Effects of Soil and Foliar Applied Fertilizers on Growth, Yield and Sugar Quality of Two Sugarcane Cultivars under Rainfed Conditions

Background: In north-eastern Thailand, sugarcane is planted normally in late rainy season wherein the plants may experience drought stress during its early growth stage in dry season and waterlogging stress during late growth stage at peak of rainy season. Hence, the objective of the present study was to investigate the effects of soil application alone and soil combined with foliar application of nutrients on growth, yield and sugar quality of sugarcane grown under rainfed conditions. Methods: The field experiment was conducted during November 2016 to December 2017. A split-plot design with three replications was laid out. The two sugarcane cultivars (KK3, K93-219) were assigned as main plots. The fertilizer application methods were assigned as sub-plots that comprised of four treatments: (1) soil applied NPK, (2) soil NPK + foliar N and K applied at 90 days after planting (DAP), (3) soil NPK + foliar N and K applied at 210 DAP and (4) soil NPK + foliar N and K applied at 90 and 210 DAP. Result: The soil NPK + foliar N and K applied at 90 and 210 DAP improved yield components and cane yield. The cultivar K93-219 produced significantly higher cane yield than KK3. The fertilizer application methods and cultivars had no significant effect on sugar quality such as brix (%), purity (%), polarity (%), fiber (%) and commercial cane sugar (CCS-%).

Physiological and Agronomic Traits of Certain Sugarcane Genotypes Grown under Field Conditions as Influenced by Early Drought Stress

Drought is one of the important problems that drastically affect sugarcane production in several countries. The objective of this research was to investigate the effects of early drought stress on physiological parameters and agronomic traits of six sugarcane genotypes under field conditions. The experiment was arranged in a split plot in a completely randomized block design with three replications. The main plot was represented by three different water regimes: field capacity (FC), ½FC and rain-fed (RF) whereas, the subplot consisted of six sugarcane genotypes: KK3 (drought tolerant), Q117 (drought tolerant), LK92-11 (drought susceptible), Ths98-271 (S. spontaneum), KK08-214 (the F1 hybrid derived from S. spontaneum × S. officinarum) and E08-4-019 (the F1 hybrid derived from Erianthus sp. × S. officinarum). The six sugarcane genotypes were subjected to three irrigation treatments. The 45-day-old plants of all sugarcane genotypes were exposed to drought by withholding water for 72 days. Certain photosynthetic parameters were measured in the leaves of four-month-old plants. Certain cane yield parameters were measured in the 12-month-old plants. The results showed that early drought stress decreased the maximum quantum yield of PSII efficiency, net photosynthetic rate, transpiration rate and stomatal conductance. Drought stress significantly (p ≤ 0.01) decreased cane yield. The cane yield and sugar yield of KK3 were significantly (p ≤ 0.01) higher than those of the other genotypes. The wild-type sugarcane and the F1 hybrids derived from the wild and commercial sugarcane could maintain better photosynthetic performance while encountering early drought stress.

Potassium and Water-Deficient Conditions Influence the Growth, Yield and Quality of Ratoon Sugarcane (Saccharum officinarum L.) in a Semi-Arid Agroecosystem

Groundwater and soil potassium deficiencies are present in northern India. Sugarcane is a vital crop in the Indian Punjab; it is grown on approximately 91,000 hectares with an average yield of 80 tonnes ha−1 and a sugar recovery rate of 9.59%. The role of potassium (K) fertilizer under both sufficient and deficient irrigation in ratoon sugarcane crops is not well documented. We conducted a split-plot ratoon cane experiment during 2020–2021 at the Gurdaspur Regional Research Station of Punjab Agricultural University, India, on K-deficient soils. Main treatments were fully irrigated (I1) and water stressed (I0) conditions, with sub-treatments reflecting K fertilizer application rates of 0 (M1), 67 (M2), 133 (M3), and 200 (M4) kg K ha−1. The ratoon sugarcane performance was assessed in terms of growth, productivity, sugar quality and incidence of key insect pests. At harvest, trends in the growth and yield parameters in I1 were improved over the I0 treatment, with cane height (+12.2%), diameter (+3.3%), number of internodes (+5.4%), biomass yield (+7.6%) and cane yield (+5.9%) all higher, although little significant difference was observed between treatments. Ratoon cane yield under irrigation was 57.1 tonnes ha−1; in water-stressed conditions, it was 54.7 tonnes ha−1. In terms of sugarcane quality parameters, measured 12 months after harvesting the initial seed crop, values of Brix (+3.6%), pol (+3.9%), commercial cane sugar percentage (+4.0%) and extractable sugar percentage (+2.8%) were all higher in the irrigated treatments than the water-stressed plot. Irrigated treatments also had a significantly lower incidence of two key insect pests: top borer (Scirpophaga excerptalis) was reduced by 18.5% and stalk borer (Chilo auricilius) by 21.7%. The M3 and M4 treatments resulted in the highest cane yield and lowest incidence of insect pests compared to other K-fertilizer treatments. Economic return on K-fertilizer application increased with increasing fertilizer dosage. Under the potassium-deficient water-stressed conditions of the region of north India, a fertilizer application rate of 133 kg K ha−1 is recommended to improve ratoon sugarcane growth, yield, and quality parameters and economic returns for sugarcane farmers.

