Optimum Sowing Date Research Articles

The Effect of Polyethylene Film and Polypropylene Non-Woven Fabric Cover on Cobs Parameters and Nutritional Value of Two Sweet Maize (Zea mays L. var. saccharata Bailey) Hybrids

In 2012–2014, at the Research and Didactic Station of the Department of Horticulture at Wroclaw University of Environmental and Life Sciences (51°19′06″ N, 17°03′49″ E), field studies were conducted to evaluate the responses of two sweet maize hybrids to sowing dates (early and optimum) and five methods of maize plant coverings—polyethylene film: perforated (PE), red (PER), green (PEG), polypropylene non-woven fabric (PP), and control (C), with non-irrigation systems. Total yield and morphological characteristics of cobs were compared. In 2012 soluble sugars and carotenoids content were measured. The use of maize cover at the beginning of growth (PE and PER) significantly influenced the number of rows, while PE and PEG increased the number of grains per cob. Covering maize sown at a later date, with polyethylene film and non-woven fabric, ensured better production effects than using such covers after earlier sowing. Signet F1 hybrid was charact0erized by significantly higher sugar content and Rustler F1 by higher lutein and zeaxanthin levels. The application of the optimum sowing date resulted in a significantly higher yield of cobs, by 11.3%, than after early sowing. The yield increase as a result of the applied covers was higher after sowing at a later date. The content of dry matter in grains was positively correlated with the content of sucrose, glucose, and fructose. The change in carotenoids content also depended on the accumulation of dry matter in the kernels. The study confirmed the correlation of sweet maize accumulated growing degree days (AGDD), and revealed dependence of grain quality on dry matter content in the grain.

EFFECT OF SOWING DATE ON CHOCOLATE SPOT AND RUST FOLIAR DISEASES REACTION, YIELD COMPONENTS AND SEED QUALITY IN FABA BEAN (VICIA FABA)

In order to study the effect of early sowing date on plant characteristics, chocolate spot and rust foliar diseases reaction, and yield characters of twelve faba bean genotypes, an experiment was conducted at the farm of Sakha Agricultural Research Station, Kafr El-Sheikh Governorate during 2018/2019 and 2019/2020 growing seasons. The early sowing date (1st October) caused high infection of foliar diseases infection (chocolate spot and rust), reduced flowering date, No. branches, No. pods, No. seeds plant-1, 100 seed weight and seed yield compared with optimum sowing date (1st November). Electrical conductivity, crude protein % and total carbohydrate % were significantly increased under early sowing date compared to optimum one. Line 6 and Line 7 had the highest seed yield and stable performance across different sowing dates and showed high values for No. seeds per plant, and/or 100 seed weight. The cluster analysis classified the tested genotypes to two main different groups, the first group contained Line 3 and Line 4, which differed in origin and performance and had the heaviest 100-seed weight, but had low No. seeds plant-1. The rest genotypes were found in the second main branch. Line 6 had the highest seed yield under early sowing date and recorded low percentage of decline in yield as a result of early sowing, so it is suitable to sown in the case of early sowing date.

Interrelationships among different grain characteristics of wheat grown under optimum and late sowning date conditions in the Eastern Indo-Gangetic plains of India

Wheat growth has been severely affected by increases in global temperature. The Eastern Indo-Gangetic Plains of India face similar constraints due to the traditional wheat–rice cropping system where wheat planting is often delayed leading to high temperature induced terminal heat stress. Grain characters like grain length, width, area along with starch synthesis are affected severely during heat stress. Considering the importance of grain traits, we screened the response of 55 wheat genotypes under terminal heat stress conditions to ten grain characteristics. We found that the means of all the grain traits were reduced in heat stress conditions. The effect of heat stress shows a significantly reduced grain width and perimeter, but the extent of damage is less on different grain starch characteristics e.g., grain starch area (GSA), grain starch length (GSL) and grain starch volume (GSV). Stepwise multiple regression analysis revealed that grain starch area and grain volume are the best predictors of yield under optimum sowing date conditions whereas, grain width is the best predictor under late sowing date conditions. Interrelationship studies among ten grain characters showed that the genotypes with higher levels of grain starch characteristics (GSA, GSL and GSV) in combination with the five grain size characters (grain length, grain width, grain perimeter, grain area, A/B-type starch granules) under late sowing date conditions should be promoted for the cultivation of wheat in heat stress prone areas. The present study identified and recommends some heat tolerant wheat genotypes in terms of higher yield and grain starch characteristics namely, CRPW-33, CRPW-17, CRPW-12, CRPW-126 and CRPW-21.

