Unsprayed Control Research Articles

Inoculum sources and management of bean scab caused by Elsinoë phaseoli

AbstractBean scab caused by Elsinoë phaseoli is a major challenge to common bean cultivation in Kenya. However, knowledge about its epidemiology and management is limited. This study conducted three experiments in Kakamega, Kenya, evaluating scab inoculum sources and control options. The first experiment evaluated three different inoculum sources over two seasons; bean crop residue caused the highest scab incidence in both the 2021 (62.1%) and 2022 (81.1%) seasons. The second experiment assessed the effect of rotation history on scab over three seasons. Scab incidence consistently surpassed 90% within the first 30 days after planting in half‐yearly rotated fields across all seasons, while the disease was absent after planting in fields with no recent history of legumes. Fields rotated out of legumes consistently had the highest grain yield, averaging 1.5 t ha−1 over the seasons. Additionally, the rotation land treatment displayed significantly more pods per plant during the 2021 (9.7), 2022a (9.8), and 2022b (12.5) seasons. In the third experiment, the impact of five fungicides and four cropping systems on bean scab was investigated over two seasons. Neither fungicide treatments nor cropping systems had an effect on bean scab incidence even when only severe symptoms were considered. Carbendazim had the highest yield (1.9 t ha−1) outperforming the unsprayed control only in the 2022 season while none of the other fungicides outperformed the control treatment in yield parameters in either season. This study emphasizes the challenge of managing bean scab without proper crop rotation and underscores the role of crop residue as a critical inoculum source.

Sustaining the Yield of Maize, Blackgram, Greengram, Groundnut, Cotton, Sugarcane, and Coconut through the Application of Nutrients and Plant Growth Regulator Mixture.

The foliar application of nutrients and plant growth regulators (PGRs) at critical crop growth periods can improve the yield of field crops. Hence, the present study was conducted to quantify the effects of the combined application of nutrients and PGRs (crop-specific formulation) on maize, blackgram, greengram, groundnut, cotton, sugarcane, and coconut yield. In all the crops except coconut, the treatments included (i) a foliar spray of crop-specific nutrients and PGR combinations and (ii) an unsprayed control. In coconut, the treatments included (i) the root feeding of coconut-specific nutrients and PGR combinations and (ii) an untreated control. Crop-specific nutrient and PGR formulations were sprayed, namely, Tamil Nadu Agricultural University (TNAU) maize maxim 1.5% at the tassel initiation and grain-filling stages of maize, TNAU pulse wonder 1.0% at the peak flowering stage of green gram and black gram, TNAU groundnut-rich 1.0% at the flowering and pod-filling stages of groundnut, TNAU cotton plus 1.25% at the flowering and boll development stages of cotton, and TNAU sugarcane booster 0.5% at 45 days after planting (DAP), 0.75% at 60 DAP, and 1.0% at 75 DAP of sugarcane. The results showed that the foliar application of TNAU maize maxim, TNAU pulse wonder, TNAU groundnut-rich, TNAU cotton plus and TNAU sugarcane booster and the root feeding of TNAU coconut tonic increased the yield of maize, pulses, groundnut, cotton, sugarcane, and coconut, resulting in higher economic returns.

Management of Sesame Phyllody: A Destructive Disease of East- Central Rajasthan, India

Sesame (Sesamum indicum L.) is one of the important annual oldest oil seed crop grown in tropical to temperate zones in India. It belongs to family Pedaliaceae is native of India and plays an important role in the oilseed economy throughout the world. The sesame crop suffers from phyllody disease caused by phytoplasma. The effect of different treatments on “percent” disease incidence. The results obtained revealed that all the treatments reduced the disease significantly compared to unsprayed control. Seed treatment with imidachlorprid 70 % WG + spraying of imidachlorprid 17.8% SL+ spraying of tetracycline hydrochloride recorded the least disease incidence (7.27 %), minimum leaf hopper population and maximum “percent” disease control (65.59 %) and while seed treatment with imidachlorprid 70 % WG was least effective in which disease incidence of 15.46 “percent” and maximum leaf hopper population was recorded. The disease incidence in untreated check was 21.13 “percent” was recorded. Out of 22 germplasms/varieties screened against sesame phyllody 1 genotype was susceptible, 10 were moderately susceptible, 7 were moderately resistant and 4 genotypes were found resistant against phyllody of sesame.

