Evaluation of the control effect of SAR inducers against citrus Huanglongbing applied by foliar spray, soil drench or trunk injection

AbstractHuanglongbing (HLB) or greening disease, associated with the bacterial pathogen Candidatus Liberibacter asiaticus (Las), is currently the most devastating citrus disease worldwide and no cure is available. Inducers of systemic acquired resistance (SAR) are effective and sustainable to combat various plant diseases. In this study, the SAR inducers acibenzolar-S-methyl (ASM), imidacloprid (IMI), 2,6-dichloroisonicotinic acid (INA), and salicylic acid (SA), applied individually by foliar spray, soil drench or trunk injection at various rates and frequencies, were evaluated for control of HLB in a 3-year field trial with mature Hamlin sweet orange trees in central Florida, USA in the 2016, 2017, and 2018 crop seasons. Six foliar sprays, six soil applications, and three trunk injections of ASM, IMI, INA, or SA per year were conducted with the untreated as a negative control. HLB disease severity, Las titers, pre-harvest fruit drop, yield and fruit quality were investigated for the treatments. By the end of the 2018 season, all trunk injection treatments at 0.25 g/tree and foliar sprays of INA or SA (but not ASM or IMI) at 0.5 g/tree significantly reduced disease severity, Las population, and fruit drop, and increased fruit yield; whereas all foliar spray treatments at 0.25 g/tree, trunk injection treatments at 0.125 g/tree, and soil drench treatments at 0.25 or 0.5 g/tree did not provide effective control of HLB. Additionally, all trunk injection treatments at 0.25 g/tree had shown a significant decrease in fruit drop and increase of fruit yield starting from 2016 after 1 year of applications, whereas foliar sprays of INA or SA at 0.5 g/tree exhibited similar effects at 2018 after 3 years of applications. None of the SAR inducer treatments had significant effect on fruit quality. Economic analysis suggested that the trunk injection treatments at 0.25 g/tree might produce financial benefits. Overall, this study presents useful information for management of citrus HLB with SAR inducers.

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Control of Phytophthora canker with phosphonate in artificially inoculated almond and cherry trees

Australian Journal of Experimental Agriculture ◽

10.1071/ea9900413 ◽

1990 ◽

Vol 30 (3) ◽

pp. 413 ◽

Cited By ~ 10

Author(s):

TJ Wicks ◽

B Hall

Keyword(s):

Effective Treatment ◽

Foliar Spray ◽

Inhibitory Effect ◽

Mature Trees ◽

Foliar Sprays ◽

Soil Drench ◽

Trunk Injection ◽

Cherry Trees

Phosphonate (H3P03; as FOLI-R-FOS 200) applied as either a soil drench, foliar spray or trunk injection before infection inhibited the development of cankers in almond and cherry trees inoculated with Phytophthora cambivora. Phosphonate applied to the foliage in autumn and spring at rates up to 2 g a.i./L was the most effective treatment. Soil drenches up to 10 g a.i./L were also effective, particularly on young trees. Trunk injections completely inhibited the development of P. cambivora in many cases, but due to a possible phytotoxic reaction, the treatment was most suited for mature trees. Foliar sprays of phosphonate are likely to be most practical treatment as these could be applied with other foliar treatments. The inhibitory effect of phosphonate on canker growth persisted for at least 48 weeks after treatment, irrespective of the method of application.

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Influence of Foliar Sprays of Nutrients on Yield and Yield Accrediting Characters of Kinnow Mandarin: A Review

Agricultural Reviews ◽

10.18805/ag.r-2012 ◽

2020 ◽

Author(s):

Reetika . ◽

G. S. Rana ◽

Komal . ◽

Sanjay Kumar ◽

Poonam Saini

Keyword(s):

Environmental Sustainability ◽

Nutrient Management ◽

Foliar Application ◽

Foliar Spray ◽

Fruit Yield ◽

Foliar Sprays ◽

Fruit Drop ◽

Macro And Micronutrients ◽

Kinnow Mandarin

Plant nutrients both macro and micro plays a major productive and qualitative role in bringing stability and sustainability in the production system particularly in fruits crops like citrus and therefore, effective nutrient management is critical. The aim of our paper is to study the influence of foliar sprays of nutrients on yield and yield attributing characters such as fruit drop, final fruit retention, number of fruits per plant and fruit yield of Kinnow mandarin as appropriate rate, time and method of application of fertilizers in Kinnow are considered to be the major indices in deciding the desired level of productivity and quality of fruits. Therefore, many studies around the world, evaluating the yield and yield attributing characters of Kinnow mandarin with respect to foliar application of nutrients were studied and their results showed that the foliar application were economically viable and beneficial for both Kinnow productivity and environmental sustainability. Hence, for obtaining better fruit yield and minimizing fruit drop with aim to achieve desired level of productivity and improved fruit quality, foliar spray of macro and micronutrients could be used effectively.