Effect of future climate change on the water footprint of major crops in southern Tajikistan

Danghara, a major food production area in southern Tajikistan, is currently suffering from the impact of rapid climate change and intensive human activities. Assessing the future impact of climate change on crop water requirements (CWRs) for the current growing period and defining the optimal sowing date to reduce future crop water demand are essential for local/regional water and food planning. Therefore, this study attempted to analyze possible future climate change effects on the water requirements of major crops using the statistical downscaling method in the Danghara District to simulate the future temperature and precipitation for two future periods (2021–2050 and 2051–2080), under three representative concentration pathways (RCP2.6, RCP4.5, and RCP8.5) according to the CanESM2 global climate model. The water footprint (WFP) of major crops was calculated as a measure of their CWRs. The increased projection of precipitation and temperature probably caused an increase in the main crop’s WFP for the current growing period, which was mainly due to the green water (GW) component in the long term and a decrease in the blue water (BW) component during the second future period, except for cotton, where all components were predicted to remain stable. Under three scenarios for the two future periods, a 10 ​d early sowing time was defined as an optimal sowing date, in which the WFPs of potato and winter wheat decreased from 5.7% to 4.8% and 3.4% to 2.2%, respectively. Although the WFP of cotton demonstrated a stable increase, according to the optimal sowing date, a decrease in irrigation demand or BW was expected. The results of our study might be useful for developing a new strategy related to irrigation systems and could help to find a balance between water and food for environmental water demands and human use.

Yield and Sowing Qualities of Winter Bread Wheat Seeds Depending on the Preceding Crops and Sowing Dates in the Forest-Steppe of Ukraine

Wheat is one of the most important crops in the world due to its wide geographical adaptation and nutritional value. The use of high-quality seeds of the best varieties being adapted to local growing conditions is an important requirement for increasing wheat yields. The purpose of this research was to establish the influence of preceding crops and sowing dates on yield and seed sowing quality of winter bread wheat varieties. On average, maximum yield capacity in 2016–2018 was obtained in the variety Trudivnytsia myronivska (7.41 t/ha) when sowing on 15 September after green manure, the minimum yield was in the variety MIP Kniazhna (4.03 t/ha) when sowing on 15 October after soybean as preceding crop. Shifting the sowing dates to later ones led to decrease in yield capacity by 0.97 and 0.62 t/ha after the preceding crops green manure and soybean, respectively. After the preceding crop soybean, the maximum yield (5.77 t/ha) was formed by the variety MIP Valensiia when sowing on 25 September. By ANOVA it was found that the level of wheat yield was the most significantly affected by hydrothermal conditions of the year (63%), the interaction “preceding crop  conditions of the year” (12%) and preceding crop (11%). It was revealed that an increase in weight of 1000 seeds in the varieties on average was 3.9 g after the preceding crop green manure in comparison with the preceding crop soybean. There was a slight effect of preceding crops and sowing dates on seed vigor and laboratory germination. These rates were slightly higher for early and optimal sowing dates after green manure as compared with the soybean. Thus, it was confirmed that in the Right-Bank Forest-Steppe green manure is the best preceding crop for seed production, especially for growing pre-basic seeds, while 15 and 25 September are the best sowing dates. For the preceding crop soybean, when sowing on 25 September and 05 October, the yield of wheat varieties was the highest in comparison with sowing on 15 October. Locations of winter wheat seed crops after the best preceding crops in crop rotation and optimal sowing dates will promote the most efficient using of climatic and anthropogenic factors, increase grain yield per area unit, and improve seed sowing quality.

