Effect Of Different Sowing Dates Research Articles

Kanolada (Brassica napus L.) Farklı Ekim Zamanı, Çeşit ve Tohumluk Miktarının Verim ve Kalite Özelliklerine Etkisi

This study was carried out to determine the effect of different sowing dates and seeding rate on seed yield, oil and protein contents of seed in two rapeseed cultivars in the field of experiment and application of Aydin Adnan Menderes University Faculty of Agriculture during 2014/2015 and 2015/2016. The experiment was the split-split-plot design with 4 replications. The sowing dates, cultivars and seeding rates were arranged to main, sub and sub-sub plots, respectively. This experiment was conducted applying two sowing dates (early and late), two winter type cultivars (NK Petrol and NK Caravel) and five seeding rates (3, 5, 7, 9 and 11 kg ha-1). The early sowing date and 7.0 kg ha-1 seeding rate given the highest seed yield for both cultivars based on two-year results. The interaction between sowing dates and cultivars for crude oil rate was significant, and the highest crude oil rate was recorded in NK Petrol cultivar (43.34 - 43.54%) at the first sowing date in both years. Non-significant protein content for all factors and interactions varied from 19.10% to 23.72%. Finally, it was recommended the earliest possible sowing with 7.0 kg ha-1 seeding rate for seed yield and quality in winter rapeseed growing. Moreover, it was recommended that NK Petrol for early sowing dates and NK Caravel for late sowing dates should be used as a cultivar.

Mehmet Yagmur and Omer Sozen

This experiment was conducted to determine the effects of different sowing dates (5th October, 20th October, 5th November, and 20th November) and sowing depths (2, 4, 6 and 8 cm) on yield and some yield characters in two rowed barley (cv. Tokak 157/37) under rainfed conditions. The field study was conducted in Kirsehir ecological condition during 2014-15 and 2015-16 winter growing seasons. Grain yield and important yield traits such as plant height, spike length, number of fertile spike per square meter, number of grain per spike and grain weight per spike were determined. Sowing dates and depths influenced significantly the grain yield and yield components in two consecutive years. Most of the yield components were adversely affected by deeper sowing depths and delayed sowing dates. Based on two-year average, the highest grain yield was recorded with 2733 kg ha-1 at 20th October sowing date and 4 cm depth; in contrast the lowest grain yield was 513 kg ha-1 by the 20th November and 8 cm depth. Keywords: Cereals, Hordeum vulgare, crop production, dryland, arid agriculture, seedling emergence, grain yield.

Performance of Chickpea Varieties Based on Growth and Yield Parameters Influenced by Different Sowing Dates at Toke Kutaye District, Ethiopia

One of the basic agronomic practices to improve the yield of chickpea are ideal sowing date and high yielding varieties. Thus, a field experiment was conducted to assess the effect of different sowing dates on yield and yield components of chickpea varieties in the main cropping season of 2019 at Toke Kutaye District. Four sowing dates (September 4th, September 14th, September 24th, and October 5th) and four kabuli varieties. Four Kabuli types of chickpea varieties were Dalota, Ejere, Teji and Dube (local check). Experiment was laid out in split plot design using factorial arrangement with three replications and sowing date treatments were assigned to the main plots and varieties to sub plots. The main effect of sowing date showed highly significant effect on days to emergence, days to 50% flowering and physiological maturity. Highest days to emergence (12.4 days) were recorded from a plot sown on October 5th, while longest days to 50% flowering (54.92 days) and physiological maturity (122.5 days) were recorded from a plot sown on September 14th. Moreover, varieties had significant effect on days to physiological maturity of chickpea. Longest days to physiological maturity (133 days) were recorded from local variety and early days to physiological maturity (113.3 days) was recorded from Dalota variety. The main effects of sowing date and variety were significant on plant height, as the tallest plant height (42.75 cm) was recorded from September 24th sown plants. Similarly, the tallest (41.42 cm) plant was recorded from Dalota variety. In addition, the highest number of primary branches (6.83) and secondary branches (16.42) per plant were recorded from Dalota variety, while the lowest number of primary branch (5.5) and secondary branches (8) were scored from Ejere and Teji varieties, respectively. Highest grain yield (2415.4 kg ha-1) was obtained from plots sown on September 14th whereas Dalota variety produced highest grain yield (2051.25 kg ha-1). Hence, Dalota variety and September 14th sowing date emerged as best among all tested treatments and can be recommended for chickpea production in the study area and similar agro-ecologies. Conclusive recommendation could be obtained if the study is repeated at more locations and seasons in the future.

