A major challenge of the Sustainable Development Goals linked to Agriculture, Food Security, and Nutrition, under the current global crop production paradigm, is that increasing crop yields often have negative environmental impacts. It is therefore urgent to develop and adopt optimal soil-improving cropping systems (SICS) that can allow us to decouple these system parameters. Soil salinization is a major environmental hazard that limits agricultural potential and is closely linked to agricultural mismanagement and water resources overexploitation, especially in arid climates. Here we review literature seeking to ameliorate the negative effect of soil salinization on crop productivity and conduct a global meta-analysis of 128 paired soil quality and yield observations from 30 studies. In this regard, we compared the effectivity of different SICS that aim to cope with soil salinization across 11 countries, in order to reveal those that are the most promising. The analysis shows that besides case-specific optimization of irrigation and drainage management, combinations of soil amendments, conditioners, and residue management can contribute to significant reductions of soil salinity while significantly increasing crop yields. These results highlight that conservation agriculture can also achieve the higher yields required for upscaling and sustaining crop production.

It is proposed that the main advantage provided by production of staminate flowers in olive is to enhance male fitness by increasing pollen output at the whole plant level, although a relict function of attracting pollinators cannot be completely discarded.

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We investigated pollination and fruit set parameters in `Manzanillo' olive (Olea europaea L.) following self-pollination and pollination with `Sevillano', `Ascolano', and `Mission' pollen. Results of analyses and experiments conducted over 2 years in central California indicated that `Manzanillo' behaves as a self-incompatible cultivar (index of self-incompatibility = 0.22 to 0.24). Pollination with `Sevillano' resulted in a more than 4-fold increase in fruit set over self-pollination. When `Mission' or `Ascolano' pollen was used, there was no increase over self-pollinated samples. Analyses of pollen tube growth, fertilization, initial fruit set, and final fruit set were consistent with `Manzanillo' being considered as a self-incompatible cultivar cross-incompatible with `Mission' and `Ascolano'. Our results indicate that `Manzanillo' is likely to be more productive when interplanted with `Sevillano' rather than when planted without a pollinizer or with `Mission' or `Ascolano'.

Background: Commercial olive pollen from uncertain cultivar origin is the common material used for clinical and biological studies. We aimed to assess the putative heterogeneity of olive cultivars with regard to the presence of the major pollen allergen Ole e 1 and to determine whether these differences have clinical relevance. Methods: The Ole e 1 content of several cultivars was determined by immunoblotting and ultrastructural immunocytochemistry and compared to that of a commercially available olive pollen extract designed for diagnosis. Reverse transcription-polymerase chain reaction analysis of Ole e 1 transcripts was also performed. Crude protein extracts were used to carry out skin prick tests (SPTs) on 30 allergic patients in order to evaluate the clinical importance of such differences. Results: Ole e 1 was present in all cultivars, although significant quantitative differences were detected. Ole e 1 transcripts positively correlated with the amount of the allergen. Significant variations in the average reactivity of allergic patients to SPTs were observed depending on the cultivar considered. Conclusions: The presence of the Ole e 1 allergen in all the cultivars suggests that this allergen may play an essential biological role. The expression of the allergen is controlled at the transcriptional level. The significant differences in the Ole e 1 content are likely responsible for the different average reactivity exhibited by patients to the cultivars studied, although the role of other allergens cannot be excluded. Our results suggest that the use of the commercial pollen mixtures currently available may lead to mistakes in allergy diagnosis and to limited success in immunotherapy. Therefore, further standardization is strongly recommended.