Maize sterile stunt — a delphacid transmitted rhabdovirus disease affecting some maize genotypes in Australia

1982 ◽  
Vol 33 (1) ◽  
pp. 13 ◽  
Author(s):  
RS Greber

A rhabdovirus disease causes severe stunting and sterility of a few susceptible maize (Zea mays L.) genotypes in eastern Australia. Maize sterile stunt virus (MSSV) also infected Aegilops variabilis Eig, barley (Hordeum vulgare L.), barnyard grass (Echinochloa colona (L.) Link.), triticale (x Triticosecale Wittmack), wheat (Triticum aestivum L.), T, aethiopicum Jakubz., T, monococcum L, and T. turgidum L. MSSV was transmitted with low efficiency by the maize planthopper Peregrinus maidis (Ashm.) and by Sogatella kolophon (Kirk.), but the chief natural vector was Sogatella longifurcifera Esaki and Ishihara, a delphacid found commonly on affected maize and on E. colona. The incubation period of MSSV in P, maidis was 10-14 days after acquisition on infected plants or 9-12 days after injection of infective sap. Transmission was demonstrated during a period of up to 23 days or until the insects died. Field incidence in the maize lines B37 and H84 often exceeded 90 %, but most maize lines were resistant and resistance was highly dominant. Temperate cereals were severely affected only during summer and triticale was the most susceptible. Particle dimensions were 230 by 50 nm in negative stain and 255 by 45 nm in thin section, with accumulations of particles found only in cytoplasmic vesicles. MSSV particles occurred mainly in companion cells, phloem parenchyma and bundle sheath cells in maize. Virus-like particles were also found in the brain and salivary glands of infective P. maidis.

1979 ◽  
Vol 30 (3) ◽  
pp. 433 ◽  
Author(s):  
RS Greber

An undescribed rhabdovirus was found in eight species of Gramineae at locations extending over 1000 km of the tropical and subtropical Australian east coast. The incidence in maize was usually low but sometimes reached 50% in susceptible hybrids. Cereal chlorotic mottle virus (CCMV) was shown experimentally to infect Avena sativa L., Digitaria ciliaris (Retz.) Koeler, Dinebra retroflexa (Fahl.) Panz., Echinochloa colona (L.) Link., Eleusine coracana (L.) Gaertn., Eleusine indica (L.) Gaertn., Hordeum vulgare L., Triticum aestivum L. and Zea mays L. Symptoms in all hosts began as chlorotic striations, but were often reduced to a fine chlorotic mottle in subsequent growth. After a 3-day acquisition, 50% of individuals of the cicadellid Nesoclutha pallida (Evans) transmitted CCMV in consecutive test feeds with only occasional failures, but some insects then failed to transmit for up to 30 days before death. The time between acquisition and first transmission was 11–24 days and the time for symptom development in the plant was 11–21 days. The virus was acquired and transmitted by both nymphs and adults and by males and females. Transmission continued through the moult to adult. In negative stain the particles were bullet-shaped, 214 by 75 nm, with a net-like surface pattern and core width of 28 nm. There were c. 48 helix cross-striations and 52 surface projections around the full perimeter of bacilliform particles when viewed after brief fixing with glutaraldehyde before staining.


2020 ◽  
Vol 71 (10) ◽  
pp. 894
Author(s):  
M. K. Conyers ◽  
J. E. Holland ◽  
B. Haskins ◽  
R. Whitworth ◽  
G. J. Poile ◽  
...  

Soil testing guidelines for sulfur (S) under dryland cropping in south-eastern Australia are not well developed. Our objective was to assess the value of soil and tissue tests for S and nitrogen (N), because the two minerals frequently interact), in predicting S-deficient sites and hence increasing the probability of response to application of S (and N). Here, we report three proximal experiments in 2014–16 for barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) on a sandy soil in a semi-arid environment near Merriwagga in western New South Wales. The trials contained a factorial combination of four rates of each of applied N as urea and S as high-grade gypsum. Responses to S were obtained for dry matter (DM) quantity and nutrient content at flowering in 2014, but no grain-yield response was obtained in any year. DM response to applied S was obtained when the concentration of S in the DM was increased from 0.08% in barley and 0.09% in wheat without S application to 0.10–0.11% in both crops with S applied as gypsum. Because we obtained no grain-yield responses to applied S, the 0.10% S in grain was likely to have been adequate for both crops in these experiments. A pool of subsoil S was accessed during each season and this compensated for any DM deficiencies of S by the time of grainfill. Shallow soil tests (0–10 cm) for S can therefore indicate sufficiency but not necessarily deficiency; therefore, in grain-cropping areas, we recommend soil S tests on the same samples as used for deep N testing (to 60 cm) and that an S-budgeting approach be used following the soil tests. Furthermore, for marginal nutritional circumstances such as occurred in this study, the supporting use of N:S ratio is recommended, with values >17 in DM or grain likely to indicate S deficiency for both barley and wheat.


