Absence of Yield Reduction after Controlled Water Stress during Prehaverst Period in Table OliveTrees

María Martín-Palomo,Ana Centeno,Alejandro Galindo,Ignacio Girón,David Pérez-López,Luis Andreu,Alfonso Moriana,Mireia Corell

doi:10.3390/agronomy10020258

Abstract

Deficit irrigation scheduling is becoming increasingly important under commercial conditions. Water status measurement is a useful tool in these conditions. However, the information about water stress levels for olive trees is scarce. The aim of this experiment was to evaluate the effect on yield of a moderate controlled water stress level at the end of the irrigation season. The experiment was conducted in the experimental farm of La Hampa (Coria del Río, Seville, Spain) during three years. A completely randomized block design was performed using three different irrigation treatments. Deficit irrigation was applied several (4 or 2) weeks before harvest. Irrigation was controlled using the midday stem water potential, with a threshold value of −2 MPa and compared with a full irrigated treatment. This water stress did not reduced gas exchange during the deficit period. The effect on yield was not significant in any of the three seasons. In the high-fruit load season, fruit volume was slightly affected (around 10%), but this was not significant at harvest. Results suggest an early affection of fruit growth with water stress, but with a slow rate of decrease. Moderate water stress could be useful for the management of deficit irrigation in table olive trees.

Highlights

Olive orchards grow around the world in semi-arid or arid conditions, with great water scarcity.Deficit irrigations are very common in these areas
The irrigation season lasted mid-spring the of end of summer, around mid-September, when irrigation season lasted fromfrom mid-spring untiluntil the end summer, around mid-September, when trees trees were harvested
The vertical solid line indicates the beginning of the regulated deficit irrigation (RDI) 2 treatment

Summary

Introduction

Olive orchards grow around the world in semi-arid or arid conditions, with great water scarcity.Deficit irrigations are very common in these areas. The yield response to water stress conditions is related to the duration, the level and the moment when the plant water status is affected [1]. Olive trees are considered extremely resistant to drought conditions [2], the full bloom/fruit set period [3]. Irrigation scheduling for table olive cultivars is more complex than for oil ones, especially in the case of green olives. The main limitations of regulated deficit irrigation (RDI) for table cultivars are the importance of the fruit size in the final value of the yield and the short period available for rehydration. The harvest period for green table olives occurs at the end of the irrigation season, when there is a very small amount of irrigation water available and rains are scarce

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Conclusion