Evaluating the effects of different sowing dates and tillage methods on dry-land wheat grain dry matter accumulation based on the APSIM model.

Accurate simulation of dry matter accumulation in wheat grains can provide important technical support for regulating wheat production in hilly areas of Loess Plateau. Using the APSIM model, we analyzed dryland wheat grain dry matter accumulation and distribution using the meteorological data from 1971 to 2017 in Anding District, and the field test data from 2016 to 2017 in Anjiagou Village, Fengxiang Town, Anding District, Dingxi City, Gansu Province. Furthermore, the influence of sowing date and tillage method on dry matter accumulation of wheat grain was quantitatively analyzed on the basis of model validation. The results showed that the root mean square error (RMSE) between the simulated and measured values of grain dry matter was 57.5-143.1 kg·hm-2 and the normalized root mean square error (NRMSE) was 1.4%-9.9% under the three sowing dates and four tillage methods, respectively. The precision of the APSIM model was satisfactory. Under different sowing dates, the order for beneficial degree of tillage treatment to dry matter accumulation in wheat grains was no tillage with straw cover > conventional tillage with straw cover > no tillage > conventional tillage. The treatment of no tillage with straw covered was the most favora-ble to dry matter accumulation in wheat grains, with no significant difference between no tillage and conventional tillage treatments. Under different farming methods, early sowing was better than normal sowing and late sowing for the dry matter accumulation process of wheat. Late sowing had stronger impacts on dry matter accumulation, with the least ideal accumulation process.

Performance of rice cultivars for yield and yield attributes at twelve different dates of sowing

A field investigation was conducted to evaluate the effect of different sowing dates on yield and yield components of six rice cultivars during 2018-2019 at Indian Institute of Rice Research, Rajendranagar, Hyderabad. Experiment constituted of twelve sowing dates i.e. from 20th June 2018 to 01st Feb 2019 with an interval of 20 days between each sowing. Data on morphology, yield attributes and yield of six rice genotypes were recorded and statistically analysed by split plot design (main plot- cultivars, subplot- dates of sowing). Significant interaction studies between cultivars and dates of sowing revealed cv. JGL 3855 to perform best for grain yield over other cultivars. The yield contributing parameters productive tiller number m-2, panicle weight, grain number per panicle and spikelet fertility attributed for the high yielding feature in cv. JGL 3855. Further, interaction studies indicated that sowing date D1 (20th Jun’2018) was best suitable for all the cultivars except WGL 24071 to attain maximum grain yield. WGL 24071 performed best (7556 kg ha-1) on D8 (20th Nov’2018) sowing indicating that this cultivar is well suited for Rabi than Kharif season. D1 (20th Jun’2018) sowing also recorded maximum plant height, number of productive (panicle bearing) tillers, panicle length, panicle weight, number of grains per panicle, 1000-grain weight, filled grain per m2 and spikelet fertility %.

