scholarly journals Comparison of weed management methods in organic carrot

2003 ◽  
Vol 9 (1) ◽  
Author(s):  
I. Gál ◽  
P. Pusztai ◽  
L. Radics
Keyword(s):  
Weed Management ◽  
Weather Conditions ◽  
Thermal Control ◽  
Dry Mass ◽  
Management Research ◽  
Growing Period ◽  
Weed Cover ◽  
Management Techniques ◽  
Hand Weeding ◽  
Weed Tolerance

14 combinations of mechanical and also physical (thermal) weed management techniques are compared for organic growing of carrot. Crop of our weed management research is carrot because of its difficulties in weed management (long growing period, poor weed tolerance) and because carrot needs to be important product of organic farming. Herbicide treatment is used as control — cultivator, brush hoe, hand hoeing and hand weeding are mechanical control tools and flame weeder is used for thermal control. Measured parameters are the weed cover, cover of the crop and dry mass of them. Result of the two appraisable years shows contradictory results, which contradiction can be justifiable with different weather conditions of these two vegetation periods. In 2000 brush hoe was significantly the best in interrows but in the year 2001 cultivator combined with hand weeding in rows seemed to show the best result. We can see in this example that agriculture and weed management depends very much on the weather of the year, so that is why it is so difficult to develop a method, which can be generally used for organic weed control of carrot.

Selection of Russian wildrye biotypes carrying economically important traits

2020 ◽  
Author(s):  
В. Кадоркина ◽  
М. Шевцова
Keyword(s):  
Weather Conditions ◽  
Dry Mass ◽  
Mass Selection ◽  
Breeding Method ◽  
Breeding Programs ◽  
Growing Period ◽  
Dry Steppe ◽  
Russian Wildrye ◽  
Green Mass Yield ◽  
K 12

В статье представлены результаты изучения биотипов ломкоколосника ситникового, выделенных в питомнике исходного материала по хозяйственно ценным признакам для дальнейшей селекционной работы. При выборе направления селекционной работы с этой культурой исходили из следующих критериев: экономического значения культуры (он долговечен, в условиях Хакасии держится в посевах 1012 и более лет), пригоден к пастбищному использованию, даёт ранний весенний корм, а осенью остаётся в зелёном состоянии и прекрасно используется как пастбищная трава. Цель исследования изучение и отбор биотипов ломкоколосника ситникового из питомника исходного материала по хозяйственно ценным признакам для дальнейшей селекционной работы. Источником исходного материала ломкоколосника ситникового (Psathurostachys juncea (Fisch.)) послужила местная популяция из сухостепного агроэкологического района Хакасии. Основным методом селекции стал массовый биотипический отбор. Коллекционный питомник исходного материала заложен на территории Ботанического сада НИИ аграрных проблем Хакасии 15 июня 2015 года в количестве 30 образцов. Сложившиеся погодные условия в разные периоды вегетации 20172019 годов были относительно положительными для роста и развития растений. Работа проведена в соответствии с методическими указаниями по селекции кормовых культур и методике Государственной комиссии по сортоиспытанию сельскохозяйственных культур. В питомнике проводились учёты и фенологические наблюдения за развитием растений. Фенологические наблюдения в период роста и развития ломкоколосника ситникового в питомнике исходного материала в среднем за 3 года показали, что начало весеннего отрастания образцов отмечалось с конца третей декады апреля первой декады мая. Высота растений составила 0,763,9 см. Период от начала вегетации до созревания семян составил 8894 дня у К 1, К 2, К 4, К 5, К 9, К 10, К 11, К 12, К 15, К 16, К 24. Наибольшая зелёная масса отмечена: у К 2 235 г К 3 243 г, К 6 200 г, К 7 321 г, К 9 235 г, К 12 226 г, К 14 215 г, К 18 241 г, по сухому веществу отмечены эти же образцы (от 66,5 до 106 г). По хозяйственно ценным признакам выделены номера К 1, К 3, К 5, К 12, К 18. Economical value, grazing potential, early growth and long growing period determined the importance of Russian wildrye for plant breeders. The aim of the research to test and select genotypes of Russian wildrye (Psathurostachys juncea (Fisch.)) with desirable traits for further breeding programs. Plant material was collected from the dry steppe of Khakassia. The collection nursery comprised 30 genotypes. The main breeding method was mass selection. Weather conditions in 20172019 were relatively favorable for plant development. For 3 years plant growth started in late April early May. Height of Russian wildrye varied within 0.763.9 cm. Growing period of K 1, K 2, K 4, K 5, K 9, K 10, K 11, K 12, K 15, K 16 and K 24 genotypes amounted to 8894 days. The following genotypes produced the highest green mass yield: K 2 235 g K 3 243 g, K 6 200 g, K 7 321 g, K 9 235 g, K 12 226 g, K 14 215 g, K 18 241 g. Their dry mass productivity reached 66.5106 g. K 1, K 3, K 5, K 12 and K 18 were selected for further experiments.

