LOW-TEMPERATURE STRESS IN FIELD AND FORAGE CROP PRODUCTION – AN OVERVIEW

1987 ◽  
Vol 67 (4) ◽  
pp. 1121-1133 ◽  
Author(s):  
C. J. ANDREWS

Low temperature is a major constraint to the productivity of field crops. It is likely to remain so even in the event of increasing global temperature, because to maximize economic potential producers will tend to use the longest season crops compatible with average weather conditions. Low temperature in the growing season may reduce germination, may retard vegetative growth by inducing metabolic imbalances and can delay or prevent reproductive development. Chilling temperature can damage the tissues of sensitive plants while freezing temperature will damage most tissues during active growth. Low temperature during the winter season may cause the death of overwintering crop plants during their dormant phase. The overwintering habit in most crops results in higher yields due to the abundance of early spring moisture available to the crop. Death of plants may occur during winter by cell membrane disorganization during severe freezing exposure, by anaerobic stress due to flooding and ice encasement, by heaving of plants from soil by the formation of ice lenses, or by the activity of low temperature pathogens under snow cover. Environmental modifications to alleviate cold stress are only practical in a limited number of situations. Genotypic modifications are being made in many field crops to increase their tolerance to cold.Key words: Cold, freezing, chilling, winter survival

2018 ◽  
Vol 1 (94) ◽  
pp. 38-44
Author(s):  
А.M. Malienkо ◽  
N.E. Borуs ◽  
N.G. Buslaeva

In the article, the results of research on the methodology for conducting studies with corn culture under various methods of sowing and weather conditions. The aim of the research was to establish and evaluate the reliability and high accuracy of the experiment, with a decrease in the area's acreage and taking one plant per repetition. Based on the results of the analysis of biometric parameters and yields, the possibility of sampling from 5 to 108 plants was established statistically and mathematically to establish the accuracy of the experiment. The established parameters of sites in experiments with maize indicate the possibility of obtaining much more information from a smaller unit of area, that is, to increase labor productivity not only with tilled crops. This is the goal of further scientific research with other field crops taking 1 plant of repetitions, observing the conditions of leveling the experimental plot according to the fertility of the soil and sowing seeds with high condition. The data obtained give grounds for continuing research on the minimum space required and the sample in the experiments.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1077D-1077
Author(s):  
Wol-Soo Kim ◽  
Xiu-Yu Wu ◽  
Soon-Ju Chung

During the early spring, embolism symptoms may be observed on the leaves of kiwi trees after a severe, cold winter. The morphological character of embolism in young leaves in early spring is typically parachute shaped, at the basal part of kiwi shoots. Deformed leaves were observed at the beginning stage of development. To test the factors, we used water stress, low temperature, and xylem bubble treatments on kiwi vines during the winter season. Low temperature treatments on trees were carried out in a –15 °C chamber for 0, 12, 24, and 48 hours. For the xylem bubble treatment, the trees were injected with 3.5 MPa compressed air at –15 °C for 24 hours. For water stress treatments, the trees were not irrigated until dry soil conditions reached as little as 50% soil moisture. Treated kiwi trees planted in plastic pots (20 cm × 25 cm) were moved into the growth chamber at 25 °C with 12 hours of light, and the rate of deformed leaf symptoms was observed. In all treatments, deformed leaves were observed and bud burst rates were lower than for the control. Therefore, we confirmed that the main factors for deformed leaves were low temperature, xylem bubbles, and water stress.


Author(s):  
V. M. Bidenko ◽  
L. A. Kalchuk ◽  
V. Z. Trochymenko

Leguminous crops grown in the radioactive contamination zone have the potential to accumulate radionuclides 137Cs and 90Sr to a large extent, thus contributing to radioactive contamination of livestock products, milk and meat. One of the effective methods in reducing the accumulation of radionuclides in crop production, in particular fodder, is the application of trace elements that are lacking in the Polissya area of Zhytomyr region. In addition, the trace elements contribute to increasing the yield of plants and improve their nutrition. As a result of the research in the Naroditsky district of Zhytomyr region, Polissya STOV, we found that the application of trace elements in the form of salts of trace elements Co, Cu, Zn, Mn contributed to the increase in the yield of green mass of white lupine and lupine of yellow on 2,4 and 3,6%, or on 10 and 10.7 g, of complexones of these trace elements, respectively, on 11,2 and 13,5%, or on 31,0 and 58,0 ts. Salts of trace elements contributed to a decrease in the specific activity of the green mass of lupine white by 18%, or 1.2 times, yellow lupine - by 11%, 1.2 times. Plasma complexes contributed to a decrease in the specific activity of green mass of white lupine and lupine of yellow on 24%, or in 1,3 times. Specific activity of the green mass of white lupine was high and exceeded the activity of the green mass of lupine yellow in 6.3 times, although the cultivation of cultures was carried out on the same fields, however, at different periods. White lupine was sown in the early spring, during which a considerable amount of precipitation fell during the vegetation period. Therefore, in our opinion, a significant increase in the specific activity of the green mass of white lupine was conditioned by the weather conditions. The maximum specific activity of the green mass of white lupine was 2003 Bq / kg, the minimum is 1526 Bq / kg, which is lower by 477 Bq. Reducing the specific activity of lupine is due to radio-blocking effect of micronutrient complexonates. Salts of trace elements contributed to a 1.2-fold decrease in the specific activity of the green mass of the culture.


