Allelopathic potentials of residues of 6 brassica species on johnsongrass [Sorghum halepense (L.) Pers.]

Johnsongrass ( Sorghum halepense (L.) Pers.) is a troublesome weed species of many crops in Turkey as well as worldwide. Allelopathic potential of residues of some brassica species, which are round white radish (Raphanus sativus L.), garden radish (R. sativus L.), black radish (R. sativus L. var. niger), little radish (R. sativus L. var. radicula, turnip (Brassica campestris L. subsp. rapa) and rapeseed (Brassica napus L. oleifera DC.) on johnsongrass were investigated under both laboratory and field conditions. All species suppressed johnsongrass in field and laboratory conditions. The lowest suppression was from garden radish, which has already been used to control johnsongrass by few farmers in Turkey. It is concluded that the plants studied can be used to control johnsongrass. Higher amount of isothiocyanates (isothiocyanate benzyl, Isothiocyanate allyl) in black radish extract and lower amount of isothiocyanates at garden radish extract were determined. Parallel results for johnsongrass suppression and amount of isothiocyanates show that allelopathy play roles in johnsongrass suppression by brassica species

Determination of critical period for weed control in the second crop corn under Mediterranean conditions

No Abstrac

Agricultural Academy

Abstract UREMIS, I., M. E. CALISKAN, A. ULUDAG and S. CALISKAN, 2009. Weed management in earlyseason potato production in the Mediterranean conditions of Turkey. Bulg. J. Agric. Sci., Early-season potato production is a profitable system in the Mediterranean part of Turkey. Weeds are problem in early-season potato production. The effect of combinations of extended season weed control techniques (none, hand-hoeing twice, black or clear plastic mulch placed at planting, or metribuzin POST and soil applied herbicides (none, trifluralin PPI, or a commercially formulated combination of pendimethalin and metolachlor PRE) on weed control and potato yield were compared. No weed species shift was observed due to treatments. Soil applied herbicides kept weeds under pressure through growing season in some extent, improved effect of black plastic mulch on weed control, caused bigger tubers and consequently higher class-A yield. Although hand-hoeing twice during the growing season resulted in the lowest percent weed cover at harvest and better yield, cost and availability of labor may not make this method feasible for a potato grower. Combinations of PPI or PRE soil-applied herbicides and plastic mulch will be necessary. Overall, black rather than clear plastic mulch seems to be the best choice for an extended-season control method following a PPI or PRE herbicide. Metribuzin controlled weeds in some extent but the effect did not translate to potato yield. Plastic mulches, especially clear one, caused earliness at emergence, which might help earlier harvest

EFFECTS OF SAGE LEAFHOPPER FEEDING DAMAGE ON HERBAGE COLOUR, ESSENTIAL OIL CONTENT AND COMPOSITIONS OF TURKISH AND GREEK OREGANO

Turkish (Origanum onites L.) and Greek oregano (Origanum vulgare L., ssp. hirtum (Link.) Ietswaart) species were investigated to determine herbage colour, essential oil content and composition changes due to sage leafhopper (Eupteryx melissae) (Hemiptera: Cicadellidae) infestation. Sage leafhopper population on both Turkish and Greek oregano did not significantly vary. The sage leafhopper damage was more severe in the lower part of the canopy than the middle and upper parts. Extensive sage leafhopper feeding dramatically reduced essential oil contents, resulting in 28.8 and 34.8% reductions for Greek and Turkish oregano, respectively. Carvacrol, the major essential oil component of both oregano species, did not remarkably vary between leafhopper infested and non-infested plants. With respect to herbage colour, the brightness, redness and yellowness values were significantly different between infested and non-infested plants. Sage leafhopper damage increased brightness and yellowness but decreased greenness of the oregano herbage. To avoid the feeding damage, it is essential to detect the sage leafhopper problem as early as possible and certain control practices are necessary when the infestation is high.Turkish&nbsp;(Origanum onites L.) and&nbsp;Greek&nbsp;oregano&nbsp;(Origanum vulgare L., ssp. hirtum (Link.) Ietswaart) species were investigated to determine&nbsp;herbagecolour,&nbsp;essential&nbsp;oil&nbsp;content&nbsp;and composition changes due to&nbsp;sage&nbsp;leafhopper&nbsp;(Eupteryx melissae) (Hemiptera: Cicadellidae) infestation.&nbsp;Sage&nbsp;leafhopperpopulation&nbsp;on&nbsp;both&nbsp;Turkish&nbsp;and&nbsp;Greek&nbsp;oregano&nbsp;did not significantly vary. The&nbsp;sage&nbsp;leafhopper&nbsp;damage&nbsp;was more severe in the lower part&nbsp;of&nbsp;the canopy than the middle and upper parts. Extensive&nbsp;sage&nbsp;leafhopper&nbsp;feeding&nbsp;dramatically reduced&nbsp;essential&nbsp;oil&nbsp;contents, resulting in 28.8 and 34.8% reductions for&nbsp;Greek&nbsp;and&nbsp;Turkish&nbsp;oregano, respectively. Carvacrol, the major&nbsp;essential&nbsp;oil&nbsp;component&nbsp;of&nbsp;both&nbsp;oregano&nbsp;species, did not remarkably vary betweenleafhopper&nbsp;infested and non-infested plants. With respect to&nbsp;herbage&nbsp;colour, the brightness, redness and yellowness values were significantly different between infested and non-infested plants.&nbsp;Sage&nbsp;leafhopper&nbsp;damage&nbsp;increased brightness and yellowness but decreased greenness&nbsp;of&nbsp;the&nbsp;oreganoherbage. To avoid the&nbsp;feeding&nbsp;damage, it is&nbsp;essential&nbsp;to detect the&nbsp;sage&nbsp;leafhopper&nbsp;problem as early as possible and certain control practices are necessary when the infestation is high.</p