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Influence of Nonpermanent Netting on Foliar Spray Deposition, Insect Pest Prevalence, and Production of ‘Nadorcott’ Mandarin (Citrus reticulata)

HortScience ◽

10.21273/hortsci13769-18 ◽

2019 ◽

Vol 54 (4) ◽

pp. 667-675

Author(s):

Ockert P.J. Stander ◽

Jade North ◽

Jan M. Van Niekerk ◽

Tertia Van Wyk ◽

Claire Love ◽

...

Keyword(s):

Treatment Group ◽

Fruit Quality ◽

Spray Deposition ◽

Insect Pest ◽

Foliar Spray ◽

Fruit Yield ◽

Control Treatment ◽

Citrus Reticulata ◽

Western Cape ◽

Thaumatotibia Leucotreta

This study aimed to determine the effects of different types of nonpermanent netting (NPN) on foliar spray deposition, insect pest prevalence, and production and fruit quality of ‘Nadorcott’ mandarin (Citrus reticulata) trees in a commercial orchard at Citrusdal (lat. 32 32′31″S, long. 19 0′42″E), Western Cape, South Africa. The deposition quantity (FPC%) of foliar spray volumes of 3500, 7000, or 15,000 L·ha−1 was greater for leaves of control trees compared with leaves treated with NPN during summer (January) (8.8 vs. 6.1; P = 0.0055) and winter (June) (4.8 vs. 3.1; P = 0.0035). Deposition uniformity (CV%) was better for control leaves during summer (64.9 vs. 75.2; P = 0.0062) and winter (59.6 vs. 80.5; P = 0.0014), and deposition quality (ICD%) was better during winter (79.4 vs. 84.2; P = 0.0393). There were no differences in FPC%, CV%, and ICD% for fruit when foliar spray volumes of 3500 and 15,000 L·ha−1 were used for the control and NPN treatment groups during winter. However, with a foliar spray volume of 7500 L·ha−1, fruit from the control treatment group had greater FPC% (19.3 vs. 6.1; P = 0.0262), CV% (70.3 vs. 50.9; P = 0.0484), and ICD% (57.1 vs. 79.9; P = 0.0157). There were no differences in macronutrient concentrations between the leaves of trees subjected to control and NPN treatments, but leaf zinc (<81%; P = 0.0317) and iron (<78%; P = 0.0041) concentrations were lower with the NPN treatment. During short NPN treatments, fruit yield was reduced by ≈37% compared with that after control treatment, and longer NPN treatments had no effect on fruit yield. The reduction in fruit yield with NPN was not related to the effects of NPN on foliar spray deposition or to lower leaf micronutrient concentrations. The lower fruit yield during short NPN treatments was most likely caused by fruit drop that was exacerbated by the removal of the NPN. In the long NPN treatment group, fruit damage caused by sunburn was reduced by 17%, but the outer canopy fruit experienced increased wind damage or scarring. Except for the lower titratable acidity content with the shortest NPN treatment and the higher Brix°:TA ratio with two NPN treatments, NPN did not impact other fruit quality attributes. The use of NPN excluded male wild false codling moths (Thaumatotibia leucotreta) (FCM) males; however, it was still possible to capture a very small amount of mass-released sterile FCM and wild fruit flies under the NPN.

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Effect of Silicon through Potassium Silicate on Yield, Nutrient Uptake and Quality of Grand Naine Banana

Asian Journal of Agriculture and Food Sciences ◽

10.24203/ajafs.v9i3.6639 ◽

2021 ◽

Vol 9 (3) ◽

Author(s):

Arthi Vijayan ◽

M. V. Sriramachandrasekharan ◽

R. Manivannan ◽

Arumugam Shakila

Keyword(s):

