Crop Production - Agronomy

Weed management in sugarcane under wide-row planting

♣ Severe weed infestation in widely spaced sugarcane plant crop can be effectively managed in an integrated manner by sequential application of early post-emergence application of metribuzin at 1250 g a.i. ha-1 at 10 DAP followed by post-emergence tank mix application of either topramezone at 29.4 g a.i. ha-1 + atrazine 625 g a.i. ha-1 or tembotrione at 120 g a.i. ha-1 + atrazine 625 g a.i. ha-1 or halosulfuron methyl 67.5 g a.i. ha-1 + metribuzin 525 g a.i. ha-1 at 65 DAP followed by one hand weeding at 120 DAP. This has proved to be cost-effective in widely spaced sugarcane plant crops with higher weed control efficiency, weed control index, broad spectrum weed control, and no phytotoxic effect, in turn improving cane growth and yield.

Photo (A)Field view of sugarcane variety Co 86032 at 15 days after planting (DAP), (B) Effect of early post-emergence application of metribuzin at 45 DAP (at the time of partial earthing up) (C) T8 (unweeded control) at 45 DAP, (D) Weed infestation before application of herbicides at 65 DAP, (E) T1 (Topramezone + atrazine) + hand weeding at 160 DAP, (F) T3 (Tembotrione + atrazine) + hand weeding at 160 DAP, (G) T5 (Halosulfuron methyl + metribuzin) + hand weeding at 160 DAP, (H): T7 Three hand weeding at 160 DAP, (I) Unweeded control at 160 DAP A simple and sensitive chromatographic method has been developed and validated to determine the residues of halosulfuron-methyl in the soil matrix. The method developed is in compliance with European Commission’s regulations for Trace Residue Analysis. By adopting this method, the persistence and dissipation kinetics of halosulfuron-methyl was studied. The initial deposits of halosulfuron-methyl were 0.288 and 0.501 µgg-1 at the recommended dose (RD) and double the recommended dose (2RD), respectively. A week after application (7 DAA), the residues were 0.177 and 0.346 µgg-1 , respectively for RD and 2RD. The residues got dissipated to a level of about 95% within 75 days of application with the half-life of 9.12 and 9.71 days.

♣ A simple and sensitive chromatographic method has been developed and validated to determine the residues of halosulfuron-methyl in the soil matrix. The method developed is in compliance with European Commission’s regulations for Trace Residue Analysis. By adopting this method, the persistence and dissipation kinetics of halosulfuron-methyl was studied. The initial deposits of halosulfuron-methyl were 0.288 and 0.501 µgg-1 at the recommended dose (RD) and double the recommended dose (2RD), respectively. A week after application (7 DAA), the residues were 0.177 and 0.346 µgg-1 , respectively for RD and 2RD. The residues got dissipated to a level of about 95% within 75 days of application with the half-life of 9.12 and 9.71 days

ICAR-CIAE-SBI Small tractor operated EPN applicator for sugarcane white grub management

♣ The white grub Holotrichia serrata (Coleoptrera: Scarabaeidae) is an important soil pest of sugarcane crop in tropical India. The larvae feed on decaying matter in the early stage but damage roots in the late stage. Through inconspicuous late larval feeding activity, H. serrata has the potential to cause complete loss in sugarcane crop. Although endemic to sugarcane tracts in high altitude or assured rainfall areas earlier, the pest has been extending its spatial range in the recent past apparently due to expansion of sugarcane area, monoculture of the crop and minimal diversity. The damage caused by this pest is observed in patches but during epidemics the entire crop may be dried up. The yield loss due to white grubs in sugarcane reported to be as high as 80- 100 per cent. EPN (Entomopathogenic nematodes) are tiny microscopic worms, barely visible to the naked eye. As the name suggests they are insect-killing (Entomopathogenic). They are natural predators of the white grubs. They have proven to be the safest and most effective way of controlling white grubs as both organisms spend a large portion of their life cycle in the soil. The majority of the farmers follow the above spot application method to control white grub manually using the crowbar to make 125 mm depth hole and drop the EPN solution to control white grub. The manual application method of EPN application involves more drudgery and a non-uniform quantity of EPN solution in the sugarcane root zone. Keeping the above view, a mini tractoroperated EPN applicator has been developed jointly by ICAR-Central Institute of Agricultural Engineering, Regional Centre, Coimbatore, and ICAR-Sugarcane Breeding Institute, Coimbatore The mini tractor-operated EPN applicator consists of a mainframe, tank holding assembly, agitator, water pump, furrow opener, and standard three-point hitch. A 150-liter tank was placed to carry the EPN solution. The tank consists of an agitator and two EPN solution outlet flexible tubes. The agitator consists of two numbers of baffles at the end of a vertical shaft. The agitator shaft was operated by a 12 V high-torque DC motor. The speed of the agitator shaft and discharge rate can be adjusted by using control units. The agitator provides continuous agitation of EPN solution and avoids suspension of particles so that it results in uniform delivery of the EPN. Pumping of the EPN solution was done by two numbers of 4.0 LPM / 12v DC Water Sprayer Motor Diaphragm pump and it was powered by 12 V Battery. This unit was field tested at ICARSugarcane Breeding Institute, Coimbatore, and the Research & Development farm of M/s. Bannari Amman Sugars Limited, Sathyamanagalam. The results indicated that the EPN delivery in the right side outlet was 30 IJs/ml and the left side out let was 32 IJs/ml. A similar trend was noticed in the farmer’s field also, where the EPN delivery on the right side outlet was 35 IJs/ml and the left side out let was 33 IJs/ml. The average actual field capacity is 0.18 ha h -1 . The cost of operation was worked out as Rs. 2550 per ha and cost saving was 47% compared to the manual method of application.

