A new combined difenoconazole and fluxapyroxad fungicide formulation, as an 11.7 % suspension concentrate (SC), has been introduced as part of a resistance management strategy. The dissipation of difenoconazole and fluxapyroxad applied to apples and the residues remaining in the apples were determined. The 11.7 % SC was sprayed onto apple trees and soil in Beijing, Shandong, and Anhui provinces, China, at an application rate of 118 g a.i. ha⁻¹, then the dissipation of difenoconazole and fluxapyroxad was monitored. The residual difenoconazole and fluxapyroxad concentrations were determined by ultrahigh-performance liquid chromatography tandem mass spectrometry. The difenoconazole half-lives in apples and soil were 6.2–9.5 and 21.0–27.7 days, respectively. The fluxapyroxad half-lives in apples and soil were 9.4–12.6 and 10.3–36.5 days, respectively. Difenoconazole and fluxapyroxad residues in apples and soil after the 11.7 % SC had been sprayed twice and three times, with 10 days between applications, at 78 and 118 g a.i. ha⁻¹ were measured. Representative apple and soil samples were collected after the last treatment, at preharvest intervals of 14, 21, and 28 days. The difenoconazole residue concentrations in apples and soil were 0.002–0.052 and 0.002–0.298 mg kg⁻¹, respectively. The fluxapyroxad residue concentrations in apples and soil were 0.002–0.093 and 0.008–1.219 mg kg⁻¹, respectively. The difenoconazole and fluxapyroxad residue concentrations in apples were lower than the maximum residue limits (0.5 and 0.8 mg kg⁻¹, respectively). An application rate of 78 g a.i. ha⁻¹ is therefore recommended to ensure that treated apples can be considered safe for humans to consume.

Traffic-based pollution causes accumulation of some elements in plant tissues and damages anatomical and physiological processes of plants. Nutrient use proficiency and litter decomposition are two basic processes of nutrient dynamics. This study aimed to determine the effects of traffic-based pollution on N and P use proficiency and litter decomposition in Malus domestica Borkh. (Rosaceae) which is a commonly cultivated fruit tree worldwide. The study was carried out in Amasya, Turkey, where the apple is the symbol of the city. Leaf samples were collected from apple trees at 0-, 100-, and 200-meter distances from the highway. N, P, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn concentrations were measured in the collected samples. All of the element concentrations varied according to the distance from the road. Traffic-based heavy metal pollution increased N and P use proficiency. It may be said that M. domestica reabsorb more N and P from senescent leaves due to the high heavy metal concentrations in their leaves. The decomposition rate was highest at 0 m and lowest at 100 m. The variations in the remaining dry weight, mass loss (%), and k value due to traffic-based pollution were not statistically significant. A significant negative relationship was determined between the initial N concentration and the litter decomposition rate. It was thought that this negative relationship resulted from recalcitrant condensation products that are formed by lignin and N.

Our experiment was conducted during the seasons of 2018 and 2019 on 10-year-old “Anna” apple trees (Malus domestica L. Borkh) planted at 4 × 4 m apart in a clay soil under drench irrigation. Sixty uniform trees were selected and subjected to the same cultural practices during both seasons. Apple trees were sprayed three times as follows: before flowering, during full bloom, and 1 month later with the following treatments: control (water only); tryptophan at 25, 50, and 100 ppm; glycine at 25, 50, and 100 ppm; and their combinations, 25 ppm tryptophan + 25 ppm glycine, 50 ppm tryptophan + 50 ppm glycine, and 100 ppm tryptophan + 100 ppm glycine. The results demonstrated that the foliar spraying of “Anna” apple trees with glycine and tryptophan at 25, 50, and 100 ppm and their combinations significantly increased shoot length and diameter, leaf area, total chlorophyll, percentages of fruit set and yield, fruit physical and chemical characteristics, and leaf mineral composition of N, P, K, Ca, Fe, Zn, Mn, and B, whereas it reduced the fruit drop percentage in both seasons in comparison with control. Better results were obtained from the concentrations of 50 and 100 ppm which were more effective in both seasons in comparison with the concentration of 25 ppm. Moreover, the combination of 50 ppm glycine 50 ppm tryptophan was the best treatment and provided the highest results in both experimental seasons in comparison with the other applied treatments and control.

Tebuconazole is a broad-spectrum fungicide extensively used worldwide for the control of many diseases such as powdery mildew and scab in apple, early blight of tomato, anthracnose of chilli, white rot and purple blotch of onion etc. Maximum residue level of this compound has not been worked out on these crops in India; the persistence and dissipation kinetics of tebuconazole on apple, tomato, chilli and onion were studied following three foliar applications of the formulation Folicur 430 SC at a standard dose (X) 322, 268.75, 215 and 215 g a.i./ha and at double dose (2X) 645, 537.5, 430 and 430 g a.i./ha, respectively, to work out the safe waiting periods and half-life period of tebuconazole. Extraction was done using QuEChERS method and cleanup by using dispersive solid-phase method. Tebuconazole residues were estimated on gas chromatograph-mass spectrometry (GC-MS). The recovery of tebuconazole in fortified matrix was above 90% with a limit of quantification (LOQ) at 0.05 mg kg⁻¹. The initial deposits of tebuconazole on apple at two locations under study ranged from 1.986–2.011 mg kg⁻¹at X dose to 3.698–3.843 mg kg⁻¹ at 2X dose. The initial deposits in tomato, chilli and onion were 1.129, 1.760 and 1.169 mg kg⁻¹ at X dose and 2.213, 2.784 and 2.340 mg kg⁻¹, respectively at the 2X dose. Dissipation of the fungicide followed first-order of kinetics and the half life of degradation ranged from 1.30–2.25 days at X dose to 1.40–2.62 days at 2X days on different crops under study. Residues declined below the determination limit (LOQ) of 15 and 20 days after spraying, respectively, at X and 2X dose in apple; 7 and 10 days in tomato; 10 and 15 days in chilli and onion. Waiting periods of 5, 2, 7 and 12 days, respectively, are suggested for apple, tomato, chilli and onion at 2X dose.