Showing papers in "Indian Journal of Agricultural Sciences in 2004"

Effect of vermicompost, biofertilizer and phosphorus on growth, yield and nutrient uptake by gram (Cicer arietinum) and their residual effect on fodder maize (Zea mays)

Abstract: An investigation was carried out during the winter and summer seasons of 1999-2000 and 2000-2001 at New Delhi, to evaluate the effect of vermicompost, biofertilizers (Rhizobium and phosphate-solubilizing bacteria), and phosphorus on 'Pusa 256' gram or chickpea (Cicer arietinum L.) and their residual effect on succeeding fodder maize (Zea mays L.). Application of vermicompost at 3 tonnes/ha resulted in higher dry matter (19.78 g/plant), leaf-area index (1.57), pods/ plant (27.38), seed (2.35 tonnes/ha) and straw yields (3.81 tonnes/ha) of chickpea. Dry fodder yield (7.51 tonnes/ha) of maize and total N (171.67 kg/ha) and P (28.61 kg/ha) uptake by the chickpea-maize cropping system also increased significantly with the application of vermicompost to chickpea only. Seed inoculation with Rhizobium and phosphate-solubilizing bacteria markedly enhanced growth and yield attributes, seed (2.40 tonnes/ha) and straw (3.80 tonnes/ha) yield of chickpea, fodder yield (7.61 tonnes/ha) of succeeding maize and total N (179.48 kg/ha) and P (29.06 kg/ha) uptake by the chickpea-maize cropping system over the uninoculated control. Phosphorus fertilization up to 26.4 kg P/ha to chickpea also improved growth; seed (2.46 tonnes/ha) and straw (3.92 tonnes/ha) yields of chickpea, and increased the fodder yield (7.91 tonnes/ha) of succeeding maize. The magnitude of increase in chickpea yield with vermicompost was greater when no biofertilizer was applied. Vermicompost along with 13.2 kg P/ha recorded similar yield as obtained with 26.4 kg P/ha, indicating an economy of 13.2 kg P/ha.

Development of artificial diet for mass rearing of American bollworm, Helicoverpa armigera

Abstract: An artificial diet was developed during 2003 for mass rearing of American bollworm, Helicoverpa armigera (Hubner) under laboratory conditions (temperature 27′1°C, relative humidity 65′5% and 16:8 hr scoto-photophase regime). The diet ingredients consisted of kabuli gram or chickpea flour (Cicer arietinum L.) (94.0 g), wheat germ, (Triticum sp) (13.0 g), distilled water (825 ml), agar-agar (15.0 g), dried yeast powder (24.5 g), casein (15.0 g), ascorbic acid (6.0 g), methyl-p-hydroxybenzoate (2.0 g), sorbic acid (1.2 g), streptomycin sulphate (0.2 g), cholesterol (0.6 g), formaldehyde 40% (1.0 ml), ABDEC drops (multivitamin solution, 1.5 ml), multi-vitamin capsules (2) and α-tacopherol (Evion 400 mg, 1 capsule). This diet supported the growth and development of H. armigera successfully for 10 generations with most suitable impact on its reproductive potential. The mean growth and development indices were higher (6.0 and 3.46) as compared to 3.16 and 2.16 on pea (Pisum sativum L.) pod respectively. On natural food, pea pod, survival percentage of the test insect was 70, whereas it was as high as 85.4% on artificial diet. All the components of the diet are easily available and economical too, as the cost of 1 litre diet was approximately Rs 90 on which 250 larvae can be reared.

