Changes in weed infestation of spring barley depending on variable pluvio-thermal conditions

The aim of the study was to analyze segetal weeds present in spring barley against the background of changes in pluvio-thermal conditions observed over the last 20 years (1993–2012) at the Field Experimental Station of the Institute of Plant Protection – National Research Institute in Winna Góra, Poland. Based on the mean value of the Sielianinov hydrothermal coefficient for the three months of spring vegetation, i.e., April, May, and June, three classes of pluvio-thermal conditions (very dry, moderately dry, humid) were distinguished. The phytosociological stability of weed species analyzed during the study period was assessed and the Shannon–Wiener index of species diversity in the communities and the Simpson dominance index were calculated for segetal weeds present in spring barley.In the 20-year period analyzed, Chenopodium album and Viola arvensis exhibited the highest phytosociological stability and the highest abundance in the spring barley crop. Over the years analyzed, the dry spring vegetation periods were characterized by significant precipitation deficiency between late April and mid-June. In the years with favorable meteorological conditions, the weed species diversity measured by the Shannon–Wiener diversity index was higher than in the years with precipitation deficiency. In the very dry years, the species dominance index in the spring vegetation period was higher than in the wet years. The yield loss caused by weed infestation in the very dry years was higher by 6% as compared to moderately dry and wet years

Changes in weed infestation of spring barley depending on variable pluvio-thermal conditions

The aim of the study was to analyze segetal weeds present in spring barley against the background of changes in pluvio-thermal conditions observed over the last 20 years (1993–2012) at the Field Experimental Station of the Institute of Plant Protection – National Research Institute in Winna Góra, Poland. Based on the mean value of the Sielianinov hydrothermal coefficient for the three months of spring vegetation, i.e., April, May, and June, three classes of pluvio-thermal conditions (very dry, moderately dry, humid) were distinguished. The phytosociological stability of weed species analyzed during the study period was assessed and the Shannon–Wiener index of species diversity in the communities and the Simpson dominance index were calculated for segetal weeds present in spring barley. In the 20-year period analyzed, Chenopodium album and Viola arvensis exhibited the highest phytosociological stability and the highest abundance in the spring barley crop. Over the years analyzed, the dry spring vegetation periods were characterized by significant precipitation deficiency between late April and mid-June. In the years with favorable meteorological conditions, the weed species diversity measured by the Shannon–Wiener diversity index was higher than in the years with precipitation deficiency. In the very dry years, the species dominance index in the spring vegetation period was higher than in the wet years. The yield loss caused by weed infestation in the very dry years was higher by 6% as compared to moderately dry and wet years

Effect of the spray volume adjustment model on the efficiency of fungicides and residues in processing tomato

This study compared the effects of a proportionate spray volume (PSV) adjustment model and a fixed model (300 L/ha) on the infestation of processing tomato with potato late blight (Phytophthora infestans (Mont.) de Bary) (PLB) and azoxystrobin and chlorothalonil residues in fruits in three consecutive seasons. The fungicides were applied in alternating system with or without two spreader adjuvants. The proportionate spray volume adjustment model was based on the number of leaves on plants and spray volume index. The modified Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was optimized and validated for extraction of azoxystrobin and chlorothalonil residue. Gas chromatography with a nitrogen and phosphorus detector and an electron capture detector were used for the analysis of fungicides. The results showed that higher fungicidal residues were connected with lower infestation of tomato with PLB. PSV adjustment model resulted in lower infestation of tomato than the fixed model (300 L/ha) when fungicides were applied at half the dose without adjuvants. Higher expected spray interception into the tomato canopy with the PSV system was recognized as the reasons of better control of PLB. The spreader adjuvants did not have positive effect on the biological efficacy of spray volume application systems. The results suggest that PSV adjustment model can be used to determine the spray volume for fungicide application for processing tomato crop

Biotypes of scentless chamomile Matricaria maritima (L.) ssp. inodora (L.) Dostal and common poppy Papaver rhoeas (L.) resistant to tribenuron methyl, in Poland

Scentless chamomile Matricaria maritima (L.) ssp. inodora (L.) Dostal and common poppy Papaver rhoeas (L.) are species which very often infest winter cereal and winter rape crops. Inhibitors of acetolactate synthase (ALS) are commonly used for control of these weeds. The herbicides are characterised by a single site of action in the plant, which has an influence on selection of the weed population and may result in a rapid development of resistance. In 2012, five seed samples of scentless chamomile and five samples of common poppy were collected from five winter wheat crop fields in Żuławy Gdańskie where the weed species were very poorly controlled. Results of greenhouse experiments showed that two biotypes of scentless chamomile and common poppy were resistant to tribenuron methyl. It was not possible to control resistant biotypes even after use of tribenuron methyl at a dose four times higher than recommended in Poland, it is the first reported case of scentless chamomile and common poppy biotypes’ resistance to herbicides. It is not of economic importance but it does prove the growing problem of weed resistance in the country

Multiple resistance to acetolactate synthase (ALS)- and acetyl-coenzyme A carboxylase (ACCase)-inhibiting herbicides in black-grass (Alopecurus myosuroides Huds.) populations from Poland