scholarly journals Chemical Weed Control in Paddy Fields Inoculated with Azospirillum lipoferum

2018 ◽  
Vol 36 (0) ◽  
Author(s):  
A. SEDDIGUI KIASARI ◽  
H. AMINPANAH ◽  
P. SHARIFI
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Weed Management ◽  
Paddy Fields ◽  
Azospirillum Lipoferum ◽  
Northern Iran ◽  
Growing Period ◽  
Management Regime ◽  
Significant Difference ◽  
Hand Weeding

ABSTRACT: Herbicides, as a major part of weed control strategy in paddy fields, have different impact on growth and activity of soil-beneficial bacteria such as Azospirillum species. A field experiment was conducted at Sefid Rood Livestock and Agricultural Company, northern Iran, to investigate the possibility of chemical weed control in paddy fields inoculated with Azospirillum lipoferum. The experiment was designed in a factorial arrangement based on a randomized complete block with three replicates. The factors were Azospirillum application (inoculation with or without Azospirillum lipoferum) and weed management regime (butachlor application with supplementary hand-weeding, bensulfuron methyl application with supplementary hand-weeding, combination of butachlor and bensulfuron methyl application with supplementary hand-weeding, hand-weeding at 15, 30, and 45 days after transplanting, and no weeding [not weeded during the rice-growing period). The results showed that plants inoculated with A. lipoferum produced 19% higher grain yield compared to plants that were not inoculated. The highest grain yields were recorded for plots treated with butachlor with supplementary hand-weeding (4,512 kg ha-1) and for those treated with a combination of butachlor and bensulfuron methyl with supplementary hand-weeding (4500.5 kg ha-1). The lowest yield (3494.3 kg ha-1) was recorded for weedy plots. No significant interaction was detected between A. lipoferum application and weed management regime for grain yield, indicating that the herbicides had no adverse effect on the efficiency of A. lipoferum in promoting growth and grain yield of rice. There was no significant difference in the dry weights of weed between inoculated and non-inoculated plots. The dry weights of weed in hand-weeded and herbicide-treated plots were significantly lower than that of the weedy plot. In conclusion, the result of this experiment confirms the possibility of chemical weed control in paddy fields inoculated with A. lipoferum.

scholarly journals Optimizing the width of strip weeding in arabica coffee in relation to crop age

2012 ◽  
Vol 30 (1) ◽  
pp. 129-138 ◽  
Author(s):  
FC. Araújo ◽  
C.P. Ronchi ◽  
W.L. Almeida ◽  
M.A.A. Silva ◽  
C.E.O. Magalhães ◽  
...  
Keyword(s):  
Weed Management ◽  
Dry Mass ◽  
Integrated Weed Management ◽  
Regression Analyses ◽  
Coffee Plant ◽  
Brachiaria Decumbens ◽  
Minimum Width ◽  
Growth Evaluation ◽  
Hand Weeding ◽  
Plot Design

