scholarly journals Seedling Establishment of Direct Seeded Rice without Coating of Oxygen-generator on the Soil Surface in Flooded Paddy Fields.

2001 ◽  
Vol 70 (3) ◽  
pp. 393-399 ◽  
Author(s):  
Yosuke UCHIMURA ◽  
Hirokazu SATO ◽  
Yuji MATSUE
1998 ◽  
Vol 48 (3) ◽  
pp. 301-307 ◽  
Author(s):  
Teruhiro Arai ◽  
Naoto Inoue ◽  
Ryoichi Ikeda ◽  
Hideo Hirasawa ◽  
Akio Ujihara ◽  
...  

1994 ◽  
Vol 70 (2) ◽  
pp. 151-158 ◽  
Author(s):  
R. L. Fleming ◽  
D. S. Mossa

A series of spot seeding experiments was set out on coarse-textured upland sites in northwestern Ontario to investigate how black spruce (Picea mariana [Mill.] B.S.P.) seedling establishment and growth could be improved by site selection and seedbed preparation. Virtually all germination occurred within the first growing season. Annual seedling mortality rates were greatest during the first year, then declined steadily and stabilized at low levels (<10%) after the third year. The highest fifth-year establishment ratios (seedlings/viable seed sown) were found on seedbeds derived from materials near the mineral soil/humus interface. On wetter sites (i.e., higher Soil Moisture Regimes) the best seedbeds occurred closer to the soil surface. Mean fifth year establishment ratios for the best seedbeds were 0.032 on moderately fresh to fresh sites, 0.146 on very fresh to moderately moist sites, and 0.082 on moist to very moist sites. On adjacent lowland sites, slow-growing, compact Sphagnum mosses had a mean establishment ratio of 0.179. Mean fifth-year seedling heights on upland sites ranged from 12 to 14 cm, and were not strongly correlated with site or seedbed type. Key words: direct seeding, black spruce, seedbed, seedling establishment, site type and germination


Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 48
Author(s):  
Chusnul Arif ◽  
Budi Indra Setiawan ◽  
Satyanto Krido Saptomo ◽  
Hiroshi Matsuda ◽  
Koremasa Tamura ◽  
...  

Subsurface drainage technology may offer a useful option in improving crop productivity by preventing water-logging in poor drainage paddy fields. The present study compared two paddy fields with and without sheet-pipe type subsurface drainage on land and water productivities in Indonesia. Sheet-pipe typed is perforated plastic sheets with a hole diameter of 2 mm and made from high-density polyethylene. It is commonly installed 30–50 cm below the soil surface and placed horizontally by a machine called a mole drainer, and then the sheets will automatically be a capillary pipe. Two fields were prepared, i.e., the sheet-pipe typed field (SP field) and the non-sheet-pipe typed field (NSP field) with three rice varieties (Situ Bagendit, Inpari 6 Jete, and Inpari 43 Agritan). In both fields, weather parameters and water depth were measured by the automatic weather stations, soil moisture sensors and water level sensors. During one season, the SP field drained approximately 45% more water compared to the NSP field. Thus, it caused increasing in soil aeration and producing a more significant grain yield, particularly for Inpari 43 Agritan. The SP field produced a 5.77 ton/ha grain yield, while the NSP field was 5.09 ton/ha. By producing more grain yield, the SP field was more effective in water use as represented by higher water productivity by 20%. The results indicated that the sheet-pipe type system developed better soil aeration that provides better soil conditions for rice.


Weed Science ◽  
1971 ◽  
Vol 19 (1) ◽  
pp. 79-81 ◽  
Author(s):  
B. A. Kratky ◽  
G. F. Warren

A mixture of activated carbon and vermiculite was used to increase the tolerance to 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine) of direct-seeded cucumbers (Cucumis sativusL., var. Wisconsin SMR-15) in greenhouse tests and direct-seeded tomatoes (Lycopersicum esculentumMill, var. Bouncer) in greenhouse and field (var. Heinz 1370) tests. The tolerance of cucumbers to dimethyl tetrachloroterephthalate (DCPA) and 4-(methylsulfonyl)-2,6-dini tro-N,N-dipropylaniline (nitralin) also was increased in field trials. When the mixture was placed in a hole (0.75 inch deep by 1 inch diam) over the crop seed to the level of the soil surface, preemergence herbicides were detoxified in the small area; and the crop plant was not injured. The herbicide remained active outside the small protected area. Also, a wafer consisting of an activated carbon-vermiculite mixture, fertilizer, and seed provided protection to direct-seeded crops.