Effects of Sowing Date and Fungicide on Seedling Establishment of Pearl Millet Genotypes Infected with Downy Mildew Disease

Downy mildew caused by Sclerospora graminicola (Sacc.) Schroet is a major limiting factor to the production of pearl millet globally. Therefore, a field trial was carried out during the 2018 and 2019 rainy seasons at Bauchi and Maiduguri located in the Northern Guinea and Sudan Savannah of Nigeria, respectively. The aim was to evaluate the effects of different sowing dates and a fungicide on seedlings establishment of three pearl millet genotypes infected with downy mildew disease. Randomized Complete Block Design was used with a factorial arrangement of treatments, which comprised three pearl millet genotypes (Gero, Maiwa, Dauro), three sowing dates (late-June, mid-July and late-July) and metalaxyl fungicide (treated and untreated). Results for genotypes consistently showed that Maiwa performed better than Gero and Dauro. In terms of the sowing date, the performance of millet was better in the first sowing date (late-June), followed by the second date (mid-July) and then the third date (late-July). Mean values of the seedling establishment were significantly decreased with delay in sowing date. Results, in respect of the fungicide treatments, generally indicated a higher seedling stands in the treated (78.6 - 87.4%) than untreated seed (70.9 - 81.1%) across the locations. These findings revealed that treated seeds with metalaxyl fungicide and early sowing give better seedling establishment in pearl millet.

Yield and some agronomic parameters of upland cotton as affected by planting dates

A field experiment was conducted at ICI Research Farm, Multan to evaluate the effect of different sowing dates on plant height, number of monopodia, number of sympodia, number of bolls per plant, boll weight, seed cotton yield kg/ha of two upland cotton varieties (ICI-2121 and ICI-2424) developed by ICI Pakistan Limited, Multan against a standard check variety IUB-2013 during 2019, and 2020 years. These varieties were planted on 1st April, 15th April, 1st May, 15th May, 1st June, and 15th June, at ICI Cotton Research Station, 19-Kasi Vehari Road, Multan. Results revealed that statistically highly significant differences in planting dates were observed for all the parameters studied except number of monopodial branches and boll weight which depicted non-significant differences. Regarding varieties and interaction between varieties and planting times, similar trend of statistical differences was observed. As regards to planting dates, generally, all the parameters under study showed their maximum performance when crop was planted on 1st May followed by 1st April planting date, whereas, minimum performance of the parameters was recorded when the crop was planted on 15th June followed by 1st June. Regarding varietal performance, on an average, maximum plant height (146cm) was observed in ICI-2121 followed by IUB-2013. Same trend of performance of varieties regarding number of monopodia and sympodia per plant was observed. Regarding average number of bolls per plant in different varieties, it was observed that ICI-2121 produced maximum (32 bolls) followed by ICI-2424 (31 bolls) and IUB-2013 (28 bolls) irrespective of planting dates. The same trend of varietal performance regarding boll weight was recorded. When seed cotton yield (kg/ha) was evaluated, on an average of varieties, ICI-2121 produced maximum seed cotton yield (1228 kg/ha) followed by ICI-2424 and IUB-2013 which produced 1147 and 1046 kg/ha seed cotton yield respectively irrespective of planting dates. It was concluded that under agro-climatic conditions of Multan, 1st May planting date was evaluated as optimum cotton sowing time. Before or after 1st May, this study does not recommend growing cotton in this particular zone. Among cotton varieties, ICI-2121 is recommended for sowing under this planting time being producing higher yields.

Performance of Pre Released Rice (Oryza sativa L.) Genotypes under Different Sowing Windows in Rabi Season

