Yield Forecasting for Olive Trees: A New Approach in a Historical Series (Umbria, Central Italy)

Abstract

another development in crop forecasting techniques, used particularly with long-term data series. This too In recent years, the relationship between flowering and fruit prohas performed well for herbaceous species in which the duction was studied and evaluated in several wind-pollinated species. In olive (Olea europaea L.), the pollen-monitoring technique was incidence of technical evolution (fertilization, genetic introduced to determine pollen indexes as indicators of flowering, selection) seems to be more strongly correlated. evaluating in some cases the predictive role of the variable. Recently, In the 1990s, the relationship between flowering and to investigate the reproductive efficiency, the Pollen Index (calculated fruit production was studied, and pollen was introduced during the entire flowering period) was replaced by the pollen emisas one of the variables. Pollen was monitored in the sions during the effective pollination period (EPP). In this study, in atmosphere during the entire flowering period of grape particular, an EPP elaborated (EPPe) value was derived from the (Vitis vinifera L.) and olive, which are totally or partially EPP values and the average values of the meteorological variables. anemophilous species. The flowering event can be con-The regression analysis, considering winter chill accumulation, sumsidered to be a source of historical information regardmer sums of minimum temperatures, and the EPPe, confirmed the strong relationship among meteorological variables, pollen emission, ing the vegetative and reproductive processes that lead and final production in our study areas. This study has shown the to the formation of the flower apparatus and the actual need to use pollen data obtained from aerobiological monitoring in reproductive phases of fruit formation. Some studies harvest-forecasting models in anemophilous plants such as olive. In have shown how the pollination is related to production particular, in the statistical models, pollen provides a synthesis of the (Cour and Van Campo, 1980; Besselat and Cour, 1990; historical information of the entire biological-reproductive cycle of the Candau et al., 1998) with the simultaneous use of cliplant while meteorological trends interpret the incidental phenomena. matic-type explicative variables. Recent studies have used the so-called annual Pollen Index as an indicator of flowering (Fornaciari et al.

Better prediction of Mediterranean olive production using pollen-based models

“…Some studies have attempted to model the relationship between olive crop production and different airborne pollen and weather variables prior to harvesting González-Minero et al 1998;Fornaciari et al 2002Fornaciari et al , 2005Orlandi et al 2003Orlandi et al , 2005Orlandi et al , 2010Galán et al 2004Galán et al , 2008Ribeiro et al 2007Ribeiro et al , 2008García-Mozo et al 2008;Aguilera 2012). This paper tries to improve these studies in two points: in all these studies, linear regression approach for solving the problem has been used; in this study, a novel statistical methodology based on two different steps has been used: (1) typification and (2) modelling by PLSr.…”

A bioclimatic model for forecasting olive yield

“…Several authors have used post-flowering variables, such as meteorological parameters, to represent the influence of favourable or unfavourable conditions on the final fruit production (Moriondo et al 2001;Cunha et al 2003;Gala´n et al 2004 ;Fornaciari et al 2005). In the present bioclimatic models, the RPI summarizes the historical pre-flowering conditions throughout the reproduction cycle of the plant, while 1999 20022004Year 199920022004Year 199920022004Year 199920022004Year 199920022004Year 199920022004.…”

Modeling Olive Crop Yield in Andalusia, Spain

“…Moreover, the management process requires no chemical procedures, thus reducing sources of error. Sampling characteristics make this a reliable technique for forecasting yield in anemophilous crops that release a large volume of pollen grains (Riera, 1995); optimal results have been reported for olive crop surveys (Fornaciari et al, 2002(Fornaciari et al, , 2005Moriondo et al, 2001;Galán et al, 2004).…”

“…Th e use of airborne pollen data as an indicator of fi nal harvest is a tool of proven utility, particularly in anemophilous crops. A number of published papers have charted the relationship between pollen release and fruit production in grape (Vitis vinifera L.; Baugnent, 1991), European fi lbert (Corylus avellana L.; Lletjos et al, 1993), and olive (Fornaciari et al, 2002(Fornaciari et al, , 2005Galán et al, 2004).…”