Alopecurus myosuroides seeds were sampled from 32 winter wheat fields from 2010 to 2014. Resistance to herbicides was detected in 17 A. myosuroides populations. In addition to single resistance to herbicides, cross-resistance and multiple resistance to acetolactate synthase (ALS)- and acetyl-coenzyme A carboxylase (ACCase)-inhibiting herbicides were found. Application of sulfometuron and imazapyr was unable to control some of the resistant biotypes in this study. This result implies that resistance in these populations is due to a target site mechanism. The A. myosuroides biotypes resistant to ACCase-inhibiting herbicides varied in their responses to derivatives of aryloxy-phenoxy-propionic acid (FOPs), cyclohexanediones (DIMs) and phenylpyrazolines (DENs). Resistant biotypes of A. myosuroides that could not be controlled with fenoxaprop-P-ethyl (FOP) and pinoxaden (DEN) were controlled with clethodim (DIM)

Winter wheat response to application of reduced doses of fluroxypyr + 2,4 D

Celem prowadzonych w latach 2006 i 2007 badań była ocena reakcji dwóch odmian pszenicy ozimej (Zyta i Kris) na stosowanie obniżonych dawek mieszaniny fluroksypyru + 2,4 D. Badania zostały wykonane w Instytucie Ochrony Roślin — PIB w Poznaniu i obejmowały ścisłe doświadczenia polowe z odmianami pszenicy ozimej różniących się między sobą wysokością roślin. Dobór odmian miał na celu określenie ich zdolności konkurencyjnych względem chwastów. W trakcie wegetacji wykonano dwie analizy zachwaszczenia (3–4 tygodnie i 5–6 tygodni po zabiegu) podczas których odnotowano skład gatunkowy chwastów, ich liczebność oraz świeżą masę. Po zbiorze rośliny uprawnej określono plon oraz wybrane parametry, do których zaliczały się: masa 1000 ziaren oraz masa hektolitra ziarna. Na podstawie uzyskanych wyników stwierdzono, że odmianą silniej konkurującą z chwastami była odmiana Zyta. Ponadto zastosowane w doświadczeniu obniżone dawki herbicydu ograniczyły nasilenie chwastów względem obiektów kontrolnych.Main goal of the investigation was evaluation of response of two winter wheat varieties of different plant height (Zyta -tall, Kris — short) to application of reduced doses of fluroxypyr + 2,4D mixture. The field experiments were carried out at the Institute of Plant Protection in Poznań, in the years 2006 and 2007. In order to assess competition of the wheat varieties to weed community, data were collected on weeds composition, number of weed plants per area and their fresh biomass. The data were recorded twice: 3–4 weeks and 5–6 weeks after the herbicide treatment. Grain yield, thousand kernels weight and test weight of wheat was determined after harvest. The analysis indicated, that the Zyta cultivar was more competitive to weeds than the Kris one. The reduced doses of the herbicide significantly decreased fresh mass of weeds, in comparison to the control objects

Effect of Foliar Applied Acetylsalicilic Acid on Wheat (Triticum aestivum L.) under Field Conditions

The exogenous application of salicylic acid prevents plant damage caused by various abiotic stresses (drought, high and low temperatures, salinity) and helps plants to build resistance to biotic stresses (pathogens). Acetylsalicylic acid, which is a synthetic salicylic acid derivative, has the same properties. In the face of climate change and a greater likelihood of extreme weather events, the use of these acids can significantly help to ensure proper growth and development of plants, especially sensitive species, even under stress conditions. The problem, however, is choosing the right dose (concentration) and time of application, and individual species sensitivity. The aim of the study was to assess the effect of acetylsalicylic acid on the growth and yield parameters of spring wheat. A field trial was carried out in 2013 and 2014 at the Institute of Plant Protection—National Research Institute in Poznan (Poland). The experiment was established on spring wheat cv. ‘Tybalt’, in four replications. Acetylsalicylic acid was tested in two concentrations: 0.3 and 0.5 mM. Each concentration was applied to the crop twice at growth stage BBCH 29 (end of tillering) and 7 days afterwards, and at growth stage BBCH 37 (flag leaf just visible) and 7 days afterwards. The study evaluated 12 traits of the crop, including plant height, chlorophyll content in the flag leaf, length of the ear, and quality and quantity parameters of the yield. The study showed that both the selection of the appropriate concentration and the time of acetylsalicylic acid application have a significant impact on the growth and development of the wheat. The acetylsalicylic acid increased the amount of chlorophyll in the leaves, the number of grains in the ear, the mass of a thousand grains, and grain yield. The present study did not confirm significant differences between the acetylsalicylic acid concentrations. The concentration of 0.5 mM proved more effective only for such traits as plant height and protein content in the grain. The study showed that it is not the concentration but the time of acetylsalicylic acid application that is more important for the growth of the wheat. Although there were no significant differences between the effects of earlier and later application time on plant height or chlorophyll content, most of the structural and qualitative parameters of the yield (number of grains in the ear, grain density, grain hardness, protein, gluten and starch content) were better after later application of acetylsalicylic acid (GS BBCH 37)