The aim of this study was to investigate the effect of different sowing dates on growth and yield potential of pre released rice genotypes under irrigated conditions of Northern Telangana zone. The field experiments were carried out during two consecutive rabi seasons of 2018-19 and 2019-20, on clay soils of agricultural research station, Kunaram, Telangana state, India. The experiment was laid out in strip plot design with three replications. The treatments comprised of three sowing dates i.e. 20th November, 5th December and 20th December in horizontal factor and four genotypes i.e. KNM 733, RNR 15048, KNM 1638 and KNM 118 in vertical factor. Pooled data analysis results revealed that the different sowing dates and genotypes significant effect on all the studied growth and yield characters. The rice crop sown on 20th December recorded significantly higher grain yield ( 8138 kg ha-1) and Among the genotypes, the short slender, short duration genotype KNM 733 recorded the recorded the maximum grain yield ( 8024 kg ha-1), which was on par with the other genotypes. The treatment combinations data results concluded that the, among the genotypes the genotype KNM 118 was recorded highest grain yield (8438 kg ha-1) when sowing was taken up on 20th December and followed by the genotype KNM 733 with sown on 20th November. In respect of economics of treatment combinations, the highest net returns (Rs.91,165 ha-1) and B:C (2.47) ratio were obtained when rice crop was sown during 20th December with the genotype KNM 118 and followed by sown on 20th November with the genotype KNM 733.

Effect of Different Sowing Dates and Timings of Last Cut on Yield Attributes and Seed Yield of Berseem (Trifolium alexandrinum L.)

Background: Many genetical, physiological, environmental and organizational constraints associated with the low productivity of forage crops, but the most important among them is lack of quality seeds of improved cultivars to farmers. Scarcity of green fodder and low seed setting forces the farmers not to prefer for seed production. Weather extremities like unbalanced or untimely rains or high speed winds also affected seed setting. All these extremities lead to scarcity of berseem seed in Punjab and farmer are forced to paying high prices at the time of sowing. Maintaining the proper sowing time and time of last cut for fodder and for leaving the crop for seed production may help in keeping the balance between vegetative and reproductive phases for high seed yield to tackle these problems. Therefore, optimum sowing time and last cut is a very deciding factor to achieve maximum green fodder and seed yield. The current experiment aimed to study the effect of different sowing dates and timings of last cut on yield attributes and seed yield of berseem (Trifolium alexandrinum L.).Methods: In this experiment, crop was sown on five different dates with the broadcast method and also three dates of last cut of crop left for seed production. These treatments were replicated thrice. All other cultural practices were also maintained for optimum berseem productivity. The first cutting of fodder was taken after 55 days from sowing and thereafter 30 days interval. After the time of last cut, crop was left for seed production. At maturity, data on yield attributes were recorded. Results: Our investigations revealed that late sown berseem increased the yield attributes and seed yield but decreased the green fodder yield. Therefore to get maximum seed production, it is suggested that late sown 20th October has the optimum date of sowing and optimum time for leave the crop is 25th March for seed production.

Elastic sowing dates with low seeding rate for grain yield maintenance in mechanized large-scale double-cropped rice production

Elastic sowing dates (ESDs) are correlated with rice grain yield. ESD is the easiest factor for farmers to manipulate in mechanized large-scale farming. In this study, field experiments were conducted over a 2-year period to determine the effects of different sowing dates on growth duration, effective accumulated temperature, and yield attributes in two early- and late-season machine-transplanted rice cultivars. In early rice (ER), a delay in the sowing date led to decreased grain yield and shorter growth duration. In late rice (LR), delayed sowing led to significantly lower grain yield and prolonged growth duration. In LR, significantly positive correlations were detected between effective accumulated temperature in the post-heading stage and both filling ratio and yield. Reproductive redundancy increased markedly in LR, by 7.72% over a 5-day interval. We determined that the ESDs for LR were 10 days later than the control, and that of ER was recommend early sowing rather than late sowing. These findings suggest a new strategy to meet the demands of mechanized large-scale rice farming: the development of thermal sensitive high-yield long-duration ER cultivars and high-yield short-duration LR cultivars.

