scholarly journals Identification and Toxigenicity of Aspergillus spp. from Soils Planted to Peanuts in Eastern Zambia

2016 ◽  
Vol 43 (2) ◽  
pp. 148-156 ◽  
Author(s):  
S. M. C. Njoroge ◽  
K. Kanenga ◽  
M. Siambi ◽  
F. Waliyar ◽  
E. S. Monyo
Keyword(s):  
Room Temperature ◽  
Growing Season ◽  
Mitigation Strategies ◽  
Climatic Data ◽  
Liquid Media ◽  
Population Densities ◽  
Eastern Province ◽  
Total Aflatoxin ◽  
Arachis Hypogaea L ◽  
Yeast Extract Sucrose

ABSTRACT It is not known which aflatoxigenic species are present in Zambia. Therefore, soil samples were collected during May to June 2012, at the end of the growing season in Eastern Province, from 399 farmers' fields that had been planted to groundnut (Arachis hypogaea L.) in Nyimba, Petauke, Mambwe, and Chipata Districts. Population densities of Aspergillus spp. were estimated by plating 10−3 soil dilutions on modified dichloran rose Bengal (MDRB) media. To test for toxigenicity, colonies were randomly selected from MDRB dilution plates, single-spored, transferred to vials with yeast extract sucrose (YES) liquid media, and grown for a week at room temperature. Agra Strip ® lateral flow cards were then used to test the filtered extracts, from the YES cultures, for total aflatoxin at 4 and 20 parts per billion (ppb). We identified Aspergillus flavus (small and large sclerotia strains), A. parasiticus, A. niger, A. nomius, A. oryzae, A. tamarii, and A. terreus. 100% of the S-strain A. flavus isolates produced aflatoxin at 4 and 20 ppb, whereas 86% and 56% of the L-strain A. flavus isolates produced aflatoxins at 4 and 20 ppb, respectively. All the A. nomius isolates produced aflatoxins at 4 and 20 ppb. 79% and 64% the A. parasiticus isolates produced aflatoxins at 4 and 20 ppb. To our knowledge, this is the first peer reviewed report from Zambia documenting the population densities of A. flavus across different agroecologies. In addition, it is also the first report on the identification of different Aspergillus spp., such as A. nomius, A. terreus, A. oryzae, and A. tamarii from Zambia. This information, taken together with cropping practices, soil characteristics, agroecological and climatic data, can form a basis for developing holistic pre-harvest aflatoxin mitigation strategies.

Effect of electromagnetic field on germination of groundnut seeds (Arachis hypogaea L)

2012 ◽  
Vol 2 (2) ◽  
pp. 73-78
Author(s):  
E. Rajasekhar ◽  
R. Jeevan Kumar ◽  
C. M. Subhan ◽  
P. Panduranga ◽  
T. Krishnamurthy
Keyword(s):  
Electromagnetic Field ◽  
Relative Humidity ◽  
Field Strength ◽  
Arachis Hypogaea ◽  
Exposure Time ◽  
Room Temperature ◽  
Total Weight ◽  
South Pole ◽  
Arachis Hypogaea L ◽  
Field Strengths

Present work is about the influence of Electromagnetic field [EMF] treatment on the improvement of groundnut seeds (Arachis hypogaea L) germination. The treatment consisted of different electromagnetic field strengths 2, 4, 7 and 10 milli Tesla [mT] in different exposure times 10, 20, 30 and 40 min. In every measurement, the relative humidity and room temperature were recorded. The germination [G] of seed in terms of percentage [% ], the stems length [SL] and roots length [RL] in millimeter [mm] at 6th day and 12th day after experiment, and the total weight [TW] in milligram at 12th day have been measured. Best results have been obtained for variants with exposure time of 30 min and field strength of 7 mT at south pole. Result obtained in the present investigation revealed that the energy absorbed by molecules was high at lower output strength and shorter exposure time improved biologicalfunctions, stimulation effect could be achieved.

