EFFECTS OF ACUTE SIMULATED AND ACUTE GRASSHOPPER (ORTHOPTERA: ACRIDIDAE) DAMAGE ON GROWTH RATES AND YIELD OF SPRING WHEAT (TRITICUM AESTIVUM)

1983 ◽  
Vol 115 (6) ◽  
pp. 629-636 ◽  
Author(s):  
O. O. Olfert ◽  
M. K. Mukerji

AbstractStudies showed that the type of damage, the timing of damage with the phenological stage of the crop, and the amount of available soil moisture influenced the growth response of spring wheat to acute levels of grasshopper damage and acute levels of artificial damage. Ground-level cutting of plants resulted in the greatest reduction in plant biomass and crop yield, while grasshopper damage and artificial stripping of leaf material did not result in as severe a reduction in either biomass or yield.Damaged plants were not able to recover lost biomass when damage occurred any later than the early stages of tillering despite observed relative growth rates which were higher than control plants. The greatest degree of recovery occurred in study sites with the greatest amount of available soil moisture.The most detrimental effect of damage on yield was the reduction of heads per plant and kernel weight. In most cases differences in the number of seeds per head between damaged and control plants were not evident.

Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 882
Author(s):  
Dhananjay Kumar ◽  
Sandeep Kushwaha ◽  
Chiara Delvento ◽  
Žilvinas Liatukas ◽  
Vivekanand Vivekanand ◽  
...  

Drought stress is one of the key plant stresses reducing grain yield in cereal crops worldwide. Although it is not a breeding target in Northern Europe, the changing climate and the drought of 2018 have increased its significance in the region. A key challenge, therefore, is to identify novel germplasm with higher drought tolerance, a task that will require continuous characterization of a large number of genotypes. The aim of this work was to assess if phenotyping systems with low-cost consumer-grade digital cameras can be used to characterize germplasm for drought tolerance. To achieve this goal, we built a proximal phenotyping cart mounted with digital cameras and evaluated it by characterizing 142 winter wheat genotypes for drought tolerance under field conditions. The same genotypes were additionally characterized for seedling stage traits by imaging under controlled growth conditions. The analysis revealed that under field conditions, plant biomass, relative growth rates, and Normalized Difference Vegetation Index (NDVI) from different growth stages estimated by imaging were significantly correlated to drought tolerance. Under controlled growth conditions, root count at the seedling stage evaluated by imaging was significantly correlated to adult plant drought tolerance observed in the field. Random forest models were trained by integrating measurements from field and controlled conditions and revealed that plant biomass and relative growth rates at key plant growth stages are important predictors of drought tolerance. Thus, based on the results, it can be concluded that the consumer-grade cameras can be key components of affordable automated phenotyping systems to accelerate pre-breeding for drought tolerance.


1959 ◽  
Vol 52 (3) ◽  
pp. 273-281 ◽  
Author(s):  
R. H. M. Langer

1. Pure swards of S. 48 timothy and S. 215 meadow fescue were cut (a) after ear emergence, (b) before ear emergence and in the aftermath to prevent flowering, and (c) every 4 weeks. The number and weight of tillers and leaves were determined.2. Tiller numbers declined considerably from early spring to the middle of summer. This fall was reduced by a system of frequent defoliation in the wet summer of 1956, especially in timothy.3. Leaf weight per unit area of sward increased rapidly from early spring until about the time of ear emergence; no further significant gains were recorded after ears had appeared, when the plots were cut for hay.4. The weight per leaf also increased in the spring and was similar in both species. In the regrowth following a cut meadow fescue produced considerably heavier leaves than timothy.5. As both grasses approached the flowering stage, their leaf canopy was increasingly raised above ground level. Variable proportions of foliage were thus removed by cutting according to the developmental stage of the plant. Crop growth rates following a cut appeared to be related to the amount of leaf material remaining in the sward.6. Relative growth rates during uninterrupted growth were greatest around the time of ear emergence.


