Novel approaches to circumvent the devastating effects of pests on sugarcane

Sugarcane (Saccharum officinarum L.) is a cash crop grown commercially for its higher amounts of sucrose, stored within the mature internodes of the stem. Numerous studies have been done for the resistance development against biotic and abiotic stresses to save the sucrose yields. Quality and yield of sugarcane production is always threatened by the damages of cane borers and weeds. In current study two problems were better addressed through the genetic modification of sugarcane for provision of resistance against insects and weedicide via the expression of two modified cane borer resistant CEMB-Cry1Ac (1.8 kb), CEMB-Cry2A (1.9 kb) and one glyphosate tolerant CEMB-GTGene (1.4 kb) genes, driven by maize Ubiquitin Promoter and nos terminator. Insect Bio-toxicity assays were carried out for the assessment of Cry proteins through mortality percent of shoot borer Chilo infuscatellus at 2nd instar larvae stage. During V0, V1 and V2 generations young leaves from the transgenic sugarcane plants were collected at plant age of 20, 40, 60, 80 days and fed to the Chilo infuscatellus larvae. Up to 100% mortality of Chilo infuscatellus from 80 days old transgenic plants of V2 generation indicated that these transgenic plants were highly resistant against shoot borer and the gene expression level is sufficient to provide complete resistance against target pests. Glyphosate spray assay was carried out for complete removal of weeds. In V1-generation, 70–76% transgenic sugarcane plants were found tolerant against glyphosate spray (3000 mL/ha) under field conditions. While in V2-generation, the replicates of five selected lines 4L/2, 5L/5, 6L/5, L8/4, and L9/6 were found 100% tolerant against 3000 mL/ha glyphosate spray. It is evident from current study that CEMB-GTGene, CEMB-Cry1Ac and CEMB-Cry2A genes expression in sugarcane variety CPF-246 showed an efficient resistance against cane borers (Chilo infuscatellus) and was also highly tolerant against glyphosate spray. The selected transgenic sugarcane lines showed sustainable resistance against cane borer and glyphosate spray can be further exploited at farmer’s field level after fulfilling the biosafety requirements to boost the sugarcane production in the country.

Effect of nitrogen and potash on Early shoot borer (Chilo infuscatellus Snellen) incidence in differently maturing varieties of sugarcane

It has been argued that fertilization may influence the susceptibility of insect pests, and thus, can increase the crop production by lowering the incidence of insect-pest. Here, the present investigation was carried out to study the influence of nitrogen and potash levels on the incidence of early shoot borer, Chilo infuscatellus Snellen in sugarcane varieties at Regional Research Station CCSHAU Uchani farm, Karnal. The experiment was laid out in split-split plot design with three differently maturing varieties viz., Co 0238, CoH 119 and CoH 150 as main plot, three doses of nitrogen viz., 150, 200 and 250 kg per hectare (kg/ha) as sub plot and two doses of potash viz., 0 and 50 (kg/ha) as sub-sub plot. The early shoot borer mean per cent incidence recorded in April, May and June, 2015 was highest (7.68, 12.19 and 6.35, respectively) in Co 0238 while, lowest (5.16, 8.51 and 5.40, respectively) in CoH 119 followed by CoH 150 (6.29, 8.79 and 5.43, respectively). In relation to nitrogen application, maximum mean per cent incidence (7.12, 11.19 and 6.48, respectively) in April, May and June, 2015 of early shoot borer was recorded at 250 kg N/ha and the minimum (5.68, 8.57 and 5.23, respectively) at 150 kg N/ha. Application of potassium significantly reduced the shoot borer infestation with mean per cent incidence lower at 50 kg K2O/ha (5.90, 9.24 and 5.33, respectively) in April, May and June, 2015 compared to control i.e., no application of potassium (6.85, 10.42 and 6.12, respectively). Results revealed that application of potassium with optimum dose of nitrogenous fertilizer along with selection of suitable variety acted as preventive measures to avoid shoot borer infestation.