Peanut (Arachis hypogaea L.) Response to Lactofen at Various Postemergence Timings1

2012 ◽  
Vol 39 (1) ◽  
pp. 9-14 ◽  
Author(s):  
P. A. Dotray ◽  
W. J. Grichar ◽  
T. A. Baughman ◽  
E. P. Prostko ◽  
T. L. Grey ◽  
...  
Keyword(s):  
Arachis Hypogaea ◽  
Field Experiments ◽  
Yield Loss ◽  
Growing Season ◽  
High Plains ◽  
Application Timing ◽  
Texas High Plains ◽  
Arachis Hypogaea L ◽  
Seed Fill ◽  
Preharvest Interval

Abstract Field experiments were conducted at nine locations in Texas and Georgia in 2005 and 2006 to evaluate peanut tolerance to lactofen. Lactofen at 220 g ai/ha plus crop oil concentrate was applied to peanut at 6 leaf (lf), 6 lf followed by (fb) 15 days after the initial treatment (DAIT), 15 DAIT alone, 6 lf fb 30 DAIT, 30 DAIT alone, 6 lf fb 45 DAIT, 45 DAIT alone, 6 lf fb 60 DAIT, and 60 DAIT alone in weed-free plots. Lactofen caused visible leaf bronzing at all locations. Yield loss was observed when applications were made 45 DAIT, a timing that would correspond to plants in the R5 (beginning seed) to R6 (full seed) stage of growth. At all locations except the Texas High Plains, this application timing was within the 90 d preharvest interval. Growers who apply lactofen early in the peanut growing season to small weeds should have confidence that yields will not be negatively impacted despite dramatic above-ground injury symptoms; however, applications made later in the season, during seed fill, may adversely affect yield.

Effects of photoperiod on reproductive development of peanut (Arachis hypogaea L.) in a cool subtropical environment. I. Field studies

1991 ◽  
Vol 42 (7) ◽  
pp. 1133 ◽  
Author(s):  
MJ Bell ◽  
G Harch
Keyword(s):  
Treatment Period ◽  
Arachis Hypogaea ◽  
Reproductive Development ◽  
Field Studies ◽  
Sowing Date ◽  
Climatic Data ◽  
Subsequent Paper ◽  
Temperature Regimes ◽  
Arachis Hypogaea L ◽  
Subtropical Environment

The effects of photoperiod on reproductive development and yield of two Virginia, one Spanish and one Valencia peanut (Arachis hypogaea L.) cultivar were investigated in the field at Kingaroy, Australia. The objective was to assess the importance of photoperiod as a limitation to post-flowering reproductive development in a cool subtropical environment. A total of five experimental sowings were made between the 1986/87 and 1988/89 growing seasons. Treatments consisted of either natural photoperiods (ranging from 11 to 14 h, depending on sowing date and growth stage) or long (16 h) photoperiods during a range of phenological stages, both pre- and post-flowering. Long photoperiods were achieved by using low intensity light from incandescent bulbs with equal extension periods in both morning and evening. Different sowing dates and seasons were used to produce a range of natural photoperiods, radiation and temperature regimes, while shadecloth was used to alter incident irradiance during the 1988/89 experiments. Photoperiod responses were significant in only one experiment (S2, 1986/87), and were due to effects of treatment during the immediate post-flowering period. Numbers of flowers, pegs and pods were reduced under long photoperiods in cv. Robut 33-1, and to a lesser extent, in cv. White Spanish. The Virginia cv. Uf 781 14-5 was unaffected. The effects of long photoperiods during this 30 day post-flowering treatment were not expressed until after the treatment period. Effects were relatively small and reproductive (pod) yields at maturity were not significantly reduced. The lack of strong photoperiod responses in the reportedly sensitive Valencia cv. NC17090 and the occurrence of the strongest response in the relatively insensitive cv. Robut 33-1 were unexpected. Analysis of climatic data from these experiments, and others reported in the literature, suggested interactions between photoperiod and temperature, with photoperiod effects being only significant at higher temperatures, i.e. in our studies, when mean daily temperature during the treatment period was 26-0�C. This finding is of considerable significance in assessing the importance of photoperiod sensitivity for cultivar adaptation to long day/subtropical environments. A subsequent paper in this series examines photoperiod x temperature interactions more closely under controlled environment conditions.

scholarly journals Peanut Breeding for Leafspot Resistance in Wide and Narrow Intrarow Spacings1

1989 ◽  
Vol 16 (2) ◽  
pp. 119-122
Author(s):  
D. A. Knauft ◽  
D. W. Gorbet
Keyword(s):  
Experimental Error ◽  
Growing Season ◽  
Commercial Production ◽  
Disease Assessment ◽  
Cercospora Arachidicola ◽  
Complex Interactions ◽  
Arachis Hypogaea L ◽  
Disease Rating ◽  
Breeding Selection ◽  
Large Experimental Error

