The effect ofSitona discoideusGyllenhal (Coleoptera: Curculionidae) on lucerne yields in New Zealand

1985 ◽  
Vol 75 (3) ◽  
pp. 429-442 ◽  
Author(s):  
S. L. Goldson ◽  
C. B. Dyson ◽  
J. R. Proffitt ◽  
E. R. Frampton ◽  
J. A. Logan
Keyword(s):  
New Zealand ◽  
Dry Matter ◽  
Larval Density ◽  
Yield Response ◽  
Severe Drought ◽  
Yield Losses ◽  
Wet Season ◽  
Larval Population ◽  
Adult Feeding ◽  
The Impact

AbstractThe impact of injury by larvae and adults ofSitona discoideusGyllenhal on lucerne production was studied in two consecutive seasons at two adjacent sites near Christchurch, New Zealand. The root-feeding larvae were found to be more damaging than the adults; in the first cut in the 1982–83 season in a three-year-old stand, larvae reduced dry matter yield by 18%. In the wetter following season in a one-year-old stand, second and third cut losses of 43 and 30% dry matter production, respectively, were recorded. In both seasons, the lucerne had apparently substantially recovered from larval damage by the time of the last cuts. In the drier 1982–83 season, two cuts were taken compared with four in the 1983–84 season. Adult feeding was found to reduce second cut wet yields by 20–30% in the 1982–83 season but had no measurable effect in the 1983–84 season. In both seasons, manipulated ranges of larval densities showed that damage appeared only when larval populations were in excess of a distinct larval population density threshold. At larval densities less than this threshold, yield was unaffected; above the threshold, yield losses were independent of larval density. Such a yield response curve was found to be adequately described mathematically by a simple arctan model; this approach allowed the threshold to be further defined and overall estimates to be made of the yield losses arising from larval damage. The threshold occurred at about 1200 larvae/m2in the dry season and about 2100 larvae/m2in the wet season. This suggested moisture sensitivity and the possibility that the crop may enter a damage-induced dormancy related to that observed during a severe drought.

scholarly journals Response of Sensitive and Resistant Snap Bean Genotypes to Nighttime Ozone Concentration

2020 ◽  
Vol 145 (6) ◽  
pp. 331-339
Author(s):  
Kirsten L. Lloyd ◽  
Donald D. Davis ◽  
Richard P. Marini ◽  
Dennis R. Decoteau
Keyword(s):  
Leaf Age ◽  
Acute Injury ◽  
Yield Response ◽  
Yield Losses ◽  
Foliar Injury ◽  
Snap Bean ◽  
Stirred Tank Reactors ◽  
First Results ◽  
Significant Yield ◽  
The Impact

Effects of nighttime (2000 to 0700 hr) O3 on the pod mass of sensitive (S156) and resistant (R123) snap bean (Phaseolus vulgaris) genotypes were assessed using continuous stirred tank reactors located within a greenhouse. Two concentration-response relationship trials were designed to evaluate yield response to nighttime O3 exposure (10 to 265 ppb) in combination with daytime exposure at background levels (44 and 62 ppb). Three replicated trials tested the impact of nighttime O3 treatment at means of 145, 144, and 145 ppb on yields. In addition, stomatal conductance (gS) measurements documented diurnal variations and assessed the effects of genotype and leaf age. During the concentration-response experiments, pod mass had a significant linear relationship with the nighttime O3 concentration across genotypes. Yield losses of 15% and 50% occurred at nighttime exposure levels of ≈45 and 145 ppb, respectively, for S156, whereas R123 yields decreased by 15% at ≈150 ppb. At low nighttime O3 levels of ≈100 ppb, R123 yields initially increased up to 116% of the treatment that received no added nighttime O3, suggesting a potential hormesis effect for R123, but not for S156. Results from replicated trials revealed significant yield losses in both genotypes following combined day and night exposure, whereas night-only exposure caused significant decreases only for S156. The gS rates ranged from less than 100 mmol·m−2·s−1 in the evening to midday levels more than 1000 mmol·m−2·s−1. At sunrise and sunset, S156 had significantly higher gS rates than R123, suggesting a greater potential O3 flux into leaves. Across genotypes, younger rapidly growing leaves had higher gS rates than mature fully expanded leaves when evaluated at four different times during the day. Although these were long-term trials, gS measurements and observations of foliar injury development suggest that acute injury, occurring at approximately the time of sunrise, also may have contributed to yield losses. To our knowledge, these are the first results to confirm that the relative O3 sensitivity of the S156/R123 genotypes is valid for nighttime exposure.