EFFECT OF PLANTING DATE ON GROWING DEGREE DAYS, GROWTH AND PRODUCTIVITY OF SOME MAIZE HYBRIDS

Two field experiments were carried out at the Experimental Farm of Agricultural Research Center, Egypt, to investigate the effect of different sowing dates (May 15, June 1 and June 15) on the vegetative growth, flowering traits, growing degree days, yield and grain quality of some white maize hybrids (S.C 10, S.C 128, S.C 131, S.C 2031, T.W.C 321, T.W.C 324 and T.W.C 329) during 2017 and 2018 seasons. The results obtained could be summarized as follows: 1- The results indicated that early planting surpassed the other planting dates in most growth characters (number of leaves/ plant, leaf area/ plant, stem, leaves and shoot dry weight/plant), photosynthetic pigment (total chlorophyll), physiological parameters (crop growth rate, relative growth rate and net assimilation rate), flowering characters (days to tasseling, silking and maturity), yield (plant height, ear height, ear length, ear diameter, number of rows / main ear, number of grains / row, grains weight/ ear, grain yield/fed, stover and biological yields/fed and harvest index) and grain quality (oil and protein %) in both seasons. 2- There are significant differences among the tested hybrids in most characters studied. S.C 2031 hybrid was generally superior to the other hybrids in all growth characters, chlorophyll content, yield (number of ears/plant, 100-grain weight, grain weight/ear and grain yield/fed) and protein percent in grains. However, S.C 131 and S.C 128 hybrids produced generally the highest values of days to maturity, ear diameter, stover and biological yields/fed and oil percent in grains. 3- The interactions between sowing dates and maize hybrids were found to be significant for most characters under study. It could be concluded that planting S.C 2031 hybrid which the best hybrid under early planting (May 15) condition, while S.C 131 hybrid showed the best performance under mid planting (June 1) condition compared to other hybrids. However, T.W.C 321 exhibited the maximum grain yield /fed under the late planting (June 15) in comparison with other hybrids under the environmental conditions of this experiment.

Effect of different sowing dates on yield and economics of wheat cultivars under North situations of Madhya Pradesh

A field experiment was conducted during Rabi season of 2015-16 at Research Farm, School of Agriculture ITM University Gwalior (MP). The treatments consisted of 2 dates of sowing i.e.; D1 (15th November) and D2 (10th December); and 5 varieties i.e.; V1 to V5 (HD 4730, PBW-343, Raj 4037, HD 4728 and Lok-1). The experiment was conducted in spilt-plot design with three replications. The experimental results revealed that Maximum grain yield (5027.82 kg ha-1), straw yield (6962.84 kg ha-1), gross monetary returns (110592 Rs. ha-1), net monetary returns (80378 Rs. ha-1) and benefit cost ratio (3.66) were recorded under variety HD 4728 at 15th November sowing date compared to other varieties and dates of sowing.

Effect of Different Sowing Dates on the Performance of Maize

The research experiment was conducted on maize in order to find out the effect of different sowing dates on the performance of maize at Entomology Field Laboratory, Department of Entomology, Bangladesh Agricultural University (BAU), Mymensigh during Rabi season of 2016–17. The experiment was laid out in randomized complete block design (RCBD) with three replications. BARI Hybrid Butta-09 variety of Maize and nine sowing dates viz. 3rd(S1) & 4th(S2) week of October; 1st(S3), 2nd(S4), 3rd(S5) & 4th(S6) week of November; 1st(S7), 2nd(S8) & 3rd(S9) week of December were used as experimental crop and sowing dates, respectively. All sowing dates showed significantly different effect on yield. The results of present investigation revealed that maximum morpho-physiological characters, yield components and yield was obtained with better quality sown on 1st week of November as sowing dates than others due to ensuring the highest plant height (223.66cm), number of cob/plant (1.73), cob length without husk (23.23cm), number of grain/cob (641.21), grain weight/cob(235.16) and maximum grain yield (10.56 t/ha), which was followed the increasing order of yield were S4<S5<S6< S7< S8< S9< S2< S1.In case of correlation between different sowing dates and yield, the present study showed that very strongly significant negative correlation between sowing dates and grain yield of maize. Therefore, considering all facts, 1st week of November as sowing date could be recommended to the maize grower for the most effective for producing of maize. Henceforth, in addition, 2nd week of November could also be suggested for second best effective sowing date where second crop of cropping pattern is not available or not apply in the field.

