Polyhalite improves growth, yield, and quality and reduces insect pest incidence in sugarcane (Saccharum officinarum L.) in the semiarid tropics
Rajan Bhatt, Patricia Imas, Adi Perelman, Krishan K. Verma, Laila A. Al‐Shuraym, Samy Sayed, Ahmed Gaber, Akbar Hossain
Abstract
Introduction In semiarid tropical locations, polyhalite (K 2 Ca 2 Mg(SO 4 )4H 2 O) and muriate potash (KCl) were tested for their ability to increase cane growth, yield, and recovery at potash (K)- and calcium (Ca)-deficient sites. Methods The treatments involved control plots with no potash fertilizer (T 1 ); T 2 and T 3 applied potassium through (muriate potash) MOP only at 80 and 120 kg K 2 O ha −1 , whereas T 4 and T 5 applied potassium with half of MOP and polyhalite at 80 and 120 kg K 2 O ha −1 , respectively. Results and discussion At 35 days after harvest (DAH), T 2 (10.82%), T 3 (24.1%), T 4 (34.9%), and T 5 (34.9%) had a greater ratoon resprouting rate than did the control treatment, where it was just 37.0 out of 100 harvested canes. At 308 DAH, T 2 (−5.9%), T 3 (−5.7%), and T 5 (−6.6%) presented greater leaf chlorophyll contents than did T 1 . The K-fertilized plots yielded 64.31 t ha −1 in T 2 and 65.97 t ha −1 in T 5 , whereas the control plot yielded 61.5 t ha −1 . Compared with the control plots, the T 5 plots experienced fewer stalk borer (−28.6%), top borer (−23.3%), and early shoot borer (−23.3%) attacks. T 2 , T 4 , and T 5 presented higher percentages of commercial cane sugar (CCS) (6.82, 8.83, and 8.74%, respectively) than did the control plots. T 1 and T 3 had similar CCSs (10.99 and 11.33%, respectively). The CCS weight per area ranged from 7.98 to 8.47 t ha −1 near maturity. T 4 (8.59 t ha −1 ) and T 5 (8.60 t ha −1 ) had significantly greater values than did T 1 –T 3 . Compared with the control, the applied potassium fertilizer increased the economic output by 8,711, 11,687, 13,485, and 13,857 INR ha −1 in the T 2 , T 3 , T 4 , and T 5 plots, respectively. The higher cost of polyhalite than MOP has reduced its economic advantages. Thus, the T 4 plots outperformed the other treatments in terms of growth, yield, and quality indices, but their higher values (120 kg K 2 O ha −1 ) were statistically equivalent. Conclusion Finally, the study concluded that MOP and polyhalite at a 50% ratio of 80 kg K 2 O ha −1 may help improve sugarcane growth, yield, and quality in semiarid tropical locations.