scholarly journals Effect of Relative Humidity on Sporulation of Fusarium oxysporum in Various Formulations and Effect of Water on Spore Movement Through Soil

1998 ◽  
Vol 88 (6) ◽  
pp. 544-549 ◽  
Author(s):  
J. A. Gracia-Garza ◽  
D. R. Fravel

Fusarium oxysporum f. sp. erythroxyli is being investigated as a mycoherbicide for the narcotic plant coca. Sporulation of the fungus in seven formulations containing different organic substrates and movement of its propagules through soil were studied. The formulations were a granular wheat flour/kaolin (pesta); an extruded wheat and rice flour (C-6); and five alginate pellet products containing corn cobs, soybean hull fiber, canola meal, rice flour, or rice flour plus canola oil. Formulations were incubated at 25°C for 6 weeks in desiccators with various salt solutions to provide nine relative humidities (RH), ranging from 100% (pure deionized water) to 0% (anhydrous (CaSO4). Hyphae of F. oxysporum f. sp. erythroxyli grew out of alginate pellets with canola meal, rice, and rice plus canola oil as early as 24 h at 100% constant RH. Alginate pellets of rice plus canola oil and granular C-6 and pesta formulations consistently produced more microconidia, macroconidia, and CFU than the other four formulations at all RH tested. The C-6 formulation produced more propagules than the other formulations at low RH (<53%). Canola meal pellets produced more spores than three other formulations when exposed to fluctuating RH (100 to 75%). The effect of percolating water on spore movement through soil was studied using a plant-pathogenic isolate of F. oxysporum f. sp. niveum. To determine the effect of water percolation on propagule movement, formulations were placed on soil columns and artificial rain was applied. In general, 10-fold fewer CFU were recovered at a 8- to 10-cm depth compared with a 0- to 2-cm depth.

1998 ◽  
Vol 88 (3) ◽  
pp. 185-189 ◽  
Author(s):  
J. A. Gracia-Garza ◽  
D. R. Fravel ◽  
B. A. Bailey ◽  
P. K. Hebbar

A natural epidemic of Fusarium wilt on coca (Erythroxylum coca) in Peru prompted the suggestion of possibly using the pathogen Fusarium oxysporum f. sp. erythroxyli as a mycoherbicide against this narcotic plant. During field trials conducted in Kauai, HI, to test the pathogenicity of the coca wilt pathogen, ants were observed removing formulations from test plots. While removal of formulations by ants was considered detrimental with respect to conducting field tests, ant removal was considered potentially beneficial in disseminating the mycoherbicide. Thus, research was initiated to assess the ability of formulation additives to alter the preference of ants for the formulated mycoherbicide. In Hawaii, preference of indigenous ants for removing formulations was tested using three different food bases (rice, rice plus canola oil, and wheat flour [gluten]). Similar tests were conducted at Beltsville, MD, using F. oxysporum f. sp. melonis, in which the formulation based on wheat flour was replaced by a formulation based on canola meal. Formulations based on wheat were preferred by ants in both locations; up to 90% of the wheat plus rice flour granules (C-6) and the wheat gluten plus kaolin granules (pesta) were removed within 24 h, while only 20% of those containing rice without oils were taken. However, when either canola, sunflower (Maryland only), or olive oil was added to the rice formulation, up to 90% of the granules were taken. The formulation based on canola meal was less attractive to ants, as only 65% of the granules were removed within a period of 24 h. Ants showed no preference with respect to presence or absence of fungal biomass. To alter the attractiveness of the C-6 formulation to ants, C-6 was amended with three natural products. Canna and tansy leaves were added to C-6 at a ratio of 1:5 (wt/wt), while chili powder was added at 1:25 or 1:2.5 (wt/wt). Canna, tansy, and the higher rate of chili powder significantly reduced the number of C-6 granules removed by ants. Canna and tansy leaves affected neither germination nor sporulation of the mycoherbicide, while the high concentration of chili powder reduced viability of propagules in the formulation. More F. oxysporum f. sp. erythroxyli-type colonies were recovered from inside ant nests (9 cm depth) than from nest surfaces, indicating that ants may distribute the mycoherbicide in the soil profile. Ants passively carried propagules of F. oxysporum f. sp. erythroxyli outside their bodies, as well as either very closely adhering to the outside or within their bodies.


