CONTROL OF ROOT MAGGOTS IN RUTABAGAS IN PRINCE EDWARD ISLAND

1958 ◽  
Vol 38 (3) ◽  
pp. 307-313 ◽  
Author(s):  
D. C. Read ◽  
F. M. Cannon

In 81 tests in 21 localities, from 1952 to 1955, whole-field applications of DDT sprays against adults of root maggots attacking rutabagas, chiefly Hylemya brassicae (Bouché), generally gave 50 to 90 per cent fewer infested plants than in untreated fields nearby. The sprays, each at 1 lb of toxicant per acre, were applied at weekly intervals while flies emerged from overwintered puparia, the period varying with soil type. In eight plot experiments in 1955, a pre-planting treatment with heptachlor at 5 lb. per acre in a 5-inch band, [Formula: see text] inches below the seed in the planting ridge, gave an average of 93 per cent control; a similar treatment with aldrin, 80 per cent. Furrow applications at 5 and 2.5 lb. at the same depth were less effective. Post-thinning sprays applied to the crowns of the plants and surrounding soil surface were ineffective. None of the treatments was phytotoxic.

1964 ◽  
Vol 96 (1-2) ◽  
pp. 136-137 ◽  
Author(s):  
D. C. Read

Application of 5 Ibs. toxicant Ileptachlor or aldrin per acre placed in a 4- to 5-inch hand about 1½ inches below the surface of the soil in a ridged seeding drill have controlled infestations of the cabbage root maggot, Hylemya brassicae (Bouche) in cabbage and rutabagas for eight consecutive years on one farm in Prince Edward Island without detectable indications of resktance. The insecticide is so placed in the soil as to be most concentrated against the young root maggot larvae and least concentrated against the following predators and parasites: Coenosia tigrina (Fall.) and Scatophaga stercoraria. (L.), which attack and destroy H. brassicae flies in flight, on the soil surface, or on plant foliage; various species of Carabid beetles which destroy H. brassicae eggs at or near the soil surface, Trybliographa rapae (L.), the larvae of which parasitize and destroy H. brassicae larvae in the plant roots; and Aleochara bilineata (Gyll.), with adults destroying H. brassicae eggs or young larvae near the soil surface, and larvae in the plant roots, and the larvae parasitising H. brassicae puparia and destroying the pupae. Records of field observations, supplemented with data obtained on green-house determinations of the potential reproduction of both predators and host, indicate that any one of these predators could theoretically eliminate the pest population from an area in two to three generations. They do not eliminate or even give apparent economic control of the pest because a) the aerial attackers do not find and destroy adults of the pest before many eggs are deposited in the soil; b) many eggs are hidden in the soil by wind and rain and thus protected from discovery by predators; and c) larval and puparial parasites attack after the pest has injured the crop.


1958 ◽  
Vol 38 (2) ◽  
pp. 188-198 ◽  
Author(s):  
D. C. Read

Examinations of more than 100 rutabaga fields per year, from 1951 to 1955, showed that Hylemya brassicae (Bouché) was the only species of root maggot that injured rutabagas in Prince Edward Island. H. liturata (Mg.) (= H. trichodactyla (Rond.)), H. cilicrura (Rond.), and Muscina stabulans (Fall.) were associated with H. brassicae but did not injure the roots. H. brassicae flies [note Whitcomb (12) for illustrations] began to emerge from overwintered puparia early in June in sandy soil areas and late in July in clay loam areas. Heavy texture and high moisture content of soils were closely correlated with the delay in emergence. The flies laid their eggs near rutabaga plants, usually in crevices in the soil, and upon hatching the larvae entered and fed on the roots. Larvae generally entered the roots at a depth of one inch or more below the surface of the soil. In general, early-planted rutabagas in sandy soil areas and late plantings in clay loam areas were severely damaged by larvae of H. brassicae, whereas late plantings in sandy areas and early plantings in clay loam areas were lightly infested. However, in the sandy soil areas where all of the rutabaga crops were harvested early in August damage was relatively light. Also, fields isolated by other rutabaga fields from sources of infestation such as storage bins and infested rutabaga crops, of either the current or the previous season, were usually slightly damaged. Use of barnyard manure increased H. brassicae infestations early in the season but did not significantly influence the damage caused during the whole growing season.


