Control of foliar diseases by the axillary application of systemic fungicides in Brazilian coconut palms

Endemic fungal foliar diseases, such as leaf blight – LB [Lasiodiplodia theobromae (Pat.) Griffon and Maubl] and leaf verrucosis, or “lixa-pequena” – LP [Camarotela torrendiela Batista (Bezerra) and Vitoria], reduce the productivity of the coconut palm in Brazil. Damage arises from extensive necrosis of the leaflets, resulting in early abscission of basal leaves and fruit. In Brazil, fungicide terrestrial sprayings has not been a commonly employed practice for the control of coconut foliar diseases because it is not cost-effective, once requiring high-volume of fungicide spraying. Coverage gaps and extensive drift of chemicals can occur due to technological limitations of terrestrial spraying of the tallest mature trees and is further complicated by the peculiar architecture of the palms. The aim of this study was to evaluate the efficacy of systemic fungicides applied directly to the leaf axil of the coconut palm (variety Brazilian Green Dwarf of Jiqui) for the control of foliar diseases. During 2007–2010 and 2009–2012, two field plot experiments were conducted at distinct locations (farms) in the North Fluminense region. Two to 4-monthly applications of the fungicides to the leaf axil of cyproconazole (alone), cyproconazole plus azoxystrobin, cyproconazole plus trifloxystrobin, and flutriafol (alone) were efficacious in controlling coconut palm leaf diseases, resulting in a significant reduction of the LB severity and the number of necrotic LP lesions. When compared with the control treatment, significant increases in the total number of leaves per plant were observed for the most efficacious treatments after one year (2–4 leaves more) and after the second year (3–6 leaves more) after initiating the axillary applications of fungicides in both experiments. This trend continued even after the third year, when there was an average of 8 leaves more for the most efficacious treatment (27 leaves per plant) compared to control (19 leaves per plant) at the end of second experiment. The control of foliar diseases based on the results could ensure a significant increase in regional coconut production.     

Interaction between seed treatments,surfactants and foliar fungicides on controlling dry bean anthracnose (Colletotrichum lindemuthianum)

Anthracnose, caused by fungal pathogen Colletotrichum lindemuthianum (Sacc. & Magnus) Briosi Cav. is one of the main production constraints of the dry bean (Phaseolus vulgaris L.) industry in Ontario. A field study was carried out in 2007 and 2008 to investigate the effect of two seed treatments (DCT (diazinon + captan + thiophanate-methyl) and MFA (metalaxyl-M + fludioxonil + azoxystrobin)) and two foliar fungicides (pyraclostrobin and azoxystrobin) applied with and without a surfactant under low and high disease pressure conditions at Exeter ON. Eighteen treatment combinations were tested in a randomized complete block design with four replicates. The treatment effects were examined by measuring disease development on leaf and pod tissue, pod destruction index, pick (discolored and misshaped seed), yield and return on investment (ROI). The seed treatment MFA performed similarly to DCT, and should be considered a suitable replacement to DCT for dry bean growers. However, utilizing a strobilurin fungicide in both seed and foliar treatments raises concern, as this practice increases the risk of disease resistance. The addition of a surfactant to azoxystrobin increased seed yield and ROI under high disease pressure, but had no effect when added to pyraclostrobin. Pyraclostrobin outperformed azoxystrobin for some disease indices as well as for yield under high disease pressure and for ROI under low and high disease pressure conditions.     

Managing crop losses from plant diseases with foliar fungicides, rotation and tillage on a Black Chernozem in Saskatchewan, Canada

The impact of tillage system, rotation sequence and foliar fungicides on diseases and seed yield and quality of wheat, barley, pea, canola and flax was determined in the second cycle of three, 4-year rotations from 1998 to 2001 on a Black Chernozem (Udic Boroll) at Melfort, Saskatchewan, Canada. The objective of the study was to evaluate the impact of reduced-tillage production systems, broadleaf cropping intensity and fungicide use on cereal, oilseed and pulse crops in northeastern Saskatchewan, a sub-humid region of the northern Great Plains. A split-split plot design was used with three tillage systems (conventional, minimum and no-till) as main plots, three rotations of increasing broadleaf crop intensity (1. canola-wheat-barley-barley; 2. canola-barley-pea-wheat; and 3. canola-pea-flax-barley) as sub-plots, and fungicide treatments (treated or untreated) as sub-sub-plots. Fungicides appropriate for the diseases of concern were applied at recommended crop development stages and application rates, followed by assessment of diseases. Tillage system had little impact on diseases of any crop, although seed yield was usually greater under no-till for most crops under dry conditions. Rotation was not a major factor in disease severity of most of the crops, except barley in the rotation where it was grown for two consecutive years. Under dry conditions, barley yield was reduced when it followed flax compared with other crops, most likely due to less available soil moisture after flax. Fungicide application had the greatest impact on disease control and seed yield increase, although results varied among crops and years. In conclusion, the findings indicate that tillage system had little effect on disease severity, rotation contributed to greater disease severity only when a crop was grown intensively, such as on its own stubble, and fungicide application had variable effects on both disease control and seed yield.     

