Response of soybeans to planting date in south-eastern Queensland. III.* Agronomic and physiological response of cultivars to planting arrangements

1977 ◽  
Vol 28 (1) ◽  
pp. 63 ◽  
Author(s):  
RJ Lawn ◽  
DE Byth ◽  
VE Mungomery

Results from five field experiments, designed to evaluate the response of several soybean cultivars to planting arrangement, and conducted at two locations in south-eastern Queensland during 1967–1972, are reported. Response to planting arrangement varied depending on cultivar maturity type, planting date, and availability of moisture during growth. Averaged over cultivars and planting arrangements, seed yields for irrigated soybeans were highest for December plantings, and declined as planting was delayed. A cultivar x planting date interaction was apparent. For December planting dates, yields of all cultivars were generally highest in 50.8 cm rows. A cultivar x plant population interaction occurred, with yields of the later-maturing cultivars maximized at lower plant population levels than for the earlier cultivars. When the planting date was delayed beyond December, yields of all cultivars were maximized in narrow row-high density treatments. Yields of the narrow row-high density late plantings were equivalent to, and in the case of the late-maturing cultivars, greater than, the highest December yields. Wide row widths (101 .6 cm) were consistently lower-yielding, regardless of cultivar and planting date. Seed yields were reduced substantially by periods of severe moisture stress during growth. The relative performance of cultivars of differing phenology depended primarily on the coincidence of periods of severe stress with critical stages of development, viz. pod and seed development. In the environments involving periods of severe moisture stress, seed yields were maximized in row widths narrower than 50.8 cm, and at the lowest plant populations used (c. 95,000 plants per ha). Such treatments most closely approached low density-equidistant spacings in these studies.

2019 ◽  
Vol 112 (6) ◽  
pp. 2731-2736 ◽  
Author(s):  
Nicholas J Seiter ◽  
Anne D Miskelley ◽  
Gus M Lorenz ◽  
Neelendra K Joshi ◽  
Glenn E Studebaker ◽  
...  

Abstract The sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae), has become a major pest of grain sorghum, Sorghum bicolor (L.) Moench, in the United States in recent years. Feeding by large densities of sugarcane aphids causes severe damage, which can lead to a total loss of yield in extreme cases. Our objective was to determine the effect of grain sorghum planting date on sugarcane aphid population dynamics and their potential to reduce yields. We conducted field experiments from 2015 to 2017 in which an aphid-susceptible grain sorghum hybrid was planted at four different dates, which encompassed the typical range of planting dates used in Arkansas production systems. Plots were either protected from sugarcane aphid feeding using foliar insecticide sprays, or left untreated to allow natural populations of sugarcane aphids to colonize and reproduce freely. Planting date impacted both the magnitude and severity of sugarcane aphid infestations, with the highest population densities (and subsequent reductions in sorghum yield) generally occurring on plots that were planted in May or June. Sugarcane aphid feeding reduced yields in the untreated plots in two of the four planting date categories we tested. Earlier planting generally resulted in less sugarcane aphid damage and improved yields compared with later planting dates. While the effect of planting date on sugarcane aphid populations is likely to vary by region, sorghum producers should consider grain sorghum planting date as a potential cultural tactic to reduce the impact of sugarcane aphid.


