EFFECTS OF METHODS OF BORON APPLICATION ON LEAF TISSUE CONCENTRATION OF BORON AND CONTROL OF BROWN-HEART IN RUTABAGA

1978 ◽  
Vol 58 (1) ◽  
pp. 63-68 ◽  
Author(s):  
UMESH C. GUPTA ◽  
J. A. CUTCLIFFE
Keyword(s):  
Prince Edward Island ◽  
Field Experiments ◽  
Tissue Concentration ◽  
Leaf Tissue ◽  
Complete Control ◽  
Broadcast Application ◽  
Foliar Sprays ◽  
And Control

Field experiments were carried out at five different locations in Prince Edward Island over a 3-yr period in an attempt to determine the effect of methods and rates of B application on the incidence of B deficiency (brown-heart) in rutabaga (Brassica napobrassica Mill. cv. York). Band applications of B resulted in greater tissue B concentrations than broadcast applications. Foliar sprays applied when roots began to swell (about 6 wk after seeding) resulted in lower tissue-B concentrations than those applied 4 wk after seeding but controlled brown-heart. Brown-heart was completely controlled by a band application of 1.12 kg B/ha, a broadcast application of 2.24 kg B/ha, or by two foliar sprays each at the rate of 1.12 kg B/ha. Leaf tissue B concentrations of 15–32, 33–38, and greater than 40 ppm were related to severe brown-heart, slight to moderate brown-heart, and complete control of brown-heart, respectively. An application of limestone, prior to seeding, generally reduced tissue B concentrations. Analysis of soil after harvest indicated B recoveries of 35–62% in treatments receiving broadcast B.

EFFECTS OF APPLIED AND RESIDUAL BORON ON THE NUTRITION OF CABBAGE AND FIELD BEANS

1984 ◽  
Vol 64 (4) ◽  
pp. 571-576 ◽  
Author(s):  
UMESH C. GUPTA ◽  
J. A. CUTCLIFFE
Keyword(s):  
Prince Edward Island ◽  
Field Experiments ◽  
Leaf Tissue ◽  
Water Soluble ◽  
Hot Water ◽  
Boron Toxicity ◽  
First Year ◽  
Application Rates ◽  
Seed Yields ◽  
Field Beans

Field experiments were conducted at four locations in Prince Edward Island to determine the effect of applied B on leaf tissue B and yields of beans (Phaseolus vulgaris L.) and cabbage (Brassica oleracea var. capitata L.) in the year of application of B and again the following year. Application rates of 8.8 kg B∙ha−1 reduced bean seed yields at all locations and the 4.4-kg B∙ha−1 rate reduced yields at two locations in the first year. Leaf tissue B levels > 109 μg∙g−1 are clearly toxic for beans and seriously reduced bean yields. Furthermore, the yield and visual symptom data strongly suggest that tissue B levels even as low as 60 μg∙g−1 are toxic for this crop. No significant reductions in bean yields were noted in the second year crop, even at the 8.8 kg B∙ha−1 rate. Rates of up to 8.8 kg B∙ha−1 did not cause any reduction in cabbage yield even during the year of application. Leaf tissue B concentrations as high as 71–132 μg∙g−1 were not related to any B toxicity in cabbge. Added B did not increase yield of either beans or cabbage. Even though leaf tissue B levels as low as 16 μg∙g−1 in cabbage and 26 μg∙g−1 in beans occurred, no B deficiency was found. After the first and second years of beans the hot-water-soluble B in the soil ranged from 1.4 to 1.9 and from 0.8 to 1.2 μg∙g−1, respectively, where B had been applied at 8.8 kg∙ha−1. Key words: Cabbage, beans, boron toxicity, tissue boron, yields

Characterization of multiple herbicide–resistant waterhemp (Amaranthus tuberculatus) populations from Illinois to VLCFA-inhibiting herbicides

Weed Science ◽  
2019 ◽  
Vol 67 (4) ◽  
pp. 369-379 ◽  
Author(s):  
Seth A. Strom ◽  
Lisa C. Gonzini ◽  
Charlie Mitsdarfer ◽  
Adam S. Davis ◽  
Dean E. Riechers ◽  
...  
Keyword(s):  
Dose Response ◽  
Field Experiments ◽  
Survival Rates ◽  
Acetolactate Synthase ◽  
Field Studies ◽  
Complete Control ◽  
Herbicide Resistant ◽  
Amaranthus Tuberculatus ◽  
Als Inhibitors ◽  
And Control