Effect of Iron and Urea Application on Iron Biofortification of Lentil (Lens culinaris Medik.)

ABSTRACT Agronomic biofortification with iron (Fe) may be a viable approach to combat the widespread deficiency of Fe in humans. Thus, the present study was conducted to examine the effect of Fe and urea foliar application on Fe biofortification in lentil (Lens culinaris Medik.). The field experiments were conducted at two locations viz. Ludhiana and Faridkot, India. Different treatment combinations of foliar spray of sole Fe (0.5% of FeSO4.7 H2O), sole urea (2% urea), and combined application of Fe and urea at flowering, pod formation, and flowering + pod formation stages along with unsprayed control were applied to lentil. The results of the study revealed that the combined foliar application of Fe and urea at flowering + pod formation stages was the most effective in enhancing grain yield, Fe and zinc (Zn) concentration in plants (at flowering as well as pod formation stage), stover and grain (whole and split). The highest Fe concentration in whole (36% higher over control) as well as split (32.9% higher over control) grain and protein content (21% higher over control) was obtained with foliar application of Fe + urea at flowering + pod formation stages. Conclusively, the combined foliar application of 0.5% FeSO4.7 H2O and 2% urea at flowering + pod formation stages may prove to be a feasible option for increasing grain yield and enrichment of lentils with Fe and Zn to combat micronutrient malnutrition in human populations.

Erythritol sprays reduce D. suzukii infestation without impacting honey bee visitation nor fruit quality.

Spotted-wing drosophila, Drosophila suzukii, is an economic pest of small fruits and cherries. Insecticides primarily control this pest while alternative controls are in development. Laboratory studies show that erythritol is insecticidal to D. suzukii and other pests while safe for human consumption. Moreover, erythritol combined with sucrose or non-caloric sucralose can stimulate feeding and quicken mortality. Before growers can use erythritol, the impact on crop protection, non-target insects, and fruit quality need evaluation. In three blueberry and cherry field cage trials, oviposition on fruit sprayed with erythritol:sucrose or erythritol:sucralose formulations was lowered by 59-81% compared to unsprayed controls. Fly infestation (larval or adult counts from fruit) was 90% lower in a greenhouse blueberry trial, and 49% lower in an open field blueberry trial with 2M erythritol: 0.5M sucrose. Infestation was also 57% lower in an open field cherry trial with 1.5M erythritol: 0.5M sucrose. Other field trials with very low pest pressure or frequent rains revealed no differences from controls. Field trials consistently revealed that honey bees did not preferentially visit plants sprayed with either erythritol formulation, although yellow jackets visited erythritol:sucrose-sprayed plants more frequently. Erythritol formulations consistently led to more leaf spotting, but there was no reduction in quality of treated blueberries or cherries in terms of mold development, firmness, diameter, epidermal penetration force, and Brix° (total soluble solids; TSS) at harvest. Eleven trials conducted over four years show that erythritol formulations can reduce D. suzukii pressure without attracting foraging honey bees nor negatively impacting fruit quality. This article is protected by copyright. All rights reserved.

Fruit Yield Loss Assessment of Tomato (Solanum lycopersicum Mill.) due to Late Blight (Phytophthora infestans) Disease in Central Parts of Ethiopia

Tomato is an important vegetable crop grown around the world. Tomato is the most widely cultivated and lucrative vegetable in Ethiopia in particular and in the world in general. It is well known that disease late blight affects tomato crop production and late blight is one of the most devastating diseases of tomatoes worldwide and causes significant loss in production. The objective of this study is to update fruit yield loss assessment data for tomato late blight disease. In this study, 3 treatments were used in a randomized complete block design (RCBD) with three replications. The combined analysis of variance (ANOVA) results for AUDPC and total fruit yield shows significant differences (P<0.05) among treatments. As compared to the unsprayed (control) plot both fungicides significantly controlled the disease at both early and late stage of the crop. The lowest AUDPC (560) was recorded on fungicide Fahem-Gold 72% WP sprayed treatment followed by Mancozeb (752.5). The control treatment (water sprayed) had the highest AUDPC (1592.5). The highest mean fruit yield (16.5 t ha-1) was obtained from fungicide Fahem-Gold 72% WP followed by the standard fungicide (Mancozeb) which gave (8.98 t ha -1) whereas the control treatment gave 4.67 t ha -1. The highest levels of yield loss 71.7% occurred in the unsprayed plots of variety Gulelema as compared to the best protected plot sprayed with Fahem fungicide. Generally, disease and yield parameters indicate that among the two fungicides spray; Fahem was the most effective followed by Mancozeb sprayed plot as compared to unsprayed plots.

