Southern Region Produce Safety Alliance Grower Training: Using Pre- and Post-Training Knowledge Assessments to Understand Training Effectiveness.

The Produce Safety Alliance (PSA) grower training was introduced in 2016 as the standardized curriculum to meet the training requirements of the Food and Drug Administration's (FDA) Food Safety Modernization Act's (FSMA) Produce Safety Rule (PSR). The PSR states that at least one supervisor or responsible party from each farm must have successfully completed this food safety training or one equivalent to the standardized curriculum, as recognized by the FDA. This study evaluated the effectiveness of PSA trainings conducted between 2017 and 2019 in the Southern United States by the Southern Regional Center for Food Safety Training, Outreach, and Technical Assistance by analyzing pre- and posttest assessments. Effectiveness was based on a 25-question knowledge assessment administered to participants before (n = 2494) and after (n = 2460) each training. The knowledge assessment indicated the overall effectiveness of the training, with average scores increasing significantly from pretest (15.9/25, 63.4%) to posttest (20.3/25, 81.3%) (P < 0.001). The greatest knowledge gains were seen in the Postharvest Handling and Sanitation, How to Develop a Farm Food Safety Plan, and Agricultural Water modules. Notably, these modules had lower posttest scores compared to the other modules, indicating that the amount of knowledge gained did not necessarily correspond with a sufficient understanding of the material. To ensure that participants understand all aspects of the PSR and best practices to minimize food safety risks, additional or advanced trainings may be needed. Additionally, the current testing instrument (pre-/posttest) used for PSA grower training, while validated, may not be optimal, thus alternative methods to assess the training effectiveness are likely needed.

Organic fertilizer type and dose affect growth, morphological and physiological parameters, and mineral nutrition of watermelon seedlings.

Background: Organic agriculture has grown rapidly in recent years due to its environmental friendliness, sustainability, and improved farm profitability. Transplants are commonly used for fruits and vegetables to achieve consistent quality, uniformity, and easy field spacing control. The efficacy and optimal amounts of fertilizers for organic transplant production need to be investigated. Methods: The effects of three organic fertilizers (Sustane 4-6-4, Nature Safe 7-7-7, and Dramatic 2-4-1) and one conventional fertilizer Peters Professional 20-20-20 (Conventional) with four doses (nitrogen (N) content was matched among fertilizers in each level, as 0.14 g/L, 0.28 g/L, 0.56 g/L, and 0.84 g/L N, respectively) on watermelon seedlings were compared in this study. Results: The results showed that all organic fertilizer treatments were not significantly different from the Conventional group in terms of watermelon germination. The only exception was the highest dose of Sustane 4-6-4 (0.84 g/L N) which decreased the germination rate and relative emergence index. Generally, growth index, shoot fresh and dry weights, true leaf number, and stem diameter increased as the amount of N increased within each fertilizer type. The best shoot growth was observed in the highest doses of Conventional and Dramatic 2-4-1 treatments (0.84 g/L N). However, Dramatic 2-4-1 treatments resulted in the lowest root growth when compared to other fertilizers at the same N dose. The second highest fertilization dose (0.56 g/L N) of Sustane 4-6-4 had the best root growth according to root fresh weight, root volume, root area, total root length, as well as the numbers of root tip and crossing when compared to other treatments. For seedlings, a well-developed root system can ensure a good seedling establishment and high survival rate under stressful field conditions after transplanting. Thus, Sustane 4-6-4 at 14 g/L (0.56 g/L N) is recommended to produce high-quality organic watermelon seedlings among the treatments applied in this study.

Orthogonal test design for optimizing culture medium for in vitro pollen germination of interspecific oil tea hybrids.