1966 ◽  
Vol 46 (6) ◽  
pp. 611-617 ◽  
Author(s):  
R. Kaul

Seedlings of wheat, oats, and barley were grown in nutrient solution and subjected to uniform water stresses by the addition of different amounts of polyethylene glycol to the medium. The polyethylene glycol was refined by passage through a combined millipore – ion exchange filter. The solution was circulated by an automatic system which drained and refilled growth tanks once every 45 minutes. Relative growth rates, calculated from changes in dry weight, were used as a measure of drought tolerance. Between the second and the sixth leaf stages, but not at the first leaf stage, the drought tolerance of Thatcher wheat was significantly greater than that of Exeter oats or Husky barley. Oats and barley responded similarly to water stress.


Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 126
Author(s):  
Judit Barroso ◽  
Nicholas G. Genna

Russian thistle (Salsola tragus L.) is a persistent post-harvest issue in the Pacific Northwest (PNW). Farmers need more integrated management strategies to control it. Russian thistle emergence, mortality, plant biomass, seed production, and crop yield were evaluated in spring wheat and spring barley planted in 18- or 36-cm row spacing and seeded at 73 or 140 kg ha−1 in Pendleton and Moro, Oregon, during 2018 and 2019. Russian thistle emergence was lower and mortality was higher in spring barley than in spring wheat. However, little to no effect of row spacing or seeding rate was observed on Russian thistle emergence or mortality. Russian thistle seed production and plant biomass followed crop productivity; higher crop yield produced higher Russian thistle biomass and seed production and lower crop yield produced lower weed biomass and seed production. Crop yield with Russian thistle pressure was improved in 2018 with 18-cm rows or by seeding at 140 kg ha−1 while no effect was observed in 2019. Increasing seeding rates or planting spring crops in narrow rows may be effective at increasing yield in low rainfall years of the PNW, such as in 2018. No effect may be observed in years with higher rainfall than normal, such as in 2019.


Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 74
Author(s):  
Abhishek RoyChowdhury ◽  
Pallabi Mukherjee ◽  
Saumik Panja ◽  
Rupali Datta ◽  
Christos Christodoulatos ◽  
...  

The use of insensitive munitions such as 3-nitro-1,2,4-triazol-5-one (NTO) is rapidly increasing and is expected to replace conventional munitions in the near future. Various NTO treatment technologies are being developed for the treatment of wastewater from industrial munition facilities. This is the first study to explore the potential phytoremediation of industrial NTO-wastewater using vetiver grass (Chrysopogon zizanioides L.). Here, we present evidence that vetiver can effectively remove NTO from wastewater, and also translocated NTO from root to shoot. NTO was phytotoxic and resulted in a loss of plant biomass and chlorophyll. The metabolomic analysis showed significant differences between treated and control samples, with the upregulation of specific pathways such as glycerophosphate metabolism and amino acid metabolism, providing a glimpse into the stress alleviation strategy of vetiver. One of the mechanisms of NTO stress reduction was the excretion of solid crystals. Scanning electron microscopy (SEM), electrospray ionization mass spectrometry (ESI-MS), and Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the presence of NTO crystals in the plant exudates. Further characterization of the exudates is in progress to ascertain the purity of these crystals, and if vetiver could be used for phytomining NTO from industrial wastewater.


1996 ◽  
Vol 26 (9) ◽  
pp. 1556-1568 ◽  
Author(s):  
Thimmappa S. Anekonda ◽  
Richard S. Criddle ◽  
Lee D. Hansen ◽  
Mike Bacca

Seventeen Eucalyptus species and 30 rapid-growing Eucalyptuscamaldulensis trees (referred to as plus trees), growing in a plantation were studied to examine relationships among measured plant growth and respiratory parameters, geographical origins, and growth climate. The respiratory parameters measured at two different temperatures by isothermal calorimetry were metabolic heat rate, rate of CO2 production, and the ratio of heat rate to CO2 rate. Metabolic heat rate was also measured as a continuous function of temperature by differential scanning calorimetry in the range of 10 to 40 °C. Tree growth was measured as rates of height and stem volume growth. The values of respiratory and growth variables of Eucalyptus species are significantly correlated with latitude and altitude of origin of their seed sources. The maximum metabolic heat rate, the temperature of the maximum heat rate, the temperature coefficients of metabolic rate, and the temperatures at which the slopes of Arrhenius plots change are all genetically determined parameters that vary both within and among species. Measurement of growth rate–respiration rate–temperature relationships guide understanding of why relative growth rates of Eucalyptus species and individual genotypes differ with climate, making it possible to identify genotypes best suited for rapid growth in different climates. The temperature dependence of respiration rates is an important factor determining relative growth rates of eucalypts in different climates. To achieve optimum biomass production the temperature dependence of individual plants must be matched to growth climate.


