No abstract

Cold tolerance during germination is important for ensuring fast and uniform crop establishment. Rice plants are injured at the seedling stage when they are grown in early spring in temperate or subtropical environments. The productivity of rice is particularly low during spring due to cold, which is an important abiotic constraint, where low temperature prevails below 18 ºC. The present study was taken up to evaluate cold tolerance in 86 rice genotypes based on seed and seedling parameters as per Cruz and Milach (2004). Seeds were germinated under two conditions i.e.,160C for 28 days (cold) and 280C for 7 days (control).The genotypes showed highly significant differences forparameters such as germination (%), germination index (%), percentage of seeds with coleoptile superior to 5 mm (PERCOL), percentage of reduction in coleoptile length (REDCOL) and coleoptile regrowth (COLREG, cm).Both REDCOL and COLREG seem to be the most adequate characteristics to be used to evaluate cold tolerance during the germination period in rice. Among those genotypes, AC 35548, JBT 37/164, PS 353, KMP-175 andThanu were adjudged as promising when screened for cold tolerance under laboratory conditions based on the aforementioned parameters.

The field experiment was executed to evaluate the impact of various irrigation and establishment methods on yield and water use efficiency in rice during Kharif 2018. Split plot design was used in the experiment which consists of three irrigation treatments in the main plot and five rice establishment treatments in the sub plot. The results revealed that, higher yield parameters like number of panicles/m2 (364.83), number of grains per panicle (73.98), number of filled grains per panicle (60.29) were recorded with maintenance of saturation up to panicle initiation (PI) and flooding after PI. Manual transplanting among rice establishment methods recorded significantly higher test weight (25.04 g), grain yield (5253 kg/ha) and harvest index (0.45). Whereas, mechanical transplanting recorded significantly higher number of grains per panicle (74.61) straw yield (7939 kg/ha). Among different irrigation methods, alternate wetting and drying up to PI followed by flooding after PI recorded significantly lower total water usage (94.94 cm) and higher water use efficiency (52.39 kg/ha-cm). Among rice establishment methods, mechanical transplanting recorded significantly lower total water usage (117.81 cm) and higher water use efficiency (48.80 kg/ha-cm). Interaction between alternate wetting and drying up to PI followed by flooding after PI and mechanical transplanting recorded lower total water usage  (81.88 cm) and also recorded higher water use efficiency (68.75 ha-cm).

The field experiment was conducted during 2018 Kharif at Zonal Agricultural Research Station, Vishwesharaiah Canal Farm, Mandya to study the Effect of different establishment methods and nutrient management practices on growth, yield and economics of rice (Oryza sativa L.). The experiment laid out in a split plot design with three replications. The treatments comprised of three rice establishment methods viz., semi dry, drum seeding & transplanting and five nutrient management practices. Among establishment methods, growth and yield parameters such as LAI at 60 DAS, plant height, dry matter production at harvest, panicles m-2, panicle weight, test weight, grain and straw yields recorded were statistically analyzed at par with each other. Further between nutrient management practices, application of 150% RDIF recorded significantly higher LAI at 60 DAS, plant height, dry matter production at harvest, panicles m-2, panicle weight, test weight, grain and straw yields as compared to rest of the nutrient management practices. Further semi dry and drum seeding of rice recorded higher B:C ratio (2.15) over transplanting of rice (2.10). Similarly, 150% RDIF recorded higher B:C ratio (2.37), but was closely followed by 100% RDIF (2.22).

The increasing global demand for water in many sectors has become a universal concern. Challenge is to develop advanced production systems that allow rice production to be sustained in the face of waning water availability. With the intention to find the efficient water saving technology and establishment method, a field experiment was conducted at Zonal Agricultural Research Station, V. C. Farm, Mandya, University of Agricultural Sciences, and Bangalore during Kharif 2018. The experiment was laid out in split plot design with three main plot irrigation treatments and five sub plot rice establishment treatments. The paddy variety used was ‘MTU 1001’. Objective was to study the irrigation and establishment methods on growth of rice. The results revealed that, continuous flooding recorded significantly higher plant height (80.67 cm) at harvest. Whereas, alternate wetting and drying (AWD) recorded higher leaf area index (5.06), CGR at 30 to 60 DAS, 60 to 90 DAS and 90 DAS to harvest (1.49,  3.50 and 2.47 g m-2 day-1, respectively), NAR at 30 to 60 DAS and 60 to 90 DAS (7.19 and 4.37 mg cm-2 day-1, respectively). Among establishment methods, manual transplanting recorded higher plant height (81.82 cm), LAI (5.70), DME (55.77), AGR at 30 DAS (0.36 g day-1), CGR at 30 to 60 DAS and 60 to 90 DAS (1.73 and 3.94 g m-2 day-1, respectively) and LAD at 30 to 60 DAS, 60 to 90 DAS and 90DAS to harvest (49.50, 128.70 and 272.80, respectively). However, mechanical transplanting recorded significantly more number of tillers m-2 (765.67), NAR at 30 to 60 DAS and 60 to 90 DAS (9.96 and 4.41 mg cm-2 day-1, respectively). AWD method of irrigation in mechanical transplanting and manual transplanting are found to be better among all other methods due to the higher growth and development.