Influence of Mineral Fertilizers and Other Agrotechnical Cultivation Methods on Yield and Grain Protein Content of Winter Wheat

It is established that in the conditions of the northern steppe of Ukraine to obtain comparable results in the amount of protein in winter wheat grain it is necessary after such predecessors as stubble and sunflower, to apply a higher dose of nitrogen in complete pre-sowing fertilizer, as well as in spring fertilization, than when growing on black fallow. In the case of fertilization at the end of plants tillering with nitrogen with a local dose of N₆₀, the yield after spring barley, depending on the variety of winter wheat increased by 0.66-0.82, and for black fallow - by 0.58-0.64 t/ha. Among winter wheat varieties Kokhanka, Misia Odeska and Pylypivka, the highest yields and grain quality were observed in Pylypivka variety. It was found that among nitrogen fertilizers (ammonium nitrate, Urea Ammonium Nitrate solution - UAN-32, and ammonium sulfate) the best results in protein formation in grain in most cases provided the introduction of UAN-32 and ammonium sulfate. Strong in grain quality, winter wheat varieties Niva Odeska and Uzhynok, both after sunflower and black fallow, outperformed Kokhanka variety in terms of protein content. It is established that the highest grain productivity of different varieties of winter wheat, both when grown after spring barley and black fallow, was observed at the optimal sowing date (September 22); the variety of durum wheat Burshtyn formed a higher protein content in the grain (13.5-14.6%) than varieties of soft wheat - Golubka Odeska (12.0-12.6%) and Lastivka Odeska 13.2-13.6%). It was found that in the research years the amount of protein in the grain of winter wheat depended more on crop fertilizer than on the sowing date.

Response of Milling and Appearance Quality of Rice with Good Eating Quality to Temperature and Solar Radiation in Lower Reaches of Huai River

The effects of temperature and solar radiation on milling and appearance quality of rice (Oryza sativa L.) were evaluated to find the optimal temperature and solar radiation for optimizing milling and appearance quality of rice in the lower reaches of Huai River. Field experiments were conducted with two medium-maturing japonica soft rice varieties (SMR), two late-maturing japonica soft rice varieties (SLR) and two late-maturing japonica non-soft rice varieties (LR) as experimental materials. Seeds were sown on 10 May (T1), 17 May (T2), 24 May (T3), 31 May (T4), 7 June (T5), 14 June (T6), and 21 June (T7) in 2017 and 2018. Compared with solar radiation, temperature was the main environmental factor affecting the milling and appearance quality of rice in the lower reaches of Huai River. Under the condition of ensuring relatively high-yield, the milling quality of SMR and SLR can reach the second grade of China’s national standard of high quality paddy. The mean daily temperature (Tmean) range were 20.2–22.7 °C and 20.4–22.0 °C respectively. The temperature range for LR to obtain a relatively high-yield, good milling and appearance quality was 20.4–20.7 °C. The optimal sowing dates of SMR, SLR and LR were 15 May to 1 June, 15 May to 20 May and 15 May to 20 May, respectively.

The main technological parameters of growing highly productive fodder crops on the drained lands of the humid zone of Ukraine

