Quantification of leafy vegetables loss at primary production - research limitations and proposed methodology for on-farm data collection

Abstract

Research discussed in this paper reports the difficulties related to on-farm data collection of leafy vegetables loss and proposes a method to estimate vegetable loss in an exploratory survey. Loss was estimated for rocket (Eruca sativa), coriander (Coriandrum sativum) and lettuce (Lactuca sativa) in two farms located in Federal District, Brazil. The best index to express loss due to unharvested plants was different whether the vegetable was marketed as plant units (lettuce) or bunches (rocket and coriander). The discard of rocket varied substantially between farms and between successive crops in the same farm. On Farm 1, it varied from 80.6% to 0.0% of the crop area and on Farm 2 from 42.4% to 72.4%. Loss of coriander on Farm 1 varied from 0.0% to 10.8% of the area, compared to 2.3% to 34.5% on Farm 2. The total loss for each lettuce type varied between and within farms. Considering individual surveys on both farms, the losses of lettuce varied from 1.6% to 84.8% of the plant population at harvest, depending on the lettuce type, crop and farm. Measuring losses of leafy vegetables at primary production proved to be quite challenging and time consuming. Two boundaries were particularly difficult to establish: marketable versus unmarketable produce and pre-harvest loss versus harvest loss. In view of the difficulties faced during the measurement of leafy vegetables loss at primary production, the methodology was changed in order to decrease the number of visits and the time of permanence in the farm necessary to accomplish a survey; be independent of data collection by the farmer and by the farm’ staff; reduce the costs of displacement to the farm.