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Planting Depth (planting + depth)

Distribution by Scientific Domains

Earth and Environmental Science	100%

Selected Abstracts

Soil Temperature and Planting Depth Effects on Tef Emergence

JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 3 2009
S. Evert
Abstract Tef [Eragrostis tef (Zucc.) Trotter] is an annual C4 grass crop that originated in Ethiopia. It has potential as a grain crop in the Great Plains because of its tolerance to drought and high temperatures. In Ethiopia, tef seed is typically broadcast on the soil surface and lightly incorporated. Shallow planting depths are used because the seed is very small and emergence can be limited by soil crusting. If planting equipment is to be used, planting depth may be important for successful tef production. The objective of this study was to identify optimal depths and soil temperatures to aid in developing tef planting recommendations for the central Plains. Tef was planted at five depths (0, 0.6, 1.3, 2.5 and 5.0 cm) in pots filled with a silt loam soil, and pots were placed in growth chambers at four temperature regimes (day/night: 15/19 °C; 19/23 °C; 23/27 °C and 27/31 °C). No plants emerged from the 5.0-cm depth, so this depth was not included in the analysis. Emergence was greatest for planting depths of 0.6 and 1.3 cm and lower at 0 and 2.5 cm depths. Temperature did not affect final emergence, measured 21 days after planting (DAP), but did influence emergence rates during the first 9 DAP. Plant dry matter production increased as planting depth increased, but plant dry matter per pot was not different among planting depths greater than 0.9 cm, suggesting that compensation between plants across different plant densities began early in the plants' life cycles. Our results show that tef seed can emerge from depths between 0.6 and 1.3 cm and that soil temperatures below 19 °C can slow emergence but should not affect final stands. [source]

Field Pea Seeding Management for Semi-arid Mediterranean Conditions

JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 2 2004
A. M. Tawaha
Abstract The effects of seeding rate (30, 60 and 90 seeds m,2), seeding date (14 January, 28 January and 12 February), seed weight (0.18 and 0.25 g seed,1), seeding depth (3 and 6 cm), and phosphorus fertilization rate (17.5, 35.0 and 52.5 kg P ha,1) and placement method (banded or broadcasted) on field pea (Pisum sativum L.) development and seed yields were investigated in irrigated field experiments conducted in northern Jordan in 2000 and 2001. Results and treatment responses were consistent in both years. Seeding rate, seeding date, seed weight and rate and method of phosphorus fertilization had significant effects on most traits measured; planting depth however did not affect any of the traits. Generally a positive correlation was observed between each factor and seed yield and yield components, with the exception of a negative correlation between seeding rate and yield components, and seeding date and yield and yield components. Increase in seeding rate from 30 to 90 seeds m,2, and increase in P fertilization from 17.5 to 52.5 kg ha,1 alone increased seed yields by 50 and 41 %, respectively. Each delay of 2 weeks for seeding from mid-January resulted in reductions of 12 % in seed yields. Overall, the results revealed that a combination of early seeding (14 January), of large seeds at an high seeding rate (90 seeds m,2), with P fertilizer banding (52.5 kg P ha,1) maximize field pea yields in irrigated fields in semi-arid Mediterranean environments. With such management pea seed yields can be as high as 2800 kg ha,1. [source]

Seed variation among annual ryegrass cultivars in south-eastern USA and the relationship with seedling vigour and forage production

GRASS & FORAGE SCIENCE, Issue 4 2002
B. C. Venuto
Abstract Annual ryegrass (Lolium multiflorum Lam.) is grown on more than one million ha in the south-eastern USA each year. Recommended and actual seeding rates vary substantially within the region. The objective of this study was to evaluate variation in seed weight, germination, seedling vigour and seasonal yield performance among annual ryegrass cultivars. During 1997, 1998 and 1999, seed from fourteen commercial cultivars was weighed and germinated to determine numbers of pure live seed (PLS) m,2 before yield evaluation at four locations. Seed from ten cultivars was planted at 0·7 and 2·0 cm depth in a greenhouse study to evaluate relative seedling vigour. Cultivar mean single-seed weight ranged from 2·4 to 4·8 mg in 1997, 1·8 to 4·5 mg in 1998, and 2·6 to 4·6 mg in 1999. Seed germination ranged from 78·8% to 98·0% in 1997, 82·3 to 98·3% in 1998 and 77·8 to 98·3% in 1999. Seed number, PLS m,2, ranged from 675 to 1289 in 1997, 710 to 1550 in 1998, and 717 to 1179 in 1999. Among the ten cultivars evaluated for seedling vigour, seedling weight differed between planting depths and a significant cultivar by year interaction was observed. Seedling weight was highly correlated with seed weight at each seeding depth. The effect of increasing number of PLS m,2 on subsequent yield performance, although small, was consistently negative. These results indicate that target plant populations may be obtained more economically by adjusting seeding rates for seed size differences among cultivars and seed lots of annual ryegrass. [source]