The most effective use of highly-productive crop species in fodder production and obtaining of sustainable yields of agricultural products is only possible when following scientifically sound technological processes of land reclamation in combination with a set of agronomic measures for their cultivation.
 The aim of the research is to develop the main technological parameters of growing highly productive fodder crops (Japanese millet, amaranth and fodder beans) on the drained lands in the humid zone of Ukraine.
 The results of research on determining the main technological parameters of growing highly-productive fodder crops (Japanese millet, amaranth and fodder beans) on drained lands are highlighted.
 It was specified that when cultivating these crops it is necessary to adhere to the optimal sowing dates taking into account the purpose of their use (green mass, grain). When they are sown too early there is a decrease in field seed germination and increase of germination period, thinning of crop plantings, intensive spread of weeds and also the probability of crops damage by spring frosts increases. When they are sown too late, especially in case of small-seeded crops (amaranth), drying of the top layer of soil is possible, which is unacceptable in the period of germination and emergence of seedlings. The most favorable conditions for the formation of herbage when cultivating on drained peat soils are formed when the crops are sown on May 15 (by 8.1–16.7% more of herbage and by 2.1–9.6% of dry matter is formed).
 The main technological parameters of cultivating Japanese millet, amaranth and fodder beans are determined, incl. by phases of development and taking into account the critical periods of their optimal moisture supply, agronomic measures and optimal fertilizer rates.
 The admissible terms in which the reclamation system should provide drainage of excess waters and the recommended levels of ground waters and the humidity rates in a soil root layer in the vegetative period at the crop cultivation were determined.
 It was specified that during the growing season the needs of Japanese millet, amaranth and fodder beans in moisture in the soil root layer change depending on their biological needs and current meteorological conditions. Soil moisture rates were specified as following: on peat soils the optimal one is 65–75%, the lowest permissible one in the summer period is 55–60%; on mineral soils, respectively - 65-80% and 55-60% of FMHC.
 It was established that modern climate change in the Western Polissya of Ukraine (uneven distribution of precipitation during the growing season, abnormal average daily air temperature fluctuations and low night air temperatures (˂10oС in summer months) have a negative impact on the cultivation of heat-loving crops (Japanese millet). In the context of climate change, it is necessary to provide for the accumulation of sufficient water volumes in storage tanks or reservoirs to supply them for irrigation of cultivated crops during dry growing seasons and to ensure optimal water regulation parameters.
 On radioactively contaminated reclaimed lands of the Chemerne peat-bog array with a rate of 137Cs radionuclide contamination of up to 1 Ki/km2, the contamination rates in the vegetative mass of Japanese millet, amaranth and fodder beans during the research years was within acceptable limits, so it can be used freely for feeding animals.

Effect of Sowing Dates on Genetic Behavior for Some Bread Wheat Genotypes using Five Parameters Model.

This investigation was carried out at the Experimental Farm of Sakha Agricultural Research Station, Agricultural Research Center, Egypt, through the four seasons 2016/17 to 2019/20 growing seasons to determine the genetic behavior controlling inheritance of yield traits, heterosis expression and expected genetic advance under optimum (15November) and late (15 December) sowing date conditions. The parents and their five populations (P1, P2, F1, F2 and F3) of three crosses;Line 1 × Line 2, Line 2 × Giza 171 and Misr 2 × Line 3 were layout in a randomized complete block design with three replications. Analysis of variance revealed significant differences among the population means under both sowing dates for most studied traits. Parents (Line 1 and Line2) and F1 had the best tolerance to late planting conditions. Scaling test revealed the presence of epistasis for most studied traits in the three crosses. Also results revealed the importance of both additive and non-additive gene effects in the expression of the studied traits, The inheritance of the studied traits was mostly controlled by the dominance effect under optimum sowing date and the additive effect under late sowing date. Over-dominance towards the highest parent was detected for plant height, number of kernels/spike and grain yield/plant under both sowing dates and number of spikes/plant under optimum sowing date, however partial-dominance was detected fordays to heading, days to maturity and100-kernel weight under optimum sowing date and number of spikes/plant under late sowing dates. Cross 2 (Line2 x Giza 171) under optimum sowing date displayed absence of inbreeding depression, recording highly significant and positive best-parent heterotic values in few cases. Narrow sense heritability estimates ranged from 29.75% to 89.42% under the optimum sowing date and 26.55%-93.45% under the late sowing date, indicating the low environmental influence The highest estimates of expected genetic advance (GA%) coupled with the highest narrow sense heritability (hn2) which revealed selection efficiency for the number of spikes/plant, number of kernels/spike, and grain yield/plant in these studied populations and help breeders in selecting high yielding genotypes, under optimum sowing date. The parents of Line 1, Line 2 and crosses (Line 1 × Line 2) and (Line2 × Giza 171) were considered tolerant to late sowing and could be used in breeding programs to improve bread wheat production

The Study of temperature depression and its association with grain yield in six wheat cultivars under heat stress conditions and salicylic acid application