Nutrient Uptake ◽

Fruit Quality ◽

Foliar Spray ◽

Reducing Sugar ◽

Potassium Silicate ◽

Fruit Yield ◽

Total Sugars ◽

Soil Application ◽

Silicon Nutrition

Field experiment was conducted in Farmers holding located at Rajagopalapuram village under Kuttalam taluk, Mayiladuthurai district, Tamilnadu, India belonging to Padugai series (Typic ustifluvent) low in available silicon to elucidate the response of banana in terms of yield, nutrition and quality due to silicon nutrition applied through potassium silicate. The treatment consists of T1 - NPK (RDF), T2 - NPK + Potassium silicate (FS) - 0.25%, T3- NPK + Potassium silicate (FS) - 0.50%, T4 - NPK + Potassium silicate (FS) - 1.00%, T5 - NPK + Potassium silicate (FS) - 0.25%, T6 - NPK + Potassium silicate (FS) - 0.50%, T7 - NPK + Potassium silicate (FS) - 1.00%, T8 - NPK + Potassium silicate (SA) - 50 kg ha-1, T9 - NPK + Potassium silicate (SA) - 100 kg ha-1 and T10 - NPK + Potassium silicate (SA) – 150 kg ha-1. From T2 to T4 foliar spray was done at 3rd and 5th month and from T5 to T7, foliar spray was done at 3rd, 5th and 7th month. The test crop is Banana Var. Grand Naine. The results showed that the highest fruit yield was noticed with 50 kg Si ha-1 (96.0 t ha-1) and it reduced with Si levels. Among foliar treatments, fruit yield increased with silicon concentrations (0.25 to 1%). The highest fruit yield was observed with 1% Si applied at 3rd and 5th month (92.7 t ha-1). Foliar spray of 0.25 and 0.5% Si applied thrice increased the fruit yield compared to twice application at same concentration. But fruit yield declined when Si was sprayed at 1% thrice. Soil application of silicon recorded higher nutrient uptake over foliar addition. The nutrient uptake was maximum with 150 kg Si ha-1. With respect to foliar treatments, the highest uptake was noticed with foliar spray of 1% Si applied at 3rd and 5th month. Soil application of 50 kg Si ha-1 recorded the highest fruit quality viz., TSS, total sugars, reducing and non-reducing sugar and leaf protein. The highest fruit quality was noticed with foliar spray of 1% Si applied at 3rd and 5th month.

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Foliar Sprays of Clay Reduce the Severity of Powdery Mildew on Long English Cucumber and Wine Grapes

HortScience ◽

10.21273/hortsci.36.5.934 ◽

2001 ◽

Vol 36 (5) ◽

pp. 934-936 ◽

Cited By ~ 8

Author(s):

David L. Ehret ◽

Carol Koch ◽

Jim Menzies ◽

Peter Sholberg ◽

Tim Garland

Keyword(s):

Powdery Mildew ◽

Vitis Vinifera ◽

Cucumis Sativus ◽

Disease Severity ◽

Fruit Quality ◽

Leaf Surface ◽

Uncinula Necator ◽

Sphaerotheca Fuliginea ◽

Wine Grapes ◽

Foliar Sprays

Foliar sprays of a nonswelling chlorite mica clay were applied to leaves of greenhouse-grown long English cucumber (Cucumis sativus L.) plants, either before or after an artificial inoculation with powdery mildew [Sphaerotheca fuliginea (Schlech.:Fr.) Poll.] and to field-grown wine grapes (Vitis vinifera L.) before natural inoculation with powdery mildew [Uncinula necator (Schwein.) Burrill]. In all cases, the clay sprays did not eradicate the pathogen, but resulted in significant reductions in disease severity. In cucumber, a single spray of 0.5% clay reduced colony numbers on leaves by up to 60%. Spraying after inoculation was generally more effective than spraying before inoculation. In grapes, repeated sprays of either 2% or 4% clay were applied through the season to `Reisling' and `Chancellor' vines. Four percent clay reduced the amount of leaf surface covered by mildew by 22% in `Reisling' and 51% in `Chancellor'. Both concentrations reduced the incidence of mildew on clusters and canes. No treatment effects were observed on fruit quality. Our results demonstrate that foliar sprays of clay can reduce the severity of Sphaerotheca fuliginea and Uncinula necator on cucumbers and grapes, respectively.

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Efficiency of exogenous zinc sulfate application reduced fruit drop and improved antioxidant activity of ‘Kinnow’ mandarin fruit

Brazilian Journal of Biology ◽

10.1590/1519-6984.244593 ◽

2023 ◽

Vol 83 ◽

Author(s):

M. Liaquat ◽

I. Ali ◽

S. Ahmad ◽

A. M. Malik ◽

H. M. Q. Ashraf ◽

...