Photo: Working of ICAR-CIAE-SBI Small tractor operated EPN applicator for sugarcane white grub management

This technology titled “ICAR-CIAE-SBI Small tractor operated EPN applicator for sugarcane white grub management” developed under the Collaborative project between ICAR – Sugarcane Breeding Institute, Coimbatore and ICAR – Central Institute of Agricultural Engineering, Bhopal titled “Development and Promotion of tools and machinery for sugarcane production” has been certified by ICAR, New Delhi in 2024. The technology has been commercialized to M/s GREENFIELD EQUIPMENT INDIA PVT LTD, Coimbatore by signing of MoU between ICAR-SBI & ICAR-CIAE and GREENFIELD EQUIPMENT INDIA PVT LTD on 18th September 2024 for commercial production.

SOIL SCIENCE AND CHEMISTRY

Technology developed: Sugarcane Settling Transplanting Technology

♣ Settling Transplanting Technology (STT), an integrated approach with nine basic components of sugarcane production aimed as a whole to reduce cultivation cost and improve productivity. Transplanting settlings (25-30 days old) derived from single bud setts of high yielding better quality variety treated with nutrients and pesticide using Sett Treatment Device, in paired row (1.2 x 0.6/0.6 m), intercropping (black gram, green gram, coriander, etc.), sub-surface drip irrigation scheduling based on crop demand and pan evaporation and fertigation based on soil test crop response, multiple ratooning (up to 5 ratoons) and mechanization of field operations from filed preparation to harvesting are the cultural practices under STT. STT as a package resulted in 80% savings in seed cane requirement and 30% savings in planting cost over sett planting, savings of 52% in water, 90% labor cost for irrigation, and 50% power consumption over sett planting with furrow irrigation. Intercropping resulted in a 10-20% improvement in cane yield over sole sugarcane and provided interim and additional income. The cane yield with black gram intercropping in plant crop was 147 t/ha and the average cane yield of five ratoons was 93 t/ha under STT. STT generated a benefit-cost ratio of 1.93 at the end of five years. Hence, STT results in sugarcane productivity improvement with reduced cost of cultivation and ensures ecological sustainability. This Technology was certified by NRM Division of ICAR (vide Certificate No. ICAR-NRM-SBITechnology-2024-204).

CROP PHYSIOLOGY

Drought-tolerant clones and varieties released through AICRP (2000-2024)

♣ Advanced breeder material (AVT/IVT) has been screened for drought tolerance under field conditions from 2000- to date. In the past two decades, 39 IVT and 145 AVT clones were screened for drought tolerance under field conditions, out of which 14 IVT and 43 AVT clones were identified as drought tolerant. Among these, varieties Co 99004 (Damodar), Co 2001-13 (Sulabh), Co 2001-15 (Mangal), Co 0218, Co 0212, Co 06027, Co 06022, Co 06030, Co 09009, Co 10026, Co 12009, Co 13013 and Co 14012 were released for the peninsular zone by the central variety release committee (CVRC). Co 0212, Co 06030, Co 06022 and Co 09009 varieties were released for Tamil Nadu state. Identified drought-tolerant genetic stocks (57 cones) could be used as prebreeding material for developing/ breeding varieties for drought tolerance.