In order to evaluate canopy and organs temperature depression (TD) under heat stress conditions and the effects of plant morphology on organs temperature depression and their association with grain yield, two field experiments were conducted using six wheat cultivars (Behrang, Chamran, Kauz, Koohdasht, Karim and Montana) planted on three dates (early, optimum, late) in 2014-2015 and 2015 -2016 cropping seasons in Dashtestan, Bushehr, Iran. In addition, three concentrations of salicylic acid (0, 0.5 and 1 mM) were applied to alleviate the effects of heat stress. Canopy and organs (flag leaf, peduncle and spike) temperature were measured by a hand-held infra-red thermometer (IRT). Also, some morphological traits in addition to yield components were measured. Results showed that the effects of cultivars and heat conditions were significant for most of the studied traits but salicylic acid application showed no significant effects. Under late sowing date, canopy and organs temperature depression were significantly higher than those at early and optimum sowing dates. No significant differences were found between early and optimum sowing dates for all temperature depressions. Among cultivars, Behrang had higher canopy temperature reduction (CTD), flag leaf temperature depression (FLTD) and peduncle temperature depression (PTD). Spike temperature depression (STD) was higher in Chamran and Kauz cultivars. Among plant organs, peduncle had higher temperature depression followed by flag leaf and spike. Canopy and organs temperature depression had positive correlation with stomatal conductance and grain yield. This research suggests that temperature depression can be used as an important criterion for the selection of stable genotypes under late sowing conditions. This is very helpful to improve wheat productivity under terminal heat stress resulting from late sowing conditions.

Crop growth and productivity of winter camelina in response to sowing date in the northwestern Corn Belt of the USA

Camelina [Camelina sativa (L.) Crantz] is a member of the Brassicaceae family, consisting of both winter and spring biotypes. In the northern Great Plains, USA, winter camelina has the potential to serve as a low-input oilseed crop for cover and/or as a source of oil used for advanced biofuels as well as human and animal consumption. Winter annual biotypes of camelina are well suited for double- or relay- cropping systems. The objective of this study was to determine optimum sowing dates for achieving the highest winter camelina seed yield as well as the delivery of several ecosystem services. The experiments were conducted in Fargo, ND in 2017–2018 and in Fargo and Prosper in 2018–2019 seasons. Six sowing dates from the end of June to mid-October were evaluated. The experimental design was a randomized complete block with four replicates at each location. A total of 700 pure live seeds m−2 were sown in each date. Fall stand counts ranged from 17 to 279 plants m−2 with greater stands at later fall sowing dates. Spring stand counts ranged from 7 to 84 plants m−2, with higher stand counts for sowing dates from the beginning to mid-September. Across plants in several sowing dates that survived the winter, seed yield ranged from 99 to 1317 kg ha-1. Results indicate that winter camelina sown before September usually does not survive the winter in this region. When winter camelina is used as a cover crop, sowing prior to mid-September was critical for biomass production and reducing soil residual nitrate. However, when winter camelina is harvested as a cash crop, the highest harvestable seed yield occurred with fall sowing in September and even as late as early October.

Evaluation of yield and stability of bread winter wheat genotypes (Triticum aestivum L.) depending on predecessors and sowing dates

