The case for a PET (Pictorial Evaluation Tool) for crops at harvest time....

20 years of independent (UN) and rapid crop and food supply assessment in marginal/ conflict/ post-conflict or post–disaster areas in Africa, Balkans, Middle East and Central Asia- have made AA International Ltd’s Director, Dr Ian Robinson, a firm believer in using objective in-field surveys and transects combined with detailed farm case studies at harvest time to determine the size of the harvest. He prefers these activities to elaborate questionnaires or focus group meetings or any meeting with more than one farm-family at a time; or any discussions with any combination of farmers and administrators at the same time for estimating crop production. He thinks organised observation supported by an in-country PET and single farmer in-field discussions are combinations that avoid the dramatic use/ influence of exaggeration that arises with other approaches mentioned above- causing misleading expressions of food insecurity, especially where food aid has become the norm rather than the exception. In an interview with TechTalk© that “while NGO/agency health and educational programmes rely on field data and measurement to determine their style and type of interventions, agricultural/ food aid programmes seem increasingly to rely on hearsay or the opinions of celebrities to make their cases”.  He claims that “Being preoccupied with their own activities in their own territories, few NGOs and international agencies working in the rural livelihoods sector (more often than not 85-90% farming) show a real interest and most have low levels of expertise- in objectively judging general levels of crop production in farmers’ fields at harvest time.”  He goes on to surmise that “This results in a reliance on farmer and/or administrator estimates, which are often, to varying degrees, conditioned by- ·        farmer fear of taxes and/or commandeering of surplus stocks if they tell the truth to assessors;·        following years and years of humanitarian aid, often politically deposited without apparent reason, a general lowering of local farmer opinion of visiting assessors creating a tell –them- anything-and -they-believe- you mentality; ·        a concern among politicians/ administrations that local expectations of free goods will be threatened if the truth is told.”·        IMF structural- adjustment related loss of capacity in local Ministry of Agriculture offices to conduct meaningful annual crop assessments;  He feels that “In an unfortunate alliance with the local push factors to exaggerate losses noted above, there are also international pull factors viz:- ·        NGO/ agency staff fear “missing” a local famine “on their watch”;·        competition for humanitarian aid fosters hyperbole to reinforce claims –the  “my need is greater than your need” approach in order to attract funds;·        protracted negotiations and prolonged decision-making by donors means that warnings of “disasters” are being made too early, before crops are mature and can be easily judged, with an associated increase in risk of such warnings becoming self-fulfilling prophecies for reasons noted above at local level; ·        turnover and current recruitment practices mean that  few NGO/agency staff have the practical agricultural experience in situ or training that might provide the confidence to contradict forecasts appearing in the media;·        NGO/ agency purpose and presence, and all this implies to livelihoods of local and international staff, may well be linked to food aid or the provision of some improving input.” The concern he raises is that  the reliance on hearsay or similarly subjective feelings leads generally to an underestimation of production and an exaggerated reporting of problems, which may be made with the best intentions but “The consequences of which are misleading including very silly estimates accepted as fact, false famine warnings- exacerbated by journalists and celebrities looking for stories and publicity, unnecessary food-aid requests and irrelevant extension programmes or input supply projects”. If a more rigorous approach to local crop production estimates is adopted by NGOs and agencies, many of the problems noted above could be solved at source. Unlike crop forecasting, objective crop assessment at harvest time is a simple mathematical process. What you see is what you get, give or take harvesting and transport losses, for example:- ·        “If it looks like a good field of maize, feels like a good field of maize, it probably IS a good field of maize, irrespective of the early warning published 6 weeks ago”...and its production is quite easily estimated if you consider the steps outlined below.  All you need to estimate production is patience, stamina, an accurate pocket spring- balance, a good eye and knowledge of the area farmed.  Whereas the area of a field may be calculated using simple algebra formulae from parameters measurable by walking (rectangle l x b; or circle ∏ r² or triangle b x h/2; where l=length and b=breadth; r= radius and b= base and h= “height”), to estimate production at district, regional or national levels an accurate estimate of the area usually farmed is necessary.  Such area estimates should be obtained from local administrations along with population statistics and may be available as crop area planted obtained earlier in the year in question. Thereafter, production of each crop may be roughly estimated by·        observing the comparative frequency of appearance of crops along transects within the areas being assessed (entry points) to confirm/ or estimate area per crop by applying the proportional ratios to the total area usually farmed; (in the absence of any other figures, this overall area may be calculated by multiplying number of households farming by the recognised  average farm size) ·        estimating yield per unit area for each crop in each entry point by sampling fields along suitable transects (walking, driving, or possibly low-level flying) according to the scope and the availability of time and funds;·        multiplying area per crop by yield per unit area.  Estimating yield by eye requires years of experience in the fields handling crops at harvest time, and/or weighing dry samples of the product obtained using a practically viable sampling method of the crops in the locality; and/or, if they  are available, getting direct data of the harvests from combine-harvester drivers and mobile threshing contractors. Given that combine harvesters and threshers are usually few and far between in the marginal areas being assessed; and given that NGO, agency and local MoA staff are likely NOT to have the years of practical experience nor the balances and quadrats and the skill to uses them, in the past 6 years UN WFP and UN FAO have funded the preparation of  two PICTORIAL guides to help assessors estimate with added confidence. The guides were field tested and are now in use in Ethiopia and South Sudan.  Pictorial Evaluation Tools (PET) manuals hold one of the keys to realistic rapid assessment of crops at harvest- time. Custom-built PET manuals help assessors to judge the yield by providing a visual guide to the appearance at harvest time of crops and their products at 3 different levels of performance connecting to yield per square metre.  Like many other pictorial guides for identifying flowers and insects, PET manuals can be used by non-agriculturalists AND they give confidence to agriculturalists in the face of challenges arising from lobbies by vested interest groups. PET manuals not only help assessors estimate yield per unit area, they may also be used to explain assessors findings by showing everyone what good, medium and poor yields of all the crops really look like in very clear pictorial terms. To see the real advantages PET manuals can offer field staff, the full manual PET South Sudan may be obtained free of charge from  This e-mail address is being protected from spam bots, you need JavaScript enabled to view it .   It may be possible to use this PET it in your domain/country, although our experience suggests that the pictures are MUCH more likely to be understood and accepted if they are obviously from the country concerned.

In the past 6 years UN WFP and UN FAO have funded the preparation of  two PICTORIAL guides to help assessors estimate with added confidence.

The guides were field tested and are now in use in Ethiopia and South Sudan. Pictorial Evaluation Tools (PET) manuals hold one of the keys to realistic rapid assessment of crops at harvest- time.

Custom-built PET manuals help assessors to judge the yield by providing a visual guide to the appearance at harvest time of crops and their products at 3 different levels of performance connecting to yield per square metre.  

Like many other pictorial guides for identifying flowers and insects, PET manuals can be used by non-agriculturalists AND they give confidence to agriculturalists in the face of challenges arising from lobbies by vested interest groups.

PET manuals not only help assessors estimate yield per unit area, they may also be used to explain assessors findings by showing everyone what good, medium and poor yields of all the crops really look like in very clear pictorial terms. 

To see the real advatages PET manuals can offer field staff, the full manual (PET South Sudan) may be obtained free of charge from This e-mail address is being protected from spam bots, you need JavaScript enabled to view it .

It may be possible to use this PET in another domain/country, although our experience suggests that the pictures are MUCH more likely to be understood and accepted if they are from the area concerned.