Pre-emergence processes limit seedling recruitment in two direct seeded Acacia spp.

2022 ◽  
Vol 505 ◽  
pp. 119912
Author(s):  
Scott Alexander McKendrick ◽  
Fiona Jean Ede ◽  
Rebecca Elizabeth Miller ◽  
Joe Greet
2017 ◽  
Vol 70 ◽  
pp. 160-164 ◽  
Author(s):  
G.W. Bourdôt ◽  
S. Jackman ◽  
D.J. Saville

Flupropanate (sodium 2,2,3,3 tetrafluoropropanate), a slow-acting lipid bio- synthesis-inhibiting herbicide, was recently registered in New Zealand as Taskforce (745 g/L flupropanate as the sodium salt) for the selective and long-term control of Nassella trichotoma (nassella tussock) in pastures. In five dose-response experiments in permanent hill pastures in Canterbury, conducted between 2012 and 2016, we measured the efficacy of the herbicide against established plants of N. trichotoma and its residual activity against recruiting seedlings. Mortality, as an average across the five sites, was 93% 1.5 years after applying 1.49 kg flupropanate/ha (the label-recommended rate), and 100% at 2.98 kg/ha. This indicates that an application rate higher than the label rate will be necessary for complete control of a N. trichotoma infestation. The presence of 1,000 and 6,250 visible seedlings of N. trichotoma/ha in the autumn 3.2 and 2.1 years after applying 1.49 kg flupropanate/ha (at a Greta Valley and Scargill site respectively) indicates that the herbicide’s soil residues had decayed within 12 months to a concentration lower than necessary to kill the germinating seedlings of N. trichotoma.


HortScience ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 599E-600
Author(s):  
Regina P. Bracy ◽  
Richard L. Parish

Improved stand establishment of direct-seeded crops has usually involved seed treatment and/or seed covers. Planters have been evaluated for seed/plant spacing uniformity, singulation, furrow openers, and presswheel design; however, effects of presswheels and seed coverers on plant establishment have not been widely investigated. Five experiments were conducted in a fine sandy loam soil to determine effect of presswheels and seed coverers on emergence of direct-seeded cabbage and mustard. Seed were planted with Stanhay 870 seeder equipped with one of four presswheels and seed coverers. Presswheels included smooth, mesh, concave split, and flat split types. Seed coverers included standard drag, light drag, paired knives, and no coverer. Soil moisture at planting ranged from 8% to 19% in the top 5 cm of bed. Differences in plant counts taken 2 weeks after planting were minimal with any presswheel or seed coverer. Visual observation indicated the seed furrow was more completely closed with the knife coverer in high soil moisture conditions. All tests received at least 14 mm of precipitation within 6 days from planting, which may account for lack of differences in plant emergence.


2017 ◽  
Vol 4 (04) ◽  
Author(s):  
YUJJWAL KUMAR ◽  
RAMESH CHANDRA BHARATI ◽  
RAVI KANT CHAUBEY ◽  
K. K. RAO ◽  
VED PRAKASH ◽  
...  

The study has been conducted in Madhubani district of Bihar state to analyse gender segregated key benefits, advantages, disadvantages, issues and the key decision processes and criteria for conservation agriculture technologiesadoption. Data were collected through focus group discussions involving male and female farmers. Cent per cent farmers expressed saving of labour and reduction in drudgery in Zero Tillage Direct Seeded Rice (ZTDSR). Higher yield through adoption of ZTDSR was revealed by equal percentage (75 %) of male and female farmers. Equal percentage (100 %) of male and female farmers expressed labour saving as one of the most important criteria for adoption of the ZT. Gender segregated data showed almost similar perception related to criteria adoption of ZT technology in rice-wheat system. All the female groups expressed that limited knowledge of herbicide use restricts adoption of ZTDSR. All the female groups were in the view that there is reduction of drudgery through adoption of mechanical paddy transplanter. Preparation of mat type nursery was top most disadvantages for 90 and 70 % male and female groups respectively. Eighty percent farmers groups expressed their opinion that non availability of trained tractor drivers for machine operation limits adoption of ZT machine. Preparation of mat nursery and trained operators for paddy transplanter was major criteria for adoption of mechanical paddy transplanter. There was contradiction in the perception among male and female farmers with respect to yield advantage and associated risk for poor yield due to the adoption of CA technologies.


2020 ◽  
Vol 8 (5) ◽  
pp. 2667-2669
Author(s):  
Samarth Tewari ◽  
Gurvinder Singh ◽  
Avikal Kumar ◽  
Narendra Bhandari ◽  
Saurabh Gangola

2021 ◽  
Vol 14 (1) ◽  
pp. 3-8
Author(s):  
Philip W. Tipping ◽  
Melissa R. Martin ◽  
Jeremiah R. Foley ◽  
Ryan M. Pierce ◽  
Lyn A. Gettys

AbstractThe potential of Melaleuca quinquenervia (Cav.) S.T. Blake to reinvade cleared areas was evaluated over a 13-yr period that included two wildfires and the introduction of biological control agents. The first wildfire occurred in 1998 and was followed by a mean of 591.5 recruited seedlings m−2. Recruits from that fire were cleared 7 yr later in July 2005 for a second experiment to evaluate seedling recruitment into cleared areas. Seed rain, seedling recruitment and mortality, and sapling growth rates were measured in four plots located around individual large reproductive trees. A second natural wildfire in 2007 burned through those plots, leading to increases in seed rain followed by a pulse in recruitment of 21.04 seedlings m−2, 96.5% fewer than after the 1998 fire. Recruits in half of the plots around each tree were then treated with regular applications of an insecticide to restrict herbivory by biological control agents, while herbivory was not restricted in the other half. There was no difference in seedling mortality between treatments 1,083 d post-fire (2007) with 96.6% seedling mortality in the unrestricted herbivory treatment and 89.4% mortality in the restricted herbivory treatment. Recruits subjected to the restricted herbivory treatment grew taller than those in the unrestricted herbivory treatment, 101.3 cm versus 37.4 cm. Many of the recruits were attacked by the biological control agents, which slowed their growth. Although solitary M. quinquenervia trees retain some capacity to reinvade areas under specific circumstances, there was a downward trend in their overall invasiveness at this site, with progressively smaller recruitment cohorts due to biological control agents. Land managers should prioritize removing large reproductive trees over treating recently recruited populations, which can be left for many years for the biological control agents to suppress before any additional treatment would be needed.


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