1993 ◽  
Vol 73 (3) ◽  
pp. 703-712 ◽  
Author(s):  
V. S. Baron ◽  
A. C. Dick ◽  
H. G. Najda ◽  
D. F. Salmon

Annual crops are used routinely for pasture in many parts of the world, but in Alberta they are used primarily to offset feed shortages. Experiments were conducted during 1987 and 1988 at Lacombe, Alberta under dryland conditions and at Brooks, Alberta under irrigation to determine the feasibility of using spring-planted combinations of spring and winter cereals to extend the grazing season. Treatments for simulated grazing were spring oat (Avena sativa L.), and barley (Hordeum vulgare L.) monocrops (SMC), winter wheat (Triticum aestivum L.) and winter triticale (X Triticosecale Wittmack) monocrops (WMC), spring and winter cereal binary mixtures, seeded together in the spring (intercrop-IC) and the winter cereal seeded after one clipping of the spring cereal (double crop-DC). Clippings were initiated at the jointing stage of the spring cereals and were repeated at intervals of 4 wk. The SMC produced the highest yields during the first two cuts (mid-June and mid-July), but regrowth declined thereafter. The WMC generally had superior yields after mid-July. The IC yield was similar to the higher of the SMC or WMC at any cut with more uniform productivity over the growing season. The DC was inferior to the IC for late summer and fall production. Averaged over years the IC produced 92 and 87% as much DM in the fall as the WMC at Lacombe and Brooks, respectively. Yield totalled over all cuts resulted in the sequence IC > WMC > DC > SMC. The IC is a feasible season-long pasture system under irrigation in southern Alberta and under rain-fed conditions in central Alberta. Key words: Cereals, double-crop, intercrop, monocrop, pasture, yields


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1482
Author(s):  
Silvia Pampana ◽  
Alessandro Rossi ◽  
Iduna Arduini

Winter cereals are excellent candidates for biosolid application because their nitrogen (N) requirement is high, they are broadly cultivated, and their deep root system efficiently takes up mineral N. However, potential N leaching from BS application can occur in Mediterranean soils. A two-year study was conducted to determine how biosolids affect biomass and grain yield as well as N uptake and N leaching in barley (Hordeum vulgare L.), common wheat (Triticum aestivum L.), durum wheat (Triticum turgidum L. var. durum), and oat (Avena byzantina C. Koch). Cereals were fertilized at rates of 5, 10, and 15 Mg ha−1 dry weight (called B5, B10, and B15, respectively) of biosolids (BS). Mineral-fertilized (MF) and unfertilized (C) controls were included. Overall, results highlight that BS are valuable fertilizers for winter cereals as these showed higher yields with BS as compared to control. Nevertheless, whether 5 Mg ha−1 of biosolids could replace mineral fertilization still depended on the particular cereal due to the different yield physiology of the crops. Moreover, nitrate leaching from B5 was comparable to MF, and B15 increased the risk by less than 30 N-NO3 kg ha−1. We therefore concluded that with specific rate settings, biosolid application can sustain yields of winter cereals without significant additional N leaching as compared to MF.


1977 ◽  
Vol 57 (3) ◽  
pp. 729-733 ◽  
Author(s):  
L. C. DARLINGTON ◽  
D. E. MATHRE ◽  
R. H. JOHNSTON

Isolates of Claviceps purpurea (Fr.) Tul. originally isolated from many different grass hosts in the northern Great Plains and several other areas in the United States and England were tested for their pathogenicity to selected cultivars or lines of male-sterile wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.). While there was a great range in the level of virulence, no clear-cut evidence of specific races was obtained. A few isolates were weakly virulent on two cultivars of male-sterile spring wheat but were highly virulent on the other two cultivars tested. Wheat and barley breeders are advised to use a mixture of isolates in screening germ plasm for resistance to ergot.