2018 ◽  
Vol 6 (3) ◽  
pp. 181-198 ◽  
Author(s):  
Bishal Bista

Rice (Oryza sativaL.) is a major staple food crop that feeds around 60% of the world’s population. It is a major food crop in terms of production, economy and is grown in all ecological zones of Nepal. In Nepal, traditional method of rice cultivation is widely accepted in which 20-25 days old seedlings are transplanted in the puddled field. Looming water scarcity, water-intensive traditional method of rice cultivation, escalating labour costs pressurize the development of alternative which is highly sustainable and profitable. Direct-seeded rice (DSR) offers a very good opportunity that can cope up the global need and reduces the water use to 50%, labour cost to 60% and increases productivity by 5-10%. It involves sowing of pre-germinated seeds into wet soil surface (wet seeding), dry soil surface (dry seeding) and standing water (water seeding). Weeds are the major constraint in direct-seeded rice (DSR) reducing the crop yield upto 90% and sometimes even crop failure. Enhanced nutrient use efficiency and integrated weed management can produce comparable yields to that of transplanted rice (TPR) encouraging many farmers to switch to DSR. Methane gas emission is significantly lower in DSR than in conventionally tilled puddled transplanted rice mitigating the world’s threat of global warming. Blast disease and root-knot nematode (RKN) are other important problems associated with DSR. Based on the evidences collected, the article reviews integrated package of cultivation technologies associated with DSR, advantages, constraints and likeliness of DSR to be the future of rice cultivation in Nepal.Int. J. Appl. Sci. Biotechnol. Vol 6(3): 181-198


1975 ◽  
Vol 53 (24) ◽  
pp. 3022-3031 ◽  
Author(s):  
A. G. Thomas ◽  
H. M. Dale

In the crowded parts of patches of Hieracium floribundum Wimm. and Grab., which were established for at least a decade in an ungrazed pasture, 7–10% of the population (3700 individuals/m2) flowered. Of the plants that flowered, 94% were alive a year later, but only 5% of these flowered. Abortion of flower heads was common; one half of all those which were initiated in early June had aborted by flowering time in early July. Freshly dispersed seed had a viability of 57%, which was reduced to 17% a year later, after its storage close to the soil surface. Less than 6% of the viable seed was innately dormant. Dry, laboratory-stored seed retained its viability for the year but was slower to germinate than soil-stored seed. In field conditions, germination was temperature inhibited during most of the growing season. Maximum daytime microsite temperatures of less than 32 °C, which is necessary for germination, were found to occur only in early spring and late fall. Successful seedling establishment accounts for 1% of the individuals in a crowded population. Based on the maximum sexual reproduction from plants in crowded populations, a seed has a probability of 1 in 20 000 of becoming an established seedling. A model of population dynamics in a high-density patch traces the fate of seedling establishment, surviving adults, and stolon-derived rosettes for a single year.


HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 707-710 ◽  
Author(s):  
Theodore M. Webster ◽  
A. Stanley Culpepper

Halosulfuron is a proposed alternative to methyl bromide for managing nutsedges (Cyperus spp.) in several vegetable crops, including cucurbits. Field studies were conducted to evaluate the crop sensitivity to halosulfuron in a spring squash (Cucurbita pepo L.)—fall cucumber (Cucumis sativus L.) rotation from 2000 to 2002. Treatments included application of halosulfuron to the soil surface after forming the bed, but before laying mulch (halosulfuron-PRE), halosulfuron applied through drip irrigation (halosulfuron-DRIP) after forming bed and laying mulch, metham applied through drip irrigation after forming bed and laying mulch, a nontreated control with mulch, and nontreated control without mulch. Each treatment was applied to both direct seeded and transplanted zucchini squash. Halosulfuron treatments reduced squash plant diameter relative to metham, however plant diameters in halosulfuron-PRE (transplant and direct seed) and halosulfuron-DRIP (transplant) treatments were not different from the nontreated control. Halosulfuron-PRE delayed squash fruit production relative to the mulched nontreated control. However, application of halosulfuron-PRE and halosulfuron-DRIP did not reduce squash yield at the conclusion of the season, relative to the nontreated control. Cucumbers were transplanted and direct seeded into previous squash plots and received either an application of halosulfuron-DRIP, or were not treated. Differences in cucumber yields were not detected with second crop treatments. Cucumbers appear to have adequate tolerance to halosulfuron, making it a potential replacement for methyl bromide for nutsedge control. Suppression of early season squash growth by halosulfuron may hinder the adoption of halosulfuron as a methyl bromide alternative for squash.


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