1974 ◽  
Vol 25 (5) ◽  
pp. 723 ◽  
Author(s):  
RJ Lawn ◽  
DE Byth

Vegetative and reproductive development of a range of soya bean cultivars was studied over a series of planting dates in both hill plots and row culture at Redland Bay, Qld. Responses in the extent of vegetative and reproductive development were related to changes in the phasic developmental patterns. The duration and extent of vegetative development for the various cultivar-planting date combinations were closely associated with the length of the period from planting to the cessation of flowering. Thus, vegetative growth was greatest for those planting dates which resulted in a delay in flowering and/or extended the flowering phase. Similarly, genetic lateness of maturity among cultivars was associated with more extensive vegetative development. Seed yield per unit area increased within each cultivar as the length of the growing period was extended until sufficient vegetative growth occurred to allow the formation of closed canopies under the particular agronomic conditions imposed. Further increases in the length of the period of vegetative growth failed to increase seed yield, and in some cases seed yields were actually reduced. Biological efficiency of seed production (BE) was negatively correlated with the length of the vegetative growth period. Differences in BE among cultivar-planting date combinations were large. It is suggested that maximization of seed yield will necessitate an optimum compromise between the degree of vegetative development and BE. Optimum plant arrangement will therefore vary, depending on the particular cultivar-planting date combination. ___________________ \*Part I, Aust. J. Agric. Res., 24: 67 (1973).


2007 ◽  
Vol 21 (1) ◽  
pp. 199-205 ◽  
Author(s):  
John H. O'Barr ◽  
Garry N. McCauley ◽  
Rodney W. Bovey ◽  
Scott A. Senseman ◽  
James M. Chandler

Clomazone is an effective herbicide widely used for PRE grass control in rice. However, use of clomazone on sandy textured soils of the western Texas rice belt can cause serious rice injury. Two field experiments at three locations were conducted in 2002 and 2003 to determine the optimum rate range that maximizes barnyardgrass and broadleaf signalgrass control and minimizes rice injury across a wide variety of soil textures and planting dates. At Beaumont (silty clay loam), Eagle Lake (fine sandy loam), and Ganado (fine sandy loam), TX, PRE application of 0.34 kg ai/ha clomazone applied to rice planted in March, April, or May optimized barnyardgrass and broadleaf signalgrass control and rice yield while minimizing rice injury. Data suggest that, although injury might occur, clomazone is safe to use in rice on sandy textured soils.


HortScience ◽  
1992 ◽  
Vol 27 (7) ◽  
pp. 787-789 ◽  
Author(s):  
Aref Abdul-Baki ◽  
C. Spence ◽  
R. Hoover

Field experiments were conducted to a) maximize total yield of fresh-market field tomato (Lycopersicon esculentum Mill.) cultivars using black polyethylene mulch (BPM), and b) increase fruit size and yield during the last 5 weeks of the production period by reducing the number of synthate sinks per plant through eliminating all flowers that appeared during this period. Unmulched treatments under trickle irrigation and multiple applications of soluble fertilizer yielded an average of 43 t·ha-1 for `Sunny' and `Pik-Rite' over the two planting dates. With BPM, total yield increased by 95% to 84 t·ha-1. Although total yield increases due to BPM over the control were highly significant in both cultivars and over the two planting dates, yield increases were higher for the early than for the optimum planting date. BPM also significantly increased early production of `Pik-Rite' but not `Sunny', and the increase in early production was more pronounced for the optimum than the early planting date. Sink reduction during the last 5 weeks of the growing season had no effect on yield or fruit weight during that period.


2019 ◽  
Vol 8 (2) ◽  
pp. 26
Author(s):  
James K. Stute ◽  
D. Esther Shekinah

Sunn hemp (Crotalaria juncea L.) is recommended as a warm season cover crop in the Midwest due to its ability to produce high levels of biomass and fix atmospheric nitrogen. It can also be grown in biculture with other cover crops to enhance overall ecosystem services. Two field experiments were conducted over four growing seasons (2014 – 2017) in Wisconsin on a forest derived Fox silt loam (Fine-loamy, mixed, mesic Typic Hapludalfs) under organic certification to determine the effect of planting date on sunn hemp dry matter yield, N and C addition and to determine the effect of species ratio in a biculture with sorghum-sudan [Sorghum bicolor (L.) Moench] on the same output variables as well as seed cost and the related per unit cost of production. Planting dates significantly affected all biomass yield variables, which declined linearly from the initial date and appear related to growing degree accumulation. Regression analysis revealed a biomass yield decline of 1.3% per day (8.9% week-1) in relative yield, and 0.90 Mg day-1 (0.61 Mg week-1) in actual yield. In biculture, sunn hemp grown in a planting ratio of 50:50 with sorghum-sudan maximized N addition through nitrogen fixation and added N from dry matter, without a significant difference in the dry matter recorded. Analysis of seed cost data revealed that as the ratio of sunn hemp in the planting mixture decreased, the cost per hectare decreased. The cost of production per unit of DM, N, C and CO2 equivalent at this planting ratio were 7.08 $ Mg-1, 0.57 $ kg-1, 17.51 $ t-1 and 4.78 $ t-1 respectively. In pure culture, early planting dates (June 15th to July 15th) are recommended for sunn hemp, and in biculture, a planting ratio of 50:50 with sorghum-sudan could serve Midwestern producers well by reducing per unit cost of biomass production.