The aim of this study was to determine the weed strip control (WSC) required for adequate coffee growth after transplanting. A non-irrigated, field-planted (spaced 3.80 x 0.70 m) crop was used. The experimental design was a randomized block, with four replicates. The treatments were arranged in a 9 x 18 split-plot design to test the WSC of 0, 15, 30, 45, 60, 90, 120, 150, and 190 cm, which involved continuously hand-weeding at each side of the coffee row, and 18 coffee growth measurements. Multiple regression analyses were carried out relating to growth-variables as a function of both WSC and growth-evaluation times. Brachiaria decumbens was the main weed accomplishing 88.5% of the total weed dry mass. The minimum width of the WSC increases as the crop ages after transplanting. Assuming reductions of 2% and 5% in the maximum coffee growth, the recommended WSC was 75 and 52 cm at 4 months after transplanting (MAT), 104 and 85 cm at 6 MAT, 123 and 105 cm at 9 MAT, 134 and 116 cm at 12 MAT, 142 and 124 cm at 15 MAT, and 148 and 131 cm at 18 MAT, respectively. It was concluded that integrated weed management in young coffee crops must focus on the weed control only in a minimum range along coffee rows, which increases with coffee plant age, keeping natural vegetation in the inter-rows.

Optimum harvest date of maize for biogas and silage purposes

2009 ◽  
Vol 57 (2) ◽  
pp. 119-125
Author(s):  
G. Hadi
Keyword(s):  
Dry Matter ◽  
Biogas Production ◽  
Weather Conditions ◽  
Vegetation Period ◽  
Dry Mass ◽  
Matter Content ◽  
Harvest Date ◽  
Dry Matter Content ◽  
Dry Matter Yield ◽  
Vegetative Organs

The dry matter and moisture contents of the aboveground vegetative organs and kernels of four maize hybrids were studied in Martonvásár at five harvest dates, with four replications per hybrid. The dry matter yield per hectare of the kernels and other plant organs were investigated in order to obtain data on the optimum date of harvest for the purposes of biogas and silage production.It was found that the dry mass of the aboveground vegetative organs, both individually and in total, did not increase after silking. During the last third of the ripening period, however, a significant reduction in the dry matter content was sometimes observed as a function of the length of the vegetation period. The data suggest that, with the exception of extreme weather conditions or an extremely long vegetation period, the maximum dry matter yield could be expected to range from 22–42%, depending on the vegetation period of the variety. The harvest date should be chosen to give a kernel moisture content of above 35% for biogas production and below 35% for silage production. In this phenophase most varieties mature when the stalks are still green, so it is unlikely that transport costs can be reduced by waiting for the vegetative mass to dry.

NITROGEN NUTRITION OF CITRUS NURSERY STOCK IN PINE BARK SUBSTRATES.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1161f-1161
Author(s):  
John D. Lea-Cox ◽  
Irwin E. Smith
Keyword(s):  
Nutrient Solution ◽  
Nitrogen Nutrition ◽  
Dry Mass ◽  
Pine Bark ◽  
Growing Period ◽  
Rough Lemon ◽  
Nursery Stock ◽  
Citrus Rootstock ◽  
Cleopatra Mandarin ◽  
Nutrient Solutions

Pine bark is utilized as a substrate in citrus nurseries in South Africa. The Nitrogen (N) content of pine bark is inherently low, and due to the volubility of N, must be supplied on a continual basis to ensure optimum growth rates of young citrus nursery stock. Three citrus rootstock (rough lemon, carrizo citrange and cleopatra mandarin) showed no difference in stem diameter or total dry mass (TDM) when supplied N at concentrations between 25 and 200 mg ·l-1 N in the nutrient solution over a 12 month growing period. Free leaf arginine increased when N was supplied at 400 mg·l-1 N. The form of N affected the growth of rough lemon. High NH4-N:NO3-N (75:25) ratios decreased TDM when Sulfur (S) was absent from the nutrient solution, but not if S was present. Free arginine increased in leaves at high NH4-N (No S) ratios, but not at high NH4-N (S supplied) ratios. Free leaf arginine was correlated with free leaf ammonia. These results have important implications for reducing the concentration of N in nutrient solutions used in citrus nurseries and may indicate that higher NH4-N ratios can be used when adequate S is also supplied.