AbstractField experiments were conducted in 2016 and 2017 in Champaign County, IL, to study a waterhemp [Amaranthus tuberculatus (Moq.) J. D. Sauer] population (CHR) resistant to 2,4-D and 4-hydroxyphenylpyruvate dioxygenase (HPPD)-, photosystem II–, acetolactate synthase (ALS)-, and protoporphyrinogen oxidase–inhibiting herbicides. Two field experiments were designed to investigate the efficacy of very-long-chain fatty-acid (VLCFA)-inhibiting herbicides, including a comparison of active ingredients at labeled use rates and a rate titration experiment. Amaranthus tuberculatus density and control were evaluated at 28 and 42 d after treatment (DAT). Nonencapsulated acetochlor, alachlor, and pyroxasulfone provided the greatest PRE control of CHR (56% to 75%) at 28 DAT, while metolachlor, S-metolachlor, dimethenamid-P, and encapsulated acetochlor provided less than 27% control. In the rate titration study, nonencapsulated acetochlor controlled CHR more than equivalent field use rates of S-metolachlor. Subsequent dose–response experiments with acetochlor, S-metolachlor, dimethenamid-P, and pyroxasulfone in the greenhouse included three multiple herbicide–resistant (MHR) A. tuberculatus populations: CHR-M6 (progeny generated from CHR), MCR-NH40 (progeny generated from Mclean County, IL), and ACR (Adams County, IL), in comparison with a sensitive population (WUS). Both CHR-M6 and MCR-NH40 are MHR to atrazine and HPPD, and ALS inhibitors and demonstrated higher survival rates (LD50) to S-metolachlor, acetochlor, dimethenamid-P, or pyroxasulfone than ACR (atrazine resistant but HPPD-inhibitor sensitive) and WUS. Based on biomass reduction (GR50), resistant to sensitive (R:S) ratios between CHR-M6 and WUS were 7.5, 6.1, 5.5, and 2.9 for S-metolachlor, acetochlor, dimethenamid-P, and pyroxasulfone, respectively. Values were greater for MCR-NH40 than CHR-M6, and ACR was the most sensitive to all VLCFA inhibitors tested. Complete control of all populations was achieved at or below a field use rate of acetochlor. In summary, field studies demonstrated CHR is not controlled by several VLCFA-inhibiting herbicides. Greenhouse dose–response experiments corroborated field results and generated R:S ratios (LD50) ranging from 4.5 to 64 for CHR-M6 and MCR-NH40 among the four VLCFA-inhibiting herbicides evaluated.

EFFECTS OF LIME AND GYPSUM ON YIELDS AND NUTRITION OF TWO CULTIVARS OF BRUSSELS SPROUTS

1988 ◽  
Vol 68 (3) ◽  
pp. 611-615 ◽  
Author(s):  
J. A. CUTCLIFFE
Keyword(s):  
Key Words ◽  
Prince Edward Island ◽  
Nutrient Concentration ◽  
Field Experiments ◽  
Leaf Tissue ◽  
Dolomitic Limestone ◽  
Brussels Sprouts ◽  
Initial Ph ◽  
Internal Browning ◽  
Tissue Nutrient Concentration

Field experiments were carried out at different locations in Prince Edward Island each year for 3 consecutive years to determine the effects of calcific limestone, dolomitic limestone, and gypsum on yields and nutrition of two cultivars of Brussels sprouts (Brassica oleracea var. gemmifera). The soils at the sites selected had initial pH levels of 4.9–5.7. Preplant, broadcast applications of gypsum at 5.5 t ha−1 resulted in yield increases of about 30% at all locations. Analysis of leaf tissue collected when the sprouts began to form indicated that Ca, Mg, Mn and Zn concentrations of approximately 1.4–2.6%, 0.25–0.32%, 88–274 μg g−1 and 26–35 μg g−1, respectively, are within the sufficiency range. The incidence of internal browning was not affected by either the lime or gypsum treatments at the two locations where this disorder occurred. Key words: Lime, gypsum, yield, leaf tissue nutrient concentration, internal browning, Brussels sprouts