1977 ◽  
Vol 17 (84) ◽  
pp. 143 ◽  
Author(s):  
GA Constable

Field experiments in three seasons examined the effects of plant population and row spacing on the yield of two cotton cultivars. For the early maturing cultivar, Riverina Poplar, 36 cm rows yielded 18 per cent more than 100 cm rows with no additional benefit being obtained from 18 cm rows. The medium maturing commercial cultivar, Deltapine 16, had the same average yield at all row spacings. The effect of plant population on yield was significant in all row spacings, with populations above 40 plants m-2 in 18 cm rows, above 30 plants m-2 in 36 cm rows, and above 13 plants m-2 in 100 cm rows yielding less. In all experiments, narrow rows and high plant populations had smaller bolls, more barren plants and smaller plants than wide rows and low plant populations. At low yield levels, Riverina Poplar in narrow rows was superior to wide rows and to Deltapine 16 in any row spacing. At high yield levels, Deltapine 16 was superior, particularly in wide rows


1998 ◽  
Vol 130 (4) ◽  
pp. 431-449 ◽  
Author(s):  
P. J. O'BRIEN ◽  
D. M. FIRMAN ◽  
E. J. ALLEN

Twelve field experiments, carried out over 7 years, examined effects of shading and seed tuber spacing on plant growth, initiation and retention of tubers in four cultivars: Estima, Maris Piper, Maris Peer and Record. Ten of the experiments were carried out at Cambridge and two near Valencia, Spain. Other treatments included in some experiments were floating polythene mulch and planting date.Shading by up to 75% did not affect the timing of onset or cessation of tuber initiation in Estima but shading by 50% or more delayed the completion of tuber initiation in Maris Piper compared with less severe shading. Except for intensely shaded treatments (50% or more), the majority of tubers were initiated in a very short period (4–7 days). Shading by 37% or more during the period of tuber initiation and increasing planting density, decreased number of tubers per stem initiated in all experiments, but number of tubers was not affected by shading at other stages of growth. At Cambridge, effects of shading on number of tubers >10 mm retained later in growth from normal planting dates (March to early May) were similar to effects on number of tubers initiated, but effects were much reduced or absent following later plantings at Cambridge and in both experiments in Valencia. The decreased effects of shading on number of tubers >10 mm at late plantings at Cambridge were associated with the initiation of fewer tubers at these plantings. Effects of shading, planting density and planting date on number of tubers were a consequence of changes in the frequency of occurrence and tuberization of different stolon types. Increasing shading and planting density and delaying planting reduced the number of lateral and branch stolons and the frequency of their tuberization but there were no effects on number of primary stolons or their tuberization. Consequently, at Cambridge a similar number of tubers was borne on primary stolons in shaded and unshaded crops. In Valencia a greater proportion of initiated tubers was retained at final harvest from shaded treatments than at Cambridge, which accounts for the absence of effects of shading on number of tubers >10 mm. The greater retention of tubers late in growth in Spain may have been associated with the higher peak growth rates achieved in higher radiation fluxes than at Cambridge.Linear regressions of the data for normal planting dates at Cambridge and from Valencia indicated that the number of tubers >10 mm late in growth was dependent on the radiation environment during the period of tuber initiation. Radiation flux during the brightest period of the first few days of initiation appeared to be the most crucial aspect of radiation affecting number of tubers. As incident radiation can vary greatly over the short period of tuber initiation, it is potentially an important factor affecting number of tubers in field crops.


