Abstract Spray deposition patterns from agricultural sprayers are traditionally sampled discretely along a field transect accounting for 0.5% or less of the treated area. Such methods may not fully capture the dimensional variability inherent in large‐scale, multiple‐pass spray applications, especially evident from an agricultural spray drone (ASD). This study investigated the utilization of UV‐fluorescent dye and nighttime aerial imaging techniques to assess large‐scale, multipass spray deposition patterns. Accuracy of digital hue from UV‐fluorescent photography to predict deposition of proxy dye was confirmed via fluorometry assessed intensity levels of extracted UV‐fluorescent dye from 384 Petri dishes placed prior to treatment. Results showed that ASD applications, regardless of nozzle type, exhibited greater spatial variability within the target area compared to ride‐on sprayer applications, primarily due to overapplication. Additionally, the ASD generated spray drift to adjacent nontarget areas that was at least three times more than that of ride‐on and spray‐gun sprayers. Multipass deposition was further assessed via in situ smooth crabgrass infestation following treatment with quinclorac or topramezone by multipass ASD or hand‐held, four‐nozzle spray boom. Weed infestation annotated from overlaid grids with 9.3‐dm2 ground resolution inconsistently detected spatial heterogeneity between transects assessed along the center and edge of each sprayer pass. The ASD controlled smooth crabgrass 11% more than the hand‐held sprayer, albeit with an 18% increase in spray drift to nontarget areas, similar to the UV‐fluorescence study. Digitally assessed average hue of fluorescence photography appears to be a viable method to assess multidimensional and continuous spatial relationships of spray deposition.

Abstract Combining large multi‐environment trial (MET) datasets to decide which genotypes to move forward in the breeding process can be challenging, especially when dealing with negatively correlated traits. The use of a selection index has long been identified as an effective strategy in these situations. However, the method has found limited application in turfgrass breeding. The objective of this study was to use MET data for St. Augustinegrass [ Stenotaphrum secundatum (Walt.) Kuntze] breeding lines evaluated across the southern United States to compare genetic gains achieved with the additive additive genetic index (AI) versus the turf performance index (TPI) incorporating agronomic as well as consumer preference traits. The use of either selection index produced more positive genetic gains across traits than direct selection even in the presence of negative correlations. However, the higher genetic gains obtained with AI versus TPI indicate that the use of an index that weighs traits according to their importance is a better approach for selection. Moreover, under a more stringent selection intensity, none of the best lines identified with AI would have been selected with TPI emphasizing the importance of choosing selection criteria that provide a more nuanced ranking of lines. Additionally, higher heritability values and gains from selection were obtained for turfgrass quality under stress (drought and shade) than under normal conditions indicating that selection under stress environments might be more efficient. Most of the evaluated St. Augustinegrass lines outperformed the checks, further supporting the value of cross‐institutional breeding collaborations.

Abstract Sorghum (Sorghum bicolor) has the ability to inhibit the conversion of ammonium to nitrate (biological nitrification inhibition [BNI]) in the rhizosphere, which in turn prevents the loss of bioavailable nitrogen. Sorgoleone is a lipidic compound secreted by sorghum root hairs and is responsible for roughly 60% of BNI activity in sorghum. Previous studies revealed variation in sorgoleone secretion among different accessions and cultivars. However, little information is available regarding the genetic inheritance of sorgoleone secretion in sorghum. To increase sorgoleone through breeding, an understanding of the inheritance of this trait is required. In this study, 21 seed parents and 21 pollinator parents from the Texas AgriLife Research sorghum breeding program were crossed in an incomplete factorial design to generate 158 hybrids, and sorgoleone secretion from both hybrids and inbreds was quantified. There was significant variation in sorgoleone secretion across hybrids and inbred lines, and small but significant mid‐parent heterosis was observed in the hybrids. A linear mixed model analysis to calculate general and specific combining abilities for inbred parents and hybrids detected significant genetic effects for the male, the female, and male × female interactions (p < 0.001). Broad‐sense heritability was high ( = 0.87), while narrow‐sense heritability for the seed parents and pollinator parents was moderate (= 0.35 and = 0.39, respectively). These results indicate that sorgoleone exudation is primarily driven by additive genetic effects, but dominance effects are important for optimum production. These findings indicate that selection for increased sorgoleone root exudation among elite, adapted grain sorghum hybrids and inbred should be effective.