Purpose. To determine the effectiveness of using contrasting sowing dates after different predecessors to assess the genotypes of bread winter wheat in terms of yield and stability.Methods. Field, laboratory, mathematical statistics.Results. A different, but reliable level of influence on the yield of bread winter wheat genotypes of such factors as conditions of the year of cultivation (66.2%), predecessors (12.5%), sowing date (6.1%) and genotype (1.7% ) was revealed. Significant differences were noted in the response of the studied genotypes to the sowing date after different predecessors. Relatively less influence of the predecessors on the yield of the varieties ‘Estafeta Myronivska’ and ‘Vezha Myronivska’ was revealed, more – for the varieties ‘MIP Darunok’, ‘MIP Kniazhna’ and ‘MIP Vyshyvanka’. The sowing dates had less influence on the yield of the varieties ‘MIP Fortuna’, ‘MIP Vyshyvanka’ and ‘Trudivnytsia Myronivska’. A general tendency for decrease in the average annual yield was established in the experiment with a shift in the sowing dates from September 26 to October 16. However, for the number of genotypes after certain predecessors, the optimal sowing date was the 5th of October: after the predecessor, green-manure fallow – for varieties ‘Trudivnytsia myronivska’, ‘MIP Assol’ and ‘MIP Dniprianka’, after mustard – ‘Vezha Myronivska’, after sunflower – ‘MIP Fortuna’, after corn – ‘MIP Fortuna’ and ‘Podolianka’. In terms of sowing dates, the least variation in yield was found after the predecessors green manure, mustard and corn varieties ‘MIP Vyshyvanka’, ‘Balada Myronivska’, ‘MIP Kniazhna’, ‘Estafeta Myronivska’. Using the GGE biplot, it was found that close to the ‘ideal environment’ for the realization of the yield level of most genotypes was the second sowing date after greenmanure fallow predecessor. For different sowing dates and predecessors, on average for three years, the optimal combination of the level of yield and stability was noted for the varieties ‘Trudivnytsia Myronivska’, ‘MIP Vidznaka’, ‘MIP Assol’, ‘Estafeta Myronivska’, ‘MIP Valensiia’.Conclusions. Thus, the use of different so wing dates after various predecessors is an effective approach to organization of genotype-environmental tests. It makes it possible to identify the genotypes which are specifically adapted to certain conditions (predecessors and sowing dates) and genotypes with a relatively high level of stability when sowing after various predecessors and on different dates. This approach can be used both at the final stage of breeding to differentiate breeding lines for yield and stability, and in the development of basic elements of technology for growing newly created varieties.

Effects of different sowing time to phenology and yield of winter wheat

This study aims to determine optimal sowing date for winter wheat (Triticum aestivum L.) and invoke DSSAT Nwheat model to analyze impact of modified sowing date to phenological development and grain yield. Wheat was grown for three seasons in two locations across Lithuania and sowing was carried out one time per week from 1 September to 29 September. Average three-year temperature of vegetation period gets lower every week by 0.16 °C, and available GDD by 94.5 °C when sowing time is delayed. Modeling results showed that tillering rate is affected by sowing time winter wheat grew 232 (tillers m-2) less with each week of delayed sowing. Grain filling stage was shortened by 1.25 days with each delayed sowing week. Depending on sowing time yield varied from 8.58 t ha-1 to 6 t ha-1 while simulated harvest was 8% lower. We conclude that best winter wheat sowing time for current climatic conditions in Lithuania is mid-September and DSSAT model proves as a useful tool in anticipating sowing time while facing problems caused by a climate change.

Monitoring and Modelling Analysis of Maize (Zea mays L.) Yield Gap in Smallholder Farming in Ghana

Modelling and multiple linear regression were used to explore the reason for low maize yield in the Atebubu-Amantin and West Mamprusi Districts of Ghana, West Africa. The study evaluated maize yields on twenty farms against measures of soil fertility, agronomic attributes and soil water availability. Correlations between yield, soil fertility, rain, crop density, and weed biomass, were low, and no single factor could explain the low yields. A 50-year virtual experiment was then set up using the Agricultural Production Systems Simulator (APSIM) to explore the interactions between climate, crop management (sowing date and nitrogen fertilization) and rooting depth on grain yield and nitrate (NO3-N) dynamics. The analysis showed that a lack of optimal sowing dates that synchronize radiation, rainfall events and nitrogen (N) management with critical growth stages explained the low farm yields.

Dual-purpose wheat technology: a tool for ensuring food security and livestock sustainability in cereal-based cropping pattern

ABSTRACT Wheat cultivation under a dual-purpose (DP) system holds great potential to provide additional fodder for livestock with marginal grain reduction. This study explores the potential of wheat as a DP crop for improving both, forage and grain cropping system by finding out optimal sowing dates and cultivars suitable for DP cropping. Field experiments with four cultivars (Saleem-2000, Bathoor-2007, Fakhre Sarhad-99 (FS-99) and Siran-2008), three sowing dates (October 15, October 30 and November 15) and two cutting treatments (cut and no-cut) determines the effects on yield and physiology of wheat. Wheat sown either in mid or end of October resulted in 11 and 8% increase in grain yield while 13 and 9% in biological yield over mid November sowing, respectively. This increase in yield was due to higher grain spike−1, chlorophyll content, transpiration rate and relative water content. The cultivars Siran-2008 and Saleem-2000 had higher biological and grain yields than other cultivars across cutting and sowing dates treatments. Biological and grain yields were reduced by 4% and 3%, respectively under the DP wheat compared with no-cut treatment, but grains N content was unaffected. Conclusively, DP wheat system (cut treatment) had higher profitability (11.2%) than wheat crop sown only for grain purposes.