Stability and efficiency of cropping systems in Chhattisgarh and Madhya Pradesh

Abstract: An experiment was conducted from 1991-92 to 1998-99 through Cropping Systems Research Centres, located at Raipur, Sehore and Indore, to identify efficient cropping systems for Chhattishgarh and Madhya Pradesh. Based on 8 years study at Raipur, rice (Oryza saliva L.)-berseem (Trifolium alexandrinum L.) system was identified to be more efficient and most suited for Chhattisgarh, with highest wheat (Triticum aestiwm L. emend. Fiori & Paol.)-grain-equivalent yield (13 479 kg/ha/year), system productivity (36.93 kg/day/ha), stability (0.90), energy production (39.2 × 10 6 K cal/ ha), land-use efficiency (71%), nutrient use productivity (94.93 kg grain/kg nutrient), net monetary returns (Rs 62 526/ha/ year), profitability (Rs 171.3/ha/day) and benefit: cost ratio (Rs 4.68). This sequence was found specially suited for fodder-scarce animal-based farming situations having good irrigation facilities. The next best choice was rice-tomato (Lycopersicon esculentum Miller nom. cons.) with wheat-grain-equivalent yield of 11 317 kg/ha/year, system productivity of 31.01 kg/ha/day, energy production of 16.6 ×10 6 K cal/ha, land-use efficiency of 70%, water use productivity of 98.40 kg grain/ha-cm water, nutrient use productivity of 31.44 kg grain/kg nutrient and profitability of Rs 126/ha/day, but with comparatively low stability of 0.48. At Sehore in Vindhyan plateau zone of Madhya Pradesh, representing medium black soils and limited irrigation water conditions, soybean [Glycine max (L.) Merr.]-based systems, viz soybean-wheat and soybean-chickpea (Cicer anetmum L.) systems were identified to be more efficient only in terms of production (5 128 and 4 990 kg/ha/year as wheat-grain-equivalent yield), productivity (14.50 and 13.67 kg/ha/day) and stability (0.56 and 62). But, in terms of economic viability, blackgram (Phaseolus mungo L.)-linseed (Linum usitatissitimum L.) and maize (Zea mays L.)-linseed were more viable in terms of net returns of Rs 10 339 and 9 865/ha/year and benefit: cost ratio of 1.82 and 1.72. At Indore, under the very deep black soil conditions of Malwa plateau zone of Madhya Pradesh, soybean-wheat system was found to be distinctly better and efficient with the highest wheat-grain-equivalent yield (7 426 kg/ha/ year), productivity (20.35 kg/ha/day), stability (0.51) and economic viability (Rs 22 813/ha/year as net returns with Rs 62.5/ha/day as profitability and Rs 2.09 as benefit: cost ratio on per rupee investment). But in terms of water use productivity, pigeonpea [Cajanus cajan (L.) Millsp.]-wheat system was most efficient (105.2 kg grain/ha-cm water used). The soil fertility could be maintained with use of recommended doses of fertilizers over the years under different cropping systems.

Antloxldant phytochemicals in tomato (Lycopersicon esculentum)

Abstract: An experiment was conducted during 2001-2002 to study the major phytochemicals having antioxidant activity in 14 cultivars of tomato (Lycopersicon esculentum Miller nom. cons.). Significant differences (P < 0.05) were observed amongst the cultivars for the principal antioxidants, viz total carotenoids, lycopene, ascorbic acid and phenolics. Vitamin C content ranged from 15.70 to 28.56 mg /100 g fresh weight, the total carotenoids content from 4.99 to 20.88 mg /100 g, and the lycopene content from 2.13 to 9.76 mg /100 g. The total phenolics, another important antioxidant, also differed significantly [LSD (P = 0.03) 0.481] amongst the cultivars, being 12.19 to 32.55 mg gallic acid equivalent/100 g. Significant variation (P < 0.03) was also observed forpH and titratable acidity. The pH varied from 4.18 to 4.4 and anhydrous citric acid ranged from 0.348 up to 0.911%. The total soluble solids were 3.13 to 4.96%. The maximum vitamin C content was recorded in FEB 2' (28. 36 mg /100 g), closely followed by 'H88' (27,48 mg /100 g) and 'H 36' (27.16 mg/100 g), whereas the maximum carotenoids content was recorded in 'DT 10' (20.88 mg/100 g), followed by 'Agata' (19.95 mg/100 g) and 'H 36' (19.73 mg/ 100 g) respectively. The maximum lycopene content was recorded in 'Sel.7' (9.76 mg/100 g), and 'Agata' (8.90 mg/100 g), and 'Arka Vikash' (32.55 mg/100 g) and 'H 24' (31.28 mg/100 g) had the maximum phenol content.