喷施硒对大豆品质和大豆食品硒水平的影响

用田间试验研究喷施亚硒酸钠对大豆品质和大豆食品硒水平的影响。结果表明，叶面喷施亚硒酸钠浓度小于400mg/L对产量无显著影响，亚硒酸的浓度大于600mg/L，大豆产量显著下降。喷施亚硒酸钠显著提高大豆脂肪含量，特别是亚油酸含量提高1％左右，但对大豆蛋白质含量和氨基酸组成影响不显著。利用富硒大豆生产的大豆食品含硒量显著提高，大豆分离蛋白含硒量为7．487μg/g，豆奶粉为1．023μg/g，豆芽为1．033μg/g,白豆腐干为1.412μg/g.大豆分离蛋白可作为富硒功能食品的有机硒源，豆渣可作为动物饲料添加剂。     

Impacts of foliar fungicides on infection of soybean by Phomopsis spp. in Iowa, USA

Fungicides pyraclostrobin (strobilurin) and tebuconazole (triazole) were applied to soybean [Glycine max (L.) Merr.] at growth stages R3, R5 or R3 + R5, in 2008 and 2009 at two locations in Iowa. Incidence of infection of stems and seeds by Phomopsis spp. was evaluated, along with yield and seed quality. Stem infection by Phomopsis spp. was reduced in both years by pyraclostrobin applied at R3 + R5, and in 2008 by pyraclostrobin at R5, by approximately three-fold compared to the untreated control. In 2009, treatments including applications of tebuconazole at R3 and pyraclostrobin at R5 significantly reduced infection of seed by Phomopsis spp., by approximately two-fold compared to the untreated control. Only the application of pyraclostrobin at R3 + R5 reduced both stem and seed infection by Phomopsis spp. in 2009. None of the treatments had a significant effect on yield, or seed quality, evaluated by warm and cold germination tests. Seed infection by Phomopsis spp. was negatively correlated with seed quality. Fungicides applied at these growth stages can have an impact on infection by Phomopsis spp., but their effectiveness varies with environment and disease intensity.     

The effect of systemic fungicides,applied as seed treatments or early foliar sprays,on speckled leaf blotch of wheat, Mycosphaerella graminicola (Fuckel) Schroeter

Control of speckled leaf blotch (Mycosphaerella graminicola) of wheat (Triticum aestivum) with systemic fungicides used as seed treatments or foliar sprays was studied. Seed treatment with either imazalil (1·125 g/kg seed), nuarimol (0·2 g/kg), thiabendazole (1·5 and 0·75 g/kg), triadimenol (0·3 and 0·2 g/kg) or Shell WL 47675 (0·415 g/kg) reduced the number of infected plants by 28–62% when assessments were made 11 weeks after sowing. Thiabendazole (1·5 and 0·75 g/kg) and triadimefon (0·3 and 0·2 g/kg) slowed the development of speckled leaf blotch for c. 15 weeks after sowing. A single foliar spray of triadimefon (125 g/ha) slowed the development of the disease for c. 10 weeks, but a single spray of benomyl controlled it for the whole season. There was no additional benefit from combining a seed treatment of triadimefon (0·225 g/kg) with the foliar spray.     

Integrated management of major wheat diseases in Brazil: an example for the Southern Cone region of Latin America

Wheat is an important crop in the Southern Cone region of Latin America. Some of the common wheat diseases in this region are Xanthomonas streak, spot blotch, tan spot, and leaf blotch and the rusts. Rice blast on wheat could also be a problem in certain years. Disease management through varietal resistance, cultural practices including appropriate fungicidal spraying schedule, levels of tolerance for field and seed infections and seed treatment criteria, have been integrated and used for several years in Brazil. Emphasis in integrated disease management (IDM) is on reduction in use of fungicides and consequently in the cost of production. Wheat productivity in Brazil has almost doubled during the past 10 years, owing mainly to the IDM approach. The IDM practices used in Brazil for each of the major diseases can also be adopted in other Latin-American countries with similar agroecosystems.     

