The influence of tree management practices on phenological growth stages of Ulmus pumila L. (Siberian elm)

2021 ◽  
Author(s):  
María Cruz Amorós ◽  
Pedro Vicente Mauri ◽  
María Dolores Curt
Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 605
Author(s):  
Peder K. Schmitz ◽  
Hans J. Kandel

Planting date (PD), seeding rate (SR), relative maturity (RM) of cultivars, and row spacing (RS) are primary management factors affecting soybean (Glycine max (L.) Merr.) yield. The individual and synergistic effects of PD, SR, RM, and RS on seed yield and agronomic characteristics in North Dakota were herein investigated. Early and late PD, early and late RM cultivars, two SR (408,000 and 457,000 seed ha−1), and two RS (30.5 and 61 cm) were evaluated in four total environments in 2019 and 2020. Maximizing green canopy cover prior to the beginning of flowering improved seed yield. Individual factors of early PD and narrow RS resulted in yield increase of 311 and 266 kg ha−1, respectively. The combined factors of early PD, late RM, high SR, and narrow RS improved yield by 26% and provided a $350 ha−1 partial profit over conventional practices. Canopy cover and yield had relatively weak relationships with r2 of 0.36, 0.23, 0.14, and 0.21 at the two trifoliolate, four trifoliolate, beginning of flowering, and beginning of pod formation soybean growth stages, respectively. Producers in the most northern soybean region of the USA should combine early planting, optimum RM cultivars, 457,000 seed ha−1 SR, and 31 cm RS to improve yield and profit compared to current management practices.


Weed Science ◽  
2021 ◽  
pp. 1-23
Author(s):  
Katherine M. Ghantous ◽  
Hilary A. Sandler

Abstract Applying control measures when carbohydrate levels are low can decrease the likelihood of plant survival, but little is known about the carbohydrate cycles of dewberry (Rubus spp.), a problematic weed group on cranberry farms. Weedy Rubus plants were collected from areas adjacent to production beds on commercial cranberry farms in Massachusetts, two locations per year for two years. For each site and year, four entire plants were collected at five phenological stages: budbreak, full leaf expansion, flowering, fruit maturity, and after onset of dormancy. Root sections were analyzed for total nonstructural carbohydrate (TNC; starch, sucrose, fructose, and glucose). Overall trends for all sites and years showed TNC were lowest at full leaf expansion or flowering; when sampled at dormancy, TNC concentrations were greater than or equal to those measured at budbreak. Starch, a carbohydrate form associated with long-term storage, had low levels at budbreak, leaf expansion and/or flowering with a significant increase at fruit maturity and the onset of dormancy, ending at levels higher than those found at budbreak. The concentration of soluble sugars, carbohydrate forms readily usable by plants, was highest at budbreak compared to the other four phenological samplings. Overall, our findings supported the hypothesis that TNC levels within the roots of weedy Rubus plants can be predicted based on different phenological growth stages in Massachusetts. However, recommendations for timing management practices cannot be based on TNC cycles alone; other factors such as temporal proximity to dormancy may also impact Rubus plants recovery and further research is warranted. Late-season damage should allow less time for plants to replenish carbohydrate reserves (prior to the onset of dormancy), thereby likely enhancing weed management tactics effectiveness over time. Future studies should consider tracking the relationship between environmental conditions, phenological stages, and carbohydrate trends.


2020 ◽  
Vol 41 (6) ◽  
pp. 1781-1787
Author(s):  
R.S. Yadav ◽  
◽  
H.N. Meena ◽  
N.K. Jain ◽  
D. Bhaduri ◽  
...  

