Background Biochar is widely assumed as an effective soil amendment. It improves soil structure and fertility, thereby enhancing crop growth and development. There is still a knowledge gap in research on the beneficial impact of biochar on root growth and root architecture in perennial woody plants. Therefore, in our 14-week greenhouse study, pinewood-based biochar was applied as soil amendment for muscadine grape cultivation to investigate its effects on soil physical properties and crop root growth. Muscadine grape cv. Alachua was grown on Ultisols soil mixed with five rates of biochar on weight basis. Soil mixture properties and root attributes were determined. Results The soil bulk density decreased 40% and the total porosity increased 50% by adding 20% biochar into pure sandy soil. The soil water-holding capacity (WHC) of 20% biochar amendment soil was 1.9 times as pure as sandy soil. In addition, the incorporation of biochar did not only ameliorate soil acidity at the beginning but also increased soil pH buffering capacity, providing suitable soil pH a few months after application. Moreover, biochar induced woody plant finer roots development and significantly promoted root length, number of root forks, and crossings, while decreasing root average diameter. Conclusions Pinewood biochar significantly improved soil physical properties by moderating soil thermal properties, buffering soil pH, improving soil WHC, decreasing soil bulk density, and increasing soil porosity. In addition, biochar also strengthened the root architecture by improving root length, number of root forks, and crossings. Furthermore, roots from the amended treatment had longer root length with less average diameter than unamended roots, indicating that biochar may stimulate muscadine fine root development. The incorporation of biochar in soil enhanced woody plant root growth and development improved soil structure in sandy soils. It could potentially be a good strategy to tackle water loss, particularly in sandy soils.

In recent decades, increasing attention has been paid to food safety and organic horticulture. Thus, people are looking for natural products to manage plant diseases, pests, and weeds. Essential oils (EOs) or EO-based products are potentially promising candidates for biocontrol agents due to their safe, bioactive, biodegradable, ecologically, and economically viable properties. Born of necessity or commercial interest to satisfy market demand for natural products, this emerging technology is highly anticipated, but its application has been limited without the benefit of a thorough analysis of the scientific evidence on efficacy, scope, and mechanism of action. This review covers the uses of EOs as broad-spectrum biocontrol agents in both preharvest and postharvest systems. The known functions of EOs in suppressing fungi, bacteria, viruses, pests, and weeds are briefly summarized. Related results and possible modes of action from recent research are listed. The weaknesses of applying EOs are also discussed, such as high volatility and low stability, low water solubility, strong influence on organoleptic properties, and phytotoxic effects. Therefore, EO formulations and methods of incorporation to enhance the strengths and compensate for the shortages are outlined. This review also concludes with research directions needed to better understand and fully evaluate EOs and provides an outlook on the prospects for future applications of EOs in organic horticulture production.

The subtropical peach cultivar UFSun grafted on five different rootstocks ('Flordaguard', 'Barton', 'MP‐29', 'P‐22', and 'Okinawa') was investigated in terms of the pomological and biochemical parameters of the fruit. Significant differences in fruit weight and size, soluble solids content, titratable acidity, and firmness were found among some rootstocks. The fruit length and diameter were different between the 'MP‐29' and other rootstocks. It was also found that firmness of 'UFSun' fruit was affected by the rootstock. The highest firmness value was found when 'UFSun' was grafted on 'Flordaguard'.' 'MP‐29' fruit had the highest soluble solids content, but there were no differences among the other rootstocks. 'UFSun' fruit from trees grafted on 'MP‐29' were smaller and had the most intense color compared to 'UFSun' fruit from other rootstocks. Rootstock had a significant influence on total fruit phenolic compounds, anthocyanin content, and total antioxidant activity, with fruit from 'UFSun' on 'MP‐29' having the highest values in all of them. A high correlation between fruit total antioxidant activity and total phenolic content was found. Overall, the results showed that 'MP‐29' seems to induce the highest fruit quality, showing higher contents of total soluble solids, total titratable acidity, total phenolic compounds, total antioxidant activity, and total anthocyanin content. Selecting the right combination of the rootstock and cultivar is important for optimizing fruit quality parameters.

In commercial fruit production, synchronized ripening and stable shelf life are important properties. The loosely clustered or non-bunching muscadine grape has unrealized potential as a disease-resistant cash crop, but requires repeated hand harvesting due to its unsynchronized or long or heterogeneous maturation period. Genomic research can be used to identify the developmental and environmental factors that control fruit ripening and postharvest quality. This study coupled the morphological, biochemical, and genetic variations between “Carlos” and “Noble” muscadine grape cultivars with RNA-sequencing analysis during berry maturation. The levels of antioxidants, anthocyanins, and titratable acids varied between the two cultivars during the ripening process. We also identified new genes, pathways, and regulatory networks that modulated berry ripening in muscadine grape. These findings may help develop a large-scale database of the genetic factors of muscadine grape ripening and postharvest profiles and allow the discovery of the factors underlying the ripeness heterogeneity at harvest. These genetic resources may allow us to combine applied and basic research methods in breeding to improve table and wine grape ripening uniformity, quality, stress tolerance, and postharvest handling and storage.

Muscadine grape is a perennial crop that is highly responsive to local environmental factors and viticulture practices. Biochar is a promising soil amendment used to improve soil water and nutrient retention and promote plant growth. The present study aimed to assess the effects of different pinewood biochar rates on nutrient status and vegetative parameters of muscadine grape cv. Alachua grown on a nutrient-poor sandy soil, Ultisols (97.2% sand, 2.4% silt, and 0.4% clay), and mixed with five different rates (0%, 5%, 10%, 15%, and 20%) of biochar based on weight. Variations in soil moisture, temperature, and leaf greenness value [soil plant analysis development (SPAD) reading], net photosynthesis rate, and plant root and shoot dry weights were measured. In addition, the nutrient status of the soil, plant root, and shoot were determined. The results indicated that the higher rate of biochar could significantly (P < 0.05) improve soil moisture. Biochar can also decrease soil temperature, although there were no significant differences among treatments. Regarding the nutrient status, the biochar amendment increased the nutrient content of phosphorus (P), potassium (K), magnesium (Mg), and calcium (Ca), as well as the soil organic matter content and cation exchange capacity. Higher nutrient contents in soil lead to increased P and Mg in both aboveground and belowground muscadine plant tissues and decreased nitrogen (N), iron (Fe), and copper (Cu) in the root part. There were no significant differences observed in SPAD values, net photosynthesis, or dry weights of the root and shoot. This study demonstrates that the addition of biochar may enhance the soil water and nutrient status as well as improve plant P and Mg uptake; however, it showed no significant differences in the physiological performance of muscadine grape plants.

Fruit size is an important factor in a fruit crop’s marketability. This 6-page document discusses fruit thinning, a process that is critical to achieving larger-sized peaches, and thus is critical to the success of peaches grown in Florida. Written by Yuru Chang, Ali Sarkhosh, Jeffrey Brecht, and Peter Andersen and published by the UF/IFAS Horticultural Sciences Department, January 2018. http://edis.ifas.ufl.edu/hs1324

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