Performance of Winter-Seeded Spring Wheat in Inner Mongolia

Growing spring wheat in Inner Mongolia is challenging because of the short growing period, dry-hot winds, and heat-forced maturity. There are also problems with growing winter wheat varieties, such as frost damage, spring droughts, and “late spring cold”. These factors have restricted efforts to increase yields. In order to address these challenges, this study adopted a “spring wheat winter-sowing” planting model for growing wheat in the Hetao Plain Irrigation District in Inner Mongolia and studied wheat varieties with different vernalization requirements through three consecutive field trials. The effects of different sowing dates were analyzed on seed germination and seedling emergence, growth, material accumulation, and yield formation, and the differences were characterized from traditional spring wheat. The results indicated that delaying the sowing date increased the spring emergence rate of the wheat varieties. The winter-seeded spring wheat germinated and ripened after three and seven days, respectively, earlier than the spring-seeded. The grain yield for the winter-seeded wheat was parallel to the spring-seeded wheat. Compared with the spring-seeded wheat, the winter-seeded wheat displayed less panicles, but greater grains per spike, and a 1000-grain weight. When seeded in winter, Yongliang 4 performed better than Ningdong 11 and Henong 7106 in terms of the emergence rate, material accumulation, and grain yield. The best seeding time for the winter-seeded spring wheat in the Hetao Irrigation District of Inner Mongolia is early November.

Effect of Sowing Date and Humic Acid Foliar Application on Yield and Yield Components of Canola Cultivars

In order to investigate the effects of different sowing dates and humic acid foliar application on some agronomic traits of six canola cultivars a two-year experiment was carried out in 2015 and 2016 growing seasons. The experiments were laid out in a randomized complete block design arranged in factorial split plot with three replicates. The factorial combination of three sowing dates (7th, 17th and 27th October) and two humic acid levels (0 and 0.2%) were allocated to the main plots and six canola cultivars (HW118, WPN6, HL3721, L14, Tassilo and Natali) were randomized in subplots. The results indicated that the main effects of experimental factors were significant on all studied traits, except for harvest index. Interaction between sowing date and cultivar was also significant on all traits except for branch number and harvest index. In general, early seed sowing caused the highest yield and yield component as well as oil percentage and yield. Similarly, humic acid foliar application could increase agronomic traits in canola cultivars. In sum, early seed sowing and humic acid foliar application are highly recommended in canola production.

Is Irrigating Soybean Profitable In Uruguay? A Modeling Approach

Core Ideas AquaCrop model was suitable for simulating the soybean biomass and yield at harvest. Goodness of fit obtained for all variables of soybean is considered satisfactory. Supplemental irrigation increase the soybean yield under different El Niño/Southern Oscillation cycle. Profit margins were around 6 to 36% higher under irrigation than rainfed conditions. Rainfed crop may be suitable when the sale price was lower than 350 US$ t–1. Use of climatic models to predict the El Niño/Southern Oscillation (ENSO) cycle coupled with decision support system tools can optimize management of the major crops grown in South America. AquaCrop model was applied in this paper based on field data from a soybean deficit irrigation trial in the northwestern region of Uruguay. The AquaCrop model was suitable for simulating the biomass and yield at harvest, as well as the soil water content of the soybean crop root zone, with an acceptable goodness of fit (Willmott aggregation index [IoA] &gt; 0.80) and low estimation errors (NRMSE &lt; 20%). After calibration and validation, AquaCrop was used to simulate 35 characteristic years for this area to analyze soybean production under irrigation and rainfed conditions, as well as to study the effect of different sowing dates and the ENSO cycle on soybean yield. This research concluded that irrigation would significantly increase the crop yield, providing stable yields for farm systems regardless of the sowing date and the ENSO cycle considered. Additionally, irrigation reducing the dependence on favorable weather for planting, allowing more flexibility in sowing date for growers. The calculated profit margins were between 6 to 36% higher using irrigation than under rainfed conditions when soybean sale price was higher than 275 US$ t−1. With lower soybean sale price, the rainfed crop may be the most desirable option for growers regardless of ENSO cycle.