Abstract Equidistant plant arrangements have shown positive impacts, in the United States over the last century, on soybean (Glycine max L.) yield and seed quality by reducing intraspecific plant competition and enhancing early canopy cover. This study aims to (i) assess the effects of equidistant versus non‐equidistant plant arrangements on soybean yield and seed quality across different regions in the United States; (ii) explore the effect of modified soybean plant canopy resulting from different plant arrangements on yield and seed quality. In 2021 and 2022, 13 trials were conducted in Kansas, Mississippi, and South Dakota. The treatments consisted of three equidistant plant arrangements of 13 cm × 13 cm, 15 cm × 15 cm, and 20 cm × 20 cm (620,000, 430,000, 242,363 seeds ha−1, respectively), and a non‐equidistant with 38 cm of row space (321,236 seeds ha−1). Soybean yield and yield components were collected, and canopy coverage (%) was monitored throughout the growing season. Overall, there is no evidence of any advantage of equidistant over non‐equidistant arrangements in soybeans. Yield differences related to spatial arrangement were observed in only three trials: the non‐equidistant increased yield compared to the 20 cm × 20 cm equidistant arrangement (lowest density) in two trials, while the 13 × 13 and 15 × 15 patterns (highest density) showed higher yield compared to the 20 cm × 20 cm arrangement in one trial. Furthermore, seed quality remained constant across spatial arrangements in the 13 trials. In contrast to prior research, our study found no correlation between canopy coverage development and yield improvement. The tested equidistant arrangement while promising did not provide substantial evidence of yield improvement relative to the non‐equidistant.

Abstract In an effort to find alternatives to paraquat for weed control and basal foliage removal in hops (Hummus lupulus L.), due to regulatory and safety concerns, a study was conducted across Oregon and Washington in 2020 and 2021. The study compared the efficacy of tiafenacil and tolpyralate against a nontreated control and carfentrazone. Applications were made early when hops were 2‐ to 3‐m tall (early), and at over 4 m (late). Tiafenacil showed 55%–85% effectiveness in basal foliage control, slightly higher than carfentrazone, and did not cause crop injury. Tiafenacil at 50 and 100 g a.i. ha−1 controlled Lolium multiflorum (Lam.) Husnot (63%). The mixture of tiafenacil and tolpyralate controlled 80% of L. multiflorum, Cirsium arvense L., and Bassia Scoparia (L.) A.J. Scott. In all cases, control was followed by weed regrowth. No signs of crop injury were observed in any of the studies with tiafenacil. Early applications of tiafenacil reduced yield between 0% and 40% relative to the nontreated control. Late applications of tolpyralate and tiafenacil did not significantly reduce yield. Tolpyralate was as effective as carfentrazone for weed control and basal foliage removal. Early applications of tolpyralate reduced plant height and yield relative to the nontreated control and consistently induced phytochemical injury. Tolpyralate yield reductions ranged from 0% to 84% relative to the nontreated control, depending on the trial. A mixture of tolpyralate and tiafenacil was the most effective treatment tested. We conclude that both tiafenacil and tolpyralate are safe for sucker applications in hops, but careful timing is needed to reduce the risk of injury with tolpyralate. The mixture of tiafenacil and tolpyralate can improve weed control comparable to available options.

Abstract Diversifying and perennializing cropping systems can increase productivity while supporting ecosystem services such as soil protection, nutrient retention, and greenhouse gas mitigation. New crops can help achieve these goals, and advanced computational tools allow plant breeders to rapidly domesticate new crops and select for many traits that support both ecosystem services and profitable production. Intermediate wheatgrass [Thinopyrum intermedium (Host.) Barkworth. & D.R. Dewey; IWG] is a cool‐season perennial grass undergoing domestication to function as a perennial grain crop. Key aboveground domestication traits have been improved to support economically viable yields using genomic selection. However, few studies have quantified belowground traits despite their potential role in conferring ecosystem services. We present a platform for using minirhizotron cameras and machine learning software to analyze rhizotron images for inclusion in genomic selection models. The strength and direction of pairwise correlations between traits were variable with correlation coefficients (r) ranging from −0.27 to 0.99. Grain yield was positively, although weakly, correlated with total root length, area, and volume (r = 0.21, 0.21, and 0.19, respectively). Estimates of narrow sense heritabilities ranged from 0.41 to 0.76 for all traits and 0.46 to 0.66 for root traits. Root trait predictions using a genomic prediction model, measured by correlating model‐predicted values and field‐observed values, ranged from 0.08 to 0.23. Aboveground traits were better predicted (0.17 < r < 0.33). Simply selecting for aboveground traits could result in populations with desirable root traits, but our results demonstrate the potential for genomic selection to aid in advancing populations with specific root traits important for ecosystem services.