Weed Science ◽  
1971 ◽  
Vol 19 (1) ◽  
pp. 82-86 ◽  
Author(s):  
G. A. Wicks ◽  
O. C. Burnside ◽  
C. R. Fenster

Downy brome (Bromus tectorumL.) seedling emergence was greatest from soil depths of 1 inch or less, but occasionally seedlings emerged from depths of 4 inches. Downy brome seed covered by soil germinated more rapidly than those seed on the soil surface. More downy brome seedlings emerged, and from greater depths, from coarse-textured soils than fine-textured soils when moisture was not limiting. Soil type did not influence longevity of downy brome seed buried in the soil. Most (98%) 8-month-old downy brome seed buried 8 inches in the soil germinated but did not emerge in 1 year; and none remained viable in the soil after 5 years. The moldboard plow was more effective in reducing downy brome populations than a sweep plow or one-way disk in a continuous winter wheat (Triticum aestivumL.) cropping system.


2019 ◽  
Vol 11 (16) ◽  
pp. 1932 ◽  
Author(s):  
Elena Prudnikova ◽  
Igor Savin ◽  
Gretelerika Vindeker ◽  
Praskovia Grubina ◽  
Ekaterina Shishkonakova ◽  
...  

The spectral reflectance of crop canopy is a spectral mixture, which includes soil background as one of the components. However, as soil is characterized by substantial spatial variability and temporal dynamics, its contribution to the spectral reflectance of crops will also vary. The aim of the research was to determine the impact of soil background on spectral reflectance of crop canopy in visible and near-infrared parts of the spectrum at different stages of crop development and how the soil type factor and the dynamics of soil surface affect vegetation indices calculated for crop assessment. The study was conducted on three test plots with winter wheat located in the Tula region of Russia and occupied by three contrasting types of soil. During field trips, information was collected on the spectral reflectance of winter wheat crop canopy, winter wheat leaves, weeds and open soil surface for three phenological phases (tillering, shooting stage, milky ripeness). The assessment of the soil contribution to the spectral reflectance of winter wheat crop canopy was based on a linear spectral mixture model constructed from field data. This showed that the soil background effect is most pronounced in the regions of 350–500 nm and 620–690 nm. In the shooting stage, the contribution of the soil prevails in the 620–690 nm range of the spectrum and the phase of milky ripeness in the region of 350–500 nm. The minimum contribution at all stages of winter wheat development was observed at wavelengths longer than 750 nm. The degree of soil influence varies with soil type. Analysis of variance showed that normalized difference vegetation index (NDVI) was least affected by soil type factor, the influence of which was about 30%–50%, depending on the stage of winter wheat development. The influence of soil type on soil-adjusted vegetation index (SAVI) and enhanced vegetation index (EVI2) was approximately equal and varied from 60% (shooting phase) to 80% (tillering phase). According to the discriminant analysis, the ability of vegetation indices calculated for winter wheat crop canopy to distinguish between winter wheat crops growing on different soil types changed from the classification accuracy of 94.1% (EVI2) in the tillering stage to 75% (EVI2 and SAVI) in the shooting stage to 82.6% in the milky ripeness stage (EVI2, SAVI, NDVI). The range of the sensitivity of the vegetation indices to the soil background depended on soil type. The indices showed the greatest sensitivity on gray forest soil when the wheat was in the phase of milky ripeness, and on leached chernozem when the wheat was in the tillering phase. The observed patterns can be used to develop vegetation indices, invariant to second-type soil variations caused by soil type factor, which can be applied for the remote assessment of the state of winter wheat crops.