Effect of Foliar Application of NPK and Micronutrient (Zn and Fe) on the Yield and Quality of Sugarcane Crop

The foliar application of nutrients help the plant leaves to readily absorb the applied nutrients through the nutrient solution and increases the nutrient use efficiency and thus improves the crop yield. The field experiment was conducted for two consecutive years to find out the affect of foliar spray of NPK and micronutrient on cane yield, yield parameters and juice quality of sugarcane during 2019-20 and 2020-21.The present study was carried out on clay loam soils of Research farm of Regional Research Station, CCS Haryana Agricultural University, Karnal, Haryana. The research revealed that cane yield and yield parameters i.e., cane length, and cane weight was significantly affected with the foliar spray of NPK and micronutrient but non-significant effect was observed for cane girth and number of internodes. With respect to juice quality parameters viz., commercial cane sugar (CCS) %, pol % and sugar yield, significantly affected with foliar spray of NPK and micronutrient. The highest cane yield, cane weight and cane length was recorded with the foliar application of 2% NPK (19:19:19) + 0.5% ZnSO4 +1% FeSO4 (78.16 t/ha, 1.21 kg and 207.3 cm) followed by foliar spray of 0.5% ZnSO4 + 1% FeSO4+ 2.5% urea recorded 76.75 t/ha, 1.20 kg and 207.1 cm, respectively. The lowest cane yield (70.68 t/ha) was recorded with the application of recommended dose of fertilizer (RDF) alone. The highest CCS % (12.16), pol % (17.36) and sugar yield (9.51 t/ha) was observed in the treatment 2% NPK + 0.5% ZnSO4 +1% FeSO4. Thus, foliar application with NPK and micronutrient could significantly improve the cane yield, yield parameters and juice quality of sugarcane crop.

Water deficit modifies C:N:P stoichiometry affecting sugarcane and energy cane yield and its relationships with silicon supply

Climate change has increased the occurrence of water deficit in regions where sugarcane and energy cane are cultivated, jeopardizing dry matter production of stems. It was hypothesized that the reasons behind this fact relate to C:N:P stoichiometric modifications in these species that impair the conversion rates of accumulated nutrients in the stems, which could be attenuated by supplying silicon (Si) to the crops. Thus, the aims of this study were to evaluate the effects of water deficit in sugarcane and energy cane ratoons in the presence and absence of Si, in the C:N:P stoichiometry of stems, in the use efficiency of these nutrients and in the accumulation of dry matter in stems. Two experiments were carried out, using sugarcane (Saccharum officinarum) and energy cane (S. spontaneum), cultivated in pots filled with a Typic Quartzipisamment. The treatments for both experiments were arranged in a factorial scheme 2 × 2, without (70% of the soil’s water retention capacity) and with (30% of the capacity) water deficit, without and with the application of Si via fertirrigation, associated with foliar pulverization, both at a concentration of 2.5 mmol L−1, arranged in randomized blocks. The reduction in dry matter production of stems in both species caused by water deficit was due to modifications of the C, N and P stoichiometric homeostasis, but the benefit of Si in these plants when increasing dry matter production was not a reflection of the change in homeostasis, thus it may be involved in other mechanisms that remain unknown and should be further studied.

Simulating the impact of climate change on sugarcane production in Punjab

The present study was performed at three diverse agro-climatic zones of Indian Punjab. A validated DSSAT-CANEGRO model was used to simulate the response of different climate change scenarios on cane yield of four sugarcane varieties (CoPb 91, CoJ 88, Co 118 and Co 238) for each zone. Results described that elevated and lowered minimum temperature upto 3.0°C may alter cane yield by -17.9 to 18.0 per cent. Similarly, ±3.0°C altered maximum temperature may change the cane yield by -17.6 to 17.5 per cent. The sugarcane yield may be decreased by 2.4 to 14.4 per cent, 3.3 to 17.6% and 0.3 to15.4 per cent with 2.5 to 15 per cent reduced solar radiation and increase in the same unit may enhance the yield by 1.9 to 9.0 per cent, 1.3 to 13.6 per cent and 2.0 to 12.3 per cent at Faridkot, Gurdaspur and Kapurthala, respectively. A±30 mm rainfall may change the cane yield by 9.2 to 18.0 % similarly, rise and fall in CO2 by 5 to 30 ppm was able to increase and decrease the cane yield by 2.4- 22.6 and 3.5 - 27.8 per cent, at different regions. This study confirmed that for sugarcane cultivation in Punjab CoPb 91 should be preferred. However, CoJ 88 and Co 238 may suffer cane yield loss of 7.8 and 9.9 per cent respectively.