Transgenic cotton expressing Mpp51Aa2 does not adversely impact beneficial non-target hemiptera in the field

The modified Mpp51Aa2 (previously Cry51Aa2.834_16) insecticidal crystal protein derived from Bacillus thuringiensis (Bt) protects against feeding damage caused by targeted hemipteran and thysanopteran pests, and was transformed in cotton to produce the MON 88702 cotton event. As part of an ecological risk assessment, we evaluated the relative impact of MON 88702 on the abundance of predatory Hemiptera, compared to a conventional control. Field trials were established in 2018 at six sites within cotton production regions of the U.S. Specific arthropod populations in MON 88702 and its conventional control (DP393), grown under different insecticide regimes within a randomized complete block design, were assessed at each field site. Arthropod samples were collected 10 times, starting at early squaring and weekly thereafter, over the course of the season at each site, using vertical beat sheets, sweep nets and visual counts. Across the sites, no significant differences were detected in abundance of predatory Hemiptera (Orius spp., Geocoris spp., Nabis spp., and Zelus spp.) between unsprayed MON 88702 and the unsprayed conventional control. In contrast, a broad-spectrum insecticide treatment significantly reduced the abundance of these and other taxa. Consistent with laboratory studies, the lack of differences between unsprayed MON 88702 and the unsprayed control indicates that the cultivation of MON 88702 is unlikely to adversely impact the predatory function associated with these beneficial Hemiptera in the cotton agro ecosystem.

Effect of Conventional and Conservation Agriculture Practices on Dissipation of Metribuzin and Clodinafop-Propargyl, Soil Enzymatic and Microbial Activities in Wheat in a Rice-Wheat System

ABSTRACT Soil enzymes and microbial activity are an indicator of soil quality for assessing the sustainability of agricultural ecosystems. The present study determined the persistence of metribuzin and clodinafop-propargyl and response of soil quality indicators to (1) conservation agriculture (continuous zero tillage and surface residue retention) and conventional agriculture (continuous tillage and removal/incorporation of residues) practices and (2) weed management practices in a wheat field under rice-wheat system. The shift from conventional to conservation agriculture practices increased the dissipation of metribuzin and clodinafop propargyl and significantly enhanced soil dehydrogenase (DHA) and urease activity. The residues of metribuzin and clodinafop in grain and straw samples from all treatment were below maximum residue limits (<0.01 µg g−1). Post-emergence application of clodinafop-propargyl plus metribuzin caused significant inhibition in DHA and urease activity at 7 days after treatment (DAT) compared to unsprayed control. However, from 31 DAT till crop harvest (115 DAT), herbicide treated plots had higher enzymatic activity than unsprayed plots. Intervention of one hoeing following herbicide application had greater stimulation in enzyme activity than sole herbicide. Conservation agriculture practices had higher colony development (CD) and ecophysiological (EP) indices than conventional agriculture practices for heterotrophic bacteria, fungi and actinomycetes. All tillage, residue and weed management practices had non-significant effect on alkaline phosphatase activity and phosphate solubilizers, in soil. Adoption of conservation agriculture practices along with integrated weed management seems to be the best way of sustaining the soil biological parameters and cycling of various important soil nutrients which may potentially alter vital soil processes resulting in increased agricultural sustainability.

