Understanding Growth Rate Patterns among Different Drought Resistant Sugarcane Cultivars during Plant and Ratoon Crops Encountered Water Deficit at Early Growth Stage under Natural Field Conditions

Abstract

Drought-tolerant sugarcane genotypes have been proposed to alleviate the issue of early water deficits; however, it is important to investigate the impact of phenology on the crop growth rate and growth patterns. This study aimed to investigate the responses of different water deficit-tolerant cultivars on crop growth rate patterns of both plant crop and ratoon under rain-fed and well-irrigated conditions, and to determine the relationship between final stalk dry weight and crop growth rates during water deficit, recovery, and maturity phases. A 2 × 6 split plot in a randomized complete block design with four replications was used. Two water regimes, namely, field capacity (FC) and rain-fed conditions, were assigned as the main plot, whereas six sugarcane cultivars differing in water deficit-tolerant levels were assigned as sub-plots. Sugarcane cultivar KK3 consistently possessed high potential and low reduction in dried shoot weight. A correlation was found between stalk dry weight and stem growth rate, shoot growth rate, and height growth rate (HGR) during the recovery period in the first season, and HGR at the recovery stage was correlated with the dry weight of ratoon. The recovery phase of early water deficit stress was a key stage for determining the final stalk dry matter. The desired cultivars having a good adaptation to water deficit stress at the formative stage, such as KK3, showed a gradually increased growth rate during the early water deficit stage, but this growth accelerated, and the maximum growth rate was reached, during the recovery period. This knowledge will help to clarify the selection of sugarcane cultivars in breeding programs that can resist water deficit at the early growth stage.

Determination of Morpho-Physiological Traits for Assessing Drought Tolerance in Sugarcane

“…Similar findings for the HGR have been reported by previous research [ 30 , 31 ]. It has also been positively correlated with stalk dry weight in sugarcane under early season drought [ 6 ]. This correlation might partially explain how drought can reduce yield in sugarcane.…”

“…Plant height was measured from the ground to the top visible dewlap (TVD) of the main stem, while the number of stems per pot was recorded by counting the total number of stems that emerged from the soil. The HGR and SGR were calculated as follows [ 6 ]: where ∆H represents the difference in plant height between the two measurements (plant height at 104 DAP–height at 90 DAP), ∆T represents the time interval between the two measurements (104 DAP–90 DAP), and ∆SN represents the difference in stem numbers between the two measurements (stem numbers at 104 DAP–stem numbers at 90 DAP)…”

“…Plant height was measured from the ground to the top visible dewlap (TVD) of the main stem, while the number of stems per pot was recorded by counting the total number of stems that emerged from the soil. The HGR and SGR were calculated as follows [6]:…”

“…However, sugarcane yield is frequently impacted by suboptimal growth conditions, particularly drought stress, during the formative growth stage, which is the most sensitive stage for moisture stress in sugarcane [2][3][4][5]. This is common in tropical regions [6], leading to substantial yield reductions by inhibiting growth and development, sometimes reaching up to 60% in rainfed areas [7]. Developing drought-tolerant sugarcane varieties with high yield potential and minimal reduction under drought stress is essential for enhancing the productivity and sustainability of rainfed sugarcane agriculture.…”

Mitigating the repercussions of climate change on diseases affecting important crop commodities in Southeast Asia, for food security and environmental sustainability—A review

“…• Thick white strands of mycelia on infected roots and collar regions, with wood appearing cream-colored and soft due to lignin degradation byfungus (RRISL, 2013) deficits (Khonghintaisong et al, 2021). Meanwhile, new highyielding sugarcane varieties are being developed in Indonesia as part of the nation's crop improvement initiative (Riajaya, 2021;Riajaya et al, 2022).…”