ВЛИЯНИЕ ПРЕДШЕСТВЕННИКОВ И СРОКОВ ПОСЕВА НА ПЕРЕЗИМОВКУ И УРОЖАЙНОСТЬ ОЗИМОЙ ПШЕНИЦЫ В ИЗМЕНЯЮЩИХСЯ УСЛОВИЯХ РЕГИОНАЛЬНОГО КЛИМАТА

The research was carried out in order to determine the optimal time for sowing winter wheat according to various predecessors in the changing climate of Volga forest-steppe. The work was carried out in 2013–2019 in Ulyanovsk region on heavy loamy leached chernozem using conventional techniques. The experimental scheme provided for the study of two predecessors (peas and pure fallow) of winter soft wheat of Marafon variety, sown at 6 sowing dates with an interval of 10 days (from August 20 to October 10). The seeding rate for pure fallow is 5.0 million viable seeds per hectare, for peas - 5.5 million viable seeds per hectare. Average annual air temperature for 1961–2018 increased by 1.8°С. Its most significant increase was noted in the last twenty-five year period of time in the winter months. The increase in the frequency of extremely warm winters and temperature variability in the winter period significantly changed the conditions for overwintering winter crops. The danger of the development of wintering weeds, damping diseases, and soaking of winter crops has increased, and the conditions for overwintering pests have improved. It is possible to mitigate the danger of the natural and climatic vulnerability of crops during the wintering period by observing the optimal sowing dates, which should be postponed to a later period (7 ... 12 days), compared with the previously recommended ones. The optimal sowing period for winter wheat in Ulyanovsk region is from August 30 to September 10. Earlier crops are more intensively affected by diseases (powdery mildew and brown rust), and later crops, which have left in the winter in the germination phase, form a low density, form a small ear and provide low productivity or completely die

Results of the coriander (Сoriandrum sativum L.) study at different sowing date in the conditions of Absheron

Relevance.The article presents the results of studying the economic and biological indicators of various coriander samples planted at the Absheron Experimental Base of the Genetic Resources Institute in the autumn and spring, to select the most promising of them and determine the optimal sowing dates that ensure production for most of the year. Material and methods. The research material was the seeds of 5 coriander samples (Coriandrum sativum L.) from various early maturity groups introduced on Absheron: Ordubad (cat. No. 31); Iranian (Cat. No. 87); Azerbaijani (cat. No. 157); Dagestan (cat. No. 171); Borchali (cat. No. 167). When carrying out phenological observations, the onset of economic suitability, bolting, flowering and seed maturation was noted. The total yield from the plot was determined.Results. Phenological observations have shown that depending on the date of coriander samples sowing, the duration of the vegetation period and individual phases of development changed. Sowing dates also significantly affected the early maturity and productivity of the samples, but for different samples to varying degrees. Optimal for the Absheron part of Azerbaijan is the timing of sowing coriander from mid-March to the end of April and in September. The most promising were the coriander samples: Azerbaijan (cat. No. 157), Dagestan (cat. No. 171) and Iranian (cat. No. 87). Sowing at the optimum time of the most productive varieties with a long period of harvest can ensure the uninterrupted supply of fresh coriander greens for most of the year.

