Influence of the Color,Shape, and Size of the Clay Model on Arthropod Interactions in Turfgrass

Many predatory arthropods occur naturally in turfgrass, and they provide adequate control of lepidopteran pests, such as fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), and black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae). Recording predation is challenging under field conditions because predators rarely leave any evidence. Clay models were successfully employed for studying predation, and this technique is underutilized in turfgrass. Little is known about whether the characteristics of clay models, such as color, shape, and size, influence arthropod interactions in turfgrass. To improve the utility of clay models in turfgrass, the influence of the color, shape, and size of clay models on arthropod interactions was studied by exposing clay models during daytime and nighttime in a turfgrass field. The results showed that arthropods interacted with clay models, and various types of impressions were recorded, including paired marks, scratches, cuts, and pricks. Although the color of the clay model had no significant effects on arthropod interactions during the night, significantly greater numbers of impressions were noticed on the blue and green models than on the yellow models during the daytime. The caterpillar-shaped models captured significantly greater densities of impressions than the beetle-shaped models. Additionally, the number of impressions significantly increased with an increase in the size of the model regardless of shape.     

Phenotypic tendency of achene yield and oil contents in sunflower hybrids

ABSTRACT

The knowledge about heterosis breeding of achene yield in sunflower is known; however, dissection of the genetic components of achene yield and seed quality traits is limited. Therefore, the prescribe study was conducted using Line × Tester design to determine combining abilities, and about the maternal-and-paternal gene actions involved in achene yield and seed quality traits in 21 single cross hybrids. Significant mean differences for achene yield and seed quality traits were observed, with total attributed variation (R^2?=^?0.89). Principal component analysis (P?<?0.05) explained 92.6% variation and using factor analysis, we found factor 1 had primary variables (AW, AL, AT, HD, PH, PC, LA and OC) contributed 35.6% variation to achene yield. Combining ability analysis showed the positive general combining ability for E%, HD, PH, 100 AW and AYP in parental inbred lines, whilst, hybrids had positive specific combining ability for E%, HD, PH, 100 AW, DTF, DTM, OA, LA, OC and AYP. Females contributed significantly higher (P?<?0.05) for AYP, E%, HD, NWPH, PH, 100 AW, LA and OA than that of males. Two-way hierarchical clustering showed the most promising hybrid H₅ (A-18?×?G-79) in Cluster V. The hybrid H₅ also showed heterosis, heterobeltosis and commercial heterosis, therefore, genetic exploitation of H₅ is highly desirable in future breeding to map QTLs/genes in arid/semi-arid zones and /or similar growing conditions to boost up yield and seed quality traits.     

Australian rice varieties vary in grain yield response to heat stress during reproductive and grain filling stages

Climate change may lead to an increase in both day and night time temperatures in rice (Oryza sativa L) growing regions, but the impact of such temperature increases on yields of Australian rice varieties is not known. We evaluated the biomass and grain yield response of eleven Australian rice varieties including long, medium and short grain types, and the Californian cultivar M205, to heat stress during the reproductive phase and grain filling stages. Heat stress (day/night = 35/25°C) was applied at one of three stages: from panicle exertion to anthesis (PE), from anthesis to 10 days after anthesis (EGF) and from 10–20 days after anthesis (LGF) periods after which the effect on biomass and grain yield was compared to control plants. When heat stress was applied at PE and early grain filling stages, mean grain yield losses across rice varieties were 83% and 53%, respectively, though significant genotype × heat stress treatment interactions were observed. Notably, three varieties—YRM 67, Koshihikari and Opus—appeared to possess greater tolerance to heat stress at these growth stages. A significant genotype × heat stress treatment interaction was also observed in the LGF treatment, where significant yield reductions were only observed in Opus (21% loss) and YRM 67 (25% loss). A lack of effect of heat stress on total grain yield in most varieties at late grain filling appeared to be due to late tiller grain yields which were either unaffected by the heat stress or increased significantly compared to control plants. While genetic variation for tolerance to heat stress across the three growth stages was observed, there was no rice genotype that was consistently tolerant (in terms of yield under stress) across all three heat stress treatments. In the absence of a genotype that showed broad heat stress tolerance during reproductive growth, we suggest screening of a wider pool of more diverse rice germplasm is warranted.     

