scholarly journals Growth, development and productivity of plants of the sunflower depending on sowing dates and plant density in the Right-Bank steppe of Ukraine

2019 ◽  
Vol 108 ◽  
pp. 78-85
Author(s):  
H.V. Pinkovskyi ◽  
2020 ◽  
pp. 115-123
Author(s):  
H. Pinkovskyi ◽  
S. Tanchyk

The article covers the results of research on the management of elements of technology and the influence of factors on the productivity of sunflower. The field experiment was conducted in the experimental field of IAS NAAS Kirovohrad region. The level of sunflower productivity is determined by the conditions of water and nutrient regimes of soil. According to the results of research it was established that at the time of sowing reserves of available moisture in 0–100 cm of the soil layer were the largest during the first sowing period and amounted to 178.6 mm. Such moisture reserves create favorable conditions for moistening the seed layer of soil to obtain friendly and full seedlings when sowing in the first – second decade of April. The use of moisture by sowing sunflowers can be regulated by sowing dates to some extent. Shifting sowing dates to earlier ones makes it possible to change the conditions of growth and development of sunflower plants, namely, the plants are better provided with moisture, and it is possible to avoid critical temperature periods of plant development. The high reserves of productive moisture for plants in 0–100 cm soil layer, in crops of Forward, LG 56.32, LG 54.85, LG 55.82 hybrids were for plant density of 60 thousand per hectare, at the first sowing period – in the flowering phase they were 127 mm. The content of nutrients the soil changed both over the years and under the influence of different fertilizer backgrounds. Application of nitrogen, phosphorus, potassium fertilizers in the dose of N40P40K40 and N40P40K40 + by-products of the predecessor allows to increase the content of nutrients available to plants in soil and to increase soil fertility. Due to economic indicators, the optimal time of sunflower sowing for hybrids LG 55.82 and LG 54.85 is warming soil at the depth of seed wrapping up to 5–6 °C, for hybrids Forward and LG 56.32 is warming soil at the depth of seed wrapping up to 9–10 °C, optimal density – 60 thousand/ha. In such conditions, the LG 55.82 hybrid formed the highest yield – 3.85 t/ha, LG 54.85 hybrid – 3.64 t/ha, Forward – 3.09 t/ha, LG 56.32 hybrid – 3.62 t/ha. Key words: sunflower, soil nutrient regime, water regime of soil, yield, profitability, net profit.


Author(s):  
L. S. Sampaio ◽  
R. Battisti ◽  
M. A. Lana ◽  
K. J. Boote

Abstract Crop models can be used to explain yield variations associated with management practices, environment and genotype. This study aimed to assess the effect of plant densities using CSM-CROPGRO-Soybean for low latitudes. The crop model was calibrated and evaluated using data from field experiments, including plant densities (10, 20, 30 and 40 plants per m2), maturity groups (MG 7.7 and 8.8) and sowing dates (calibration: 06 Jan., 19 Jan., 16 Feb. 2018; and evaluation: 19 Jan. 2019). The model simulated phenology with a bias lower than 2 days for calibration and 7 days for evaluation. Relative root mean square error for the maximum leaf area index varied from 12.2 to 31.3%; while that for grain yield varied between 3 and 32%. The calibrated model was used to simulate different management scenarios across six sites located in the low latitude, considering 33 growing seasons. Simulations showed a higher yield for 40 pl per m2, as expected, but with greater yield gain increments occurring at low plant density going from 10 to 20 pl per m2. In Santarém, Brazil, MG 8.8 sown on 21 Feb. had a median yield of 2658, 3197, 3442 and 3583 kg/ha, respectively, for 10, 20, 30 and 40 pl per m2, resulting in a relative increase of 20, 8 and 4% for each additional 10 pl per m2. Overall, the crop model had adequate performance, indicating a minimum recommended plant density of 20 pl per m2, while sowing dates and maturity groups showed different yield level and pattern across sites in function of the local climate.


1982 ◽  
Vol 33 (3) ◽  
pp. 531 ◽  
Author(s):  
DA Grantz ◽  
AE Hall

Earliness of an indeterminate crop, Vigna unguiculata (L.) Walp., was studied to aid development of selection techniques for improving adaptation to semiarid environments. Earliness was based upon the time of first appearance of floral buds and flowers, proportion of shoot dry matter in reproductive parts at midseason, and time of maturity. A cowpea land race, Chino 3, was earlier than cultivars California Blackeye No. 3 and No. 5, with respect to all of these criteria. Time to flowering from different sowing dates was related to heat units, which were calculated from daily mean air temperature above a base temperature of c. 10�C. The proportions of shoot dry matter in reproductive parts during early stages of pod-filling were greater with moderate drought but were unaffected by severe drought, compared with the response of adequately irrigated plants. Widely spaced plants exhibited greater proportions of shoot dry matter in reproductive parts at midseason than did closely spaced plants. Adaptation of cowpeas to semiarid environments may be improved by selecting for early partitioning of carbohydrates to reproductive parts. Selection for early partitioning may be more effective in adequately watered conditions, owing to extreme variability under drought, and at wide and precise spacing.