Effect of Foliar Applied Acetylsalicilic Acid on Wheat (<i>Triticum aestivum</i> L.) under Field Conditions

The exogenous application of salicylic acid prevents plant damage caused by various abiotic stresses (drought, high and low temperatures, salinity) and helps plants to build resistance to biotic stresses (pathogens). Acetylsalicylic acid, which is a synthetic salicylic acid derivative, has the same properties. In the face of climate change and a greater likelihood of extreme weather events, the use of these acids can significantly help to ensure proper growth and development of plants, especially sensitive species, even under stress conditions. The problem, however, is choosing the right dose (concentration) and time of application, and individual species sensitivity. The aim of the study was to assess the effect of acetylsalicylic acid on the growth and yield parameters of spring wheat. A field trial was carried out in 2013 and 2014 at the Institute of Plant Protection—National Research Institute in Poznan (Poland). The experiment was established on spring wheat cv. ‘Tybalt’, in four replications. Acetylsalicylic acid was tested in two concentrations: 0.3 and 0.5 mM. Each concentration was applied to the crop twice at growth stage BBCH 29 (end of tillering) and 7 days afterwards, and at growth stage BBCH 37 (flag leaf just visible) and 7 days afterwards. The study evaluated 12 traits of the crop, including plant height, chlorophyll content in the flag leaf, length of the ear, and quality and quantity parameters of the yield. The study showed that both the selection of the appropriate concentration and the time of acetylsalicylic acid application have a significant impact on the growth and development of the wheat. The acetylsalicylic acid increased the amount of chlorophyll in the leaves, the number of grains in the ear, the mass of a thousand grains, and grain yield. The present study did not confirm significant differences between the acetylsalicylic acid concentrations. The concentration of 0.5 mM proved more effective only for such traits as plant height and protein content in the grain. The study showed that it is not the concentration but the time of acetylsalicylic acid application that is more important for the growth of the wheat. Although there were no significant differences between the effects of earlier and later application time on plant height or chlorophyll content, most of the structural and qualitative parameters of the yield (number of grains in the ear, grain density, grain hardness, protein, gluten and starch content) were better after later application of acetylsalicylic acid (GS BBCH 37)

Herbicides with natural and synthetic biostimulants in spring wheat

ABSTRACT: Although the knowledge on agricultural using of biostimulants increases, there is still little information on their interactions with other chemicals i.e. herbicides. The aim of the study was to assess the influence of popular herbicides (MCPA + dicamba, dicamba + triasulfuron, florasulam+2,4-D) used with and without biostimulants based on seaweed extract (Kelpak) and nitrophenols (Asahi) on weed control efficiency, yield and quality of the crop. Field trial was carried out in the years 2014 and 2015 in the Institute of Plant Protection - National Research Institute in Poznan (Poland). The experiment was established on spring wheat cv.‘Torridon’, in 4 replications, using randomized block design. In the experiment two variants of application were tested. In the first variant preparations (herbicide and biostimulant) were applied as tank mixtures at the crop growth stage BBCH 30 and in the second variant in some combinations herbicide application was followed by biostimulant used alone. Weather conditions had a profound impact on tested preparations activity. Addition of biostimulants to herbicide had not affected weed control efficacy but application of herbicide and biostimulant mixture revealed its influence on yield parameters of wheat. Biostimulants influenced yield quality parameters e.g. by enhancing gluten amount in grains

Effect of Exogenous Application of Amino Acids L-Arginine and Glycine on Maize under Temperature Stress

Temperature strongly influences the growth of maize, particularly in the early growth stages. The exogenous application of some amino acids has been proven to have a positive effect on plant growth and development under stressful conditions. The objective of the study was to evaluate the response of maize that was grown under an optimal and stress (fluctuating) temperature to L-Arginine (L-Arg) and Glycine (Gly) application. In the study, it was assumed that the exogenously applied amino acids would alleviate the adverse effects of temperature stress on the maize height, as well as on the biomass of shoots and roots. Ten concentrations of each amino acid from 0.006 mM to 9.0 mM were tested under constant temperature conditions 20&ndash;22 &deg;C/23&ndash;25 &deg;C (night/day) an fluctuating stress of rising and dropping temperatures between 12&ndash;15 &deg;C (night) and 30&ndash;38 &deg;C (day). The amino acids were applied to the crop at growth stages V3&ndash;V4. In plants that were obtained from seeds pre-treated with L-Arg and Gly, the amino acids increased both the length of radicles and the number of lateral roots. A large discrepancy between the effects of the two amino acids was observed after foliar application. Under optimal thermal conditions, L-Arg increased the mass of shoots and roots by 55&ndash;59%. Under stress conditions, root mass was increased even by 100% when compared to the control plants. The best results were recorded at concentrations of 6 mM and 3 mM. Plants that were treated with Gly concentrations generally reached the height of untreated plants or less. It was shown that Gly applied at concentrations of 0.2 mM to 3 mM has a negative effect on the fresh mass of the crop