1967 ◽  
Vol 7 (29) ◽  
pp. 523
Author(s):  
JE Coaldrake

Measurement of 2400 clumps of root suckers of Brigalow (Acacia harpophylla F. vM.) showed that in over 90 per cent of clumps the depth from the soil surface to the centre of the parent root was less than 4 inches. Suckering was significantly shallower on non-gilgai than on gilgai soils. An experiment on gilgai soil compared the effectiveness of ploughing to depths of 4 inches and 8 inches for the elimination of suckers. After four ploughings in two pears both treatments gave an identical kill of 80 per cent. A final overall ploughing at 4 inches increased the kill to 91 per cent. Apart from reducing costs, shallow ploughing should also reduce other deleterious effects associated with the high salinity and low pH that are common in many subsoils of the brigalow region.


1986 ◽  
Vol 66 (4) ◽  
pp. 747-750 ◽  
Author(s):  
M. R. CARTER ◽  
R. P. WHITE

The spatial variability of soil strength, porosity, and microbial biomass was determined under 4-yr continuous direct-planted silage corn (Zea mays L.) on Prince Edward Island. All soil properties changed relative to the row position. Microbial biomass C and N were lower in the in-row compared to the between-row position. Positional and depth differences for soil bulk density and volume of macropores (EPD > 50 μm) were only evident at the soil surface (0–8 cm). Temporal and spatial variations in soil strength indicated the extent of the rooting potential within the soil profile, the depth to compacted soil layers, and the degree of soil structure regeneration during the winter period. Key words: Spatial variability, soil strength, soil porosity, microbial biomass, direct-planted corn, Zea mays L.


2016 ◽  
Vol 96 (5) ◽  
pp. 887-894 ◽  
Author(s):  
A. Moussavi ◽  
S.Z.H. Cici ◽  
C. Loucks ◽  
R.C. Van Acker

Taraxacum Kok-saghyz (L.E. Rodin) (TKS) is a natural source of rubber. There is a rising interest in TKS establishment as a new crop in Ontario. Trials were conducted at Simcoe and Guelph, Ontario between 2013 and 2014 to explore the possibility of establishing TKS plants from seed in fields in Ontario. The effects of seeding depth, watering regimes, polymer, and covering mulch on the recruitment of TKS were explored. It was found that TKS displays very low field recruitment levels regardless of treatment. KNO3 did not have any significant effect on TKS seed germination. Seedling emergence was greatest when seeds were placed on the soil surface and decreased with increasing seeding depth. Two years of field experiments highlighted that TKS seedlings recruit better in moderate conditions when the temperature is optimum for TKS germination (warm but not hot, <25 °C). TKS seedlings recruited better at Simcoe (with a sandy soil type) than at Guelph (with a loamy soil type). Overall, however, field recruitment from seed was low (15% at best) and these results suggest that establishing TKS from seed in Ontario fields remains a challenge.


2018 ◽  
Vol 28 (1) ◽  
pp. 44-47
Author(s):  
Jacob S. Bravo ◽  
Thomas Okada Green ◽  
James R. Crum ◽  
John N. Rogers ◽  
Sasha Kravchenko ◽  
...  

The soil sterilant, dazomet, is the primary product in the turfgrass industry set to take the position of methyl bromide, which is no longer available for use on turfgrass. With turf surface renovations taking place throughout the country, the need for an effective soil sterilant is critical. This study focused on the ability of dazomet to inhibit germination of annual bluegrass (Poa annua) seeds when it is used as per the current, turf focused, label which decreased legal application rates across all surfaces. This study was a four-way factorial in a split-split plot design with whole plots in a randomized complete block design arrangement with three replications. The first factor, soil type, included two levels. Soil-type plots (60 × 95 ft) were either sand capped from topdressing over the native Capac loam or they were the native Capac loam. Sand topdressing was applied biweekly at a rate of 0.14 yard3/1000 ft2, April to September since 2011; accumulating a total of 1.5 inches of sand. Each of three replicated blocks consisted of two soil-type plots. The second factor was time trials, with two levels of starting times, June and August. Each soil-type plot was split into two subplots and the trials were assigned at random to subplots within each plot. The third factor, soil preparation, involved either removing the upper 1.5 inches of the sod/soil layer or spraying plots with glyphosate and then heavily cultivating them. This cultivation included a vertical-cut and a core cultivation with an aerator using 0.5-inch hollow tines at 2 × 2-inch spacing. The fourth factor, treatment regime, comprised 11 parameters that encompassed dazomet application rate, incorporation method, and the technique used to seal the soil surface. Dazomet treatments were applied with a shaker bottle, at rates that included 262, 421, 525, and 262 lb/acre applied twice at a 5-day interval. The treatments were incorporated into the soil either through 1 inch of irrigation, through four consecutive days of irrigation following this schedule: 1, 0.5, 0.25, 0.125 inch each day after application, respectively, or physically (P) with a rotary tiller set to 1.5 inches, the depth of the topdressing layer. All P incorporated plots were hand rolled following application, regardless of the tarping procedure. Water-incorporated plots were either sealed with a clear plastic 4-mil tarp or they were left unsealed. Researchers evaluated the level of germination control by counting individual annual bluegrass seedlings using a 1 × 1-ft grid. A significant interaction occurred between soil type and soil preparation as well as between soil type and treatment. A three-way interaction also occurred between trial, treatment and soil preparation. In general, tarped treatments showed better annual bluegrass control compared with nontarped treatments. Furthermore, sand topdressed soils showed lower numbers of annual bluegrass as compared with native soils. Finally, reduced annual bluegrass germination was found in plots that had the top 1.5 inches of material removed.