Genomic Selection in Sugarcane: Current Status and Future Prospects

Sugarcane is a C4 and agro-industry-based crop with a high potential for biomass production. It serves as raw material for the production of sugar, ethanol, and electricity. Modern sugarcane varieties are derived from the interspecific and intergeneric hybridization between Saccharum officinarum, Saccharum spontaneum, and other wild relatives. Sugarcane breeding programmes are broadly categorized into germplasm collection and characterization, pre-breeding and genetic base-broadening, and varietal development programmes. The varietal identification through the classic breeding programme requires a minimum of 12–14 years. The precise phenotyping in sugarcane is extremely tedious due to the high propensity of lodging and suckering owing to the influence of environmental factors and crop management practices. This kind of phenotyping requires data from both plant crop and ratoon experiments conducted over locations and seasons. In this review, we explored the feasibility of genomic selection schemes for various breeding programmes in sugarcane. The genetic diversity analysis using genome-wide markers helps in the formation of core set germplasm representing the total genomic diversity present in the Saccharum gene bank. The genome-wide association studies and genomic prediction in the Saccharum gene bank are helpful to identify the complete genomic resources for cane yield, commercial cane sugar, tolerances to biotic and abiotic stresses, and other agronomic traits. The implementation of genomic selection in pre-breeding, genetic base-broadening programmes assist in precise introgression of specific genes and recurrent selection schemes enhance the higher frequency of favorable alleles in the population with a considerable reduction in breeding cycles and population size. The integration of environmental covariates and genomic prediction in multi-environment trials assists in the prediction of varietal performance for different agro-climatic zones. This review also directed its focus on enhancing the genetic gain over time, cost, and resource allocation at various stages of breeding programmes.

The Potential of Ethanol Production from Sweet Sorghum in Sub-Saharan Africa as Affected by Variety and Sowing Time

Renewable bio-energy is receiving worldwide importance in view of depleting fossil energy. Research works on sorghum as bio-fuel crop in sub-Saharan Africa are meager. The study aimed to investigate the potential of sweet sorghum for ethanol production from stem-juice. The experiment was conducted in Sudan, Khartoum State, during 2016-2017. Forty local and exotic sweet sorghum varieties arranged in RCB Design were investigated under irrigated conditions across three sowing times. Yields of cane, juice, sugar, ethanol and related attributes were studied. Highly significant differences (P=.01) were detected among varieties and interaction with sowing time. Ethanol yield potentials for some varieties were comparable to those reported in India and USA (1162-1416 L ha-1). High brix values (20-22%) and cane yields (45-51 ha-1) were encountered. Juice yield was low (3673-13743 L ha-1) probably due to reduced milling efficiency. The exotic materials performed better than the local ones in theoretical ethanol productivity and related attributes other than cane yield. Eight exotic and five local varieties were recommended for ethanol production. None of the Ankolib materials appeared to have notable potential for ethanol production. Interaction of sowing time with variety has great impact on ethanol yield implying the importance of variety option for different sowing times. It was concluded that the study furnished basic data needed for assessing the economic feasibility of ethanol production from irrigated sweet sorghum in sub-Saharan Africa-Sudan.

Delineation of genotype × environment interaction for identification of stable genotypes for tillering phase drought stress tolerance in sugarcane

Sugarcane is a trans-seasonal long-duration crop and tillering phase (60–150 days) is the most sensitive phase for moisture stress, causing significant reduction in biomass accumulation. The study focussed to assess the Genotype × Environment Interaction (GEI) for tillering phase moisture stress and to identify the stable genotypes in sugarcane. The study dealt with 14 drought tolerant genotypes and two standards (Co 86032 and CoM 0265) which were evaluated in two plant and one ratoon trials at four locations in Maharashtra, India. The moisture stress was imposed for 60 days from 90 to 150 days after planting and corresponded to tillering phase by withholding the irrigation. The AMMI ANOVA showed significant GEI for cane and CCS yield accounting 18.33 and 19.45 percent of variability respectively. Drought and genotype main effects were highly significant accounting 49.08 and 32.59 percent variability for cane yield and, 52.45 and 28.10 percent variability for CCS yield respectively. The first two interactive principal component (IPCA) biplots of AMMI showed diverse nature of all four environments and the Discriminative vs Mean biplots of Genotype + genotype × environment interaction (GGE) model showed that ‘Pune’ as the highly discriminating environment. The genotype ranking biplots of GGE showed that Co 85019 was the most stable genotype followed by Co 98017. Similar results were also observed in Yield vs IPCA1 biplot of AMMI, which revealed Co 85019 and Co 98017 as high yielding stable varieties. Yield related environmental maximum (YREM) showed thirteen and nine percent loss due to crossover interactions in Co 85019 for cane yield and CCS yield respectively. The multi-environment BLUP and genotype stability index (GSI) has reaffirmed that Co 85019 as a drought proof and stable genotype with high yield under tillering phase drought stress. The results suggested using Co 85019 for cultivation in drought prone regions and the usefulness of the methodology for identifying more such sugarcane varieties for the benefit of resource poor famers in drought affected regions.