scholarly journals Economic values for evaluating pasture plant traits

2012 ◽  
pp. 209-215 ◽  
Author(s):  
D.F. Chapman ◽  
J.R. Bryant ◽  
W.H. Mcmillan ◽  
E.N. Khaembah
Keyword(s):  
New Zealand ◽  
Dry Matter ◽  
Nutritive Value ◽  
Plant Traits ◽  
Cultivar Differences ◽  
Future Research ◽  
Dry Matter Yield ◽  
Production Traits ◽  
Economic Values ◽  
The Impact

Economic values (EVs) are an estimate of the change in farm system profit per unit of change in a defined plant trait. Cultivars within species such as perennial ryegrass differ in the major production traits of dry matter yield, nutritive value and persistence, but the impact of those differences on farm financial performance is seldom calculated and reported. This paper explains what EVs are, describes how they can be calculated, and discusses some of the associated methodological issues. EVs have been derived for seasonal dry matter yield in New Zealand dairy systems. Extra feed produced in late spring has consistently low economic value, while extra feed produced in early spring has consistently high value. There have been no systematic investigations into the EVs of nutritive value and persistence in New Zealand pastures; this is a clear opportunity for future research. The lack of data on cultivar differences in these traits will restrict the application of EVs to pasture cultivar evaluation. This gap is now being addressed by new industry initiatives. Keywords: pasture cultivars, evaluation, traits, economic values, performance values

scholarly journals EFFICIENCY OF UTILIZATION OF NITROGEN AND PHOSPHORUS BY YORKSHIRE FOG (HOLCUS LANATUS)

1973 ◽  
pp. 288-302
Author(s):  
R.S.Scott A. Hardacre
Keyword(s):  
New Zealand ◽  
Perennial Ryegrass ◽  
Dry Matter ◽  
Moisture Stress ◽  
The Other ◽  
Yield Response ◽  
Holcus Lanatus ◽  
Nitrogen And Phosphorus ◽  
Climate Conditions ◽  
Pot Experiments

Two pot experiments compared the yield response and uptake of N and P by five New Zealand, two exotic ecotypes and one bred cultivar of Yorkshire fog and Ruanui perennial ryegrass under varying levels of applied N and P. One experiment was conducted in a heated glasshouse and the other under controlled climate conditions. Of the Yorkshire fog strains examined, the bred cultivar 'Massey Basyn' and an ecotype from Rotorua provided highest yields of dry matter. Their superiority was attributed in part to their ability to extract greater amounts of N and P from the soil. The former was more efficient under high levels of applied N and the latter under high levels of applied P. Under two distinct climatic environments, 'Massey Basyn' Yorkshire fog gave similar yields and uptake of N and P to Ruanui perennial ryegrass. Under a third climate, with higher temperatures and moisture stress, 'Massey Basyn' outyielded Ruanui. This was associated with a greater ability by 'Massey Basyn' to utilize absorbed P.

scholarly journals Potato Response to Polyhalite as a Potassium Source Fertilizer in Brazil: Yield and Quality