Abstract Sixteen peanut (Arachis hypogaea L.) genotypes were grown without the use of fungicides for two years in two planting arrangements, one an intrarow spacing typically used in commercial production (5 cm between plants) and the other typically used in breeding selection plots (30 cm between plants). At 10-day intervals throughout each growing season the proportion of necrotic leaf area caused by leafspots (Cercospora arachidicola Hori and Cercosporidium personatum (Berk. & Curt.) Deighton), leafspot disease rating (0-9), and stage of vegetative growth (v stage) were assessed. Leafspot disease ratings of genotypes spaced 30-cm apart were significantly correlated with the ratings of genotypes in 5-cm spacing. There was no interaction between genotypes and spacing. Percentage necrotic area in 30-cm and 5-cm plantings was significantly correlated. However, large experimental error and complex interactions among spacings, genotypes, and time of observation lessened the value of this method of disease assessment. While the correlation of v stage in the two spacings was highly significant, differences among genotypes were not consistent.

Influence of Oxadiazon on Peanuts and Weeds1

1977 ◽  
Vol 4 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Gale A. Buchanan ◽  
Paul A. Backman ◽  
R. Rodriguez-Kabana
Keyword(s):  
Weed Control ◽  
Arachis Hypogaea ◽  
Growing Season ◽  
Mixed Population ◽  
Annual Grass ◽  
Predominant Species ◽  
Time Treatment ◽  
Arachis Hypogaea L ◽  
Substantial Control

Abstract Oxadiazon [2-tert-butyl-4-(2, 4-dichloro-5-isopropoxyphenyl)- Δ2-1,3,4-oxadiazolin-5-one] was applied alone as a preemergence treatment and in combination with dinoseb (2-sec-butyl-4,6-dinitrophenol) as a cracking-time treatment to peanuts (Arachis hypogaea L.). During the years 1970 to 1972 the experimental area was heavily infested with a mixed population of annual grass and broadleaf weeds. During the years 1973 to 1975, the predominant species present were sicklepod (Cassia obtusifolia L.) and Florida beggarweed [Desmodium tortuosum (Sw.) D.C.]. Grass control was acceptable with 3.36 kg/ha of oxadiazon in 2 of the 3 years when benefin (N-butyl-N-ethyl-∝, ∝, ∝ -trifluoro-2, 6-dinitro-p-toluidine) was not included. Commercially acceptable control of Florida beggarweed and sicklepod occurred with application of 3.36 kg/ha of oxadiazon. Substantial control was obtained with an application of 1.68 kg/ha. Generally, the addition of 1.68 kg/ha dinoseb to oxadiazon resulted in slightly improved weed control, particularly at lower rates of oxadiazon. Oxadiazon at rates of 6.7 kg/ha or more was phytotoxic to peanuts during the early part of the growing season. This phytotoxicity generally did not result in lower peanut yields. However, treated plants were more compact.

Distribution, population density, race and type determination of soybean cyst nematode, Heterodera glycines, in Iran

Nematology ◽  
2008 ◽  
Vol 10 (6) ◽  
pp. 919-924 ◽  
Author(s):  
Mansour Salati ◽  
Robert Riggs ◽  
Zahra Tanha Maafi
Keyword(s):  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Growing Season ◽  
Cyst Nematode ◽  
Soil Samples ◽  
Population Densities ◽  
Northern Iran ◽  
Second Stage ◽  
The World

AbstractThe soybean cyst nematode (SCN), Heterodera glycines, found in most soybean growing regions in the world, is considered the most economically damaging pathogen of soybean worldwide. A survey conducted in the northern provinces of Mazandaran and Golestan, the main soybean-producing areas in Iran, revealed SCN was widespread in different localities of these regions. Of the 55 and 88 soil samples collected from soybean fields in Mazandaran and Golestan provinces, respectively, ten (18.8%) and 23 (26%) samples were infested with H. glycines; the population densities of second-stage juveniles (J2) and eggs ranged from 500 to 60 000 and 500 to ≥100 000 per 250 cm3 soil, respectively. These population densities of H. glycines are indicative of reductions in soybean yield. HG Type tests were conducted on 16 field populations. HG Type 0 (race 3) was the most common with 94% frequency, whereas HG Type 7 (race 6) was found in 6% of tested populations. Most populations of H. glycines parasitised PI88788 and PI548316. Eight of the most commonly used soybean cultivars were tested against H. glycines HG Type 0; seven of them, Sepideh, Sahar (Pershing), Gorgan 3, Williams 82, JK (Sari), BP (Telar) and Hill, had high female indices and were considered susceptible to HG Type 0. Only the cultivar DPX showed low female indices and was resistant to race 3. The initial observations showed that the first life cycle of SCN required 30-34 days in early-planted fields (late May and early June), whereas in late-planted fields (early July), white females were visible 20 days after planting. Several generations could be expected in a single growing season under field conditions in northern Iran.

