Biology subjects

Rubinovich, L.

Publications and source records attributed to Rubinovich, L..

3 recordsLinked to original sources

bioRxiv2023

The potential of young vegetative quinoa (Chenopodium quinoa) as a new sustainable protein-rich winter leafy crop under Mediterranean climate

The demand for protein products has significantly risen in the last few years. In western countries, animals are the primary source of protein; however, plants could take a share of this market due to lower production costs, among other advantages. Quinoa (Chenopodium quinoa Willd.) is a well- known but under-utilized protein-rich crop, commonly cultivated for grain production. These plants were recently evaluated for their use as a non-traditional, green leafy crop. Here we assessed the potential of young vegetative quinoa as a new sustainable winter leafy crop in Israel--serving as a model for Mediterranean semi-arid regions, by evaluating yield, protein content and quality. Five quinoa accessions were sown on three winter sowing dates over two consecutive years. Plants were harvested when they reached 10-13% dry matter (DM). DM yield ranged between 574 and 1,982 kg ha-1 and was generally higher in the second year. Protein content ranged from 14.4-34% and was generally higher in the first year. Protein yield ranged from 111-471 kg ha-1 and was greatest on the December sowing date. DM and protein yields were positively correlated with plant density. Protein content was negatively correlated with plant density and DM yield. Our findings show that 200 g DM of young vegetative quinoa can meet the protein and most essential amino acid requirements for a 70 kg human adult. Prospects for cultivating young vegetative quinoa in Mediterranean countries as a new sustainable, protein-rich winter leafy crop are therefore high, as supported by its high protein yields and quality, and its requirement for only scant irrigation. Further studies should examine economic and other agrotechnical parameters toward the geographical distribution and expansion of young vegetative quinoa cultivation.

plant biology↗

bioRxiv2023

Solar Induced Fluorescence Retrieved from Avocado (Persea americana Mill.) Canopies Along the Season Correlates with Sugar Levels in the Developing Fruit

Solar Induced Fluorescence (SIF) emitted from the photosynthetic apparatus is related indirectly to biomass production. It can be remotely sensed from airborne platforms, yet, the spatial resolution from satellites, for example, is too low for commercial agricultural uses. We used a non-imager point spectroradiometer mounted on SIF-UAV (Unmanned Aerial Vehicle) system, and retrieved SIF at high spatial resolution, which is fitted for precision agriculture applications. In this study, we tracked the spatial variation of SIF along the season over a commercial avocado (P. americana Mill) orchard. The retrieved SIF signals were Krieg-interpolated to create a continuous SIF layer that allowed the estimation of SIF values for each tree in the orchard. We show that the SIF signal retrieved over the canopies in the main fruit development stage is highly correlated with the levels of sugars accumulated in the ripening avocado fruit. It established the foundations for high-spatial resolution detection of the natural variation of photosynthesis activity, which may lead to in-season adjustments of agronomic inputs using precision agriculture technologies.

plant biology↗

bioRxiv2023

Effects of Covering Mature Avocado `Pinkerton` Trees with High-Density Shading Nets during Cold Winters on Microclimate, Chlorophyll Fluorescence, Flowering and Yield

Avocado (Persea americana Mill.) is a subtropical fruit tree of high commercial value with increasing global demand. Most avocado cultivars are vulnerable to cold climates, which may reduce yields and restrict their geographical expansion. This includes the green-skinned avocado cv. Pinkerton, which accounts for 45% of the avocado cultivated in northeastern Israel. Shading nets can protect agricultural crops from cold environments. We therefore evaluated the effect of covering mature Pinkerton trees with high-density shading nets during the winter. Trees were covered with Silver-coloured 50% or 70% shading nets during three consecutive winters, while uncovered trees served as controls. Photosynthetically active radiation in plots covered with the Silver 50% or 70% nets was significantly lower than for the control by 52% and 90%, respectively. Minimum air temperature was similar between treatments. Maximum air temperature was generally lower under the shading nets compared to the control. The ratio of variable to maximum fluorescence (Fv/Fm) measured in February 2019 and 2020 was 0.72 and 0.8 in the control trees, 0.79 and 0.83 in the Silver 50% trees and 0.81 and 0.84 in the Silver 70% trees, respectively. Flowering intensity was lower in the net-covered trees compared to the control, by up to 42%. Interestingly, the three-year average yield of trees covered with the Silver 50% or 70% nets was insignificantly higher by 27% and 38%, respectively, compared to the control trees. These results suggest that the reduction of daytime solar irradiance in the winter by the shading nets may mitigate cold stress and increase yield. Additional long-term studies should examine the effects of shading nets and other shading strategies on different avocado cultivars.

plant biology↗