Aim: To investigate efficient utilization of soil phosphorus for peanut nutrition through integration of management practices in medium black clay soils of Saurashtra region in Gujarat. Methodology: Soil phosphorus availability and uptake by peanut plants were assessed at five plant growth stages under six different management practices in Kharif season. The availability of soil P was estimated by Olsen P and Resin P extraction methods. The biomass production and phosphorus uptake at each growth stages were observed in order to draw the relationship between these parameters.? Results: The management practices like raised bed with polythene mulch, integrated and organic nutrient management was consistently found promising for enhanced availability and uptake of soil phosphorus under peanut cultivation. The Olsen P decreased with plant growth under all the management options, except organic and integrated nutrient management practices.? In contrary, the resin P generally increased with plant growth, especially under inorganic and organic nutrient management and raised bed with polythene mulch practices. Irrespective of growth stages, the phosphorus uptake by peanut plants was significantly and strongly correlated with biomass production (r=0.85, p<0.01) and Olsen P (r=0.41, P<0.05).? Interpretation: The results indicate that phosphorus requirement of peanut plants can be efficiently met by integrating land and nutrient management practices in these medium black clay soils.


1994 ◽  
Vol 34 (7) ◽  
pp. 949 ◽  
Author(s):  
KA Gravois ◽  
RS Helms

Establishing a uniform rice (Oryza sativa L.) stand is an important beginning to managing a rice crop and attaining high yields. Most rice management practices in the United States are timed according to rice growth stages. Non-uniform rice stands, and subsequently non-uniform growth stages, present problems for the timely application of management practices for attaining high yields. Our objective was the determination of the effects of uneven emergence on rice yield, milling yield, and yield components. Experiments were conducted in 1988 and 1989 on a Hebert silt loam (Vertic Hapludoll) at the Southeast Branch Experiment Station near Rohwer, Arkansas. Uneven emergence was simulated by delayed (18 days from emergence) interseeding of rice to achieve 0, 20, 40, 60, and 80% uneven emergence. Each experiment was planted with the cultivars Lemont (semi-dwarf) and Tebonnet (tall) and was replicated 4 times. Rice yields for the uneven emergence treatment levels were significantly less than the rice yields seeded exclusively at PD1 (planting date 1), except for the uneven emergence levels 80-20 (80% planted at PD1 and 20% planted at PD2) and 60-40 for Tebonnet, and 60-40 in 1988 for Lemont. In 1989, there was a trend for head rice yields to decrease as uneven emergence levels increased. Average panicle density and number of grains per panicle for both Lemont and Tebonnet decreased with increasing uneven emergence, indicating a failure in the typical compensatory relationship between panicle density and grain per panicle. Lemont exhibited reduced average grain weights due to uneven emergence, especially at 80-20, 60-40, and 40-60 uneven emergence levels. Harvest indices were higher for PD1 than for PD2, except at 20-80 uneven emergence level. Essentially, the later emerging rice from the second planting acted much like a weed by competing against rather than contributing to rice yields. Late interseeding to enhance poor rice stands is unlikely to produce an economic return that could be expected from an adequate initial plant stand.


2021 ◽  
Author(s):  
Philip Kuriachen ◽  
Asha Devi ◽  
Anu Susan Sam ◽  
Suresh Kumar ◽  
Jyoti Kumari ◽  
...  

Abstract Climate change and consequent variations in temperature pose a significant challenge for sustaining wheat production systems globally. In this study, the potential impact of rising temperature on wheat yield in the north Indian plains, India's major wheat growing region, was analyzed using panel data from the year 1981 to 2009. This study deviates from the majority of the previous studies by including non-climatic factors in estimating the impact of climate change. Two temperature measures were used for fitting the function, viz., Growing Season Temperature (GST) and Terminal Stage Temperature (TST), to find out the differential impact of increased temperature at various growth stages. Analysis revealed that there was a significant rise in both GST as well as TST during the study period. The magnitude of the annual increment in TST was twice that of GST. Wheat yield growth in the region was driven primarily by increased input resources such as fertilizer application and technological development like improved varieties and management practices. Most importantly, the study found that the extent of yield reduction was more significant for an increase in temperature at terminal crop growth stages. The yield reduction due to unit increase in TST was estimated to be 2.26 % while rise in GST by 1◦C resulted in yield reduction of 2.03%.