Influence of different organic geo-sorbents on Spinacia oleracea grown in chromite mine-degraded soil: a greenhouse study

Purpose

Potentially toxic element (PTE) concentrations in mine-degraded soil and their bioaccumulation in food crops is a public health concern worldwide. The current study investigates the influence of organic geo-sorbents including biochar (B), farmyard manure (FYM), and peat moss (PTM) on PTE in chromite mine-degraded soil and their subsequent effects on spinach biomass, PTE uptake, average dietary intake (ADI), and health risk (HRI) associated with PTE via spinach consumption.

Materials and methods

Chromite mine-degraded soil samples were collected from different mining sites in Kohistan region. Pot experiments were carried out in the greenhouse environment. The selected geo-sorbents (B, FYM and PTM) were mixed at application rates of 1%, 2%, and 5%. Contaminated soil without geo-sorbents (control treatment) was also included in each batch of the experiments. Local FYM and PTM were used in this experiment, while B was provided by the Institute of Urban Environment (CAS) Xiamen, China. The total carbon (C), total nitrogen (N), and total sulfur (S) contents in mine-degraded soil and organic geo-sorbents were measured using a macro-elementor (VarioMax CNS, Germany). Total (acid digestion) and bioavailable PTE (As, Cd, Cr, Ni, Zn, and Pb) concentrations in mine-degraded soil and spinach were determined using inductive coupled plasma mass spectrophotometer (ICP-MS 7500 CX, Agilent Technologies, USA).

Results and discussion

The addition of organic geo-sorbents effectively immobilized the PTE concentrations in mine-degraded soil, and increased the major nutrient contents and thereby reduced the bioaccumulation of PTE (Cr, As, Ni, Cd, Zn, and Pb) in spinach. Consequently, B2, B5, FYM2, FYM5, PTM2, and PTM5 amendments significantly (p?<?0.001) increased the biomass, whereas the B1, FYM1, and PTM1 addition showed no significant increase in spinach biomass as compared to the control treatment. The results showed that all the organic geo-sorbents had significantly (p?<?0.001) reduced the As uptake in spinach, while B2, B5, FYM2, FYM5, and PTM5 significantly (p?<?0.001) decreased PTE bioaccumulation as compared to the control treatment.

Conclusions

The highest application rate (5%) showed the best result in increasing the spinach growth and biomass as well as reducing the PTE mobility in soil, and their bioaccumulation in spinach, as compared to 1% and 2% application rates and also with the control treatment. Furthermore, the average dietary intake (ADI) of PTE and health risk indices (HRIs) reduced via spinach consumption for both the children and adults, due to the addition of selected organic geo-sorbents used for soil amendments.

     

Effect of Azospirillum and Azotobacter Species on the Performance of Cherry Tomato under Different Salinity Levels