1985 ◽  
Vol 65 (4) ◽  
pp. 1011-1018 ◽  
Author(s):  
C. S. TAN ◽  
B. N. DHANVANTARI

Two tomato (Lycopersicon esculentum Mill.) cultivars, Heinz-2653 and Campbell-28, were grown on Fox loamy sand in the subhumid region of southern Ontario from 1979 to 1982. Irrigation increased the marketable yields of H-2653 in a dry year, 1982, but not in the other years. Irrigation substantially increased marketable yields of C-28 in 1979 and 1982. Irrigation, when the available soil moisture (ASM) level reached 50%, was no more effective than when the ASM level in the soil was allowed to drop to 25%. Without irrigation yield increased as plant population increased in normal and wet years, but not in a dry year. Blossom-end rot (BER) of C-28 cultivar was markedly reduced by irrigation. Effects of irrigation or plant population treatments on the incidence of fruit speck did not appear to be significant.Key words: Available soil moisture, Lycopersicon esculentum, Pseudomonas syringae pv. tomato, fruit speck


1969 ◽  
Vol 62 (2) ◽  
pp. 367-384 ◽  
Author(s):  
A. M. Sackler ◽  
A. S. Weltman ◽  
R. Schwartz ◽  
P. Steinglass

ABSTRACT This report was designed to determine combined effects of maternal endocrine imbalances and abnormal behaviour due to prolonged isolation stress of female mice on the behaviour, developmental growth rate and endocrine function of their offspring. Sixty female albino mice averaging 19 g were divided equally into isolated and control groups. The isolated females were housed singly; control females were maintained in groups of 2 mice per cage. After observation of behavioural and physiological effects characteristic of isolation stress in the test mice, all isolated and control mice were mated after a 6½ month experimental, isolation period. No differences were observed in fertility and fecundity of the two groups of mothers. Analyses of developmental growth rates of the litters of the isolated versus control mothers showed significantly lower body weights in the test offspring at 3 and 4 weeks of age. The body weights of the female offspring remained significantly lower from the 4th to 11th weeks. The effects on the body weights of the male offspring declined and were no longer statistically significant at the 5th to 11 weeks. Locomotor activity at 4½ and 8 weeks of age was markedly or significantly higher in the male and female mice from isolated mothers. Tail-blood samples taken prior to autopsy at 5 and 11 weeks of age revealed significant decreases in the total leukocyte and eosinophil counts of both sexes. At the two ages, the absolute and relative spleen and thymus weights of the male and female offspring were markedly and/or significantly lower than the values observed in counterpart young from control females. Significant decreases were also observed in the absolute gonadal organ weights of both sexes at 11 weeks of age. The various data indicated inhibited growth rates, heightened locomotor activity and evasiveness, as well as evidence of increased adrenocortical function in the offspring from test mothers. The gonadal weight decreases suggested retarded gonadal development. Further studies using split-litter techniques are required to differentiate the effects of prenatal endocrine imbalances versus postnatal maternal influence (i. e., nursing care) on the offspring.


2013 ◽  
Vol 726-731 ◽  
pp. 3803-3806
Author(s):  
Bing Ru Liu ◽  
Jun Long Yang

In order to revel aboveground biomass of R. soongorica shrub effect on soil moisture and nutrients spatial distribution, and explore mechanism of the changes of soil moisture and nutrients, soil moisture content, pH, soil organic carbon (SOC) and total nitrogen (TN) at three soil layers (0-10cm,10-20cm, and 20-40cm) along five plant biomass gradients of R. soongorica were investigated. The results showed that soil moisture content increased with depth under the same plant biomass, and increased with plant biomass. Soil nutrient properties were evidently influenced with plant biomass, while decreased with depth. SOC and TN were highest in the top soil layer (0-10 cm), but TN of 10-20cm layer has no significant differences (P < 0.05). Moreover, soil nutrient contents were accumulated very slowly. These suggests that the requirement to soil organic matter is not so high and could be adapted well to the desert and barren soil, and the desert plant R. soongorica could be acted as an important species to restore vegetation and ameliorate the eco-environment.


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