山区茶园管理机器换人技术集成应用与效益分析

本文基于遂昌山地茶园的技术试验,对比分析了机器换人与人工管理的效益,总结了机器换人技术集成应用的关键点.     

Integrated management of Phytophthora capsici on bell pepper by combining grafting and compost treatment

In 2010 and 2011 an initial set of trials were carried out in order to evaluate the susceptibility of rootstocks used for grafting bell pepper (Capsicum annuum L.) in Italy to Phytophthora capsici, in comparison with widely used cultivars of pepper. In a second set of trials carried out in 2011 and 2012, grafting bell pepper onto resistant or partially resistant rootstock was combined with the use of compost-amended soil, to control Phytophthora blight. Trials were carried out in artificially or naturally infested soil, using five bell pepper cultivars (Fenice, Sienor, San Marco, Fiume, Cuneo) as susceptible not-grafted controls. In three trials, carried out in the presence of soil artificially infested with P. capsici, disease incidence in control plots ranged from 73 to 100% for the cvs. Cuneo and Fiume. Both cvs. Cuneo and Kaiman grafted on “Tecnico F1” rootstock provided complete control of P. capsici. A lower disease control, on the same cultivar, was provided by “Robusto” and “Capsifort”. On the cv. Fiume, “Terrano” provided complete control of the disease. By grafting all cultivars on “Robusto”, “Brutus”, “Snooker” and “Capsifort” a disease reduction by 68%–93%, 86%–100%, 67%–100% and 55%–78%, respectively, was provided. The general linear model analysis showed that for trials carried out under natural infestation the addition of compost to the soil, as well as the interaction of compost-amended soil with grafting, were significant factors influencing disease incidence reduction. The effect of grafting was a significant factor in reducing the percentage of diseased plants in all the trials. The addition of compost to the soil resulted in an effective and low-cost disease management solution, particularly when combined with susceptible not-grafted hybrids of bell pepper or when partially resistant rootstocks were used.     

Improving chemical and sensory quality of high-oleic peanut by application of foliar fertilizer

High-oleic peanut is favored by consumers because its a longer shelf life and benefits for cardiovascular health.Up to the high-oleic standard and with good taste is essential for peanut products in food processing.The aim of present study was to explore the effect of foliar fertilizers on chemical and eating quality of high-oleic peanuts.Three high-oleic peanut cultivars,namely Huayu 09C2,Huayu 9621,and Huayu 962,were used as materials.Huayu 09C2 and Huayu 9621 were planted in Fuxin,Liaoning,foliar sprayed with Fosforil at 2250 mL/ha,and Huayu 962 was sown in Jvnan,Shandong,foliar sprayed with Foliplus at 1500/3000 mL/ha.The chemical and sensory quality of peanut harvested from the treatment plots and controls was evaluated.Results showed that,Huayu 09C2 and Huayu 9621,foliar spraying with Fosforil in Fuxin,Huayu 962,foliar spraying with Foliplus in Jvnan,all still maintained high oleate content levels,and the Fosforil treatment was effective in raising the intensity of sweetness of roasted kernels.This study demonstrated the feasibility of improving chemical and sensory quality of high-oleic peanut through foliar fertilizer.     

Differential feeding by grasshoppers and levels of foliar diseases in various cultivars of spring cereals

Sixty-four cultivars and strains of cereals were evaluated under field conditions for differential feeding by grasshoppers, (Orthoptera:: Acrididae) and for their resistance to foliar disease. Grasshoppers actively fed on all triticale and durum wheat lines, on 11 of 12 bread wheat lines, and on 11 of 24 barley lines. Both the incidence and severity of foliar disease were high in all cereals. There was no correlation between grasshopper damage and resistance to foliar disease (r+ −0·059) in the barley but a positive trend appeared in wheat lines (bread r= +0·487; durum r= +0·295). The data suggest that present trends in breeding disease-resistant cereal cultivars will not introduce increased susceptibility to grasshopper damage.     

