نوع مقاله : مقاله پژوهشی
نویسندگان
1 سازمان تحقیقات کشاورزی
2 دانشجوی دکتری اگرو تکنولوژی-فیزیولوژی گیاهان زراعی، گروه کشاورزی، دانشگاه آزاد اسلامی، گرگان، ایران.
3 گروه کشاورزی، واحد گرگان، دانشگاه آزاد اسلامی، گرگان، ایران.
4 گروه کشاورزی، واحد آزادشهر، دانشگاه آزاد اسلامی، آزادشهر، ایران.
5 استاد، موسسه تحقیقات پنبه کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، گرگان، ایران.
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and objectives: Conventional agricultural practices, particularly intensive tillage and continuous monocropping, remain the dominant production systems for cotton worldwide. However, improper management of these practices may accelerate soil nutrient depletion and threaten the sustainability of cotton production.
Materials and methods: A factorial split-plot experiment based on a randomized complete block design with four replications was conducted at Aliabad Katoul, Golestan Province, I. R. Iran. Tillage system, including conventional tillage, conservation tillage, and no-tillage, was assigned to the main plots. Cotton cultivars (Sajedi and Golestan) and plant densities (66, 83, 111, and 166 thousand plants ha⁻¹) were arranged factorially within the subplots. Growth duration, plant height, number of fruiting branches, boll shedding percentage, boll number per plant and per unit area, boll weight, seed cotton yield, lint yield, lint percentage, and total biomass were determined. Biomass accumulation was described using a logistic growth model. Data were subjected to analysis of variance using SAS software,
Results: Tillage system significantly affected all measured traits except the number of fruiting branches per plant and boll number per plant. Cultivar significantly influenced almost traits , whereas plant density significantly affected all studied characteristics. The no-tillage system produced the greatest plant height (102.1 cm), growth duration (112.2 days), seed cotton yield (2,846 kg ha⁻¹), and total biomass (8,264 kg ha⁻¹). Compared with Sajedi, the Golestan cultivar exhibited superior seed cotton yield (2,779 vs. 2,437 kg ha⁻¹) and total biomass (8,007 vs. 7,021 kg ha⁻¹). The plant density of 111 thousand plants ha⁻¹ resulted in the highest seed cotton yield (2,968 kg ha⁻¹), boll number per unit area (87.06 bolls m⁻²), and total biomass (8,550 kg ha⁻¹). The tillage × cultivar interaction indicated that Golestan under no-tillage achieved the longest growth period (115.1 days), the highest number of fruiting branches per unit area (114.50 m⁻²), and the greatest lint yield (1,089 kg ha⁻¹). Logistic growth analysis demonstrated that the density of 111 thousand plants ha⁻¹ initiated the rapid biomass accumulation phase earlier (approximately 49 days after emergence) and exhibited the highest mean and maximum biomass accumulation rates, indicating greater dry matter partitioning efficiency. PCA revealed that the first two principal components explained 84.61% of the total variation (49.12% and 35.49%, respectively), and identified the combination of no-tillage × Golestan cultivar × 111 thousand plants ha⁻¹ as the most desirable treatment based on overall agronomic performance.
Conclusion: The combination of no-tillage, the Golestan cultivar, and a plant density of 111 thousand plants ha⁻¹ is recommended as the optimum management strategy for double-cropped cotton production. This treatment improved growth characteristics, increased boll number per unit area and reproductive biomass accumulation, and enhanced seed cotton yield by approximately 22% compared with lower plant densities. t
کلیدواژه‌ها [English]
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