Phosphorus Fertilization in Ebb and Flow Production of Bedding Plants

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 523b-523 ◽  
Author(s):  
Erin James ◽  
Marc van Iersel
Keyword(s):  
Dry Mass ◽  
Plant Production ◽  
Phosphorus Fertilization ◽  
Time Interval ◽  
Nutrient Runoff ◽  
Growing Period ◽  
Bedding Plants ◽  
Lack Of Information ◽  
Bedding Plant ◽  
Ebb And Flow

The quantity and quality of available water in the Southeastern United States continues to decline as demands on limited resources increase. Growers will soon be forced to comply with legal limitations on water consumption and limits on nutrient runoff from their operations. A lack of information on standard growing practices using alternative irrigation systems such as ebb and flow is hindering their acceptance and implementation. We are currently conducting a series of experiments to establish basic growing guidelines for the use of ebb and flow in the greenhouse in bedding plant production. In the third of these experiments, Petunia × hybrida Hort. Vilm.-Andr. `Blue Frost' and Begonia × hiemalis Fotsch. `Ambassador Scarlet' were grown for 5 weeks on ebb and flow tables with fertigation solutions (225 ppm N) containing three different levels of phosphorus (0, 50, and 100 ppm). Three soilless media were also used, which varied in their percentage content of vermiculite, perlite, pine bark and coconut coir. For both the begonias and petunias dry mass of the shoot was greatest in plants grown with higher levels of phosphorus. In comparison to plants grown with 0 ppm phosphorous, petunias and begonias grown with 50 or 100 ppm P were 44% and 25% greater in mass, respectively. However, begonias had 38% more flowers when fertigated with the higher levels of phosphorous while petunias flowered earlier with 0 ppm P fertigation solution. The electrical conductivity of the media did not change significantly over the course of the growing period, but the pH dropped by an average of 1 over the same time interval.

Using a sensitivity analysis of a weed dynamics model to develop sustainable cropping systems. I. Annual interactions between crop management techniques and biophysical field state variables

2012 ◽  
Vol 151 (2) ◽  
pp. 229-245 ◽  
Author(s):  
N. COLBACH ◽  
D. MÉZIÈRE
Keyword(s):  
Weed Management ◽  
Cropping Systems ◽  
Crop Management ◽  
State Variables ◽  
Long Term Effects ◽  
Dynamics Model ◽  
Previous Crop ◽  
Field State ◽  
Management Techniques ◽  
Weed Dynamics

SUMMARYEnvironmental problems mean that herbicide applications must be drastically reduced and optimized. Models that quantify the effects of crop management techniques on weed dynamics are valuable tools for designing weed management strategies. Indeed, the techniques to be optimized are numerous and diverse, and their effects vary considerably with environmental conditions and the state of the weed flora. In the present study, a mechanistic weed dynamics model,AlomySys, was used to carry outin silicoexperiments in order to: (1) rank crop management components according to the resulting decrease in weed infestation, and (2) study the sensitivity of the major component effects to biophysical field state variables in order to identify indicators and thresholds that could serve for future decision-rules for farmers. The various results were compiled into rules for optimizing timing and other options (tillage tools, herbicide types) for the different crop management techniques. The rules were based on a series of biophysical field state variables, i.e. cumulated rainfall, thermal time, soil moisture and weed densities prior to the operation, in the previous and pre-previous crops. For instance, the first tillage should be delayed until the cumulated rainfall since harvest exceeds 50 mm and be carried out in moist conditions. Mouldboard ploughing is advised if the infestation of the previous crop exceeds 20 weeds/m2and particularly if this exceeds 0·3 times that of the pre-previous crop. Ploughing should occur when the cumulated rainfall since harvest reaches 100–200 mm. The effects of crop succession and long-term effects of management techniques have been studied in a companion paper (Colbachet al. 2012).

scholarly journals Comparative Study of the Effect of Different Weed Management Strategies on Disease Severity and Marketable Yield of Paprika (Capsicum Annuum L.) in the Smallholder Farming Sector of Zimbabwe