Effect of rice (Oryza sativa) straw removal, burning and incorporation on soil properties and crop productivity under rice-wheat (Triticum aestivum) system

Abstract: A long-term field experiment was conducted during 1996-97 to 2000-2001 on a Typic Ustrochrept soil at the experimental farm of the Directorate of Wheat Research, Karnal, Haryana, to study the potential of rice (Oryza saliva L.) residue in the presence as well in the absence of green-manure crop prickly sesban or dhaincha [Sesbania cannabina (Retz.) Pers.; syn S. aculeata Pers.] as a soil amendment to improve soil and crop productivity under rice-wheat (Triticum aestivum L.emend. Fiori & Paol.) cropping system. Rice straw was incorporated in the soil before sowing of wheat, while Sesbania cannabina was incorporated before puddling for rice. Wheat yield under straw-incorporated plots was low (6.7-9.1%) in the initial 2 years compared to rice residue removal and burning of rice straw treatments, but the yield started improving (4%) in the third cropping season in the straw-incorporated treatment-both in the presence as well absence of green-manure. Green-manuring alone had little effect (8.0% increase) on organic carbon content of soil and availability of phosphorus (4.8%) and potash (1.3%) in the soil. Incorporation of crop residue alone or in combination with green-manure increased the organic matter (21%) content of soil and available P (12.7) and K content (14.3%) of soil. Green-manuring and straw incorporation had a favourable effect on bulk density (1.9% decrease) of soil.

Foliar nutrition as a supplement to soil fertilizer application to increase yield of upland cotton (Gossypium hirsutum)

Abstract: A field experiment was conducted with upland cotton (Gossypium hirsutum L.) at Ludhiana from 1998-99 to 2001-2002 on a course loamy, non-calcareous soil, low in organic carbon, medium in available P and K, to study the effect of foliar nutrition as a supplement to soil-applied nutrients on cotton. Treatments consisted of the control (soil-applied fertilizer) and 4 supplement sprays each of 2% potassium nitrate, 2% urea and 2% muriate of potash at weekly intervals, starting from flower initiation. Average data of 4 years showed that seed-cotton yield increased from 1 443 kg/ha in the control plot to 1 967, 1 836 and 1 766 kg/ha with the foliar application of 2% potassium nitrate, 2% urea and 2% muriate of potash, recording an increase of 36.3, 27.2 and 22.4% respectively. The corresponding increase in the number of flowers and bolls/plant was 42.7,37.9 and 42.2% and 39.4, 32.8 and 18.5% respectively. Application of potassium nitrate increased the N and K contents by 4.2 and 31.6%, while urea enhanced the N and K content by 11.3 and 21.1% in cotton leaves respectively. Muriate of potash increased the K content by 47.4% and decreased the N content by 3.8%. The foliar application of potassium nitrate was most profitable (net returns Rs 8 980/ha), whereas muriate of potash the least (Rs 6 170/ha). The net returns from foliar application of urea were Rs 7 903/ha.

Effect of planting and fertigation on growth and yield of green chilli (Capsicum annuum)