Effectiveness of Indoor Residual Spraying as A Method of Controlling Dengue Fever in Communities: A systematic review

Background: Dengue remains a significant public health issue in the Western Pacific Region. In the absence of a vaccine, vector control is the mainstay for dengue prevention and control. This study aimed to explore the effectiveness of Indoor Residual Spraying as A Method of Controlling Dengue Fever in Communities. Subjects and Method: A systematic review was conducted by searching articles from PubMed, ResearchGate, Science Direct, Google Scholar, and EBSCO is an article published from 2013 to 2023. The keywords were “dengue hemorrhagic fever” OR “DHF” AND “community” OR “family” AND “disaster” AND “IRS” OR “indoor residual spraying”. The inclusion criteria were a Cross-sectional study. The articles were selected by PRISMA flow diagram method. Results: A total of 9 studies were included in this review. All of the studies stated that IRS can have both an immediate and sustained effect on reducing adult and immature A. aegypti populations and should be considered as an adult mosquito control strategy by dengue vector control programs also IRS led to 86-96% reduction in dengue cases in sprayed premises, compared to unsprayed controls. Conclusion: IRS significantly reduces the malaria burden in high-transmission settings. Keywords: dengue hemorrhagic fever, DHF, family, community. Correspondence: Titik Anggraeni. School of Health Sciences Estu Utomo Boyolali, Central Java, Indonesia. Jl. Tentara Pelajar 7, Mudal, Boyolali, Central Java, Indonesia. Email: titik.anggraeni146@gmail.com. Mobile: +62 858-6729-2673.

The Efficacy of Selected Insecticides Against Wheat Aphids on Irrigated Wheat in North Western Amhara, Ethiopia

Aphid infestations cause significant losses in wheat production. The experiment was conducted at the Koga irrigation site during 2021 to evaluate the efficacy of commercial insecticides for the management of wheat aphids. Seven types of insecticides with unsprayed control were laid in a completely randomized block design with three replications. The result showed a reduced aphid infestation with maximum grain yield were from dimethoate, imidacloprid, lambda-cyhalotrin, profenfos + lambda-cyhalothrin, imidacloprid + lambda-cyhalothrin, and profenofos-sprayed plots. However, the greater net benefit and marginal rate of return were provided by the applications of imidacloprid and dimethoate insecticides. The economically feasible insecticide application can be considered as an effective aphid management practice in wheat production.

Assimilate Partitioning and Photosynthetic Parameters of Rice (Oryza sativa L.) in Response to Salicylic Acid Application

Salicylic acid (SA), a signaling molecule is known to affect various physiological processes like growth and development, photosynthesis, absorption and translocation of assimilates etc. Therefore, an experiment was conducted to study the effect of salicylic acid on assimilate partitioning and yield of rice. The experiment comprised of 14 treatments replicated thrice in Randomized Complete Block Design (RCBD). Foliar application of SA @ 50, 100, 150 &amp; 200 µg ml-1 was done at boot leaf stage (BL), one week after boot leaf stage (1WABL) and at BL + 1WABL. Treatment of water spray and unsprayed (control) were also included. Findings reveal that application of 100 µg ml-1 SA at BL + 1WABL resulted in the highest grain yield, which was statistically similar to 150 µg ml-1 SA at BL + 1WABL. The higher productivity under respective treatments can be ascribed to higher crop growth rate, relative growth rate, net assimilation rate and improvement in partitioning of dry matter from vegetative parts to grains due to improved vascularization. Also there was improvement in photosynthetic efficiency in terms of total chlorophyll content; carotenoid content and Hill reaction activity under SA treated plots. Thus, the productivity enhancement in rice can be achieved through 2 foliar sprays of salicylic acid @ 100 µg ml-1 each at boot leaf stage + one week after boot leaf stage.

Anthracnose intensity and per cent pod infection of cowpea in Beed district

The importance of pulses has been realized due to their high protein, better nutritional food, and fodder and soil enrichment qualities. Pulses have been considered as an integral part of our diet from time immemorial and have also found their reference in ancient scriptures such as Puranas and Mahabharata. The major fungal diseases of cowpea anthracnose caused by Colletotrichum destructivum. In this study all the botanicals, bioagents and fungicides tested against anthracnose disease of cowpea during Kharif 2013 and Kharif 2014 were found effective and significantly reduced the mean disease intensity and pod infection over unsprayed control. Anthracnose intensity and pod infection slightly increases in Kharif 2014 as compared to Kharif 2013.

