, 1996).

Fungicide strategy of the IPM wheat model (After Verreet and Klink, 2000).

Rhynchosporium secalis: Dependence of fungicide effects on the incubation time determined by the sum of daily average °C (Data from Appel, 1996).

Decision scheme for the fungicide control of Rhynchosporium secalis in barley based on threshold values and weather data exceeded (After Appel, 1996).

Damage thresholdThe damage boundary is the lowest level of injury that can be measured. This level of injury occurs before economic loss.

A basic IPM principle ensues from the damage boundary/economic damage relationship; it is that no injury level below the damage boundary merits suppression, but injury predicted to result in economic damage does.

Damage thresholdhttp://ipmworld.umn.edu/chapters/pedigo.htm

Damage threshold

Economic Injury Level Another of the basic elements, the economic injury level, is the lowest population density that will cause economic damage. The EIL is the most basic of the decision rules; it is a theoretical value that, if actually attained by a pest population, will result in economic damage.

Therefore, the EIL is a measure against which we evaluate the destructive status and potential of a pest population.

Economic Injury Level

Economic Injury Level

Economic threshold The economic threshold (ET) differs from the EIL in that it is a practical or operational rule, rather than a theoretical one. It is the population density at which control action should be determined (initiated) to prevent an increasing pest population(injury) from reaching the economic injury level.

Although measured in insect density, the ET is actually a time to take action, i.e., numbers are simply an index of that time.

ET is the action threshold.

Economic threshold

Graphical representation of the interactions of the ecological and socioeconomic scales that define the regional characteristics of the scales of agricultural systems and levels of IPMintegration within the context of the ecological, socioeconomic, and agricultural scales.