Oil Tea (Camellia oleifera) is an important woody edible oil plant in China. Oil Tea suffers from low rate of fruit set during production, which is related to poor pollination and fertilization. Pollen vigor is directly related to pollination and fertilization. Using the interspecific hybrid Y3 (C. grijsii × C. oleifera) as plant material, we studied the effects of sucrose, H3BO3, MgSO4, and IAA on pollen germination using an orthogonal design to determine the best culture medium. Results indicated that pollen germination rates were significantly affected by medium components and ranged from 29.13% to 56.84%. Pollen tube length was the longest in the T5 medium surpassing the control group by 489.36 µm. MgSO4 turned out to be the most important germination medium component having great effect on the pollen germination rate. The optimal culture medium to promote pollen tube growth of Oil Tea Y3 was: 1% agar, 150 g·L-1 sucrose, 0.15 g·L-1 H3BO3, 0.07 g·L-1 MgSO4, and 0.01 g·L-1 IAA. The results of this paper may provide information for foliar application of Mg and IAA, which can improve pollen tube growth of Oil Tea in practice.

Stability of yield and its components in grafted tomato tested across multiple environments in Texas.

Grafting with vigorous rootstocks could offer tomato growers in Texas sustainable and efficient option to achieve reliable yield across a range of production systems and locations. Genotypes (G) of grafted and non-grafted tomato were grown in different environments (E) in the 2017 and 2018 spring seasons. The objectives of the study were to (i) evaluate the effects of production system and grafting on tomato yield traits, (ii) determine the size of genotypic and genotype by environment interaction (G × E) variance components, and (iii) evaluate the relative stability of tested genotypes for yield and its components across production environments. In 2017, genotypes were non-grafted 'TAMU Hot Ty' (TAM) and 'Tycoon' (TY) and each grafted on commercial tomato rootstocks 'Estamino' (TAM/ES, TY/ES) and 'Multifort' (TAM/MU, TY/MU) while in 2018, TAM and 'HM1823' (HM) were grafted on 'Estamino' (TAM/ES, HM/ES) and 'Multifort' (TAM/MU, HM/MU). Testing environments were high tunnel (HT) and open-field (OF) in Uvalde in 2017 while in 2018, these were HT and OF in Lubbock (LU-HT, LU-OF), Overton (OV-HT, OV-OF), Uvalde (UV-HT, UV-OF), and Weslaco (WE-HT, WE-OF). Total and marketable yields, fruit number per plant, and average fruit weight were significantly affected by E, G, and G × E interaction. Environmental component contributed 71-86% to the total variation for all these traits, while genotype explained 1.5-10.8%, and the contribution of G × E ranged between 4.3 to 6.7%. Estimation of the univariate statistic parameters and genotype plus genotype × environment (GGE) biplot analysis indicated that HM/MU and HM/ES were the most stable graft combination with the highest total and marketable yields, while TAM/ES was very unstable for yields across test environments. TAM/MU was stable but with yield lower than the grand mean. These results suggest that high tomato yields could be consistently achieved with grafted combination (HM/MU and HM/ES) especially under high tunnel production system across the regions of Texas.

Phosphorus relieves aluminum toxicity in oil tea seedlings by regulating the metabolic profiling in the roots.

Oil tea (Camellia oleifera Abel.) is an important edible oil tree mainly grown in acidic soils, whose growth and yield can be severely limited due to soil aluminum (Al) toxicity and phosphorus (P) deficiency. In this study, we investigated the physiological and metabolic responses of oil tea to Al and P treatment for an 8-week duration. Al reduced root length, root volume, and plant biomass, while P addition alleviated the effects of Al toxicity. P addition increased P content and reduced Al accumulation in roots. The profiles of 58 metabolites were significantly changed in roots of oil tea seedlings. Al toxicity increased various amino acids, but decreased many kinds of organic acids and carbohydrates. Interestingly, P addition reduced the amino acids accumulation which were induced by Al toxicity, while only a few organic acids changed under P supply. Most carbohydrates, including sucrose and glucose, significantly increased with P addition under Al toxicity. Results indicated that Al toxicity increased the accumulation of amino acids and reduced the accumulation of organic acids and carbohydrates, while the addition of P promoted root growth by alleviating the inhibition of protein synthesis and increasing carbohydrates content. However, P addition did not increase the organic acids content in roots.