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A nondestructive fluorescence-based technique for evaluating Vitis vinifera L. grape maturity using a portable sensor (Multiplex) is presented. It provides indices of anthocyanins and chlorophyll in Cabernet Sauvignon, Merlot, and Sangiovese red grapes and of flavonols and chlorophyll in Vermentino white grapes. The good exponential relationship between the anthocyanin index and the actual anthocyanin content determined by wet chemistry was used to estimate grape anthocyanins from in field sensor data during ripening. Marked differences were found in the kinetics and the amount of anthocyanins between cultivars and between seasons. A sensor-driven mapping of the anthocyanin content in the grapes, expressed as g·kg(-1) fresh weight, was performed on a 7-ha vineyard planted with Sangiovese. In the Vermentino, the flavonol index was favorably correlated to the actual content of berry skin flavonols determined by means of HPLC analysis of skin extracts. It was used to make a nondestructive estimate of the evolution in the flavonol concentration in grape berry samplings. The chlorophyll index was inversely correlated in a linear manner to the total soluble solids (°Brix): it could, therefore, be used as a new index of technological maturity. The fluorescence sensor (Multiplex) possesses a high potential for representing an important innovative tool for controlling grape maturity in precision viticulture.

Excessive use of nitrogen fertilizer and inappropriate fertilization designs have negative results in agricultural ecosystems, such as considerable nitrogen losses through nitrogen dioxide (NO2) soil leaching and ammonia NH3 volatilization. In addition, climate change, with rising summer temperatures and reduced precipitation, leads to production declines and water shortages in the soil. This review aims to highlight the characteristics of natural zeolite and focus on their multiple uses in agriculture. These minerals are tectosilicates showing an open three-dimensional structure involving the cations required to balance the framework electrostatic charge of aluminum and silicon tetrahedral units. Different research groups reported more than fifty natural zeolites; chabazite, clinoptilolite, phillipsite, erionite, stilbite, heulandite, and mordenite are the most well-known. Zeolites are great tools to help the farmer and agronomist cope with several issues, such as soil or water pollution, contamination by heavy metals, loss of nutrients, and loss of water-use efficiency (WUE) of drylands. These natural crystalline aluminosilicates are considered soil conditioners to improve soil chemical and physical properties, such as saturated hydraulic conductivity (Ks), infiltration rate, cation exchange capacity (CEC), and water-holding capacity (WHC). Owing to their properties, these materials are able to reduce nitrate leaching and ammonia volatilization. Zeolites are also known for their carrying capacity of slow-release macronutrients, micronutrients, and fertilizers. However, the potential of these materials in agricultural areas is apparent, and zeolites show the promise of contributing directly to improve agricultural ecosystems as a sustainable product.

The hypothesis was tested that effects of late-season European Red Mite (ERM) [Panonychus ulmi (Koch)] injury on apple (Malus domestica Borkh.) fruit development are better explained by carbon physiology than by pest densities. Midseason ERM populations were allowed to develop in mature semi-dwarf `Starkrimson Delicious'/M26 trees with moderately heavy crops, then were controlled with miticides at different mite-day (activity of one mite per leaf for 1 day) levels as estimated by weekly leaf sampling. The range of final mite-days was from 250 to 2100 on individual trees. Seasonal fruit growth patterns were monitored. Diurnal whole-canopy net CO2 exchange rate (NCER) was measured in eight clear flexible balloon whole-canopy chambers on several dates before and after mite infestations. Mite injury reduced fruit growth rates. Leaf and whole-canopy NCER were reduced similarly. Late season fruit growth and final fruit size were correlated with accumulated mite-days, but were better correlated to whole-canopy NCER per fruit. Fruit firmness, color, soluble solids and starch ratings showed no correlation to mite-days. Number of flower clusters per tree and final fruit per tree the following year were not related to accumulated mite-days, but final fruit per tree the following year were better correlated to whole-canopy NCER per fruit. These results generally supported the hypothesis.

Climate change and disproportionate anthropogenic interventions, such as the excess of phytopharmaceutical products and continuous soil tillage, are jeopardizing viticulture by subjecting plants to continuous abiotic stress. One of the main physiological repercussions of abiotic stress is represented by the unbalanced redox homeostasis due to the overproduction of reactive oxygen species (ROS), ultimately leading to a state of oxidative stress (detrimental to grape quality). To these are added the direct and indirect damages caused by pathogens (biotic stresses). In light of this scenario, it is inevitable that sustainable techniques and sensitivity approaches for environmental and human health have to be applied in viticulture. Sustainable viticulture can only be made with the aid of sustainable products. Biostimulant (PB) applications (including resistance inducers or elicitors) in the vineyard have become interesting maneuvers for counteracting vine diseases and improving grape quality. These also represent a partial alternative to soil fertilization by improving nutrient absorption and avoiding its leaching into the groundwater. Their role as elicitors has important repercussions in the stimulation of the phenylpropanoid pathway by triggering the activation of several enzymes, such as polyphenol oxidase, lipoxygenase, phenylalanine ammonia-lyase, and peroxidase (with the accumulation of phenolic compounds). The present review paper summarizes the PBs’ implications in viticulture, gathering historical, functional, and applicative information. This work aims to highlight the innumerable beneficial effects on vines brought by these products. It also serves to spur the scientific community to a greater contribution in investigating the response mechanisms of the plant to positive inductions.