Abiotic stress has a negative impact on plant physiology, influencing the overall growth and development of plant crops. Saline stress is one of the most serious environmental issues limiting crop plant production. Biofertilizers are reparative elements used in soil to increase tolerance to salinity and drought stress. We investigated the effect of salinity stress on qualitative and quantitative characteristics of cherry tomato plants (Lycopersicon esculentum cerasiforme) with biofertilizer application 0, 15 and 30 days after transplanting in this study. After different days of transplantation, different levels of salinity (0, 50, 100, and 150?mM) were used with biofertilizer (Azospirillum sp. and Azotobacter sp.) application (0, 15 and 30 days). The salinity (150?mM NaCl) significantly affected the studied variables, which were recorded with minimum levels of leaf area (52.42?cm²), root length (6.54?cm), fresh root weight (13.64?g), yield (6.52 tons/ha), leaf chlorophyll content (36.11?mg/m²) and maximum levels of total soluble solids (TSS, 8.87 °Brix). Control samples had higher leaf area (58.35?cm²), root length (15.23?cm), fresh root weight (17.86?g), yield (9.39 tons/ha), leaf chlorophyll content (44.09?mg/m²), and lower TSS (7.93 °Brix). Plants that received biofertilizer (15 days after transplanting) had higher plant height (73.41?cm), stem diameter (0.74?cm), leaf area (61.16?cm²), root length (15.35?cm), fresh root weight (18.38?g), root dry matter (60.41%), yield (10.43?t/ha), leaf chlorophyll content (42.55?mg/m²), fruit dry matter content (10.12?g), pH 4.52, and TSS (9.30 °Brix). The minimum plant height (51.33?cm), stem diameter (0.55?cm), leaf area (49.60?cm²), root length (7.04?cm), fresh root weight (12.76?g), root dry matter (42.16?g), yield (5.15 tons/ha), leaf chlorophyll content (35.18?mg/m²), fruit dry matter content (6.59?g), pH 4.27 and TSS (7.55 °Brix) were recorded in plants with no application of biofertilizer. The present study revealed that most growth and quality variables were negatively affected by salinity except for TSS, which showed positive effect with application of 150?mM of NaCl. Biofertilizer application at 15 days significantly influences the quantitative and qualitative attributes of cherry tomato under different levels of salinity.

     

Impact of Irrigation Timing and Weed Management Practices on Chlorophyll Content and Morphological Traits of Tomato (Solanum lycopersicum Mill.)

Weeds are a major biotic constraint; compete with crop for the same resources and ultimately reduce productivity. This study evaluated the impact of irrigation intervals and weed management treatments on chlorophyll content and morphological growth of tomato to find an appropriate integrated weed management strategy. Two-year field experiments (2018/2019) were conducted at district Mardan (34°15′38″ N and 72°6′36″ E). Tomato F1 hybrid (Taj?3592) was transplanted during March. The experiments were laid out in a randomized complete-block design in split-plot arrangement with three replications. The main block comprised three irrigation intervals (3, 6, and 9 days) and the sub-block included weed management treatments: transparent polythene, black polythene, weeding except Orobanche, sole weeding of Orobanche, weeding of all weeds, copper oxychloride 1.5?kg a.i ha^?1 (single dose), copper oxychloride 1.5?kg a.i ha^?1 (split doses), copper oxychloride?+?humic acid 25?kg ha^?1 (single dose), copper oxychloride?+?humic acid 25?kg ha^?1 (split doses), copper sulphate 2?kg ha^?1 (single dose), copper sulphate 2?kg ha^?1 (split doses), ammonium sulphate 200?kg ha^?1 (single dose), ammonium sulphate 200?kg ha^?1 (split doses), pendimethalin 33 EC 1.44?kg a.i ha^?1, glyphosate 48 SL 1.5?kg a.i ha^?1, and weedy check. Lowest relative weed density (RWD) of O. cernua (2.23%) and highest RWD of O. cernua (38.01%) were recorded in the 3? and 9?day irrigation intervals, respectively. However, 3?day irrigation interval resulted in highest fresh weed biomass (5794?kg ha^?1). Moreover, the 6?day irrigation interval significantly increased chlorophyll content by 11 and 5%, leaf area by 23 and 6%, and number of branches plant^?1 by 30 and 22% compared to 9? and 3?day irrigation intervals, respectively. Among the weed management treatments, black polythene resulted in the highest weed control efficiency (96%), increasing chlorophyll content by 16%, leaf area by 33%, and number of branches plant^?1 by 64% vs. weedy check. Consequently, 6?day irrigation intervals?×?black polythene could be the best weed management strategy, followed by transparent polythene, weeding of all weeds, pendimethalin, glyphosate, and ammonium sulphate.