Sowing date effects on dry matter remobilization and yield of triticale (Triticosecale wittmack) under late season drought stress

A 2-year field experiment using a randomized complete block design with the treatments arranged as split-split-plot with three replicates was conducted to investigate the effects of different sowing dates. Different irrigation regimes and different triticale cultivars were tested during 2014 and 2015 growing seasons. Under cutting off irrigation at the milk development stage, Sanabad with 46.2% had higher relative water content on December 3 sowing date. Assimilate remobilization in cutting off irrigation at dough development was more than that at milk development and Sanabad had the highest assimilate remobilization on 3 December sowing date in both years. In both years, Sanabad had the highest remobilization efficiency. The highest contribution of pre-anthesis assimilates to grain was obtained on 3 December sowing date in both years in Sanabad. Lower grain yield in Juanillo cultivar under cutting off irrigation, appeared to be due to reduction in remobilization efficiency, especially by cutting off irrigation at milk development stage in late sowing date. Overall, Sanabad was more tolerant to cutting off irrigation than Juanillo.

Changing of Vegetative to Reproductive Ratio as a Response to Different Sowing Dates in Sunflower

AbstractSunflower is an important source for edible oils and biodiesel production. Its productivity is limited by many agronomical practices one of which is the sowing date. In this study, the effects of different sowing dates from early April to late June on phenology and yield of sunflower cultivars were investigated. The results showed that sunflower has a relatively long period of possible sowing dates, stretching from early April to late June in North West of Iran. However, delayed sowing dates significantly decreased the number of days needed for phenophases. For every day of delay, the model predicted (R2=0.97) a losing rate in achene yield by 22.2 kg h−1 from the first sowing date. For relationships between growing degree days (GDD) and yield, almost the same results were obtained. About 22 kg h−1 reduction (R2=0.79) in yield per day was estimated by GDD index when the average GDDs per day was 14.2. However, helio-thermal units (HTU) did not predict this reduction accurately. A suggested comprehensive model, that used the percent of yield losses and changes in vegetative to reproductive ratio, found a significant and positive relationship between the indices and yield losses. For all indices, an increase in vegetative to reproductive ratio resulted in increased grain yield losses.

Effect of different sowing dates on growth, yield and quality of soybean cultivars

Effect of different sowing dates on growth, yield and quality of soybean cultivars

Associations between Plant Density and Yield Components Using Different Sowing Times in Wheat (Triticum aestivum L.)

The yield potential of wheat depends not only on genetic × environmental interactions, but also on various agronomic factors such as sowing date or the seed rate used for sowing. The main aim of this work was to determine possible correlations between the effects of different sowing dates and plant densities on the yield components of a collection of 48 wheat genotypes. Two-way analysis of variance on the data revealed that both sowing date and plant density, as main components, only had a minor effect on the yield component patterns. Correlation analysis, however, indicated that the sowing date had a greater effect on the yield components, while plant density was in closer correlation with the heading time (r = 0.90). The patterns determined for individual yield components at two different sowing dates and plant densities showed significant differences for spike length, spike fertility, grain number in the main spike, number of productive tillers, grain number on side tillers, mean grain number and grain weight. Genotypes that carry the winter (recessive) alleles of genes regulating vernalisation processes (VRN-A1, VRN-B1, VRN-D1) and the sensitive (recessive) alleles of the two genes responsible for photoperiod sensitivity (PPD-B1, PPD-D1) may have better tillering and consequently higher grain yield, though this may depend greatly on the year.