Efficacy of Botanical Mixture and Fungicides to Combat Sigatoka Disease in Banana Cultivation

Black Sigatoka disease caused by Mycosphaerella fijiensis seriously threatens banana cultivation worldwide. This infirmity is controlled by the recurrent application of synthetic fungicides, which leads to several adverse effects. Plant extracts with antifungal potential have long been investigated as they contain secondary bioactive compounds for protecting crops from microbial infection. This study compared the antifungal activities of both botanical mixtures and recommended fungicides to control Black Sigatoka in banana. Laboratory and field studies were conducted to assess the antifungal activity of the botanical mix prepared from eight different herbal plant parts against M. fijiensis, with two recommended fungicides as the positive control. In vitro results showed that the radial growth of the fungus was significantly impaired (P&lt;0.05.) by the addition of the botanical mixture, fungicides, and combination of the botanical mixture (BM) and fungicides in the PDA media. Mycosphaerella fijiensis differed in their reaction to the BM and fungicides, and combination of BM and fungicides, but on the whole, growth inhibition increased with the concentration. In field experiments, all the treatments reduced the disease incidence significantly compared to the unsprayed control, where the disease severity index (DSI) increased from 43.88 to 67.77 within 28 days. After the first spray, the botanical mixture and fungicides (Chlorothalonil and Carbendazim) reduced the disease severity index to 39.7, 41.19, and 44.44, respectively. Fungicides and combinations of Chlorothalonil + BM and Carbendazim + BM showed the lowest DSI, 34.07 and 35.83, respectively. The results show that combining the synthetic and botanical mixture is more effective for controlling the disease. The study reveals the possibility of utilizing a botanical mixture as an integrated approach to manage Black Sigatoka disease more efficiently and in an eco-friendly manner.

Integration of host resistance and fungicides reduced ascochyta blight pressure and minimised yield loss in field pea (Pisum sativum L.) in southern Ethiopia

ABSTRACT Ascochyta blight complex causes substantial yield losses and deteriorates seed quality of field pea worldwide. Field experiments were conducted to determine the effectiveness of an integrated approach consisting of host resistance and fungicides to reduce ascochyta blight progression and enhance yield performances of field pea for two seasons at Bonke and Chencha, Southern Ethiopia. Three field pea (Bursa, Burqitu and Tegegnech) varieties and three systemic (Carbonchlor, Matico and Othello-Top) fungicides, along with unsprayed controls, were arranged in a factorial randomised complete block design with three replications. Results showed that fungicide treated plots of each variety recorded the lowest progress rate, while control plots of Bursa, Burqitu and Tegegnech recorded the highest rate parameter (0.67, 0.60 and 0.451 units day−1), respectively at Bonke. Terminal mean severities were reduced by up to 24.6–43.7% and 20.1–43.7% due to fungicide applications over unsprayed plots at Chencha and Bonke, respectively. Moreover, triple applications of Othello-Top enhanced grain yield by 211% (Bursa), 204% (Burqitu) and 140% (Tegegnech) as compared to control plots at Bonke. A related pattern was noticed at Chencha areas. Economically, Burqitu with Othello-Top showed the highest net benefit and benefit–cost ratio of $2.35 × 103 ha−1 and 4.77 (Bonke) and 2.27 × 103 ha−1 and 3.76 (Chencha) in that order of presentation, followed by Matico, and found to be the most profitable management option due to monetary advantage; and it could be suggested for field pea growers.

Insecticide spray regimes to manage Helicoverpa armigera (Hubner) and their impact on natural enemies in cotton under high density planting system

