Author(s)

Kalim Ullah¹, Muhammad Idrees Khan², Zahid Mahmood², Toheed Iqbal³, Saeed Muhammad², Hafiz Abdul Haq², Aftab Ahmad⁴, Sabahat Hussain²

¹The PCCC, Cotton Research Station, Dera Ismail Khan, Pakistan.
²The PCCC, Central Cotton Research Institute, Multan, Pakistan.
³Agricultural Research Institute, Ratta Kulachi, Dera Ismail Khan, Pakistan.
⁴Global Change Impact Study Centre Islamabad, Islamabad, Pakistan.

Cotton growth and development is effected by various ecological issues like temperature fluctuations, distribution and quantity of rainfall, relative humidity and winds which are the climate change attributes. A field experiment was carried out to find out the response of cotton to weather variables in terms of total variation in yield and quality. The effect of planting times and thermal temperatures (cumulative heat units) on yield of 4 cotton cultivars viz; CIM-600, CIM-616, CIM-622 & CRIS-641 was evaluated. Plants were sown on 6 planting times during the year 2015-2016 and 2016-2017 in an experiment conducted in randomized complete block design having three replications. Cotton cultivars depicted significant variances for number of bolls plant^-1, boll weight and seed cotton yield. The cultivar CIM-616 depicted the highest seed cotton yield of 2083.60 kg·ha^-1 on interpretation of highest bolls and boll weight. Maximum seed cotton yield was noted in planting time from 1^st April to 15^th April whereas early and late planting decreases the seed cotton yield on account of less accretion of cumulative heat units. Regression analysis depicted that rise of one unit (15 days) from early to optimal date (15^th March to 15^th April) enhanced the seed cotton yield by 93.76 kg·ha^-1 (y = -93.764x² + 521.04x + 1364). Delayed planting also reduces the seed cotton yield with the same ratio. It is therefore established that cotton must be cultivated from 1^st April to 1^st May to harvest good production in this type of climate.

G. hirsutum, Planting Time, Cumulative Heat Units, Cotton Cultivars

Ullah, K., Khan, M.I., Mahmood, Z., Iqbal, T., Muhammad, S., Haq, H.A., Ahmad, A. and Hussain, S. (2017) Response of Yield and Related Attributes of Upland Cotton to Weather Variables. American Journal of Plant Sciences, 8, 1711-1720. doi: 10.4236/ajps.2017.87118.