SPATIAL VARIABILITY OF RAINFALL DUE TO AN ANTI-HAIL SYSTEM IN MICHOACÁN AVOCADO BELT

Abstract

Hail formation has caused important losses, up to 100% of fruit yield in avocado (Persea americana) orchards of the state of Michoacán, México. Hail avoidance with currently utilized electronic technology, may generate changes in this climatic factor. The aim of this paper was to evaluate the spatial variability of rainfall due to an anti-hail system (CAA) in the avocado strip of Michoacán. This experimental trial was carried out in Tacámbaro, Cheranguerán y Peribán, during the Summer of 2011. First two sites have a working CAA, but in the last site it was out of service. Rainfall pluviometers (P) were set to 0, 500, 1000, 1500 y 2000 m of distance on both sides of the CAA intersecting an East-West line, the main incoming pathof the rainfalls in this region. Evaluated variables were rainfall amount and number of events. Analyses of variance of measured rainfall in each pluviometer were performed under a completely randomized design taking each rainfall event as a replication, followed by means comparisons with a Tukey (α = 0.05) test. Spatial variability of rainfall was analyzed with a χ² test. Results indicated significant difference among P in Cheranguerán y Peribán, but not in Tacámbaro. However, this effect is not caused by CAA since in Cheranguerán and Tacambaro the highest rainfall amount occurred in the pluviometer placed along the CAA,and in Peribán the CAA was out of service the whole rainfall season. Rainfall spatial variability in all P did not show statistical differences caused bythe CAA usage to decrease rainfall in any of the three sites, instead there is an inversesignificant effect.