This study evaluated some new class insecticides viz., chlorantraniliprole 18.5SC, flubendiamide 480SC, spinosad 45%SC, indoxacarb 14.5SC and emamectin benzoate 5%SG in cotton under high density planting system (HDPS). These were evaluated against Helicoverpa armigera (Hubner) and their impact on natural enemies were also observed. Experiments were conducted at the ICAR-Central Institute for Cotton Research, Nagpur during 2013-14. Each of the new molecules were sprayed in eight different windows 60 days after sowing (DAS), 60 and 80 DAS, 60, 80 and 100 DAS, 60, 80 100 and120 DAS, 100 and 120 DAS, 80,100 and 120 DAS, 120 DAS and unsprayed control along with three replicates each were analysed in randomized complete block design. The damage by H. armigera was observed by counting healthy and damaged squares and bolls, and % worked out. The whole plant incidence was recorded in case of major predators sampled including spiders and coccinellids. The spray regime 2 (60 and 80 DAS), regime 3 (60, 80 and 100 DAS), regime 4 (60, 80, 100 and 120 DAS) and regime 6 (80, 100 and 120 DAS) were found superior in managing bollworms with by recording least square damage. The results on natural enemies’ populations (spiders and coccinellids) clearly revealed that, all spray regimes were more or less safe to the natural enemies. However, spray regime 1 (spray at 60 DAS), regime 2 (spray at 60 and 80 DAS) and regime 3 (spray at 60, 80 and 100 DAS) recorded maximum natural enemies. Maximum natural enemies was reported at 80 DAS in all the insecticidal spray regimes. Chlorantraniliprole, flubendiamide, spinosad, indoxacarb and emamectin benzoate through the spray regime 2 (spray at 60 and 80 DAS) was observed to be the best option against H. armigera by controlling it in early stage itself and to sustain natural enemies in the cotton ecosystem.

Composition of Pinot Noir Wine from Grapevine Red Blotch Disease-Infected Vines Managed with Exogenous Abscisic Acid Applications

Grapevine red blotch disease (GRBD) has negative effects on grape development and impacts berry ripening. Abscisic acid (ABA) is a plant growth regulator involved in the initiation of berry ripening. Exogenous abscisic acid application was compared to an unsprayed control on GRBD-positive Pinot noir vines during two vintages, and the total monomeric anthocyanin, total phenolics, phenolic composition, and volatile profile were measured in wines. In addition, untargeted metabolites were profiled using high-resolution LC-MS/MS. Results showed that the wine composition varied by vintage year and was not consistent with ABA application. Wines from the ABA treatment had a lower total anthocyanin and total phenolic content in one year. The untargeted high-resolution LC-MS/MS analysis showed a higher abundance of phenolic compounds in ABA wines in 2019, but lower in 2018. The wine volatile compounds of ABA treatments varied by vintage. There were higher levels of free β-damascenone, β-ionone, nerol, and several fermentation-derived esters, acids, and alcohols in ABA wines, but these were not observed in 2019. Lower 3-isobutyl-2-methoxypyrazine (IBMP) was also observed in wines with ABA treatment in 2019. The results demonstrated that ABA application to the fruit zones did not consistently mitigate the adverse impacts of GRBD on Pinot noir wines.

Efficacy and optimal timing of low-volume aerial applications of copper fungicides for the control of red needle cast of pine

Background: Red needle cast (RNC) is a foliar disease of radiata pine (Pinus radiata D.Don), caused by Phytophthora pluvialis Reeser, Sutton &amp; E.Hansen and occasionally Phytophthora kernoviae Brasier, Beales &amp; S.A.Kirk. The disease has impacted plantations in New Zealand since at least 2008. To develop management recommendations for red needle cast, research has focused on identifying chemical control options and understanding pathogen epidemiology to guide optimal timing of spray application. The objectives of this study were to: (1) assess the efficacy of aerial copper fungicide application for the control of red needle cast in mature radiata pine plantations; and (2) investigate optimal spray timing. Methods: To address these objectives, three operational-scale field trials were undertaken in successive years between 2017 and 2019 at a forest in the Central North Island of New Zealand. RNC severity was assessed in canopies of forest blocks exposed to cuprous oxide applied at 0.855 kg ha-1 active ingredient in low-volume aerial spray at different times of the year (November, February and April (or May)). Needle cast from plantation trees and infection levels on trap plants were also assessed in some years. Results: Application of cuprous oxide significantly reduced RNC severity in all three trials. As well as reducing disease severity, application of cuprous oxide also tended to reduce needle cast from plantation trees and infection on trap plants in years when these were also assessed. No consistent effect of spray timing was observed. Generally, all three spray timings reduced disease severity compared to the unsprayed control, but differences were not always significant, and few differences were detected between different spray timings. Conclusions: The results reported here are the first to show that low-volume aerial applications of cuprous oxide applied at 0.855 kg ha-1 active ingredient can reduce the severity of RNC in commercial radiata pine plantations. No consistent effect of spray timing was detected. These findings support the development of management recommendations for RNC.