2019 ◽  
pp. 173-182
Author(s):  
Inna Palamarchuk

The results of studies on the dynamics of the formation of the area of leaves of plants of beetroot canteen depending on varietal characteristics and sowing time in the conditions of the Forest-Steppe of Right-Bank Ukraine are presented. The dependence of the growth and development of beetroot plants on varietal characteristics and sowing dates, as well as on weather conditions that were in the studied time, was revealed. The largest number of leaves in the phase of intensive root formation was formed by plants with a sowing period of I decade of May: 13.3 pcs. / plant – Bordo Kharkivskiy, 13.1 pcs. / plant – Opolskiy. The greatest mass of the root crop in the phase of intensive root formation was planted at a sowing period of the third decade of April: the Bordo Kharkivskiy – 72.4 g, the variety Opolskiy – 43.5 g. The same pattern was observed when taking into account the mass of the aerial part of beetroot. In the Bordo Kharkivskiy variety, it varied from 92.4 g to 87.5 g depending on the sowing time, in the Opolskiy variety from 33.7 g to 31.7 g, that is, the beet plants of the Bordo Kharkivskiy cultivar formed a significantly larger mass of the aerial part in comparison with the Opolskiy variety. Plants were sown with the largest leaf area at a sowing period of the 3rd decade of April: in the Bordo Kharkivskiy – 1.2 – 4.0 thousand m2 / ha, in the Opolskiy variety – 1.0 – 2.3 thousand m2 / ha. According to the results of the crop accounting, it was found that it depended on the variety and sowing period of beetroot. On average, over the years of research, the highest yield was observed with a sowing period of the third decade of April: 63.1 t / ha for the Bordo Kharkivskiy variety, 55.9 t / ha for the Opolskiy variety.


1986 ◽  
Vol 37 (5) ◽  
pp. 513 ◽  
Author(s):  
R Ferraris ◽  
DA Charles-Edwards

Well-watered crops of sweet sorghum (cv. Wray) and forage sorghum (cv. Silk) were grown in south-eastern Queensland. Treatments consisted of four sowing dates, two intra-row spacings and harvests taken at six physiological growth stages from the third ligule to 3 weeks after grain maturity. Plant density effects on the concentration of sugars and nitrogen were slight, and changes in yields of these components were a function of density effects on dry matter yields. At any growth stage, the concentration of sugars in both cultivars was decreased with delay in sowing date. The delay in sowing date led to an increased nitrogen concentration in cv. Wray, but in cv. Silk the nitrogen concentration was highest in early and late sowings. At maturity, the concentration of sugars in cv. Wray averaged 40'70, 10 times the level in cv. Silk. In both cultivars, accumulation was a near linear function of either time or radiation sum. The partitioning of carbohydrate differed little between cultivars but altered with their ontogeny. The efficiency of light use for sugars production was greater in cv. Wray and altered with ontogeny. In contrast, concentration of nitrogen was similar for both cultivars and decreased curvilinearly with time or degree days. The partitioning of nitrogen altered with ontogeny and the amount partitioned to leaf material was greater in cv. Silk pre-anthesis but was less post-anthesis. Yield of stem sugars in cv. Wray exceeded 10 t ha-1 when the crops were sown early in the season, but was only 3 t ha-1 with late-sown crops.


1998 ◽  
Vol 38 (2) ◽  
pp. 195
Author(s):  
T. Botwright ◽  
N. Mendham ◽  
B. Chung

Summary. The effect of plant density on growth, development, yield and quality of kabocha (buttercup squash) (Cucurbita maxima) was examined during 1992–93, at a field site in Cambridge, Tasmania. Plant densities ranged between 0.5 and 4.7 plants/m2. Marketable and total yields were fitted to a yield–density model. Total yield followed an asymptotic trend, approaching 33 t/ha at 4.7 plants/m2, while marketable yield had a parabolic relationship with density. Marketable yield increased to a maximum of 18 t/ha at 1.1 plants/m2, while declining at higher densities because of increased numbers of undersized fruit. Yield of vine marked and callused fruit did not vary with density, but represented a significant proportion of the total yield at all densities. High plant density reduced vegetative growth per plant due to competition for limited resources; as shown by decreased leaf area, number and length of vines, and plant dry weight. Yield tended to decline at high densities because of fewer female flowers and increased fruit abortion per plant. Plants at low densities had more vegetative growth but decreased yields, as increased abortion of fruit relative to the higher plant densities left only 1–2 large fruit per plant. Economic returns varied with plant density. At high densities, variable costs increased (particularly due to high seed cost) while gross income declined reflecting the relationship between marketable yield and plant density. The gross margin therefore declined at high densities.


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