چكيده فارسي :
به منظور ارزيابي تأثير كاربرد روغن‌هاي گياهي بر كارايي ستوكسيديم در كنترل قياق آزمايشي به‌صورت فاكتوريل بر پايه طرح كاملاً تصادفي با چهار تكرار در سال 1396 در گلخانه تحقيقاتي دانشكده كشاورزي دانشگاه بيرجند انجام شد. تيمارها شامل غلظت ستوكسيديم در شش سطح (0، 46/875، 93/75، 187/5 ، 281/25 و 375 گرم ماده مؤثره در هكتار) و نوع ماده افزودني گياهي در 8 سطح شاهد (بدون روغن گياهي) و روغن‌هاي گياهي ذرت، زيتون، هسته انگور، زيره، سياه‌دانه، نعناع و آفتابگردان بودند. نتايج حاصل از برازش داده‌هاي اندازه‌گيري شده به مدل سه پارامتري لجستيك نشان داد كه غلظت مؤثر 50 درصد براي تمام صفات اندازه‌گيري شده در حضور روغن‌هاي گياهي در مقايسه با كاربرد ستوكسيديم بدون روغن گياهي كاهش يافت كه نشان‌دهنده بهبود كارايي ستوكسيديم در كنترل قياق است. توانايي نسبي محاسبه‌شده در حضور روغن‌هاي گياهي ذرت، زيتون، هسته انگور، زيره، سياه‌دانه، نعناع و آفتابگردان براي ارتفاع گياه به ترتيب 1.30, 1.57, 1.18, 1.23, 1.27, 1.24, 1.07 برابر، وزن تازه اندام هوايي به ترتيب 3.75, 1.49, 1.59, 3.52, 2.93, 1.81 و 1/58 برابر، وزن خشك اندام هوايي به ترتيب 2.63, 1.30, 1.35, 2.57,
1.99, 1.48, و 1/86 برابر، وزن خشك اندام‌هاي زيرزميني به ترتيب 2.21, 1.27, 1.47, 2.09, 1.67, 1.82 و 1/71 برابر، و حجم اندام‌هاي زيرزميني به ترتيب 1.74, 1.56, 1.55, 2.13, 1.58, 1.38 و 1/41 برابر بود. بنابراين كاربرد روغن‌هاي گياهي به همراه ستوكسيديم باعث بهبود كارايي شده و مي‌تواند منجر به كاهش ورود اين علف‌كش به محيط زيست و همچنين كاهش خطر انتقال به محل غير هدف گردد.
چكيده لاتين :
Introduction: Weed management is one of the most important aspects of successful crop production for
supplying food needed for the rising population. Johnsongrass (Sorghum halepense L.) is among the most
noxious weeds in the world due to its superior biology and tremendous ecological adaptations. It causes
substantial yield loss in different field crops including corn, soybean, wheat, and sorghum. Therefore,
management of Johnsongrass is crucial for optimum crop production. Prevention by clean cultivation, cultural
management by using weed-competitive, mechanical management by hand hoeing, biological management by
applying pathogens, and eventually applying herbicide as chemical management can be used for controlling
Johnsongrass. Chemical management is an effective method to control Johnsongrass. For decreasing adverse
effects of herbicide and costs of production, optimizing herbicides performance is very essential. It appears that
the use of adjuvants seems to be a best solution to achieve optimized herbicides performance. In spite of these
advantages, some synthetic adjuvants have shown side effects on living organs. Therefore, using
environmentally safe adjuvants is a key point for applying this technology. This study was conducted for
evaluating vegetable oil effects on Johnsongrass control by sethoxydim herbicide.
Materials and Methods: To study the effects of vegetable oils on the performance of sethoxydim on
Johnsongrass (Sorghum halepense L.) control, a factorial experiment based on completely randomized design
including sethoxydim concentration at six levels (0, 46.875, 93.75, 187.5, 281.25 and 375 g ai ha-1) and
vegetable oils at 8 levels (with and without corn, olive, grape seed, cumin, fennel flower, mint and sunflower
oils) with four replications was conducted in the research greenhouse of college of agriculture Birjand university
in 2017. For increasing seed germination and breaking seed dormancy of Johnsongrass, the seeds were treated by
sulfuric acid for 3 min and then washed by tap water for 30 minutes. The seeds were then sown in potting trays
(3 cm × 3 cm × 5 cm) filled with moistened peat. One week after sowing, at the one-leaf seedlings stages, they
were transplanted to plastic pots with 2 liter volume and filled with a mixture of sand, clay loam soil, and peat
(1:1:1; v/v/v). The pots were sub-irrigated every two days. The seedlings were thinned to four per pot at the twoleaf stage. Spraying was done at the four-leaf stage by using a chargeable sprayer equipped with an 8002 flat fan
nozzle tip delivering 250 L ha-1 at 2 bar spray pressure. Four weeks after spraying, height of plant was measured
and then the shoots and roots of plant were harvested and weighed immediately after the root volume was
measured. The plant parts were oven-dried and reweighed.
Results and Discussion: When emulsified vegetable oils alone were sprayed against Johnsongrass, none of
vegetable oils had phytotoxic effects on plant height, fresh and dry weight of shoot and root, root volume and
root length of Johnsongrass (Table 2). This finding was similar to the results of Tworkoski (2002) (42) and Izadi
darbandi et al (2013) (17). The ED50 parameter was estimated by dose response model based on Johnsongrass
plant height, shoot and root dry and fresh weight, and root volume. All emulsifiable vegetable oils improved
significantly the effectiveness of sethoxydim on Johnsongrass. Relative potency in the presence of corn, olive,
grape seed, cumin, fennel flower, mint and sunflower oils was 1.30, 1.57, 1.18, 1.23, 1.27, 1.24, and 1.07 times
for plant height, 3.75, 1.49, 1.59, 3.52, 2.93, 1.81, and 2.58 times for shoot fresh weight, 2.63, 1.30, 1.35, 2.57,
1.99, 1.48, and 1.86 times for shoot dry weight, 2.21, 1.27, 1.47, 2.09, 1.67, 1.82, and 1.71 times for root dry
weight, and 1.74, 1.56, 1.55, 2.13, 1.58, 1.38, and 1.41 times for root volume, respectively, as compared to the
condition without vegetable oils. Among emulsifiable vegetable oils, the highest effect on shoot and root dry
weight was observed in corn and cumin oils while olive oil showed the lowest effect.
Conclusion: Our result showed that vegetable oil including corn, olive, grape seed, cumin, fennel flower, mint and sunflower oils had not only the phytotoxic effects on produced biomass by Johnsongrass, but also
improved the performance of Sethoxydim for Johnsongrass control. Therefore, using vegetable oils mixed with
sethoxydim can decrease the adverse impacts of this herbicide on the environment.