EFFECTS OF ADDED NITROGEN AND POTASSIUM ON YIELD AND STORABILITY OF RUTABAGAS

1989 ◽  
Vol 69 (4) ◽  
pp. 1359-1363 ◽  
Author(s):  
J. A. CUTCLIFFF ◽  
J. B. SANDERSON
Keyword(s):  
Prince Edward Island ◽  
Field Experiments ◽  
Leaf Tissue ◽  
Storage Period ◽  
Period Analysis ◽  
Weight Losses

Field experiments were carried out at two different locations in Prince Edward Island each year for 3 consecutive years to determine the effects of added nitrogen and potassium on yields of rutabagas (Brassica napobrassica Mill.) and subsequent losses during a 6-mo period in two storage regimes. Preseeding applications of nitrogen at 120 kg ha−1 compared to 40 kg ha−1 increased marketable yields by 7–18%. Applications of potassium at 180 kg ha−1 compared to 60 kg ha−1 had no effect on marketable yields. Mean weight losses from dehydration of rutabagas held for 6 mo at about 2 °C and 95% RH and at about 5 °C and 90% RH were 5.2% and 10.8%, respectively, and were not affected by the nitrogen and potassium treatments. Also, the nitrogen and potassium treatments had no effect on the proportion of the rutabagas that remained in marketable condition during the storage period. Analysis of leaf tissue collected when the rutabaga roots began to enlarge indicated that nitrogen and potassium concentrations of approximately 5.0–6.0% and 2.1–5.9%, respectively, are within the sufficiency range.Key words: Rutabaga, Brassica napobrassica, yield, storability, nitrogen, potassium

COPPER AND ZINC NUTRITION OF RUSSET BURBANK POTATOES GROWN ON PRINCE EDWARD ISLAND

1990 ◽  
Vol 70 (1) ◽  
pp. 357-362 ◽  
Author(s):  
J. B. SANDERSON ◽  
UMESH C. GUPTA
Keyword(s):  
Solanum Tuberosum ◽  
Specific Gravity ◽  
Prince Edward Island ◽  
Field Experiments ◽  
Tuber Yield ◽  
Solanum Tuberosum L ◽  
Leaf Tissue ◽  
Zn Content ◽  
Zinc Nutrition ◽  
Toxic Concentrations

Field experiments were conducted on potatoes (Solanum tuberosum L.) at two locations in P.E.I. to determine the response to soil- and foliar-applied Cu and Zn on tuber yield and leaf tissue nutrient concentration over a period of 3 yr. Foliar applications of 0.5–2 kg Cu ha−1 applied 1–2 wk prebloom reduced total tuber yield, number of tubers over 55 mm in diameter, average tuber weight, and specific gravity. The mean potato yield of tubers over 55 mm from the foliar-applied Cu treatments was less than the soil applied Cu by 4.5, 0.74, and 7.5 t ha−1 for 1985, 1986, and 1987, respectively. The toxic concentrations of Cu in potato leaves ranged from 63 to 139 μg g−1. Soil-applied Cu increased tissue Cu in the first sampling but had no effect in the second sampling. Foliar applications of Zn at 1–2 kg ha−1 reduced total tuber yield, tuber yield and tuber count over 55 mm, and specific gravity. The toxic concentrations of Zn in potato leaves ranged from 97 to 224 μg g−1. For the first sampling, the leaf tissue Zn concentrations ranged from 21 to 30 μg g−1 for the control and 27 to 70 μg g−1 for soil-applied Zn treatment. There was no difference in the Zn concentration between these two treatments for the second sampling. Copper and Zn concentrations as low as 7 and 21 μg g−1, respectively, in potato leaves were not related to deficiency of these nutrients, based on tuber yields. Soil applications of Cu or Zn would appear preferable to foliar sprays, which may cause phytotoxicity, as a means of increasing plant Cu or Zn content where a deficiency is suspected.Key words: Solanum tuberosum L., tuber yield, leaf copper, leaf zinc, Podzolic soil, potato

Inter-row Cultivation Timing Effects on Waterhemp (Amaranthus tuberculatus) Control and Sugarbeet Yield and Quality

2021 ◽  
pp. 1-39
Author(s):  
Nathan H. Haugrud ◽  
Thomas J. Peters
Keyword(s):  
Weed Management ◽  
Field Experiments ◽  
Leaf Tissue ◽  
Sucrose Content ◽  
Climate Data ◽  
Crop Canopy ◽  
Control Practice ◽  
Amaranthus Tuberculatus ◽  
Residual Herbicide ◽  
Weed Emergence