1966 ◽  
Vol 66 (3) ◽  
pp. 379-389 ◽  
Author(s):  
R. K. Scott ◽  
P. M. Bremner

1. A series of three field experiments, concerning the effects on growth, development and yield of sugar beet of extension of the growing season by transplantation, were carried out in 1962, 1963 and 1964. The first two experiments were subject to sequential sampling programmes for growthanalysis purposes, but in the third only yield data were recorded.2. Root yield increased with advance in planting date and increase in plant population in all 3 years. Nitrogen had no effect on root yield in any year. There was no consistent interaction between time of planting and plant population in their effects on root yield. The advantage for transplanting over field sowing ranged from 4 tons washed beet per acre in the case of an early field sowing (20 March) to 10 tons in a late one (23 April). There were no treatment effects on the concentration of sugar in the roots. The roots of transplants were more globular in shape and fanged than were those of field-sown beet.


2018 ◽  
Vol 24 (2) ◽  
pp. 163-173
Author(s):  
Natalia Teixeira Schwab ◽  
Nereu Augusto Streck ◽  
Lilian Osmari Uhlmann ◽  
Camila Coelho Becker ◽  
Bruna San Martim Rolim Ribeiro ◽  
...  

The planting date is an important factor affecting the developmental cycle and quality of final product. Indications from the literature are that gladiolus is a species that can be cultivated throughout the year, but in some periods, adverse conditions may occur, reducing the quality of the flower. Two field experiments (Experiment 1: August 2011 to July 2012 and Experiment 2: August 2012 to July 2013) were conducted in Santa Maria, RS, Brazil, to quantify the influence of planting dates on the duration of the developmental cycle and on the quality of flower stems in gladiolus, identifying possible damages by high and low temperatures in the final product. It is concluded that it is possible to cultivate gladiolus throughout the year, but the duration of gladiolus cycle is higher when planting is carried out in periods of low temperatures, and this is important for scheduling the planting date, mainly for meeting specific market demand (commemorative dates). Extreme temperatures (above 35 ºC and below 0 ºC) reduce the commercial flowers quality and even cause the death of plants.


Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 596
Author(s):  
Nick R. Bateman ◽  
Angus L. Catchot ◽  
Jeff Gore ◽  
Don R. Cook ◽  
Fred R. Musser ◽  
...  

As fluctuating commodity prices change the agriculture landscape on a yearly basis, soybean (Glycine max (L.) Merr.) has become the predominant crop in the southern USA, accounting for 65 percent of the total row crop production in the state. To accommodate increased soybean production, planting dates have expanded, spanning from late March through July. To determine the impact of this expanded planting window on soybean development and yield, field experiments were conducted at Starkville and Stoneville, MS, in 2013 and 2014. Treatments included seven planting dates ranging from 25 March to 15 July and two soybean cultivars (one Maturity Group IV and one Maturity Group V cultivar). These studies were conducted in irrigated high––yielding environments. Experimental units were sampled weekly for insect pests and insecticides were applied when populations exceeded the levels at which applications were recommended. Planting date had a significant impact on crop development, plant height, canopy closure, and yield. As planting date was delayed, the time required for crop development decreased from 122 total days for plantings on 25 March to 83 days for plantings on 15 July. For plantings after 2 June, plant height decreased by 1.1 cm per day. Canopy closure decreased by 1.01% per day after 27 May. Soybean yield decreased 26.7 kg/ha per day when soybean was planted after 20 April. This research demonstrates the importance of early planting dates for soybean producers in the southern US to ensure profitability by maximizing yield potential.


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