抛秧技术在杂交制种中的应用及管理

抛秧技术是近年来水稻生产上推广的一种新技术,具有省时、省工、高产等优点。而用工集中的矛盾一直制约杂交制种效益的提高。本文以特优175的制种为例,详细介绍了抛秧在杂交制种上的应用及管理技术,指出抛秧是提高杂交制种效益的一条可行之路。     

The control of leatherjackets, Tipula paludosa Meig., in grassland by early application of insecticide

To determine whether leatherjackets might be controlled by application of a pesticide in summer, before oviposition by crane flies, chlorpyrifos was applied to perennial ryegrass (Lolium perenne) swards on dates from July to September in anticipation of leatherjacket infestation. Subsequent winter population estimates showed that leatherjacket numbers had been reduced by at least 85% by 0·72 kg chlorpyrifos ha^-1 applied on 13 July, and by 0·60 kg ha^-1 applied on 3 August or later.
The significance of leatherjacket control by pesticide application on these dates is discussed in relation to previously recorded effects of pesticide treatment on other known pests. It is concluded that control of all common arthropod pests of proven significance in established grassland may be achieved with one application of pesticide.     

Control of silver scurf on potato by dusting or spraying seed tubers with fungicides before planting

Silver scurf of potato caused byHelminthosporium solanl Dur. & Mont. is a blemish disease that has become economically important in recent years and is considered primarily seedborne. The objective of the present study was to compare the effectiveness of various fungicides, alone or in combination, applied to seed tubers prior to planting, in controlling silver scurf on the daughter tubers. Disease incidence and severity were significantly reduced by all treatments in three experimental locations, with the exception of fluazinam, which was not effective. Among the fungicides tested in these experiments, the most effective were fludioxonil and prochloraz-Zn applied as a LV spray (control efficiency of 88% and 82%, respectively) and propineb and mancidan applied as a dust treatment (control efficiency of 78% and 77%, respectively). Azoxystrobin and imazalil treatments were less effective with control efficiencies of 68% and 43%, respectively. None of the various treatments affected crop yields in the three experimental sites.     

Protein quality of peas as influenced by location,nitrogen application and seed inoculation

A study was conducted to evaluate the contribution of location, N application andRhizobium seed inoculation to variations in seed protein content and amino acid (AA) composition of field peas. The magnitude of AA variations with protein level and the nature of the relationships that are involved were determined. Regression equations to predict AAs from protein were developed for the cultivar Bohatyr. The experiments were carried out at two locations in southern Manitoba in 1994. The levels of N fertilization investigated were: 56, 75, 100, 125, 150, 200, 250 and 300 kg/ha. At each level of N application, seeds planted were eitherRhizobium inoculated or not inoculated. The combination of location, fertilizer treatments and inoculation yielded 192 samples for chemical analyses. The samples were analyzed for dry matter (DM), N and AA contents. Location and N fertilization had significant (p0.001) effects on seed protein content and AA composition. Seed protein content increased with increasing levels of N application. The response of protein to fertilization was not the same in both locations as evidenced from the presence of interaction (p0.01) between location and N application. Except for methionine and cystine, percent AAs in DM increased with increasing levels of N application. The effects of N application on the concentrations of methionine and cystine were not consistent. On protein basis, the concentrations of AAs decreased with increasing levels of N application. The only exception was arginine which strongly increased in concentration. There was no effect (p0.05) of seed inoculation observed in this study. Strong positive correlations (r>0.80) between seed protein content and AA concentrations expressed as percent of DM were found for all AAs except for methionine (r=0.76) and cystine (r=0.51). When AA concentrations are expressed as g per 16 g N, 15 of the 17 AAs were negatively correlated to seed protein content. Only arginine (r=0.78) and aspartic acid (r=0.17) had positive correlations. The regression equations developed from this study could be used to predict the concentrations of AAs except methionine and cystine for the cultivar Bohatyr once the protein content is known.     

Aspects of insecticide resistance and reproductive biology ofAphis gossypii glover on seed potatoes

Summary For several years the aphid population patterns and the incidence of the main potato virus diseases have been monitored in Italian potato-growing areas. Starting from 1992, an increase inAphis gossypii, as compared toMyzus persicae, Macrosiphum euphorbiae andAphis fabae, was observed on seed potato fields in the north of Italy. Laboratory tests revealed thatA. gossypii was insensitive to the pesticide pirimicarb, even at the maximum dose tested (2400 μg/ml). Moreover, in the presence of pirimicarb the reproductive capacity increased up to 30% as compared with the control, and the new-born aphids began to appear 2 days earlier in the treated group. By contrast,M. persicae was controlled at a lower dose (300 μg/ml). Lambda-cyhalothrin and imidacloprid were very effective against both aphids.