SUSCEPTIBILITIES OF SPECIES AND CULTIVARS OF CANOLA AND MUSTARD TO INFESTATION BY ROOT MAGGOTS (DELIA SPP.) (DIPTERA: ANTHOMYIIDAE)

1994 ◽  
Vol 126 (2) ◽  
pp. 251-260 ◽  
Author(s):  
L.M. Dosdall ◽  
M.J. Herbut ◽  
N.T. Cowle
Keyword(s):  
Brassica Napus ◽  
Quantitative Determination ◽  
Brassica Juncea ◽  
Brassica Rapa ◽  
Growing Season ◽  
Sinapis Alba ◽  
Root Damage ◽  
Population Densities ◽  
Short Growing Season

AbstractFour species of Cruciferae [canola species Brassica rapa L. and Brassica napus L., and mustard species Brassica juncea (L.) and Sinapis alba L.], and various cultivars of each species, were evaluated for susceptibilities to infestation by Delia spp. (Diptera: Anthomyiidae) under field conditions in central Alberta, Canada. Susceptibility was measured throughout the season by recording numbers of eggs of Delia spp. laid on or near individual plants, and at the end of the season by a semi-quantitative determination of injury inflicted by larvae on taproots. Differences in susceptibility occurred among and within canola and mustard species. Plants of B. rapa were most susceptible to Delia spp.; both mean eggs per plant and mean damage ratings per plant on B. rapa significantly exceeded those of all other species studied. Intermediate susceptibility was observed for plants of B. napus and B. juncea; plants of S. alba were least susceptible. In general, differences in susceptibility were greater among species than among cultivars within species. Root damage generally correlated with oviposition among and within species, suggesting that the mechanism of resistance by cruciferous species to infestation by Delia spp. is antixenosis or nonpreference. Results of this study indicate that canola growers in regions infested annually by high population densities of Delia spp. should seed B. napus or B. juncea rather than B. rapa. However, if a short growing season necessitates seeding B. rapa, then growers should select the more resistant cultivars of this species.

BIOLOGY OF Alternaria alternata, THE CAUSAL AGENT OF BLACK POD DISEASE OF WHITE BEAN IN SOUTHWESTERN ONTARIO

1985 ◽  
Vol 65 (4) ◽  
pp. 913-919 ◽  
Author(s):  
J. C. TU
Keyword(s):  
Alternaria Alternata ◽  
Growing Season ◽  
Phaseolus Vulgaris L ◽  
Weed Species ◽  
Population Densities ◽  
Stages Of Growth ◽  
Bean Plants ◽  
White Bean ◽  
Leaf Tissues ◽  
Black Pod

During the growing season Alternaria alternata was isolated from leaves of many weed species commonly found in or around a bean (Phaseolus vulgaris L.) field. The fungus was also found on bean plants at all stages of growth. Population densities of A. alternata on the leaves of bean plants grown from surface-sterilized and non-sterilized seeds were similar. Population densities of A. alternata on the leaves of weeds and beans increaased as the growing season advanced. The increase in the population of A. alternata was correlated with natural senescence of leaf tissues. Sugars and ninhydrin positive substances (NPS) in the leaf wash increased with plant age. At a given growth stage, the concentration of sugars and NPS found in leaf washes of cultivars susceptible to A. alternata were higher than those tolerant to it.Key words: Bean (field), Alternaria alternata

scholarly journals Effects of Seed Treatments and Planting Depth on Emergence of Sea Buckthorn Species

1999 ◽  
Vol 9 (2) ◽  
pp. 213-216 ◽  
Author(s):  
Thomas S.C. Li ◽  
Douglas A. Wardle
Keyword(s):  
Plant Height ◽  
Room Temperature ◽  
Nitrate Solution ◽  
Growing Season ◽  
Potassium Nitrate ◽  
Seed Treatments ◽  
Planting Depth ◽  
Potassium Nitrate Solution ◽  
Average Plant ◽  
Average Plant Height

The influence of seed treatments and planting depth on the percentage of seed emergence of Hippophae rhamnoides L. `Indian-Summer', H. tibetana Schlecht., H. neurocarpa Liu & He, H. salicifolia D. Don, and H. rhamnoides subsp. rhamnoides, sinensis, turkestanica, and mongolica were studied. Surface seeding had higher percentages of seed emergence and more rapid completion of emergence compared to a 1- or 2-cm (0.4- or 0.8-inch) seeding depth. Seeds soaked in water or potassium nitrate solution at room temperature emerged in higher percentages. Average plant height of the eight species and subspecies varied significantly at the end of first growing season.

