Sowing

About: Sowing is a research topic. Over the lifetime, 33888 publications have been published within this topic receiving 273438 citations. The topic is also known as: seeding.

Simulating evolution of glyphosate resistance in Lolium rigidum II: past, present and future glyphosate use in Australian cropping

Abstract: Summary Glyphosate is a key component of weed control strategies in Australia and worldwide. Despite widespread and frequent use, evolved resistance to glyphosate is rare. A herbicide resistance model, parameterized for Lolium rigidum has been used to perform a number of simulations to compare predicted rates of evolution of glyphosate resistance under past, present and projected future use strategies. In a 30-year wheat, lupin, wheat, oilseed rape crop rotation with minimum tillage (100% shallow depth soil disturbance at sowing) and annual use of glyphosate pre-sowing, L. rigidum control was sustainable with no predicted glyphosate resistance. When the crop establishment system was changed to annual no-tillage (15% soil disturbance at sowing), glyphosate resistance was predicted in 90% of populations, with resistance becoming apparent after between 10 and 18 years when sowing was delayed. Resistance was predicted in 20% of populations after 25–30 years with early sowing. Risks of glyphosate resistance could be reduced by rotating between no-tillage and minimum-tillage establishment systems, or by rotating between glyphosate and paraquat for pre-sowing weed control. The double knockdown strategy (sequential full rate applications of glyphosate and paraquat) reduced risks of glyphosate and paraquat resistance to <2%. Introduction of glyphosate-resistant oilseed rape significantly increased predicted risks of glyphosate resistance in no-tillage systems even when the double knockdown was practised. These increased risks could be offset by high crop sowing rates and weed seed collection at harvest. When no selective herbicides were available in wheat crops, the introduction of glyphosate-resistant oilseed rape necessitated a return to a minimum-tillage crop establishment system.

Efficiency of the magnetic treatment of broad bean seeds cultivated under experimental plot conditions

Abstract: A b s t r a c t. The tests were carried out in the Institute of Soil Science and Plant Cultivation in Pu³awy under experimental plot conditions in the years 2000-2001. The factor of the first order were two varieties of broad bean: Nadwiœlanski – a traditional form and Tim – a self-determining form, while the second factor wa s–3e xposure doses of magnetic induction intensity: The magnetic treatment of the seed was done in the Department of Physics at the University of Agriculture in Lublin using a specially constructed device for the magnetic treatment of seeds prior to sowing equipped with an electromagnet with fluent regulation of magnetic induction. The research confirmed the positive effect of the magnetic treatment on the germination and emergence of both broad bean cultivars. Plant emergence was more regular after the use of the aforementioned treatment and occured 2-3 days earlier in comparison to the control plants. The magnetic treatment of broad bean seeds prior to sowing exerted a significant influence on the increase of seed yield. However, the efficiency of this treatment was dependent on the weather. The gain in seed yield resulting from the pre-sowing treatment of seeds with a magnetic field for both forms of broad bean was due to the higher number of pods per plant and the fewer plant losses in the unit area in the growing season.

Effect of maize (Zea mays L.) - cowpea (Vigna unguiculata L.) intercropping on light distribution, soil temperature and soil moisture in arid environment

Abstract: Sole crops and intercrops of maize (Zea mays L.) and cowpea (Vigna unguiculata L.) were studied at eight planting ratios of maize: cowpea (100:100, 50:100, 100:50, 25:75, 75:25, 50:50, 0:100 and 100:0 ) and two harvest times (milky stage and doughy stage). This experiment was carried during two years (2007 and 2008) on Research Center, University of Zabol, Iran, to investigate the influence of cowpea on the microclimate of their intercrop and sole maize (SM) as control. Measurements of photosynthetically active radiation (PAR), soil temperature (ST), soil moisture (SM) and crop yield were carried out to study the effects of intercropping on crop yield in a cowpea-maize intercropping system in Sistan at southeast of Iran. We found that intercropping increased the amount of absorption PAR compared to sole crop of maize. The highest amount of PAR was obtained at 100% cowpea + 100% maize with no significant difference to 100% cowpea + 50% maize. The lowest amount of PAR was obtained at 75% maize + 25% cowpea. Intercropping system had significant effects on soil temperature and soil moisture (P<0.01). The highest soil temperature was obtained at sole maize and the lowest temperature was at sole cowpea. Soil moisture was lowest at sole maize and highest at sole cowpea. LER (land equivalent ratio) values were greater in all intercropping systems with different planting ratios which indicated yield advantage of intercropping over sole cropping of maize. Results indicate that intercropping can increase light interception and increased shading in intercropping system compared to sole maize and reduce water evaporation and improve conservation of soil moisture. Based on high grain and suitable environmental condition, intercrop productivity compared to sole crop could be selected for improving the productivity of maize/cowpea mixture in the Southeast of Iran.

Cover-Crop Roller–Crimper Contributes to Weed Management in No-Till Soybean

Abstract: Termination of cover crops prior to no-till planting of soybean is typically accomplished with burndown herbicides. Recent advances in cover-crop roller–crimper design offer the possibility of reliable physical termination of cover crops without tillage. A field study within a no-till soybean production system was conducted in Urbana, IL, from 2004 through 2007 to quantify the effects of cover crop (cereal rye, hairy vetch, or bare soil control), termination method (chemical burndown or roller–crimper), and postemergence glyphosate application rate (0, 1.1, or 2.2 kg ae ha−1) on soybean yield components, weed–crop interference, and soil environmental variables. Biomass of weeds surviving management within a soybean crop following either a vetch or rye cover crop was reduced by 26 and 56%, respectively, in the rolled system compared to the burndown system. Soybean yield loss due to weed interference was unaffected by cover-crop termination method in soybean following a rye cover crop, but was high...

Effects of Plant Growth-Promoting Rhizobacteria on Loblolly and Slash Pine Seedlings

Abstract: Loblolly and slash pine seed were inoculated at sowing with 1 of 12 different strains of plant growth-promoting rhizobacteria (PGPR) in the greenhouse. Time to germination and seedling densities were determined at 21 days, and seedling biomass was measured at 12 wk after sowing. All bacterial strains significantly increased the speed of seedling emergence over nontreated pine seed. By 12 wk, however, no differences in stand densities were observed between bacteria-treated and nontreated seed for either pine species. Postemergence damping-off was reduced in loblolly pine when seed was treated with 3 of the 12 bacterial strains; however, postemergence damping-off on slash pine seedlings was not affected by rhizobacteria. Treatment with rhizobacteria had a significant positive and negative effect on seedling growth and biomass, which depended on tree species. Loblolly pine shoot and root lengths, as well as the aboveand belowground biomass, were significantly reduced when seeds were treated with strains BS1 and BS2. In contrast, loblolly pine seeds treated with strains BS3, PM2, and INR7 significantly increased the below ground biomass of the seedling root systems. Slash pine seedlings had similar interactions with the bacterial strains. Strain BS1 significantly reduced shoot lengths compared with nontreated seeds, while strains 90-166, INR7, and SE49 increased shoot biomass. Slash pine root lengths and biomass were also reduced when treated with strains BS1 and BS2. Unlike loblolly pine, no bacterial strain increased slash pine root length or biomass. This study suggests that the effects of rhizobacteria inoculation on seedling emergence and plant growth are independent and that the effects are species specific. FOR. SCI. 44(1):139-144. Additional