HortScience ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 373-379 ◽  
Author(s):  
Simone da Costa Mello ◽  
Francis J. Pierce ◽  
Rachel Tonhati ◽  
Guilherme Silva Almeida ◽  
Durval Dourado Neto ◽  
...  
Keyword(s):  
Dry Matter ◽  
Winter Season ◽  
Ammonium Phosphate ◽  
Tropical Soils ◽  
Application Rate ◽  
Soluble Solids ◽  
Yield Response ◽  
Wet Season ◽  
Potato Quality ◽  
Application Rates

Polyhalite (PH) is a hydrated sulfate evaporite mineral containing potassium, calcium, magnesium, and sulfur, nutrients all required in significant quantities by crops, but has limited evaluation as a fertilizer for potato (Solanum tuberosum L.). Fertilizer source and application rate field trials were conducted to evaluate PH as a fertilizer for potato production in the weathered tropical soils in Brazil. We selected two locations in the potato producing region of Southeast Brazil in 2015–16, one trial was conducted during the wet season at Tapira in São Paulo and the other during the winter season at Casa Branca in Minas Gerais. A common blend, 4–14–8, was made with either muriate of potash (MOP), sulfate of potash (SOP), or PH as the K source; with kieserite and gypsum added to the SOP to make a synthetic PH with similar composition; P either as single super phosphate (SSP) for the MOP blend or mono ammonium phosphate (MAP) for the PH and SOP blends; and N as urea adjusted for the N in MAP. All blends were applied at four application rates of 62, 125, 187, and 249 kg K/ha. A control was also included consisting of N and P as urea and MAP but no K, Ca, Mg, or S. Total and marketable yields as well as potato quality including dry matter, starch, soluble solids, hardness, and crunchiness were measured at harvest using standard techniques. At Tapira, potato yields increased linearly with increasing K application rate from 22.4 t·ha−1 for the control to the highest yield of 29.2 t·ha−1 and were higher for PH and SOP than MOP (28.8, 29.2, and 25.3 t·ha−1, respectively). At Casa Branca, yields increased from 31.5 t·ha−1 for the control to 42.4 kg·ha−1 at the 62 kg K/ha application rate with no further increases at higher rates and no differences among fertilizer blends at any application rate. Polyhalite blend increased dry matter and starch at the higher application rates compared with MOP and SOP at Tapira and increased potato hardness and crunchiness at the optimum 62 kg K/ha application rate at Casa Branca. Yield response was similar for PH and SOP but quality differences between these two fertilizer blends were observed even though they were similar in composition. Differences between PH and MOP may be related either to Cl or lack of Mg in the MOP blend. PH performed well as a fertilizer for potatoes as it produced equal or higher yields and provided benefits to potato quality when compared with MOP or SOP as a K source in a common fertilizer blend.

scholarly journals The impact of land-use intensification on soil physical quality and plant yield response in the North Otago Rolling Downlands

2006 ◽  
pp. 165-172 ◽  
Author(s):  
D.J. Houlbrooke ◽  
J.D. Morton ◽  
R.J. Paton ◽  
R.P. Littlejohn
Keyword(s):  
Land Use ◽  
New Zealand ◽  
Soil Quality ◽  
Irrigation Water ◽  
Cattle Grazing ◽  
Yield Response ◽  
Plant Yield ◽  
Land Use Intensification ◽  
The North ◽  
The Impact