1970 ◽  
Vol 102 (6) ◽  
pp. 667-678 ◽  
Author(s):  
D. C. Read

AbstractExperiments with rutabagas, cabbage, and cauliflower were conducted on mineral soils, mainly with pre plan tin g soil treatments of insecticides applied in bands placed about 2.5 cm below the soil surface (1.25 cm below the seed) in shallow ridges to determine the best insecticides for use in controlling the cabbage maggot. Drench or granular spot applications were also used for transplanted stem crucifers. Broadcast, surface band, and supplementary drench treatments had been tested earlier but were discarded in favor of the band-in-row treatments, mainly because of hazard to beneficial predators and parasites. Of the many materials tested, carbofuran, fensulfothion, and chlorfenvinphos have consistently given the best control throughout the growing season. Trichloronat, E.I. 47031, and mecarbam also gave good results. Thionazin and phorate gave excellent control until 1968 when applied at the exact required depth in the row with machinery; control was often erratic when these materials were applied on a field scale with hand applicators. In 1968, these two insecticides gave less effective early season control and poorer residual control than in previous years. Carbofuran, and phorate, appeared to influence the development of rhizoctonia rot lesions on the sides of the roots more than other materials in all experiments. Rot lesions were more numerous and severe on rutabagas that followed potatoes than on land that had previously been used for cereals. Root maggots in stem crucifers were controlled with a number of insecticides. Methods of application for all cruciferous crops are discussed.


Jurnal Agrium ◽  
2018 ◽  
Vol 15 (1) ◽  
pp. 17
Author(s):  
Delima Delima ◽  
Halim Akbar ◽  
Muhammad Rafli

Infiltration is the inclusion of water into the soil through the soil surface due to differences in matrix potential, gravitational potential and pressure potential Infiltration is an important component in soil conservation.  It is because the efforts are fundamental in managing the relationship between rainfall intensity and infiltration capacity, as well as run off. The magnitude of surface flows due to disruption of characteristics and potential land will change the ecosystem which can reduce the function of river basin (DAS). This study aims to measure the infiltration rate in the Krueng Mane watershed in North Aceh District. The method used in this research was survey method where to measure infiltration rate using infiltrometer method. The results revealed that the highest infiltration rate was 8.20 cm / h. It  was found in mixed plantation land cover, 0-3% slope and latosol soil type. The lowest infiltration rate was 1.906 cm/h, found in oil palm plantation cover, slope of 3-8% and yellow podzolic soil type (PMK). Soil texture is dominated by clay fraction, porosity value is 43,23-45,56%, moisture content is between 1.01-4,38%, C-organic content is 0,32-2,93%, soil permeability is 0, 28-11.12 cm / hour and bulk density ranged from 1.13 to 1.35 gr / cm³. The result of statistical analysis indicated that the fraction of dust had a positive correlation with the C-organic content (r = 0.851 **). The porosity of the soil is positively correlated with the permeability (r = 0.844 **).


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