Effect of field levelling quality on irrigation efficiency and crop yield

Proper land levelling in areas irrigated by canals is an essential pre-requisite for judicious use of scarce irrigation water. The concept of land levelling index, which is different from land uniformity coefficient used hitherto, has been adopted to evaluate quantitatively the precision or quality of land levelling work. Using this concept the quality of land levelling work being done in newly canal commanded areas has been assessed and it is demonstrated that the prevalent deficiency in levelling quality ranges from 21.4 to 42.2%. Field investigations have been carried out to assess quantitatively the effect of land levelling quality on irrigation and water-use efficiencies and crop yield. The study comprised five levelling indices viz., 1.2, 2.0, 2.5, 3.0 and 3.7 cm and two irrigation treatments, i.e., fixed depth and complete irrigation. The results show that irrigation application, distribution, and water-use efficiency are appreciably reduced with increase in levelling index or deterioration in levelling quality. The wheat grain yield is also similarly reduced and it is significantly less for levelling index values higher than 2.5 cm. The fixed irrigation depth treatment gives better results from the point of water economy than does the complete irrigation treatment. From this study, it can be inferred that to obtain reasonably high yield and judicious use of water at a reasonable cost the field levelling index should not have a value greater than 3.0 cm.     

Comparative study of cytotoxicity of Aeromonas spp. on four different cell lines

In vitro cytotoxicity is an important virulence property of motile mesophilic Aeromonas species. Cell-free supernatant prepared from 55 Aeromonas isolates including one A. hydrophila type strain (MTCC 646) were examined for their cytotoxic potential on four different cell lines (Vero, BHK-21, MDBK, B 95a). Results of the study revealed cytotoxic potential in 92.72% of the isolates. Analysis of data exposed significant variation among isolates in respect of their cytotoxicity. Vero cells proved to be most sensitive to aeromonal toxins and B 95a cells showed significantly (P<0.01) lower response compared to other cell lines. Sensitivities of BHK-21 and MDBK cell lines were in between Vero and B 95a.     

Plant water requirement of ‘Hamlin’ sweet orange in cold temperature conditions

Citrus irrigation scheduling is usually based on evapotranspiration (ET) multiplied by a crop coefficient that varies throughout the year. However, ET at 10°C and less has not been investigated. Citrus acclimate to temperatures below 10°C, which affects ET, and therefore may allow irrigation scheduling to be adjusted accordingly. Three separate growth chamber experiments were conducted in complete block design with two temperature treatments and 8-one tree replications with the objective of determining water use of ‘Hamlin’ orange exposed to cold temperatures. The treatments included: full cold-acclimating temperatures, alternating 10 days cold and 3 days warm temperatures, and alternating 10 days warm and 3 days cold temperatures. Although well-watered, trees exposed to temperatures ≤10°C demonstrated lower water use compared to trees held at temperatures that promoted growth. Reduction of water use of cold-treated plants than the controls was 66, 20–57, and 14–28% during full cold-acclimating temperatures, alternating 10 days cold and 3 days warm, and alternating 10 days warm and 3 days cold temperatures, respectively. Reduced water use of cold-treated plants was due to stomatal closure, increased root resistance, and decreased leaf area. Effective irrigation scheduling based on water requirements as they change during cold-acclimating temperatures should save water while providing adequate water for yield and quality.     

Effect of feeding some plant foods as source of dietary fibre on biological utilisation of diet in rats

Isoproteinous diets containing 1% cholesterol and 10% fibre derived from plant foods namely,peepalbanti (Ficus religiosa),barbanti (Ficus bengalensis),gullar (Ficus glomerata),teent (Capparis decidua) andkhejri beans (Prsopsis cineria) or pure cellulose, were fed to rats for 40 days. Effect of incorporation of these whole plant parts on feed intake, weight gain, feed efficiency ratio (FER), dry matter digestibility (DMD) and true protein digestibility (TPD) in weanling rats was studied. Their inclusion did not affect the weight gain significantly whereas all other parameters were influenced to a varying extent. Foods rich in lignin had relatively lower FER, DMD and TPD whereas cellulose and pectin rich foods had higher DMD and TPD.     

Energy Use and Output Assessment of Food-Forage Production Systems

An assessment of the energy requirements of different intensive forage production systems was carried out at the Indian Grassland Fodder, and Agroforestry Research Institute, Jhansi. This included assessment of energy use and output for five intensive crop production systems: (1) sorghum (single‐cut)–berseem, (2) cowpea–sorghum (single‐cut)–berseem + mustard–maize + cowpea, (3) sorghum (multi‐cut)–berseem + oats, (4) guar–oats–maize and (5) sorghum (single‐cut)–wheat–fallow. In all the systems, the Napier bajra hybrid (IGFRI‐3) was transplanted in regular plots of 50 m × 13 m. Results revealed that the total annual energy use was highest for sorghum (multi‐cut)–berseem + oats (36 606 MJ ha^?1), followed by sorghum (single‐cut)–berseem + mustard, sorghum (single‐cut)–berseem–cowpea, guar–oats–maize and sorghum (single‐cut)–wheat–fallow (for which values were 31 086, 30 449, 29 867 and 25 956 MJ energy ha^?1, respectively). The high value found for sorghum (multi‐cut)–berseem + oats might be attributable to the multi‐cuts in this system. Energy use by fertilizers represented the major part of the total energy use, amounting to 28–38 % in all treatments, followed by energy used in electricity, machinery, seeds, human labour and farmyard manure (FYM), in case of all with slight increase in input. In sorghum–wheat, energy use by seeds occupied the second position, followed by energy used in electricity, human labour, FYM and machinery/diesel. Pesticides contributed the least energy utilization in all the treatments. Herbicides were used for the control of weeds. Among the five forage production systems, sorghum (single‐cut)–berseem + mustard–maize + cowpea was found to be the most energy efficient, followed by sorghum (multi‐cut)–berseem + oats–sorghum (multi‐cut), sorghum (single‐cut)–berseem–cowpea, guar–oats–maize and sorghum (single‐cut)–wheat–fallow. Sorghum (single‐cut)–berseem + mustard–maize + cowpea increased the fertility of the soil, resulting in a higher percentage of organic carbon, higher availability of nitrogen and optimal balancing of the C:N ratio in the upper layers of the soil. These intensive crop production systems also maintain the optimum microbial population in the crop root zone. The benefit–cost ratio (B:C ratio) for the most energy‐efficient forage production system was 1.37 : 1. However, the highest B:C ratio was found in the sorghum–wheat rotation (1: 1.57).     

Agrobacterium tumefaciens mediated genetic transformation and regeneration of Morus alba L.

An efficient method was established for genetic transformation of Morus alba clone M5 using Agrobacterium tumefaciens mediated gene transfer. Cotyledon explants from in vitro grown seedlings were co-cultivated with disarmed strain LBA 4404 harbouring the binary vector p^BI121 carrying chimeric β-glucuronidase (GUS) and neomycin phosphotransferase (npt II) genes. Maximum transformation frequency of 18.60% was recorded with 48 h of pre-conditioning followed by co-cultivation for the same duration. Expression and presence of transgene was confirmed by histochemical test and polymerase chain reaction. The transgenic plants were micropropagated and successfully acclimatised.