Abstract Genome of Piper longum (long pepper, Piperaceae), an important medicinal plant, is being reported. The sequencing was carried out on Illumina Novaseq‐6000 platform at 150x coverage, and de novo scaffold‐level assembly has resulted in a 447.7 Mb genome (89,204 scaffolds with an N50 value of 10.7 kb). Even though long pepper is valued for its pungent alkaloids, especially piperine, mechanism of piperine biosynthesis is yet to be revealed. Functional annotation of the genes has given a better understanding of the genomic features and genes involved in piperine biosynthesis. Phylogenetic relationship of long pepper with other members of Piperaceae family and the expression of Piperine synthase and Piperamide synthase genes in the developing leaves and spikes were also analyzed. The results indicated that this medicinal plant may have genes similar to black pepper involved in the biosynthesis of piperine. Raw reads and the assembly are made publicly available.

Abstract Litchi (Litchi chinensis Sonn.) fruit, with its bright red color and sweet and juicy aril, is an important fruit crop in Asia, Africa, Australia, and South America. A major cause of the postharvest loss of litchi fruit is browning and decay. Chlorophyll breakdown and flavonoid synthesis occur simultaneously during the maturation of this nonclimacteric fruit. However, once litchi fruit is harvested, pericarp desiccation and membrane breakdown occur, which leads to browning with the rate of browning and later microcracking paralleling water loss rate. In addition, chilling injury can contribute to and increase pericarp browning and membrane leakage. Polyphenol oxidase and peroxidase are possibly key enzymes in the early stages of browning. An increase in the leakage of the pericarp membrane also occurs that correlates with browning. Many chemical treatments have been evaluated to retard pericarp browning, such as melatonin, hot water, acidified calcium sulfate (ACS), adenosine triphosphate, and tea seed oil. During long distance transportation, chemical treatments that involve sulfur are used, including SO2 fumigation, acid dip after SO2 fumigation, SO2 fumigation and sulfur sheet package, or SO2 fumigation followed by controlled atmosphere (CA), if approved by the importing country. Other treatments that avoid the use of SO2 include melatonin, ACS, and hot water brushing combined with an acid dip, CA, and modified atmosphere packaging. Anthracnose is a common disease that accelerates browning and decay. Penicillium species as a saprophyte is also common with fruit infection occurring in the field, during harvest, in the packhouse, cold rooms, and shipping containers. Sulfur sheet or CA is used to reduce fruit rot after SO2 fumigation and Sportak (prochloraz) for the control of penicillium. However, a replacement for postharvest SO2 use is still urgently needed.

Abstract Multi‐environment trial data from many crop variety evaluation programs are imbalanced because only a subset of varieties is selected for the following year, which leads to missing variety by year. Inspired by the US National Cotton Variety Test trial, we conducted new simulation studies to investigate selection processes that differ from the existing literature. The followings are our four main contributions. First, we adopted a framework that utilizes a logistic regression to generate imbalanced data that follow missing completely at random, missing at random, or missing not at random (MNAR). Second, our selection process can depend on multiple traits, whereas all existing studies only used a single trait for selection. Third, besides variance components (VCs), long‐term trends that reflect genetic and non‐genetic development are of interest since the simulated data span over 30 years. Last, we evaluated the prediction accuracy for variety's overall and location‐specific performance. The results show that the VC and long‐term trends estimations are the worst under MNAR using the single trait for selection. Compared to VC, the long‐term trends estimation is more influenced by the missing mechanism and missing rate. However, the prediction accuracy for variety's performance is mainly driven by the missing rate and is less sensitive to the selection process. If ignoring the genetic and non‐genetic long‐term trends, both estimation and prediction will deteriorate. More testing years would improve estimation and prediction, despite a higher missing rate.