Interaction of varieties and fungicides across seasons and locations for the control of Asian soybean rust (Phakopsora pachyrhizi) in Southwestern Ethiopia

Soybean is emerging as an important legume and oil crop in Ethiopia. However, the crop has been facing serious threats from Asian Soybean Rust (ASR), causing significant damage to the crop and not allowing it to realize its potential. This study aimed to determine the interaction of three varieties with various fungicide treatments across two seasons and two locations to manage ASR. The experiment was laid out in a RCBD in a factorial [three soybean varieties (V) and six fungicides (F)] treatment combination at two locations (L) for two years (Y) with three replications. The analysis of variance across seasons revealed highly significant V × F × Y interactions for grain yield, and F × Y interactions for severity (%) and AUDPC; while efficacy was significant (P = 0.05). The V × Y interaction showed highly significant differences for AUDPC. Across locations, there were highly significant differences for V × F × L for grain yield and V × L for AUDPC. It was only AUDPC that showed significant (P = 0.05) for the V × F interaction. There were two rates (0.75 and 1 l ha−1) of the fungicide Opera Max that provided the best protection against ASR across locations, varieties, and seasons. The yield loss on the unsprayed control treatment ranged between 29 and 65%. The evidence generated from this study clearly demonstrates the importance of identifying the right variety, rates and types of fungicides for the control of ASR for higher production and productivity of soybean in Ethiopia.

Yield and nutrient uptake of sesame (Sesamum indicum L.) as influenced by plant growth regulators

A field experiment was conducted at Pandit Jawaharlal Nehru College of Agriculture and Research Institute, Karaikal to study the effect of plant growth regulators on yield and nutrient uptake of sesame (Sesamum indicum L.) during summer 2021. The field experiment with thirteen treatments was conducted on a loamy sand soil in a randomized block design and replicated thrice. The treatments included four plant growth regulators at various concentrations (NAA 50 ppm, NAA 100 ppm, CCC 100 ppm, BA 5 ppm and HA 500 ppm) and water spray at two levels of application (one spray - at flowering stage and two sprays - at flowering and capsule formation stages) and an unsprayed control. The results revealed that spraying NAA 100 ppm twice recorded the highest seed yield (633 kg/ha), haulm yield (1296 kg/ha) as well as the uptake of NPK by sesame when compared to other growth regulators.

Fusarium head blight progression and yield response of bread wheat as affected by fungicides and spray regimes under field condition in southern Ethiopia

Fusarium head blight (FHB) is one of the destructive diseases in wheat-producing areas of the world. Field experiments were conducted during the 2019 main cropping season to determine an economically feasible time of application that consisted of fungicides and spray regimes to reduce FHB pressure and grain yield loss under field conditions at five locations in southern Ethiopia. The study was comprised of two fungicides and spray regimes. Totally seven treatment combinations were designed, including the unsprayed control plots. The field was designed by a randomized complete block design with four replications. Analysis of variance revealed interaction of fungicides and spray regimes significantly (P < 0.001) affected rates of disease progress, disease severity (DS), area under disease progress curve (AUDPC), and yield-related parameters. Lowest (0.0159 units day−1) and highest (0.0694 units day−1) disease progression rates were estimated from the application of Tebuconazole before disease onset and unsprayed control plots, respectively. Application of Tebuconazole before disease onset significantly reduced DS (67.68%), followed by application of Propiconazole + Tebuconazole before disease onset (67.16%) and Tebuconazole after disease onset (65.77%). Moreover, Propiconazole + Tebuconazole and Tebuconazole applications before disease onset considerably reduced AUDPC by 61.38%-days and 58.60%-days, respectively. The highest grain yield (5.02 t ha−1) was recorded from the application of Tebuconazole before disease onset. The grain yield loss of 44.22% was computed on an unsprayed plot compared to the plot protected with the application of Tebuconazole before disease onset. Overall, the application of fungicides' appropriate spray regimes reduces FHB pressure, and consequently, increases grain yields. However, the application of Tebuconazole before disease gave a better monitory advantage over the others. This could be suggested for the producers to manage FHB and enhance wheat production.