Document Type : Research Paper
Authors
1
Researcher of Horticulture Crop Research Department, Khorasan Razavi Agricultural and Natural Resources Resaerch and Education Center, AREEO, Mashhad, Iran.
2
Agricultural and Horticultural Science Research Department, Khorasan Razavi Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization, Mashhad, 91769-83641, Iran.
3
Assistant Professor of Agricultural and Horticultural Science Research Department, Khorasan Razavi Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization, Mashhad, 91769-83641, Ir
10.22092/ijcr.2024.365893.1215
Abstract
Background and objectives: Cotton is one of the valuable agricultural plants, which is known as white gold due to its economic, agricultural and commercial importance. This plant is very sensitive to environmental conditions, and factors such as variety, plant density, planting time, nutrition, water management methods and planting methods are effective on its performance; Therefore, it is possible to increase the yield with a proper combination of different methods of crop management, compliance with the appropriate planting date and method to achieve the potential of a variety. This research was conducted to determine the optimal planting date of new cotton cultivars and evaluate its effects on yield and yield components of cotton.
Materials and methods: This research was conducted in the two years of 2018 and 2019 at the Research and Training Station of Agriculture and Natural Resources of Kashmar as a split plot experiment in the form of a randomized complete block design with three replications. The main factor included planting date in three levels (10 May, 31 May, and 20 June) and the second factor included commercial cotton cultivars in four levels (Armaghan, Shayan, Khorshid, and Khordad). At the time of harvest, traits of boll weight, plant height, crown diameter, number of monopodial and sympodial branches, number of open and closed bolls, earliness and crop yield were measured and recorded. The yield was measured at the end of the season, after removing half a meter from the beginning and end of each plot by removing all plants from the two middle lines. Earliness was calculated from the ratio of the yield of the first harvest to the total yield multiplied by the number of hundred. Analysis of variance and mean comparison were performed using SAS software.
Results: The results showed that the highest number of closed bolls and the lowest boll weight, yield, plant height, number of monopodial and sympodial branches, and the number of open bolls were belonged to the last planting date (20 June). The delay in planting reduced the average yield of cotton by 24%. In 20 June, due to the non-opening of the bolls and exposure to the autumn cold, no yield was harvested and a 100% yield reduction was observed. The highest and lowest yield was related to Khorshid variety in 10 May and Shayan variety in 31 May, respectively. Khordad cultivar had the lowest yield reduction due to the delay in planting compared to the other cultivars, and Khorshid cultivar was ranked next.
Conclusions: The results of the current study showed that the optimal planting date of the studied cultivars in Kashmir region is up to June 10, and further delay in the planting time causes a severe decrease in yield. However, the response of cultivars to the delay in planting was different, and Khordad and Khorshid cultivars, having the highest yield, showed a lower yield reduction than the other two cultivars.
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