Month: August 2018

ABSTRACT
During the last two years (1996-1997), trials were conducted in different locations in Greece to establish an integrated crop management approach over some of the main varieties, mainly through growth regulation. An intensive use of the plant mapping to establish plant parameters (plant height, number of nodes above white flower on position one, top five node average internode length, node of first fruiting branch and fruit set) is critically evaluated. Plant regulating techniques in integrated crop management are discussed.

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ABSTRACT
The Australian cotton industry is responding to increased pressure to reduce reliance on pesticides. An important part of this program is the examination of weed control and herbicide use patterns. Attention is now being given to the significant amounts of herbicide being applied in cotton rotations and possibilities for herbicide reduction. Currently there are no known cases of herbicide resistance within Australian cotton fields but prevention and limitation of resistance is a major objective. An integrated weed management (IWM) system has existed by default in the cotton industry, due mainly to inter-row cultivation and hand hoeing to control weed escapes. However, a formalized IWM strategy needs to be developed to ensure that the use of herbicides is sustainable in a viable cropping system. Recent new advances in herbicide chemistry, genetic engineering and machinery design offer the opportunity to combine these with existing weed control techniques to achieve a more environmental and economically sustainable weed management strategy

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ABSTRACT
The systems of consumption, production and trade, speciality after the Second World War, have deteriorated as consequence of degradation of the environment and natural resources. During the last year as an answer to this situation, Conalgodón has been working around the conservation tillage to increase and protect the soil, considering it the base of the improvement for cotton growing in a tropical country like Colombia.

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ABSTRACT
The effect of two irrigation levels and two N-fertilization practices on the growth and productivity of two Greek cotton varieties (e.g. Zeta-2, Korina) was investigated in a field experiment carried out in central Greece, in 1997. The irrigation levels are 320 mm/yr (I2) which is normal for the study area, and an amount by 20% lower, viz. 250 mm/yr (I1). The fertilization practices include a) classical dressing with 160 kg N/ha (F1) and b) same amount of total N applied by fertigation (F2). The experimental design was split-split plot with five blocks. The development and growth features of cotton were determined in five distracting samplings throughout the growing period. Fiber percentage and quality characteristics were also determined. It was found that the lower irrigation did not affect the final seed- and lint-cotton yield. Contrarily, the lower irrigation exhibited a significant positive effect on crop earliness, especially for the cultivar Zeta-2, which performed by about 500 kg/ha and 200 kg/ha greater yield respectively of seed- and lint-cotton at the first pick. No effect of fertilization practice on the yield was found at any of the pickings. This was especially the case for “Zeta-2” which performed identical yields for the two fertilization practices. The plants receiving the higher irrigation (I2) performed a leaf area index (LAI) rather greater than the I1 plants, viz. 4 vs. 3.1 at the beginning of August. Also the plants under the common fertilization practice exhibited higher LAI at the first stages but these differences were disappeared later. The fiber length was the only cotton quality character significantly affected by the treatments. The combination of low irrigation and fertigation gave the longest fiber length. The above results give evidence that irrigation and fertilization in cotton may be reduced in accordance to the imposed low input agriculture in the future without a serious variation in the cost/benefit ratio. This can be of particular importance especially for adverse years when an early crop is highly required.

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ABSTRACT
A field experiment was conducted at Larissa, Greece, during 1996, on a clay soil (1% OM), to investigate the effect of three tillage systems (conventional, strip and minimum tillage) on weed emergence, cotton growth and weed-cotton competition. Mouldboard ploughing, followed by chisel ploughing and a single pass with a flexi-tine cultivator prior to cotton sowing constituted the conventional tillage. The strip tillage regime was with a 25-cm deep subsoil treatment at 95-cm intervals, followed by cultivation with a narrow crop cultivator. The minimum tillage treatment plots received a single pass with a flexi-tine cultivator. The combined effect of tillage system x herbicide application (alachlor, prometryne, fluometuron (applied alone), or alachlor EC and alachlor CS in a tank-mix with prometryne or fluometuron, respectively) on weeds and cotton was also examined. The results indicated that both conventional and minimum tillage systems gave taller cotton plants with greater leaf area, wider main stem and higher node number than strip tillage. More weeds were found with conservation tillage (strip and minimum tillage systems) than with conventional tillage. Cotton yield was higher in conventional tillage than conservation tillage systems. Fluometuron treatments produced better weed control and higher cotton yields than the other treatments.