scholarly journals Penentuan Musim Tanam Berdasarkan Perhitungan Neraca Air Lahan di Daerah Saumlaki, Pulau Yamdena

2020 ◽  
Vol 16 (2) ◽  
pp. 173-179
Author(s):  
Jenly F Uspessy ◽  
Samuel Laimeheriwa ◽  
Jacob R Patty
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Agricultural Development ◽  
Sunshine Duration ◽  
Growing Season ◽  
Climatic Data ◽  
Climate Forecasts ◽  
Water Surplus ◽  
Land Water

Climate information/data of a region plays an important role in agricultural development in the region, because by utilizing the knowledge of the relationship between crops and climate, forecasts can be made of planting time, harvest time, drought (water deficit), flood (water surplus), pest attack and disease, determining the appropriate type of crop, and so on. The purpose of this study was to assess the presence of soil water and to determine the growing season in the Saumlaki area based on two rainfall conditions. This study used monthly rainfall data for 30 years (1990-2019) as well as other climatic data, such as air temperature, air humidity, sunshine duration and wind speed for 15 years (2005-2019). Computing of the water balance was carried out using Thornthwaite-Mather Method, and determination of growing season using soil water in optimum condition. Based on the calculation of the land water balance in the rainfall conditions there was a 75% chance of being surpassed by the groundwater deficit in the Saumlaki area which lasted for 6 months (June- November), whereas the value increases by 183 mm or 45.52% compared to normal conditions, that was from 402 mm to 585 mm. On the other hand, the groundwater surplus lasted only a month (May) and tended to decrease by 686 mm or 97.03% compared to normal conditions, from 707 mm to 21 mm. The optimum soil water content for plants in rainfall conditions was 75% chance of lasting for 6 months (January-June); 2 months shorter than the normal 8 months (December-July). In conditions of 75% chance of rainfall, the growing season in the Saumlaki area lasted for 7 months (December-June); a month shorter than the growing season in normal rainfall conditions of 8 months (December-July). Keywords: growing season, land water balance, rainfall, Saumlaki area   ABSTRAK Informasi/data iklim suatu tempat berperan penting dalam pengembangan pertanian di wilayah tersebut, karena dengan memanfaatkan pengetahuan tentang hubungan antara tanaman dan iklim dapatlah dibuat prakiraan waktu tanam, waktu panen, kejadian kekeringan (defisit air), banjir (surplus air), serangan hama dan penyakit, penentuan jenis tanaman yang sesuai, dan sebagainya. Tujuan penelitian ini untuk menilai keberadaan air tanah dan menentukan musim tanam di Daerah Saumlaki pada dua kondisi curah hujan. Penelitian ini menggunakan data curah hujan bulanan selama 30 tahun (1990–2019) dan data iklim lainnya (suhu udara, kelembaban udara, lama penyinaran matahari kecepatan angin) selama 15 tahun (2005-2019). Perhitungan neraca air lahan menggunakan metode Thornthwaite-Mather, dan musim tanam ditentukan berdasarkan kondisi air tanah optimum. Berdasarkan perhitungan neraca air lahan pada kondisi curah hujan berpeluang 75% untuk dilampaui, defisit air tanah di daerah Saumlaki berlangsung selama selama 6 bulan (Juni-November) yaitu nilainya bertambah sebesar 183 mm (45,52%) dibandingkan kondisi normalnya, yaitu dari 402 mm menjadi 585 mm. Sebaliknya surplus air tanah berlangsung hanya sebulan (Mei) dan cenderung berkurang sebesar 686 mm (97,03%) dibandingkan kondisi normalnya, yaitu dari 707 mm menjadi 21 mm. Kadar air tanah yang optimum bagi tanaman pada kondisi curah hujan peluang 75% berlangsung selama 6 bulan (Januari-Juni); lebih pendek 2 bulan dibandingkan kondisi normalnya 8 bulan (Desember-Juli). Pada kondisi curah hujan peluang 75%, musim tanam di daerah Saumlaki berlangsung selama 7 bulan (Desember-Juni); sebulan lebih pendek dibandingkan musim tanam pada kondisi curah hujan normalnya 8 bulan (Desember-Juli). Kata kunci : curah hujan, daerah Saumlaki, musim tanam, neraca air lahan

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