1975 ◽  
Vol 55 (2) ◽  
pp. 529-535 ◽  
Author(s):  
M. K. POMEROY ◽  
C. J. ANDREWS ◽  
G. FEDAK

Increasing the duration of freezing of Kharkov winter wheat (Triticum aestivum L.) demonstrated that severe injury does not occur to plants at a freezing temperature (−6 C) well above the lethal temperature for at least 5 days, but progressively more damage occurs as the temperature approaches the killing point (−20 C). High levels of cold hardiness can be induced rapidly in Kharkov winter wheat if seedlings are grown for 4–6 days at 15 C day/10 C night, prior to being exposed to hardening conditions including diurnal freezing to −2 C. The cold hardiness of Kharkov and Rideau winter wheat seedlings grown from 1-yr-old seed was greater than that from 5-yr-old seed. Cold-acclimated Kharkov winter wheat and Dover winter barley (Hordeum vulgare L.) demonstrated the capacity to reharden after varying periods under dehardening conditions. The time required to reharden and the maximum level of hardiness attained by the plants was dependent on the amount of dehardening. Considerable rehardening was observed even when both dehardening and rehardening were carried out in the dark.


2021 ◽  
Author(s):  
Buddhi B Achhami ◽  
Gadi V P Reddy ◽  
M L Hofland ◽  
Jamie D Sherman ◽  
Robert K D Peterson ◽  
...  

Abstract Wheat stem sawfly, [Cephus cinctus (Hymenoptera: Cephidae)], females display complex behaviors for host selection and oviposition. Susceptible hollow stem wheat (Triticum aestivum L.) cultivars release a greater amount of attractive compound, (Z)-3-hexenyl acetate and receive a greater number of eggs compared to resistant solid stem wheat cultivars. However, barley (Hordeum vulgare L.) is becoming a more common host for C. cinctus in Montana. Therefore, how do host selection and oviposition behaviors on barley cultivars compare to what happens when encountering wheat cultivars? To answer this question, we carried out greenhouse experiments using two barley cultivars: ‘Hockett’ and ‘Craft’. Between these cultivars at Zadoks stages 34 and 49, we compared host selection decisions using a Y-tube olfactometer, compared oviposition behaviors on stems, and counted the number of eggs inside individual stems. In Y-tube bioassays, we found a greater number of C. cinctus females were attracted to the airstream passing over ‘Hockett’ than ‘Craft’ barley cultivars. Although the frequencies of oviposition behaviors were similar between these cultivars, the number of eggs was greater in ‘Hockett’. Volatile profiles indicated that the amount of linalool was greater in the airstream from ‘Craft’ than in ‘Hockett’ at Zadoks 34 while the amount of (Z)-3-hexenyl acetate was greater in airstream from ‘Hockett’ at both Zadoks 34 and 49. These results suggest that volatiles of barley plants influenced host selection behavior of ovipositing C. cinctus females, while other discriminating behaviors do not differ between cultivars.


2017 ◽  
Vol 9 (2) ◽  
pp. 242-249 ◽  
Author(s):  
Faride BEHBOUDI ◽  
Zeinalabedin TAHMASEBI SARVESTANI ◽  
Mohamad Zaman KASSAEE ◽  
Seyed Ali Mohamad MODARES SANAVI ◽  
Ali SOROOSHZADEH

Plants such as wheat and barley that are strategically important crops need to be considered to develop a comprehensive toxicity profile for nanoparticles (NPs). The present study was aimed to investigate the effects of chitosan and SiO2 NPs on wheat and barley plants. Two factorial experiments (seeds priming and direct exposure) were performed based on a completely randomized design in four replications. Results showed that the seeds priming with the NPs had not significant effect on germination parameters such as Germination Percentage (GP), Germination Rate (GR), Germination Value (GV), Mean Germination Time (MGT), Pick Value (PV) and Mean Daily Germination (MDG). In contrast, exposure of the seeds to the NPs had significant effects on these parameters. In both experiments, treatments had significant effects on shoot, seedling, root length, fresh and dry weight, as well as vigor indexes as compared to the control. In most traits, the best concentration of NPs was 30 ppm, whereas applications of the NPs with 90 ppm displayed adverse effects on majority of the studied traits. According to these results, selectivity in applications of NPs with suitable concentration and method is essential for different plant species.  


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