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ABSTRACT
An experiment to study the impact of five methods of tillage on soil physical aspects and cotton growth was established in Thessaly Greece in 1996 in order to reduce inputs in the cotton crop. The methods included conventional tillage with ploughing at 25cm, reduced tillage with heavy cultivator at 20 cm, reduced with rotary cultivator at 15cm, reduced with disc harrow at 8 cm and no-tillage. Soil in reduced tilled plots had a higher bulk density, shear strength and resistance to penetration. Cotton plants grown under reduced methods of tillage had delayed emergence, reduced growth, less bolls and lower yields. At harvest, conventional tillage gave the best yield with 4 t/ha of seed cotton followed by heavy cultivator with 3.8 t/ha. The methods of rotary cultivator and disk harrow yielded much less, with 3.2 t/ha. The no-tillage plots gave 2.8 t/ha of seed cotton and were last of all.

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ABSTRACT
The effect of previous cultivation of sugarbeet, legume, cotton and corn on the subsequent crops of cotton and corn was studied in a two – year rotation cycle at two Greek locations in 1994 and 1995. This paper only discusses the two cultivation systems, 1) sugarbeet – cotton and 2) cotton – cotton. The effect of sugarbeet in cotton cultivation is considered negative based on various field observations and the personal experience of farmers. Some of the supposed causes of this effect are evaluated. Growth analysis in cotton grown after sugarbeet showed that plants had a significant delay in appearance of squares, flowers and bolls, delayed weight development of vegetative and reproductive parts, delayed Leaf Area development and reduced chlorophyll, compared to cotton grown after cotton. This difference gradually declined or disappeared during plant life cycle. Thus although cotton grown after sugarbeet yielded less in the first picking, total yield was not inferior. Soil analytical data during the second year were not found to be influenced by the previous cultivation. Heavy rainfall in October 1994 and spring 1995 possibly leached residual N and balanced the differences between crops. In addition, no sugarbeet residues were left in the soil and it was hand harvested, possibly explaining the lack of effect on the C/N ratio and soil mycoflora. The increased soil compaction observed in plots planted to sugarbeet, combined with delayed cotton growth, support the hypothesis that the swollen sugarbeet roots increase soil compaction, prohibiting root penetration of the following cotton crop.

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ABSTRACT
Ultra-narrow cotton creates new possibilities for shortening the growing season of cotton thus decreasing costs of production inputs, but the optimum row spacing for ultra-narrow planting is still under investigation. The experiment was conducted at the Texas A&M University Agricultural Research and Extension Centre in Uvalde, Texas, during the 1997 season. The soil at the experimental site is a Uvalde silty clay loam. Transgenic RoundUp-Ready cultivars Paymaster 2200 and Paymaster 2326 were planted to a plant population of about 245,000 plants per ha in 20-, 30-, and 40-cm spaced rows. A linear-move, low-pressure overhead sprinkler system was used for in-season irrigation of the plots. There were significant differences in yield between the two cultivars across row spacing treatments. Seedcotton yield of Paymaster 2200 averaged 3089 kg/ha, while that of Paymaster 2326 averaged 2259 kg/ha. There were no significant differences among row-distance treatments. The interaction cultivar x row spacing was not significant. Our data indicates (1) there is no advantage in planting at row-distances less than 16 inches and (2) the selection of best adapted and high yielding varieties is an important consideration for a successful crop.

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