The New Zealand agricultural industry is currently undergoing a large drive for increased productivity. Fuelling this will primarily require greater 'on-farm' landuse intensification involving increasing farm inputs to gain a large increase in farm product outputs. The North Otago Rolling Downlands (NORD) region of New Zealand has traditionally been drought-prone and limited to extensive sheep farming. The establishment of a large district irrigation scheme in spring 2006 will result in large scale intensification of land-use across the NORD region. A field trial has been established in North Otago on a common NORD Pallic soil type (Timaru silt loam) to determine the effect of land use intensification on soil quality and plant yield response. The treatments compare newly sown pasture vs. winter grazed forage crop, irrigated vs. dryland and sheep vs. cattle grazing. The application of irrigation water in 2004/2005 resulted in 17.5 kg pasture DM/mm of irrigation water and 24 kg pasture DM/mm of irrigation water for the drier 2005/ 2006 growing season. Results from the pasture trial suggest that both cattle grazing and irrigation (particularly in combination) are decreasing soil quality with a macroporosity of 9% v/v from pasture plots following the 2004/2005 season compared to 18% v/v for the dryland sheep treatment. In the 2005/2006 season, cattle irrigated plots had a macroporosity of 11% v/v from pasture plots c.f 19% v/v for the dryland sheep treatment To date, this measured decrease has had no significant effect on pasture or crop yield suggesting that soil quality has not yet fallen below a critical level for production under irrigated farming systems. However, further monitoring is required to assess the long term effects as strong trends are emerging that indicate soil quality decline under the cattle grazed and cropping treatments. Keywords: land-use intensification, soil quality, irrigation, cattle grazing, sheep grazing, forage cropping, compaction, pasture yield

The effect of wet season land treatment and nitrogen fertilizer on safflower, linseed, and wheat in the Ord River valley. 3. Wheat

1968 ◽  
Vol 8 (30) ◽  
pp. 72 ◽  
Author(s):  
DF Beech ◽  
MJT Norman ◽  
GA McIntyre
Keyword(s):  
Grain Yield ◽  
Ammonium Sulphate ◽  
Nitrogen Fertilizer ◽  
Dry Matter ◽  
Nitrate Nitrogen ◽  
Yield Response ◽  
Research Station ◽  
Soil Nitrate ◽  
Dry Matter Yield ◽  
Wet Season

Gabo wheat was grown under irrigation at Kimberley Research Station in the 1964 dry season following 6 months and 18 months clean and weedy fallows. Four levels of nitrogen fertilizer, as ammonium sulphate and urea, were superimposed. After 6 months clean fallow and 6 and 18 months weedy fallows, grain and dry-matter yield responded to up to 160 lb N an acre. Grain and dry-matter yield after 6 months clean fallow were greater than those after weedy fallows at the same nitrogen fertilizer level. After 18 months clean fallow no significant responses to nitrogen fertilizer were obtained. Mitscherlich curves were fitted to the total dry-matter and grain yield responses to nitrogen fertilizer after the four fallowing treatments. The analysis indicated that 1 part of nitrogen as ammonium sulphate was equivalent to 1.61 (dry matter) or 1.72 (grain) parts of nitrogen as urea. There were strong correlations (r = 0.956 for dry matter; r = 0.917 for grain) between the Mitscherlich constants for individual replicates of the fallow treatments and soil nitrate-nitrogen measured in the 0-3 foot profile before sowing. Soil nitrate-nitrogen, mineralized and accumulated during a summer clean fallow, appears to be almost three times as effective in producing a grain yield response as nitrogen applied as ammonium sulphate at sowing, and almost five times as effective as urea nitrogen at sowing.

scholarly journals Overview: The international group for indigenous health measurement and COVID-19

2021 ◽  
pp. 1-6
Author(s):  
Michele Connolly ◽  
Kalinda Griffiths ◽  
John Waldon ◽  
Malcolm King ◽  
Alexandra King ◽  
...  
Keyword(s):  
New Zealand ◽  
Total Population ◽  
Indigenous Health ◽  
Health Data ◽  
Indigenous Populations ◽  
Health Measurement ◽  
Country Group ◽  
International Group ◽  
The Us ◽  
The Impact

The International Group for Indigenous Health Measurement (IGIHM) is a 4-country group established to promote improvements in the collection, analysis, interpretation and dissemination of Indigenous health data, including the impact of COVID-19. This overview provides data on cases and deaths for the total population as well as the Indigenous populations of each country. Brief summaries of the impact are provided for Canada and New Zealand. The Overview is followed by. separate articles with more detailed discussion of the COVID-19 experience in Australia and the US.

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