Houssem Memmi

Quality attributes of pistachio nuts as affected by rootstock and deficit irrigation

BACKGROUND In this work, the influence of two regulated deficit irrigation (RDI) treatments and three different rootstocks on the quality of pistachios was evaluated by analyzing different parameters: morphological analysis, physicochemical analysis and sensory analysis. RESULTS The results obtained in terms of the choice of rootstock revealed that Pistacia atlantica had increased production yields, nut weight, mineral content, higher intensities of characteristic sensory attributes and a higher degree of consumer satisfaction, than the other rootstocks studied. Moreover, the results established that the application of RDI on pistachio cultivation had no significant influence on production yield, weight, size, colour, water activity or mineral composition. Furthermore, T1 treatment (stem water potential < -1.3 MPa) resulted in higher intensities of characteristic sensory attributes and a greater level of satisfaction among international consumers. CONCLUSION These results confirm that the application of deficit irrigation (T1) contributes to an increase in overall product quality. Furthermore, Pistacia atlantica rootstock provided better yield and quality than the other rootstocks studied.

Water deficit during pit hardening enhances phytoprostanes content, a plant biomarker of oxidative stress, in extra virgin olive oil.

No previous information exists on the effects of water deficit on the phytoprostanes (PhytoPs) content in extra virgin olive oil from fruits of mature olive (Olea europaea L. cv. Cornicabra) trees during pit hardening. PhytoPs profile in extra virgin olive oil was characterized by the presence of 9-F1t-PhytoP, 9-epi-9-F1t-PhytoP, 9-epi-9-D1t-PhytoP, 9-D1t-PhytoP, 16-B1-PhytoP + ent-16-B1-PhytoP, and 9-L1-PhytoP + ent-9-L1-PhytoP. The qualitative and quantitative differences in PhytoPs content with respect to those reported by other authors indicate a decisive effect of cultivar, oil extraction technology, and/or storage conditions prone to autoxidation. The pit hardening period was critical for extra virgin olive oil composition because water deficit enhanced the PhytoPs content, with the concomitant potential beneficial aspects on human health. From a physiological and agronomical point of view, 9-F1t-PhytoP, 9-epi-9-F1t-PhytoP, and 16-B1-PhytoP + ent-16-B1-PhytoP could be considered as early candidate biomarkers of water stress in olive tree.

Effect of the season on the free phytoprostane content in Cornicabra extra virgin olive oil from deficit‐irrigated olive trees

BACKGROUND The effect of regulated deficit irrigation (RDI) on the phytoprostane (PhytoP) content in extra virgin olive (Olea europaea L., cv. Cornicabra) oil (EVOO) was studied. During the 2012 and 2013 seasons, T0 plants were irrigated at 100% ETc, while T1 and T2 plants were irrigated avoiding water deficit during phases I and III of fruit growth and saving water during the non-critical phenological period of pit hardening (phase II), developing a more severe water deficit in T2 plants. In 2013, a fourth treatment (T3) was also performed, which was similar to T2 except that water saving was from the beginning of phase II to 15 days after the end of phase II. RESULTS 9-F1t -PhytoP, 9-epi-9-F1t -PhytoP, 9-epi-9-D1t -PhytoP, 9-D1t -PhytoP, 16-B1 -PhytoP and 9-L1 -PhytoP were present in Cornicabra EVOO, and their contents increased in the EVOO from RDI plants. CONCLUSION Deficit irrigation during pit hardening or for a further period of 2 weeks thereafter to increase irrigation water saving is clearly critical for EVOO composition because of the enhancement of free PhytoPs, which have potential beneficial effects on human health. The response of individual free PhytoPs to changes in plant water status was not as perceptible as expected, preventing their use as biomarkers of water stress.

Fruit Response to Water-Scarcity Scenarios. Water Relations and Biochemical Changes

Abstract The aim of this chapter is to give a general idea of the fruit response to water-scarcity conditions, paying special attention to fruit water relations modification and fruit composition changes, which are key for fruit quality. The strengths and weaknesses of fruit water relations measurement parameters are discussed. The incidence of some pre- and postharvest fruit physiological disorders related to water stress (cracking, creasing, pitting, splitting, and watercore) was also considered. Current knowledge of water flow in developing fruits, fruit water relations under drought, and the effect of water deficit on fruit quality characteristics, mainly those related to human health, are discussed and new research objectives are proposed. In addition, the need to differentiate the products from deficit-irrigated trees (hydroSOS) from any others on the market is discussed.

Agronomical effects of deficit irrigation in apricot, peach and plum trees

Abstract Stone fruits are some of the most important irrigated crops around the world. Their ability to grow in different environments implies great variations in water needs. This chapter discusses the effect of water restriction on yield and quality of the fruits obtained. The information will provide enough data to make a decision in terms of the most appropriate irrigation management method based on the final commercial product that farmers would need according to the target market. In addition, a discussion about the possibility of using irrigation management with continuous measurement is also included for each species.

Fruit response to water-scarcity and biochemical changes: Water relations and biochemical changes

Abstract The aim of this chapter is to give a general idea of the fruit response to water-scarcity conditions, paying special attention to fruit water relations modification and fruit composition changes, which are key for fruit quality. The strengths and weaknesses of fruit water relations measurement parameters are discussed. The incidence of some pre- and postharvest fruit physiological disorders related to water stress (cracking, creasing, pitting, splitting, and watercore) was also considered. Current knowledge of water flow in developing fruits, fruit water relations under drought, and the effect of water deficit on fruit quality characteristics, mainly those related to human health, are discussed and new research objectives are proposed. In addition, the need to differentiate the products from deficit-irrigated trees (hydroSOS) from any others on the market is discussed.

PHENOLOGICAL BEHAVIOR OF TWO NEW MALE CULTIVARS OF PISTACHIO (PISTACIA VERA L.): 'CHAPARRILLO' AND 'GUERRERO'

In the present work, the phenology of eight female and ten male pistachio (P. vera L.) cultivars has been characterized, including the first data of agronomic behavior of two new male cultivars obtained recently: ‘Guerrero’ and ‘Chaparrillo’. A phenological synchronization index (FSI) between male and female cultivars has been determined, which will help to find the best choosing between all the different possible combinations. The experiment was conducted at the El Chaparrillo Research Station, Ciudad Real, Spain (3°56’W, 39°0’N; altitude 640 m). For this characterization of the cultivars in study, four leading phenological stages (Guerrero et al., 2008) were taken into account: initial movement, beginning, full and end of flowering period. Data have been collected during seven years. It is noteworthy ‘C-Especial’ and ‘M-38’ male cultivars as more universal to present higher rates of overlap in pollination with most female cultivars under study. The exception is marked by late flowering males, such as ‘Peter’ and ‘02-18’, being the most common for late flowering female cultivar ‘Kerman’. However, the best flowering overlaps are obtained with the two new males ‘Guerrero’ and ‘Chaparrillo’, with an FSI above 0.8 with that female cultivar. Finally, considering that annual climatic differences affect the phenology of each cultivar also differently, it is believed that combining different male cultivars with different flowering dates is recommended to ensure maximum overlap with the female cultivar.