2015 ◽  
Vol 39 (4) ◽  
pp. 323-330 ◽  
Author(s):  
Juan Carlos Álvarez-Hernández ◽  
Javier Zaragoza Castellanos-Ramos ◽  
César Leobardo Aguirre-Mancilla ◽  
María Victoria Huitrón-Ramírez ◽  
Francisco Camacho-Ferre

Cucurbita maxima x Cucurbita moschata rootstock are used to prevent infection with Fusarium oxysporum f. sp. niveum in watermelon production; however, this rootstock is not effective against nematode attack. Because of their vigor, the grafted plants can be planted at lower plant densities than the non-grafted plants. The tolerance to Fusarium oxysporum f. sp. niveum and Meloidogyne incognita was assessed in watermelon plants grafted onto a hybrid of Citrullus lanatus cv Robusta or the Cucurbita maxima x Cucurbita moschata cv Super Shintoza rootstocks. The densities of plants were 2083 and 4166 plants ha-1. Non-grafted watermelons were the controls. The Crunchy Red and Sangría watermelon cultivars were used as the scions, it the latter as a pollinator. The experiments were performed for two production cycles in soils infested with Fusarium oxysporum f. sp. niveum and Meloidogyne incognita. The incidence of Fusarium oxysporum f. sp. niveum was significantly greater in the non-grafted than in the grafted plants. The grafted plants presented similar resistance to Fusarium regardless of the rootstock. The root-knot galling index for Meloidogyne incognita was significantly lower in plants grafted onto Citrullus lanatus cv Robusta than onto the other rootstock. The yields of plants grafted onto Citrullus lanatus cv Robusta grown at both plant densities were significantly higher than in the other treatments.


Author(s):  
Claire Curry

Abstract TR4 is one of only six strains strains of F. oxysporum f.sp. cubense (Foc) that attack Cavendish bananas (AAA genome). It is much more aggressive on Cavendish than SR4. TR4 was first observed in Taiwan in 1989 but its importance as an invasive was identified in the 1990s when it was isolated from damaged Cavendish plants in Indonesia and Malaysia (Buddenhagen, 2009). TR4 is considered one of the most destructive Foc strains because it has a wider host range than other strains, attacking the important cultivar Cavendish, but also all the other cultivars that are sensitive to Foc (Cheng et al., 2019).


1999 ◽  
Vol 50 (4) ◽  
pp. 497 ◽  
Author(s):  
D. G. Masters ◽  
G. Mata ◽  
S. M. Liu

There is limited evidence that the response in wool growth resulting from feeding protected protein supplements continues after the feeding has stopped. Feeding such proteins, alternated with traditional supplements, may increase wool growth as much as continuous feeding but at a lower cost. This experiment aimed to determine whether the response to protected protein continued after the sheep were switched to a cereal supplement. Over a 2-month experimental period, 56 weaners (5 months old, weighing 26 kg) were used in a 2 × 2 factorial experiment. Half were fed a diet containing 25% canola meal [partially protected protein with high concentrations of sulfur amino acids (SAA)] mixed with oaten hay, urea, and minerals. The other half were fed the same diet but with lupin seed (highly degradable protein with low concentrations of SAA) replacing the canola meal. Within each of the 2 dietary treatments and in each of 2 months, half of the weaners were fed the diet continuously, the other half were fed the diet for 2 weeks followed by 2 weeks of a barley, oats, hay, urea, and minerals diet. Another group of 8 weaners was fed the oats–barley diet continuously for 2 months. All sheep were fed to lose 35 g liveweight/day. Weaners fed canola meal grew 11% more wool during the experiment and had a higher rate of protein synthesis in the skin than weaners fed lupins. The response to canola meal of wool and skin was the same whether feeding was continuous or alternated with oats–barley, indicating that the benefits from feeding partially protected proteins continues after feeding has stopped.


Soil Research ◽  
1997 ◽  
Vol 35 (3) ◽  
pp. 515 ◽  
Author(s):  
I. Vogeler ◽  
B. E. Clothier ◽  
S. R. Green

In order to examine whether the electrolyte concentration in the soil solution can be estimated by time domain reflectometry (TDR) measured bulk soil electrical conductivity, column leaching experiments were performed using undisturbed soil columns during unsaturated steady-state water flow. The leaching experiments were carried out on 2 soils with contrasting pedological structure. One was the strongly structured Ramiha silt loam, and the other the weakly structured Manawatu fine sandy loam. Transport parameters obtained from the effluent data were used to predict the transient pattern in the resident electrolyte concentration measured by TDR. The electrolyte concentration was inferred from the TDR-measured bulk soil electrical conductivity using 2 different calibration approaches: one resulting from continuous solute application, and the other by direct calibration. Prior to these, calibration on repacked soil columns related TDR measurements to both the volumetric water content and the electrolyte concentration that is resident in the soil solution. The former calibration technique could be used successfully to describe solute transport in both soils, but without predicting the absolute levels of solute. The direct calibration method only provided good estimates of the resident concentration, or electrolyte concentration, in the strongly structured top layer of the Ramiha soil. This soil possessed no immobile water. For the less-structured layer of the Ramiha, and the weakly structured Manawatu soil, only crude approximations of the solute concentration in the soil were found, with measurement errors of up to 50%. The small-scale pattern of electrolyte movement of these weakly structured soils appears to be quite complex.