New promising annual crops for green mass in the Far North

Relevance and methods. The article presents the results of studies conducted at the Yakutsk Research Institute of Agriculture. Scientific research on the study of promising new forage crops was carried out on site 30 "A" (on the basis of the forage production laboratory of the YANIISKh) on the second floodplain terrace of the river. Lena in 2016–2018. The effect of three sowing dates on the yield of promising annual fodder crops is studied.Results. The results of studies on the growth, development, productivity, nutritional value of promising annual crops are presented. Productivity in three sowing periods during the harvesting period of sunflower reached feed units 1.2– 2.7 t/ha, crude protein — 2.5–5.1 t/ha, corn — feed units 0.7–2.2 t/ha, crude protein — 2.8–6.9 t /ha, oilseed radish feed units 1.1–1.3 t/ha, crude protein 3.3–5.0 t/ha. The optimal sowing and harvesting dates of promising annual fodder crops for the production of high-quality succulent and voluminous feeds are established — 1 term (sowing — I decade of June, harvesting — II decade of August); 2 term (sowing — the 2nd decade of June, harvesting — the 3rd decade of August) in the phase of mass flowering and discarding panicles of the tested feed crops.

YIELD AND QUALITY OF WINTER WHEAT GRAIN DEPENDING ON SOWING TIME AND CULTIVATION CONDITIONS

In solving the food problem, the leading role belongs to the main crop - winter wheat. At observance of the cultivation technology, modern varieties of wheat provide yields of 10–12 and more tons per 1ha. Climate warming, emerging in the second half of the twentieth century, necessitates the improvement of individual elements of the technology of cultivating new winter wheat varieties and, above all, the scientific substantiation of the choice of sowing date. Based on this, the study of the timing of sowing new varieties of winter wheat in the context of climate change is very important, and is an important condition for a steady increase in yield and improving the quality of grain. The studies were conducted in 2013–2015. in the three soil-climatic zones of Kabardino-Balkaria: steppe, foothill and mountain. The experiments were laid on varieties of winter common wheat of Yuzhanka and Cheget, joint breeding of the P. Lukyanenko National Grain Center and the Institute of Agriculture of the KBNC RAS. Sowing was carried out in four terms for each zone. Research results showed that the varieties responded differently to the terms and conditions of cultivation. As a result, optimum sowing dates were established for varieties and zones, which ensured a high yield of high-quality grain. At the same time, in the best options, the yield varied in varieties and zones from 5.00 to 5.85 tons / ha. High yields were obtained in the foothill and mountain zones, and better grain was formed in the steppe zone. So, in terms of the protein content and gluten in the studied varieties of Yuzhanka and Cheget, these indicators were respectively: 14.5 and 30.4% and 14.2 and 30.6%, which is higher than in other zones. This is due to the soil-climatic conditions of cultivation zones of varieties.

The impact of El Niño Southern Oscillation on cropping season rainfall variability across Central Brazil

AbstractLocal‐level understanding of within‐season rainfall variability and its relationship with the El Niño Southern Oscillation (ENSO) can shed light on crop yield variations and establish appropriate cropping calendars in rainfed systems. This requires information on the growing season, including its length, the total rainfall, the onset and cessation of rainfall, the number of wet and dry days, and the optimal sowing window. The objective of this study was to examine the onset and cessation of both the rainy and growing seasons using historical daily rainfall datasets (1980–2013) from 50 weather stations distributed across the main grain production region of Brazil. We then correlated the interannual variability of the climate variables and crop water availability with ENSO (using the Oceanic Niño Index, ONI). Across the study region, the onset of the rainy period ranged from late September to early November, and the cessation period ranged from late March to mid‐April. The onset of the growing season followed that of the rainy season, beginning across central and northern Mato Grosso in mid‐October, followed by Goiás and Tocantins, and finally Rondônia by the end of October. The length of the sowing window was reduced, and the mean optimal sowing date was delayed during La Niña years for most weather stations in the study region. Our results infer the need to adjust the cropping calendars for specific ENSO phases only in regions that conduct crop rotations. Based on rice crop model simulations of water availability, we propose a mean optimal crop sowing calendar for annual crops in Central Brazil.Highlights We analysed the impact of El Niño Southern Oscillation (ENSO) on the growing season characteristics of Central Brazil. The length of the sowing period is markedly reduced during La Niña years across the region. We propose a mean optimal crop sowing calendar for Central Brazil based on crop modelling results of ENSO effects.