2021 ◽  
Vol 13 (6) ◽  
pp. 1204
Author(s):  
Nadia Delavarpour ◽  
Cengiz Koparan ◽  
John Nowatzki ◽  
Sreekala Bajwa ◽  
Xin Sun

The incorporation of advanced technologies into Unmanned Aerial Vehicles (UAVs) platforms have enabled many practical applications in Precision Agriculture (PA) over the past decade. These PA tools offer capabilities that increase agricultural productivity and inputs’ efficiency and minimize operational costs simultaneously. However, these platforms also have some constraints that limit the application of UAVs in agricultural operations. The constraints include limitations in providing imagery of adequate spatial and temporal resolutions, dependency on weather conditions, and geometric and radiometric correction requirements. In this paper, a practical guide on technical characterizations of common types of UAVs used in PA is presented. This paper helps select the most suitable UAVs and on-board sensors for different agricultural operations by considering all the possible constraints. Over a hundred research studies were reviewed on UAVs applications in PA and practical challenges in monitoring and mapping field crops. We concluded by providing suggestions and future directions to overcome challenges in optimizing operational proficiency.


1978 ◽  
Vol 7 (1) ◽  
pp. 77-80 ◽  
Author(s):  
Robert J. Reginato ◽  
Sherwood B. Idso ◽  
Ray D. Jackson

Soil Research ◽  
2017 ◽  
Vol 55 (8) ◽  
pp. 778
Author(s):  
G. S. A. Castro ◽  
C. A. C. Crusciol ◽  
C. A. Rosolem ◽  
J. C. Calonego ◽  
K. R. Brye

This work aimed to evaluate the effects of crop rotations and soil acidity amelioration on soil physical properties of an Oxisol (Rhodic Ferralsol or Red Ferrosol in the Australian Soil Classification) from October 2006 to September 2011 in Botucatu, SP, Brazil. Treatments consisted of four soybean (Glycine max)–maize (Zea mays)–rice (Oryza sativa) rotations that differed in their off-season crop, either a signal grass (Urochloa ruziziensis) forage crop, a second crop, a cover crop, or fallow. Two acid-neutralising materials, dolomitic lime (effective calcium carbonate equivalent (ECCE) = 90%) and calcium-magnesium silicate (ECCE = 80%), were surface applied to raise the soil’s base saturation to 70%. Selected soil physical characteristics were evaluated at three depths (0–0.1, 0.1–0.2, and 0.2–0.4 m). In the top 0.1 m, soil bulk density was lowest (P < 0.05) and macroporosity and aggregate stability index were greatest (P < 0.05) in the forage crop compared with all other production systems. Also, bulk density was lower (P < 0.05) and macroporosity was greater (P < 0.05) in the acid-neutralising-amended than the unamended control soil. In the 0.1–0.2-m interval, mean weight diameter and mean geometric diameter were greater (P < 0.05) in the forage crop compared with all other production systems. All soil properties evaluated in this study in the 0.2–0.4-m interval were unaffected by production system or soil amendment after five complete cropping cycles. Results of this study demonstrated that certain soil physical properties can be improved in a no-tillage soybean–maize–rice rotation using a forage crop in the off-season and with the addition of acid-neutralising soil amendments. Any soil and crop management practices that improve soil physical properties will likely contribute to sustaining long-term soil and crop productivity in areas with highly weathered, organic matter-depleted, acidic Oxisols.


2015 ◽  
Vol 3 (3) ◽  
pp. 541-544
Author(s):  
A. Khanal

Plant nutrient is one of the limiting factors affecting crop production. Nitrogen and boron are major nutrients in case of broccoli. So, an experiment was carried out to evaluate the effect of nitrogen and boron in seed yield and yield attributing characters of broccoli in Rampur, Chitwan during winter season. The experiment was laid out in factorial RCBD design with four levels of nitrogen and two levels of boron. Each plot consists of 25 plants which were separated by 60 * 60 cm spacing. There are altogether eight treatments replicates thrice. Local variety Calabrese was used.  Significant effect of different dose of nitrogen and boron on yield attributing characters was found. Also interactive effect of nitrogen and boron in number of pods, pod length, seed yield and number of seeds per pod was found significantly different.Int J Appl Sci Biotechnol, Vol 3(3): 541-544


Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Robert A. York ◽  
Jacob Levine ◽  
Kane Russell ◽  
Joseph Restaino

Abstract Background Young, planted forests are particularly vulnerable to wildfire. High severity effects in planted forests translate to the loss of previous reforestation investments and the loss of future ecosystem service gains. We conducted prescribed burns in three ~35-year-old mixed conifer plantations that had previously been masticated and thinned during February in order to demonstrate the effectiveness of winter burning, which is not common in the Sierra Nevada, California. Results On average, 59% of fine fuels were consumed and the fires reduced shrub cover by 94%. The average percent of crown volume that was damaged was 25%, with no mortality observed in overstory trees 1 year following the fires. A plot level analysis of the factors of fire effects did not find strong predictors of fuel consumption. Shrub cover was reduced dramatically, regardless of the specific structure that existed in plots. We found a positive relationship between crown damage and the two variables of Pinus ponderosa relative basal area and shrub cover. But these were not particularly strong predictors. An analysis of the weather conditions that have occurred at this site over the past 20 years indicated that there have consistently been opportunities to conduct winter burns. On average, 12 days per winter were feasible for burning using our criteria. Windows of time are short, typically 1 or 2 days, and may occur at any time during the winter season. Conclusions This study demonstrates that winter burning can be an important piece of broader strategies to reduce wildfire severity in the Sierra Nevada. Preparing forest structures so that they can be more feasible to burn and also preparing burn programs so that they can be nimble enough to burn opportunistically during short windows are key strategies. Both small landowners and large agencies may be able to explore winter burning opportunities to reduce wildfire severity.


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