Keyword(s):

Fruit Quality ◽

Zinc Sulfate ◽

Foliar Application ◽

Foliar Spray ◽

Soluble Solids ◽

Total Phenolic ◽

Total Production ◽

Fruit Drop ◽

Kinnow Mandarin

Abstract ‘ Kinnow’ mandarin (Citrus nobilis L.× Citrus deliciosa T.) is an important marketable fruit of the world. It is mainstay of citrus industry in Pakistan, having great export potential. But out of total production of the country only 10% of the produce meets the international quality standard for export. Pre-harvest fruit drop and poor fruit quality could be associated with various issues including the plant nutrition. Most of the farmers do not pay attention to the supply of micro nutrients which are already deficient in the soil. Furthermore, their mobility within plants is also a question. Zinc (Zn) is amongst those micronutrients which affect the quality and postharvest life of the fruit and its deficiency in Pakistani soils is already reported by many researchers. Therefore, this study was carried out to evaluate the influence of pre-harvest applications of zinc sulfate (ZnSO4; 0, 0.4%, 0.6% or 0.8%) on pre-harvest fruit drop, yield and fruit quality of ‘Kinnow’ mandarin at harvest. The treatments were applied during the month of October i.e. 4 months prior to harvest. The applied Zn sprays had significant effect on yield and quality of the “Kinnow” fruit. Amongst different foliar applications of ZnSO4applied four months before harvest, 0.6% ZnSO4 significantly reduced pre-harvest fruit drop (10.08%) as compared to untreated control trees (46.45%). Similarly, the maximum number of fruits harvested per tree (627), fruit weight (192.9 g), juice percentage (42.2%), total soluble solids (9.5 °Brix), ascorbic acid content (35.5 mg 100 g-1) and sugar contents (17.4) were also found significantly higher with 0.6% ZnSO4 treatment as compared to rest of treatments and control. Foliar application of 0.6% ZnSO4 also significantly improved total antioxidants (TAO) and total phenolic contents (TPC) in fruit. In conclusion, foliar spray of ZnSO4 (0.6%) four months prior to harvest reduced pre-harvest fruit drop, increase yield with improved quality of ‘Kinnow’ mandarin fruit.

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Foliar Sprays Containing Phosphorus (P) Have Minimal Impact on ‘Pinot noir’ Growth and P Status, Mycorrhizal Colonization, and Fruit Quality

HortScience ◽

10.21273/hortsci.45.5.815 ◽

2010 ◽

Vol 45 (5) ◽

pp. 815-821 ◽

Cited By ~ 5

Author(s):

R. Paul Schreiner

Keyword(s):

Fruit Quality ◽

Mycorrhizal Fungi ◽

Water Status ◽

Foliar Spray ◽

Pinot Noir ◽

Water Control ◽

Foliar Sprays ◽

Vine Growth ◽

Commercial Vineyard ◽

The Impact

Grapevines grown in low-phosphorus (P) soils typical of western Oregon vineyards may benefit from additional P applied to the canopy using foliar sprays. Alternatively, vines may be negatively affected by foliar P sprays because lower root colonization by arbuscular mycorrhizal fungi (AMF) could reduce uptake of other nutrients or increase vine water stress. The impact of foliar P sprays on vine growth, vine nutrient and water status, AMF colonization, and fruit yield and quality was studied in two ‘Pinot noir’ vineyards with a history of low vine P status over 3 years. Three foliar spray treatments [phosphite, phosphate, water (control)] were applied to vines three times each season using a standard air-blast sprayer at a commercial vineyard. Two foliar spray treatments (phosphite, water) were applied using a hand sprayer at a smaller research vineyard. Phosphite sprays increased leaf blade and petiole P concentrations and reduced arbuscular colonization of roots at the research vineyard, but neither phosphate nor phosphite significantly affected these variables at the commercial vineyard. Foliar P sprays had no effect on vine growth, vine water relations (leaf water potential and stomatal conductance), yield, or fruit quality attributes at either site. These results indicate that there is little benefit to spraying the canopy of grapevines with P, even in vineyards with low P status.

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Effect of Some Essential Oils for Limiting Early Blight (Alternaria Solani) Development in Potato Field

Journal of Plant Protection Research ◽

10.2478/v10045-009-0008-2 ◽

2009 ◽

Vol 49 (1) ◽

pp. 57-62 ◽

Cited By ~ 19

Author(s):

Nehal El-Mougy

Keyword(s):