Abstract The invasion of waterhemp into northern sugarbeet growing regions has prompted producers to re-integrate inter-row cultivation into weed management programs as no currently registered herbicides can control glyphosate-resistant waterhemp POST in crop. Inter-row cultivation was a common weed control practice in sugarbeet until the release of glyphosate-resistant sugarbeet cultivars in 2008 made the use of inter-row cultivation unnecessary. In the late 2010s, producers began again to use inter-row cultivation to remove weeds that glyphosate did not control, but producers need information on the effectiveness and safety of inter-row cultivation when used with soil residual herbicide programs. Efficacy and tolerance field experiments were conducted in Minnesota and North Dakota from 2017 to 2019. Results from the efficacy experiment demonstrated cultivation improved waterhemp control 11% and 12%, 14 and 28 DAT, respectively. Waterhemp response to cultivation was dependent on crop canopy and precipitation after cultivation. Cultivation had minimal effect on waterhemp density in three environments, but at one environment, near Galchutt, ND in 2019, waterhemp density increased 600% and 196%, 14 and 28 DAT, respectively. Climate data indicated Galchutt, ND in 2019 received 105 mm of precipitation in the 14 days following cultivation and had an open crop canopy which likely contributed to further weed emergence. Results from the tolerance experiment demonstrated root yield and recoverable sucrose were not affected by cultivation timing or number of cultivations. In one environment, cultivating reduced sucrose content by 0.8% regardless of date or cultivation number, but no differences were found in three environments. In-season cultivation can damage/destroy leaf tissue which is likely responsible for the reduction in sucrose content. Results indicate cultivation can be a valuable tool to control weeds that herbicide cannot, but excessive rainfall and open crop canopy following cultivation can create an environment conducive to further weed emergence.

The Effect of Trifluralin Applied Preplant on Grass Weed Control and Establishment and Yield of Barley (Hordeum vulgare)

1997 ◽  
Vol 11 (3) ◽  
pp. 515-519 ◽  
Author(s):  
Julio A. Scursoni ◽  
Emilio H. Satorre
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Herbicide Application ◽  
Planting Pattern ◽  
Weed Density ◽  
Time Of Application ◽  
Density And Biomass ◽  
And Control ◽  
Crop Planting ◽  
Grass Weed

The objective of this paper was to evaluate the effect of preplant applications of trifluralin on barley stand and yield, and control of grass weeds in field experiments during 1992 and 1993. Factors examined were: (1) crop planting patterns (conventional drill with rows 15 cm apart and deep-seeder drill with rows 25 cm apart), (2) herbicide application times (22 d before sowing and immediately before sowing), and (3) herbicide application. During 1993, hand-weeded plots also were established. Trifluralin applied preplant at 528 g ai/ha reduced weed density and biomass. Weed control was higher under conventional planting than under the deep planting pattern, and there was no effect of the time of application on herbicide efficacy. There was no herbicide injury to the crop, and grain yield was higher in treated than in untreated plots due to successful weed control.

Management of fertilizer nitrogen for direct-sown, rainfed lowland rice (Oryza sativa L.)

1988 ◽  
Vol 110 (3) ◽  
pp. 475-479 ◽  
Author(s):  
D. Panda ◽  
R. N. Samantaray ◽  
S. Patnaik
Keyword(s):  
Single Dose ◽  
Management Practices ◽  
Field Experiments ◽  
N Uptake ◽  
Split Application ◽  
Band Placement ◽  
Flood Water ◽  
Broadcast Application ◽  
Ammonium N ◽  
Coated Urea

SummaryField experiments were conducted in wet seasons (June-December) for 4 years on a clay loam Haplaquept, to study the effects of different N management practices on yield, urea and ammonium-N in flood water and N nutrition of an clite rice cv. CR 1009, grown in rainfed lowlands. During the first 3 years of the experiment, fertilizer management practices like band placement of neem-cake-coated urea (NCU), broadcast application of sulphur-coated urea (SCU) at sowing, or point placement of urea supergranules (USG) 3 weeks after germination at 40 kg N/ha gave grain yields of 3·1–3·4 t·ha, which were almost equal to that of split application of prilled urea (PU). In the 4th year of the experiment, besides NCU and USG, single dose applications of PU as band placement, incorporation in the soil at sowing or broadcast incorporation of soil-treated urea at early tillering was also found to have similar effect on grain yield and N uptake as split application of PU. The flood water of the treatment receiving broadcast application of PU at tillering contained some urea and ammonium N, which rapidly decreased to negligible amounts in 3·4 days.The results suggest that, depending upon the feasibility, any one of the single dose application methods at sowing time or 3 weeks after germination may be adopted in this system of rice culture, which avoids top-dressing of PU to surface flowing flood water of greater depths at later stages of crop growth.