2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Zhe Yang ◽  
Xue Han ◽  
Huiying Wu ◽  
Lijuan Zhang ◽  
Lanwei Zhang ◽  
...  

Rice and its products are widely consumed in Asian countries; however, starch retrogradation decreases the quality and shortens the shelf-life of rice foods particularly at low temperature. In this study sucrose ester (SE), glycerol monostearate (GMS), and sodium stearoyl lactylate (SSL) were added to rice flour and corresponding rice gels. Then, gelatinization properties, retrogradation characteristics, texture, and water content of these rice gels were investigated at 4°C and −20°C storage, respectively. The results demonstrated that the rice gels with 0.2% GMS had the lowest retrogradation index (ΔHr/ΔHg) (11.84%) and hardness (1359 g) at 4°C for a 10 d period, which was significantly lower in comparison to control and the other two emulsifiers (P<0.05). Adhesiveness and water content were increased compared to the other samples. Furthermore, the retrogradation of rice gels stored at 4°C was comparatively rapid compared to gels stored at −20°C. Gel samples stored at −20°C were still acceptable for more than 15 days. Thus it was revealed that GMS has the potential to retard starch retrogradation and produce high-quality rice products in preservation.


2021 ◽  
Author(s):  
Tiago Olivoto ◽  
Maria Inês Diel ◽  
Denise Schmidt ◽  
Alessandro Dal’Col Lúcio

ABSTRACTThe multi-trait genotype-ideotype distance index (MGIDI) was used to select superior treatments in experiments with strawberries. Twenty-three productive, qualitative, physiological, and phenological traits with negative and positive desired gains were accessed in 16 treatments, a combination of two cultivars (Albion-neutral days, and Camarosa-short days), two transplants origins (National and Imported), and four organic substrates mixes (Crushed sugarcane bagasse, burnt rice husk, organic substrate, and Carolina commercial substrate). Our results suggest that most of the strawberry traits are influenced by the cultivar, transplant origin, cultivation substrates, as well as by the interaction between cultivar and transplant origin. The MGIDI index indicated that the Albion cultivar originated from imported transplants grown in substrates where the main component (70%) is burnt rice husk provides desired values for 20 of a total of 22 traits, which represents a success rate of ~ 91% in selecting traits with desired values. The strengths and weakness view provided by the MGIDI index revealed that the looking for an ideal treatment should direct the efforts on improving the water efficiency use and reducing total acidy of fruits. On the other hand, the strengths of selected treatments are mainly related to productive precocity, total soluble solids, and flesh firmness. The MGIDI index provides a unique, robust, and easy-to-handle process, standing out as a powerful tool to develop better treatment recommendations for experiments with strawberries when multiple traits are assessed.


2019 ◽  
Vol 7 (1-2) ◽  
pp. 98-102
Author(s):  
Judit Csonka ◽  
László Friedrich ◽  
Klára Pásztor-Huszár ◽  
Karina Hidas ◽  
Anna Visy ◽  
...  

Quick frozen food are becoming increasingly popular among consumers in the last decades. During the development of a quick frozen gluten-free pie crust dough product, the aim was to develop a dough that does not suffer any harmful changes after the freeze-thaw process. The texture is one of the most important sensorial properties, and has a great influence on consumer acceptance. Texture Analyser was used to measure the hardness and the brittleness of various doughs. A quick frozen pie crust dough should be easily cut, but non-crumbling after baking. The results showed that the hardness of a dough with 10% more rice flour was bigger than the other dough’s hardness and it became harder after the freeze-thaw process, while the other dough’s hardness have not changed during the process. The first dough was less brittle than the second dough, also before and after the freeze-thaw. In conclusion, the 1st dough is harder, so it is not more easy to cut than the 2nd dough. However, the first dough being less brittle allows cutting with less crumbs. Considering the expectations, in the future the first recipe should be used to make a fast-frozen pie crust dough product.


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