Multispectral imaging: an effective tool to estimate garlic productivity and sanitary aspects

Abstract

Garlic is a relevant crop worldwide, with more than 1.6 M hectares and a production of 30 M tons. In Argentina the crop is located in the western part of the country, in the provinces of Mendoza and San Juan. The vast majority of the local production is exported, generating an average income of 150 M USD. Garlic stakeholders and growers constitute a dynamic sector which constantly demands new tools to improve their efficiency, in a cost-effective manner. In this regard, previous experiments have evaluated the use of remote sensing to estimate garlic growth variables, particularly associated to irrigation and nutrition practices and weather conditions. However, the correlation with pest/disease outbreaks are scarce and often related to controlled conditions environments. White rot (WR), caused by the soilborne fungus Stromatinia cepivora, is an increasing threaten to garlic crops worldwide. Reports mention that WR causes 50% of yield reduction and sometimes can lead to complete loss. Once present in a field, the fungus produces resistance structures called sclerotia that remain in the soil for long periods of time, infecting any Allium crop for many years after that. Hence, the early detection of the presence of WR is essential for the sustainability of the garlic production in the region. The objective of the present study was to evaluate the usefulness of multispectral images for the estimation of production variables and crop health in garlic.