Essential Oils ◽

Early Blight ◽

Disease Incidence ◽

Foliar Spray ◽

Fungal Growth ◽

Alternaria Solani ◽

Plant Diseases ◽

Effective Control ◽

Potato Field

Effect of Some Essential Oils for Limiting Early Blight (Alternaria Solani) Development in Potato FieldThe fungicidal effect of some essential oils againstAlternaria solanione of the species that cause early blight of potato was evaluated underin vitroand field conditions. Effect of carnation, caraway, thyme oils and the chemical fungicide Ridomil MZ 72 at various concentrations on mycelial growth ofA. solaniwas tested. Carnation oil had the strongest and most extensive inhibitory effect on fungal growth. Slightly less effective were caraway and thyme oils followed by the chemical fungicide. Extended field trails for two cultivation seasons proved that the application of essential oils twice as foliar spray had a superior effect to the fungicide treatment for reducing the early blight incidence comparing with untreated control. An opposite relationship between the disease incidence and concentrations of applied essential oils was observed. The increase in potato yield also followed the same trend. The highest reduction in disease incidence and yield increase was recorded in treatments with 1% of carnation, caraway and thyme oils in descending order. Ridomil MZ 72 applied at the dose recommended by manufactories had a low effect in this regard. Essential oils treatments might be used as easily applied, safe and cost effective control methods against such plant diseases.

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Control of A Tomato Plant Root-Knot Nematode By Induced Resistance Of Oxalic Acid Derived From Aspergillus Niger

10.21203/rs.3.rs-426228/v1 ◽

2021 ◽

Author(s):

Jehyeong Yeon ◽

Ae Ran Park ◽

MinKyu-Kang ◽

Van Thi Nguyen ◽

Yookyung Lee ◽

...

Keyword(s):

Aspergillus Niger ◽

Oxalic Acid ◽

Induced Resistance ◽

Tomato Plant ◽

Field Experiments ◽

Plant Root ◽

Foliar Spray ◽

Plant Diseases ◽

Systemic Resistance ◽

Soil Drench

Abstract Aspergillus niger F22 producing oxalic acid (OA) as a nematicidal component is currently used as a microbial nematicide. OA is known to induce systemic resistance in plant diseases caused by fungi, bacteria, and viruses, but the induced resistance of OA has not yet been elucidated in plant diseases caused by root-knot nematodes (RKNs). In this study, we investigated the functional mechanism of induced resistance of A. niger F22 formulation (Nemafree, 20% SC) and OA in tomato plant RKN disease caused by Meloidogyne incognita and analyzed their effectiveness against the disease. Foliar spray and soil drench treatments of Nemafree and OA were effective in the management of M. incognita in tomato plant in-pot experiments. When Nemafree and OA were applied 4 days before inoculation of M. incognita eggs, the treatments of Nemafree (4,000-fold dilution) and OA (0.22 mM) reduced root gall formation by more than 50%. The soil drench treatment also effectively suppressed RKN disease in field experiments. Moreover, the treatments of Nemafree and OA enhanced the transcriptional expression of pathogenesis-related 1 gene, plant proteinase inhibitor-II, and polyphenol oxidase genes and improved the production of total phenols, flavonoids, and lignin in the tomato plants infected with M. incognita. These results demonstrate that RKN diseases can be effectively controlled by induced resistance even at low concentrations of Nemafree or OA. Accordingly, our study provides evidence for more economical and efficient application strategies of microbial nematicides that control RKNs under field conditions.

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Effect of biological sprays on the incidence of grey mould, fruit yield and fruit quality in organic strawberry production

Agricultural and Food Science ◽

10.2137/145960607781635886 ◽

2008 ◽

Vol 16 (1) ◽

pp. 25 ◽

Cited By ~ 13

Author(s):

S. PROKKOLA ◽

P. KIVIJÄRVI

Keyword(s):

Fruit Quality ◽

Treatment Time ◽

Grey Mould ◽

Field Trials ◽

Cultural Control ◽

Fruit Yield ◽

Plant Diseases ◽

Marketable Yield ◽

Trichoderma Spp ◽

Organically Grown

Plant diseases, especially grey mould (Botrytis cinerea), may cause severe losses in organic strawberry production. In a two-year period, 20012002, the effects of different biological sprays on grey mould, the fruit yield and fruit quality of organically grown strawberry Jonsok were studied in field trials at MTT Agrifood Research Finland in Ruukki and Mikkeli. In Experiment 1 the biological sprays were seaweed, garlic and compost extracts, silicon and Trichoderma spp. on both trial sites. In Experiment 2, compost extract, Trichoderma spp. and Gliocladium catenulatum sprays were studied in Ruukki. The treatment time was chosen to control grey mould. The effect of different biological sprays on the incidence of grey mould and total and marketable yield was insignificant compared to the untreated control. In both years and in all trials the incidence of grey mould was low and rot occurred mainly in the latter part of the harvesting period, which may partly explain the small differences between treatments. Anyhow, despite of feasible biological control cultural control methods will be important to manage the fungus in organic strawberry production.;

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