نقش تاريخ كاشت و ارقام برنج بر ميزان تأثير علف هرز روي عملكرد دانه و برخي صفات زراعي در روش خشكه‌كاري

The role of planting date and rice cultivars on the effect of weed on yield and some agronomic traits in dry-bed seeding system

ﺑﻪﻣﻨﻈﻮر ﺗﻌﯿﯿﻦ اﺛﺮات ﺣﻀﻮر ﻋﻠﻒ ﻫﺮز ﺑﺮ واﮐﻨﺶ ﻋﻤﻠﮑﺮدي ارﻗﺎم ﺑﺮﻧﺞ درزﻣﺎنﻫﺎي ﻣﺨﺘﻠﻒ ﮐﺎﺷﺖ ﻣﺴﺘﻘﯿﻢ ﺧﺸﮑﻪﮐﺎري؛ آزﻣﺎﯾﺸﯽ ﺑﻪﺻﻮرت ﮐﺮتﻫﺎي ﺧﺮدﺷﺪه در ﻗﺎﻟﺐ ﺑﻠﻮكﻫﺎي ﮐﺎﻣﻞ ﺗﺼﺎدﻓﯽ، ﺑﺎ ﺳﻪ ﺗﮑﺮار اﺟﺮا ﮔﺮدﯾﺪ. ﻋﺎﻣﻞ اﺻﻠﯽ ﺗﺎرﯾﺦ ﮐﺎﺷﺖ در ﺳﻪ ﺳﻄﺢ )15 ﺧﺮداد، 25 ﺧﺮداد و 5 ﺗﯿﺮﻣﺎه( و ﭼﻬﺎر رﻗﻢ ﺑﺮﻧﺞ ﺷﺎﻣﻞ دو رﻗﻢ ﻣﺤﻠﯽ ﭼﻤﭙﺎ Oryza ( )sativa L. cv. champa و ﻋﻨﺒﻮري ﻗﺮﻣﺰ )Oryza sativa L. cv. red anbori( و ارﻗﺎم ﭘﺮ ﻣﺤﺼﻮل و اﺻﻼحﺷﺪه داﻧﯿﺎل )Oryza sativa L. cv. danial( و ﺷﻔﻖ )Oryza sativa L. cv. shafagh( ﺑﻪﻋﻨﻮان ﻋﺎﻣﻞ ﻓﺮﻋﯽ، ﮐﺸﺖ ﮔﺮدﯾﺪﻧﺪ. ﺳﭙﺲ ﻫﺮ ﮐﺮت آزﻣﺎﯾﺶ ازﻟﺤﺎظ ﻃﻮﻟﯽ ﺑﻪ دو ﻗﺴﻤﺖ ﺗﻘﺴﯿﻢ ﺷﺪ. ﻗﺴﻤﺖ ﺑﺎﻻﯾﯽ ﻫﺮ ﮐﺮت وﺟﯿﻦ ﻧﺸﺪه و ﺑﻪﻋﻨﻮان ﺷﺎﻫﺪ آن ﮐﺮت در ﻧﻈﺮ ﮔﺮﻓﺘﻪ ﺷﺪ و ﻗﺴﻤﺖ ﭘﺎﯾﯿﻦ آن وﺟﯿﻦ دﺳﺘﯽ و ﺗﻤﺎم ﻋﻠﻒﻫﺎي ﻫﺮز آن ﺣﺬف ﮔﺮدﯾﺪ. ﺑﺮ اﺳﺎس ﻧﺘﺎﯾﺞ ﺑﻪدﺳﺖآﻣﺪه، اﺛﺮ ﺗﺎرﯾﺦ ﮐﺎﺷﺖ و رﻗﻢ ﺑﺮ ﻋﻤﻠﮑﺮد ﺑﯿﻮﻟﻮژﯾﮏ، ﻋﻤﻠﮑﺮد داﻧﻪ و ﺗﻌﺪاد ﺧﻮﺷﻪ در ﻣﺘﺮﻣﺮﺑﻊ در ﺷﺮاﯾﻂ ﮐﻨﺘﺮل ﻋﻠﻒ ﻫﺮز در ﺳﻄﺢ ﯾﮏ درﺻﺪ ﻣﻌﻨﯽدار ﮔﺮدﯾﺪ. ﺑﯿﺸﺘﺮﯾﻦ ﺗﻮﻟﯿﺪ داﻧﻪ در ﺗﺎرﯾﺦ ﮐﺎﺷﺖ اول و در رﻗﻢ ﭘﺮ ﻣﺤﺼﻮل ﺷﻔﻖ ﺑﻪ ﻣﯿﺰان 5253 ﮐﯿﻠﻮﮔﺮم در ﻫﮑﺘﺎر ﻣﺸﺎﻫﺪه ﺷﺪ. ﻫﻤﭽﻨﯿﻦ ﻧﺘﺎﯾﺞ ﻣﺸﺨﺺ ﻧﻤﻮد ﻣﯿﺰان ﮐﺎﻫﺶ ﻋﻤﻠﮑﺮد داﻧﻪ ﻧﺎﺷﯽ از ﺣﻀﻮر ﻋﻠﻒ ﻫﺮز در ﺑﯿﻦ ﺗﺎرﯾﺦﻫﺎي ﮐﺎﺷﺖ ﻣﺘﻔﺎوت ﺑﻮد ﺑﻪﻃﻮريﮐﻪ ﺑﯿﺸﺘﺮﯾﻦ و ﮐﻤﺘﺮﯾﻦ ﻣﯿﺰان ﮐﺎﻫﺶ ﺗﻮﻟﯿﺪ ﺑﺎ ﻣﺘﻮﺳﻂ 1875 و 1090 ﮐﯿﻠﻮﮔﺮم در ﻫﮑﺘﺎر ﺑﻪ ﺗﺮﺗﯿﺐ در ﺗﺎرﯾﺦﻫﺎي ﮐﺎﺷﺖ اول و ﺳﻮم ﻣﺸﺎﻫﺪه ﮔﺮدﯾﺪ. در ﻣﯿﺎن ارﻗﺎم ﺑﺮﻧﺞ ﻧﯿﺰ ﮐﺎﻫﺶ ﻋﻤﻠﮑﺮد داﻧﻪ ﺑﻪ ﺗﺮﺗﯿﺐ ﺑﻪ ﻣﯿﺰان 40/85 و 32/95 درﺻﺪ در ارﻗﺎم ﭘﺮ ﻣﺤﺼﻮل و ارﻗﺎم ﻣﺤﻠﯽ دﯾﺪه ﺷﺪ.

To investigate the effect of planting date on yield and some agronomic traits in local and high-yielding rice cultivars in direct cultivation by dry-bed seeding system was conducted in the form of a splitplot in a randomized complete block design with three replications. The main plot of planting date in three levels (June 15, June 25, and July 5) and four rice cultivars including two local cultivarsChampa and Red anbori and cultivars High-yielding and improved Danial and Shafagh was grown as a subplot at each planting date. Then, each plot was divided into two parts. The upper part of plot was not weeding and was considered as a control and the lower part of the plot was removed by hand weeding. Based on the results, the effect of planting date and cultivar on biological yield, grain yield, and the number of spikes per square meter under weed control conditions was significant at the level of one percent. In this experiment, the highest yield was observed on the date of the first planting in the high-yielding cultivar Shafagh and at the rate of 5253 kg/ha. The results showed that grain yield loss due to weed presence was different depending on planting date, so that the highest and lowest production loss with the average of 1815 and 1090 kg/ha was related to the first and third planting date, respectively. Among rice cultivars, a decrease in grain yield of 40.85 and 32.95 percent was observed in high-yielding cultivars and local cultivars, respectively.