“Co 14012” – A Climate Resilient Superior Variety for Tropical & Sub-Tropical India

♣ Six sub-tropical clones (Co 0238, Co 15023, Co 15027, Co 98014, BO 91 and CoLk 8102) and six tropical clones (Co 11015, Co 0212, Co 06022, Co 13006, Co 14012 and Co 86032) were planted at two different climatic conditions viz., ICAR-Sugarcane Breeding Institute, Coimbatore (Tropical) and ICAR-SBI, Regional Centre, Karnal (Sub-tropical) to identify a superior common variety for both tropical and sub-tropical India by assessing physiological efficiency and yield potential at two locations. A comparative pooled analysis of three years of field data at two different locations indicates that some of the biometric traits (tiller production, LAI, plant height, TDMP & its partitioning efficiency), physiological (total chlorophyll content & NR ase activity) and biochemical traits (total phenolics and soluble protein content) were strongly associated with the differences in yield performance when the varieties are grown at different locations. Interestingly, we noticed that some of the physiological factors are common and some of the factors are location specific i.e., tillering potential is not a factor for sub-tropical varieties grown under tropical conditions, however, vice-versa was noticed for tropical varieties grown under subtropical conditions. Yield and yield components in tropical conditions revealed that the varieties Co 86032, Co 14012, and Co 11015 in tropical groups and Co 98014 and Co 15027 in sub-tropical groups performed better in NMC, SCW, and cane length and thickness and thus recorded higher yields compared to other varieties studied. Similarly in sub-tropical conditions, Co 15027, Co 0238, and Co 15023 in sub-tropical and Co 14012 and Co 13006 in sub-tropical groups recorded higher yield components and thus recorded higher yields. The results of G X E analysis suggest that Co 14012 and Co 98014 are identified as common varieties for cultivating both tropical and sub-tropical India, however, the latest variety Co 14012 was found superior in morphophysiological, yield, and quality to Co 98014.

Water-efficient sugarcane clones for sustaining sugarcane production under waterlimited conditions

♣ The annual water requirement for sugarcane ranges from 1000 to 2900 mm, depending on the agroecological conditions, cultivation practices, and crop cycle. In a changing climate, the delay or failure of monsoon has a direct effect on the water available for irrigation. Given these constraints, sustaining sugarcane production is challenging. A study was conducted at ICARSugarcane Breeding Institute, Coimbatore, Tamil Nadu to identify water-efficient sugarcane clones for maximizing cane yield under water-limited conditions. Experiments were conducted for four consecutive crop seasons including independent trials for commercial hybrids, and germplasm clones in split plot design, wherein irrigation scheduling was the main plot, and genotypes were accommodated in subplots. A measured quantum of water was applied according to the treatments and monitored using a water meter. Irrigation treatments were initiated at 60 Days After Planting(DAP) to ensure uniform crop establishment. The irrigation treatments included I0: full irrigation at the recommended interval, with 100% crop evapotranspiration (ET) replacement (control); I1: restricted irrigation at the recommended interval, and with 50% crop ET replacement (50% by volume). I2: restricted irrigation by skipping alternate irrigations with 50% crop ET replacement (50% by frequency) (Fig. 1A). The clones viz., Co 85019, Co 10026, Co 12009, Co 13014, Co 14002, Co 14025, Co 15015, and Co 15018 were water efficient (> 5 kg/m3 ), while among the germplasm clones, Fiji 55, ISH 111, ISH 107, Pathri, and Gungera showed better water productivity and lower water footprint in terms of sugarcane production per unit water. Further, the estimation of canopy temperature (Fig. 1 B&C) through thermal imaging was identified as a useful trait for screening large breeding populations under water-limited conditions. The results of this study highlight the superior ability of water-efficient sugarcane clones to convert water into biomass even under water-limited conditions. The implications of these results are of paramount importance in sustaining sugarcane productivity in water-limited conditions.

Photo: (A) Aerial view of an experimental field with treatments I0: control, I1: 50% by volume, I2: 50% by frequency, R1 and R2 denote replications. Thermal image representative of canopy temperature under (B) irrigated and (C) water-limited condition