2005 ◽  
Vol 56 (11) ◽  
pp. 1277 ◽  
Author(s):  
Gregory S. McMaster ◽  
W. W. Wilhelm ◽  
A. B. Frank

The timing, duration, and pace of developmental events, or phenology, are among the many responses of plants to limited soil water. Understanding and predicting plant responses to availability of soil water are important in improving the efficacy of management practices. However, the first steps towards gaining this understanding, summarising the complete developmental sequence of the shoot apex and correlating the timing of these events, have rarely been reported. Also, the effect of water-limiting conditions on crop phenology and shoot apex development is variable. The objective of this paper is to present the developmental sequence of the wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and corn (Zea mays L.) shoot apices and correlate events in these sequences with growth stages for both well-watered and water-limiting conditions. We note that phenological responses to water availability occur at 3 different scales: among crops, among cultivars of a crop, and among growth stages within a cultivar or crop. Clearly, genotype × environment interaction affects the accuracy of predicting phenology. However, the fact that plants develop in an orderly, predictable pattern allows a general foundation for synthesising the complete sequence of developmental events of the shoot apex and correlate these with growth stages when water is not limiting. These patterns and relationships are the foundation to build upon in quantifying our understanding of crop phenology under water-limiting environments.


2003 ◽  
Vol 13 (4) ◽  
pp. 610-616 ◽  
Author(s):  
Renuka Rao ◽  
Yuncong Li

The review of effects of excessive soil water on performance of various vegetable crops and selected field crops indicates that in areas where temporary flooding hazards are expected during the growing season, crops can be selected on their relative ability to tolerate excessive moisture. Field crops are generally less sensitive than vegetable crops in terms of yield. In addition to the choice of crop species, planting dates could be shifted when possible by delaying dates of sowing or planting to avoid probable periods of flooding during the sensitive growth stages. In most instances, crops are more sensitive at their early developmental phase than at the later stages in terms of yield. Soil management practices like ridging and furrowing or making raised beds before planting is recommended. In addition, amelioration with foliar application of chemicals like nutrients, growth hormones and fungicides is also recommended to overcome nutritional deficiencies, hormonal imbalances and disease infections. Every effort of amelioration should be exerted at the earliest opportunity, since water damage to crops becomes more severe with longer flooding duration.


Author(s):  
C. E. N. Savala ◽  
A. N. Wiredu ◽  
J. O. Okoth ◽  
S. Kyei-Boahen

Abstract Soybean yield within the Southern Africa falls below its potential despite similar climatic conditions across some agroecologies, replicable agronomic management practices and introduced improved varieties. Understanding physiological processes and water-use efficiency (WUE) of soybean offer information on bridging this yield gap. A field study was conducted in 2017 and 2018 seasons in two agroecologies (Angonia and Ruace) in Mozambique to evaluate the effects of Bradyrhizobium diazoefficiens strain USDA110 formerly known as Bradyrhizobium japonicum inoculant, nitrogen and phosphorus on nodulation, physiology and yield of non-promiscuous (Safari) and promiscuous (TGx 1740-2F) soybean varieties. Data on transpiration, photosynthesis, leaf area index, radiation interception and WUE from the beginning of flowering to maturity were collected. Transpiration rate varied considerably with interaction between locations, growth stages, varieties and treatments. At podding, phosphorus-treated soybean at Angonia transpired less (6.3 mmol/m2/s) than check plants (6.6 mmol/m2/s). Photosynthesis rate and WUE were distinct with variety, growth stages and inputs within agroecologies. For instance, in Angonia 2018 season, phosphorus fertilized TGx 1740-2F photosynthesized more at flowering (25.3 μmol/m2/s) while the lowest was phosphorus-treated Safari at podding with 17.2 μmol/m2/s. At the same site in 2017, inoculated soybean photosynthesized more at 22.8 μmol/m2/s leading to better WUE of 3.6 that corresponded to 2894 kg/ha yield. Overall, soybean WUE was higher when inoculated than N-treated, while P application yielded better. Results from this study will complement breeders’ effort in developing phosphorus efficient varieties suited for a wide range of changing climatical conditions.