Determination of critical period for weed control in the second crop corn under Mediterranean conditions

Weeds are a major constraint in corn production. Understanding the critical period for weed control (CPWC) can be a tool for effective weed control and reducing the impacts of weeds. Three experiments were conducted to determine CPWC in the second corn crop from 1996 to 1998. The critical period for weed control in the second crop corn in the mediterranean region was determined to be from 131 to 927 growing degree days (GDD) after sowing in 1996, from 337 to 731 GDD in 1997 and from 266 to 551 GDD in 1998 for 10% yield loss; for 2.5 - 5% yield loss, the critical period starts with germination and lasts longer. Preemergence (PRE) or presowing (PPI) herbicides would be preferred to avoid higher yield losses. If a farmer can tolerate 10% yield loss, a postemergence (POST) herbicide can be applied in the second week after crop sowing, and the field should be kept weed free for 4 or 5 weeks. The duration of weed competition and time of weed removal also affect tasseling, silking, plant height, stem diameter, first ear's height and number of kernels in an ear, all of which correlate with corn yield. © 2009 Academic Journals

Frequency-dependent effects of sequenced pulsed magnetic field on experimental diabetic neuropathy

PubMedID: 26136088Purpose: Pulsed magnetic field (PMF) as an important non- invasive alternative therapeutic option has been investigated in several pre-clinical and clinical studies. We also hypothesized that sequenced PMF formed with different frequencies can modulate the diabetes-induced neuropathic signs differently.Materials and methods: Therapeutic actions of sequenced PMF including 1, 5, 1, 5 Hz (low (L)-PMF) or 30, 40, 30, 40 Hz (high (H)-PMF) were examined on improving signs and symptoms of diabetic neuropathic pain in the streptozotocin-induced diabetic rat models by measuring nociceptive parameters such as hyperalgesia and allodynia, and various cytokine levels (tumor necrosis factor [TNF]-alpha, interleukin [IL]-1 beta, IL-6 and IL-10) of spinal cord and sciatic nerve tissues.Results: Ameliorating potential of L-PMF application on signs of diabetes is significantly higher than those of H-PMF. L-PMF partially attenuated the diabetes-induced increase in the blood glucose level, enhanced the decreased thresholds and latency during the experiments. Diabetes enhanced the pro-inflammatory cytokine, TNF-alpha, IL-1 beta and IL-6, levels in spinal cord and sciatic nerve of rats. L-PMF treatments to diabetic rats decreased these, but enhanced the production of anti-inflammatory cytokine, IL-10.Conclusions: The present results demonstrated that sequenced L-PMF treatment can relieve neuropathic signs of diabetes in rats. Anti-hyperglycemic, anti-allodynic and anti-hyperalgesic effects of L-PMF treatment can be closely correlated with each other. Furthermore, decreasing actions of L-PMF on pro-inflammatory/anti-inflammatory cytokine ratio can suggest that the therapeutic potential of L-PMF in diabetes induced neuropathy may involve the regulation of the neuroinflammatory/neuroimmune processes. © 2015 Informa UK, Ltd

Studies on different herbicide application methods in second-crop maize fields

Overall application of herbicides with hollow cone nozzles is common practice in second-crop maize in the Cukurova Region of Turkey. Effective integrated weed management tactics are needed for this region. Acetochlor and nicosulfuron, two commonly used herbicides in maize production, were applied pre-emergence and post-emergence, respectively. Spinning disc nozzles with a reduced spray volume did not improve weed control and with a reduced herbicide dose gave inadequate weed control. Banding was as effective as broadcast application. Different bandwidths with even flat fan nozzles, 15, 20, 25, 30, and 35cm, gave similar weed control and maize yield. Banding decreased herbicide and water use by up to 78%. © 2004 Elsevier Ltd. All rights reserved.Ministry of Agriculture and Rural DevelopmentAuthors thank to Dr. Martha Rowe because of her proof reading of the manuscript. The study was supported by the Ministry of Agriculture and Rural Affairs, Turkey under the Project No. TAGEM/BS/96/01/05/203

The use of maize as replacement crop in trifluralin treated cotton fields in Turkey

Maize and cotton are primary crops in Turkey. Trifluralin is commonly used in cotton. In some years heavy rain after cotton sowing kills cotton seedlings. Although maize is the best choice as a replacement crop, the trifluralin label prohibits maize sowing for 12 months. The current study was carried out to look at possible use of maize as a catch crop in trifluralin treated cotton fields. Maize varieties showed varying response to trifluralin. However, better and worse responding varieties responded to trifluralin similarly in field conditions due to environmental conditions which was favorable for higher trifluralin loss. Temperature during flooding and duration of flooding do not have any affect on trifluralin injury.TARP 2464This study supported by TUBITAK, Turkish Science Foundation, under project number TARP 2464