scholarly journals Metalearners for estimating heterogeneous treatment effects using machine learning

2019 ◽  
Vol 116 (10) ◽  
pp. 4156-4165 ◽  
Author(s):  
Sören R. Künzel ◽  
Jasjeet S. Sekhon ◽  
Peter J. Bickel ◽  
Bin Yu
Keyword(s):  
Machine Learning ◽  
Treatment Effects ◽  
Field Experiments ◽  
Average Treatment Effect ◽  
Regularity Conditions ◽  
Heterogeneous Treatment Effects ◽  
Lipschitz Continuous ◽  
Additive Regression ◽  
Underlying Mechanisms ◽  
And Control

There is growing interest in estimating and analyzing heterogeneous treatment effects in experimental and observational studies. We describe a number of metaalgorithms that can take advantage of any supervised learning or regression method in machine learning and statistics to estimate the conditional average treatment effect (CATE) function. Metaalgorithms build on base algorithms—such as random forests (RFs), Bayesian additive regression trees (BARTs), or neural networks—to estimate the CATE, a function that the base algorithms are not designed to estimate directly. We introduce a metaalgorithm, the X-learner, that is provably efficient when the number of units in one treatment group is much larger than in the other and can exploit structural properties of the CATE function. For example, if the CATE function is linear and the response functions in treatment and control are Lipschitz-continuous, the X-learner can still achieve the parametric rate under regularity conditions. We then introduce versions of the X-learner that use RF and BART as base learners. In extensive simulation studies, the X-learner performs favorably, although none of the metalearners is uniformly the best. In two persuasion field experiments from political science, we demonstrate how our X-learner can be used to target treatment regimes and to shed light on underlying mechanisms. A software package is provided that implements our methods.

Correction of manganese deficiency in barley crops on calcareous soils. 2. Comparison of mixed and compound fertilizers

1973 ◽  
Vol 13 (63) ◽  
pp. 440 ◽  
Author(s):  
DJ Reuter ◽  
TG Heard ◽  
AM Alston
Keyword(s):  
Particle Size ◽  
Field Experiments ◽  
Phosphorus Uptake ◽  
Calcareous Soils ◽  
Nutrient Content ◽  
Manganese Deficiency ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Foliar Sprays ◽  
Compound Fertilizer

Mixed and compound fertilizers made from superphosphate and manganous sulphate were compared in field experiments as sources of manganese for barley on the calcareous soils of southern Yorke Peninsula, South Australia. The compound fertilizers were made by blending manganous sulphate with 'den-fresh' superphosphate before the granulation process: mixed fertilizers were made by mixing the components after manufacture. The fertilizers were applied at sowing at rates of 19 kg haw1P and 16 kg haelMn in one experiment and 28 kg ha-1 P and 6 kg ha-1 Mn in a second experiment. In the latter, up to three foliar sprays of manganous sulphate (1.3 kg ha-1 Mn per spray) were applied in addition. The rate at which the fertilizers reacted with the soil was studied in an incubation experiment, and the nutrient content of particle-size fractions of the fertilizers was also determined. Plant dry weight, manganese and phosphorus uptake, and grain yield were increased to a greater extent by application of the compound fertilizer than by the mixed fertilizer. Application of compound fertilizers at sowing also delayed the appearance of manganese deficiency symptoms in crops by two weeks compared with mixed fertilizers. Neither fertilizer prevented the occurrence of manganese deficiency and further yield increases were obtained by subsequent foliar sprays of manganous sulphate. Fertilizer manganese was rapidly immobilized in the soil. After 167 hours' incubation, approximately three quarters of that added in manganous sulphate, and in the mixed and compound fertilizers was not extractable in divalent form. The variation in nutrient content of particle size fractions of a compound fertilizer was much less than that in a mixed fertilizer.

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