Author(s):  
Kuldeep Singh ◽  
Hardev Ram ◽  
Rakesh Kumar ◽  
R.K. Meena ◽  
Rakesh Kumar ◽  
...  

Background: Weeds are prime factor that adversely effects on growth, quality and yield of mungbean during summer and rainy season. Being a short duration crop, it faces heavy weed competition right from the early growth stages to harvesting. The critical period of crop weed competition in mungbean was initial 25-30 days, yield may be reduce up to 50-90% if weeds not manage at this stage. Hence, there is a need to find out the successful weed management strategies to realize higher growth and yield. The progressive transformation of agriculture concerning intensive use of herbicides is gaining status in recent years due to easy, lower cost, timeliness and successful controlling weeds. Therefore, keeping above information in view, the present study was undertaken to assess the effect of different weed management practices in summer mungbean under zero tillage condition to find out the better weed management, higher productivity and profitability.Methods: In this field-laboratory investigation during summer season, 2019, different herbicides were applied to manage weeds in mungbean. Eight treatments were applied based on various application windows. In the field and laboratory, the collected samples were determined for crop weed competition, yield attributes, yields and net returns. Result: The results revealed that weed free treatment was recorded lowest weed population at 30 DAS and harvest (1.8 and 2.9), weed dry weight (1.1 and 1.9g) and highest weed control efficiency (96.3 and 94.9%) followed by Pendimethalin (PE) fb one HW and Shaked (Propaquizafop + Imezathyper) application. The similar results also observed in nutrients removed by weeds. Among yield attributes, weed free treatment recorded the longest pod length, no. of pods/plant, no. of seeds/pod and test weight (7.9, 21.0, 9.7 and 43.0g, respectively) which was at par with Pendimethalin (PE) fb one HW and Shaked (Propaquizafop + Imezathyper) application. The magnitude of seed yield was increased under weed free (10.1 q/ha) and Shaked (Propaquizafop + Imezathyper) (9.5 q/ha) treatments by 127.9 and 113.8%, respectively over weedy check. Application of Shaked (Propaquizafop + Imezathyper) recorded highest net returns (Rs 55,079/ha) and B: C (2.8) over rest of the treatments. It can concluded that application of Shaked (Propaquizafop + Imezathyper) @ 2 L/ha at 20 DAS recommended for better weed control, higher yield and net returns of summer mungbean under zero tillage condition.


2016 ◽  
Vol 41 (3) ◽  
pp. 461-470
Author(s):  
MA Bakar ◽  
MMH Khan

In order to measure the diversity of insect pests and natural enemies in rice ecosystem, the present study was conducted in the research farm of Patuakhali Science and Technology University, Dumki, Patuakhali during the period from January to June, 2012 in boro rice season. Diversity indices of insect pests and their natural enemies were found to be affected by the combined effect of rice growth stages and management practices. Diversity indices of insect pests and their natural enemies differed according to treatments and crop growth stages. In case of insect pests, the untreated control treatment showed the highest diversity index (1.67) at maximum tillering stage and spray (Bipolar 55EC @ 10 ml/10 L of water) + perching at early tillering stage also showed highest richness (26.14) and the highest evenness (0.921) in spray at seedling stage. The highest reciprocal form of Berger-Parker's Dominance index (D) was found in untreated control at maximum tillering stage (3.03) for insect pests. In case of natural enemies, perching showed the highest diversity index (1.88) at reproductive stage. Spraying of insecticide at early tillering stage also showed highest richness (5.06) and the highest evenness (0.982) was in perching at seedling stage. The highest D value was found in perching at reproductive stage (4.67) for natural enemies.Bangladesh J. Agril. Res. 41(3): 461-470, September 2016


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