2008 ◽  
Vol 48 (1) ◽  
pp. 107-117 ◽  
Author(s):  
Maxwell Handiseni ◽  
Julia Sibiya ◽  
Vincent Ogunlela ◽  
Irene Koomen
Keyword(s):  
Comparative Study ◽  
Capsicum Annuum ◽  
Weed Management ◽  
Leaf Spot ◽  
Management Strategies ◽  
Smallholder Farming ◽  
Marketable Yield ◽  
Weed Density ◽  
Marketable Fruit ◽  
Hand Weeding

Comparative Study of the Effect of Different Weed Management Strategies on Disease Severity and Marketable Yield of Paprika (Capsicum AnnuumL.) in the Smallholder Farming Sector of ZimbabweOn-farm trials were conducted in the Chinyika Resettlement Area of Zimbabwe under dryland conditions to investigate the effects of different weed management methods on disease incidence, severity and paprika (Capsicum annuum) pod yield. The weed control treatments included hand weeding at 2 and 6 weeks after transplanting (WAT); ridge re-moulding at 3,6 and 9 WAT; application 4l/ha Lasso (alachlor) immediately after transplanting, and Ronstar (oxidiazinon) at 2l/ha tank mixed with Lasso at 2l/ha one day before transplanting. The herbicide-water solution was applied at the rate of 200l/ha using a knapsack sprayer. Major diseases identified were bacterial leaf spot (Xanthomonas campestrispv.vesicatoria), cercospora leaf spot (Cercospora unamunoi), grey leaf spot (Stemphylium solani) and powdery mildew (Leveillula taurica) in both seasons. For the 2000/2001 season hand weeding at 2 and 6 WAT and ridge re-moulding at 3, 6 and 9 WAT had the greatest reduction effect on the area under disease progress curve (AUDPC) and the highest marketable fruit yield. In the 2001/2002 season, both herbicide treatments had the same effect as hand weeding and ridge re-moulding on AUDPC and marketable fruit yield. The least weed density was obtained by ridge re-moulding at 3, 6, and 9 WAT in the 2000/2001 season. Weed density was statistically the same across all treatments except the check treatment in 2001/2002 season. Hand weeding operations were significantly (p < 0.05) effective and consequently gave the highest added profits mainly because of their effect on major weeds such asDatura stramonium.

scholarly journals Effect of duration of weed competition and weed control on the yield of Indian spinach

1970 ◽  
Vol 33 (4) ◽  
pp. 623-629 ◽  
Author(s):  
MSA Khan ◽  
MA Hossain ◽  
M Nurul Islam ◽  
SN Mahfuza ◽  
MK Uddin
Keyword(s):  
Weed Management ◽  
Critical Period ◽  
Field Experiments ◽  
Agricultural Research ◽  
Cyperus Rotundus ◽  
Weed Competition ◽  
Weed Species ◽  
Maximum Benefit ◽  
Hand Weeding ◽  
Crop Weed Competition

Field experiments were conducted at the research farm of Bangladesh Agricultural Research Institute, Joydebpur during kharif-1 (March to July) seasons of 2005 and 2006 to identify the critical period of crop-weed competition for Indian spinach. Major weed species were Paspalurn commersoni, Echinochlaa crusgalli. Lie nv/nc india. Cyanotis axillaris and Cyperus rotundus. The lowest weed dry matter was 76.3 g m-2 in 2005 and l01.60 g m-2 in 2006 from the plots weeded up to 40 days after transplanting (DAT). The highest yields were obtained (74.82 t ha in 2005 and 48.48 t ha in 2006) from the weed free plots. The fresh yield of Indian spinach did not vary among no weeding upto 20, 30 and 40 DAT in 2006. But weeded plot upto 30 and 40 DAT produced identical yield in 2005. Maximum BCR (4.52) was obtained from weeded plots upto 30 DAT in 2005 but BCR (2.60) was same from weeded upto 30 and 40 DA F in 2006. On an average, highest BCR (3.55) was recorded from weeding upto 30 DAT. Results revealed that the critical period of crop weed competition lies between 20 and 30 DAT and two times hand weeding would be necessary within 30 DAT for maximum benefit. Key Words: Crop-weed competitions, critical period, weed management and Indian spinach. doi: 10.3329/bjar.v33i4.2306 Bangladesh J. Agril. Res. 33(4) : 623-629, December 2008

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