Abstract: An experiment was conducted during the summer season of 2001 and 2002 to study the effect of different planting techniques (paired row, triangular and normal planting) and fertigation intervals (2 days, 4 days, 6 days and8 days interval) on growth and yield of green chilli (Capsicum annuum L.). Use of triangular planting technique (30-90 cm × 45 cm) recorded significantly higher yield of green chilli (8.55 and 9.40 tonnes/ha) in both the years compared to paired row (45-75cm × 45cm) and normal planting (60 cm × 45 cm). Fertigation of recommended dose of fertilizer (100:50:50 kg NPK/ha) at every irrigation (2-day intervals) up to 105 days resulted significantly higher yield of green chilli of 9.30 and 9.06 tonnes/ha during first and second year respectively. However, it was on a par with fertigation at every alternate irrigation (4-day intervals) up to 105 days (8.62 and 8.00 tonnes/ha). Significantly low yield was observed in surface irrigation with recommended dose of fertilizer through straight fertilizers. Significantly higher uptake of n itrogen (104.69 and 96.94 kg/ha), phosphorus (12.58 and 11.81 kg/ha) and potassium (99.10 and 86.34 kg/ha) was recorded in fertigation of recommended dose of fertilizer at every irrigation (2-day intervals) up to 105 days.

Distribution of extractable boron content in acidic soils of West Bengal in relation to soil properties

Abstract: The boron (B) content of 18 representative soils from 3 acid soil regions of West Bengal belonging to Inceptisols, Alfisols and Entisols was determined during 2001-2002 using 5, different extractants, viz hot-CaCl 2 (HCC), hydrochloric acid (HCl), tartaric acid (TA), mannitol-CaCl 2 (MCC) and potassium dihydrogen phosphate (PDP) and it was correlated with soil properties. Their relative extractability for soil B was: PDP » HCl > TA > MCC > HCC for Inceptisols and Alfisols but HCC » HCl > PDP > TA > MCC for Entisols. Almost all the experimental soils belonging to Inceptisols and Alfisols were deficient in available B. The amounts of B extracted by almost each of the extractants showed significant positive correlation with organic C, clay content, electrical conductivity and cation-exchange capacity but negative correlations with soil pH values. Multiple regression equations showed that more than 90% of the variability in the extractable B content of the soils could be explained by the analysed soil properties. Electrical conductivity and contents of clay, hydroxyl aluminium and organic C had overriding influence on extractable B content in soils.

Seed yield and quality responses of winter oilseed rape (Brassica napes) to pla density and nitrogen fertilization

Abstract: An experiment was conducted during 2000-2001 to study yield and quality responses to plant densities of 67 500 plants/ha (row spacing of 54.5 cm), 97 500plants/ha (row spacing of 38.0 cm) and 127 500 plants/ha (row spacing of 29.0 cm) and levels of nitrogen (0, 75, 150, 225 kg/ha) application of high-oil content winter oilseed rape (Brassica napes L.) cultivar 'HO 605' at Zhejiang University farm, China. Dry-matter accumulation of plant decreased with increasing plant density, but increased with increasing levels of applied N. Number of primary and secondary branches that decreased with increasing plant density (18.2 % and 18.7 %) increased with N application (22.2 % and 75.0 %). Although the differences were not significant with increasing N application, average secds/pod increased with plant density (10.8 %) and level of applied N (6.3 %), and mean seed weight (3.33-3.52 mg) varied among treatments. The increase of 16.0 % and 13.3 % in seed yield was respectively realized with increasing plant density from 67 500 to 97 500 plants/ha and from 97 500 to 127 500 plants/ha, but the increase of applied N from 150 kg/ha to 225 kg/ha showed no significant increase in seed yield. Seed oil content (42.26-44.91 %) was insignificantly affected by increasing plant density, but significant decrease (5.9 %) was observed with higher input of N (225 kg/ha). Fatty acid composition and glucosinolate content of oilseed rape was unaffected by plant density, and increasing levels of N application (225 kg/ha) increased the composition of palmitic and linolenic acids (9.0 % and 5.5 %).

Effect of sowing time and crop geometry on tetralocular indian mustard (Brassica juncea) under south-west Haryana

Abstract: A field experiment was conducted during 1999-2002 at Bawal, Haryana, to study comparative performance of tetralocular Indian mustard [Brassica juncea (L.) Czernj. & Cosson] variety 'RB 9901' in comparison with bilocular traditional cultivars 'RH 30' and 'Laxmi' under different planting times and crop geometries in light-lextured irrigated soils of semi-arid climate. Crop planted on 14 and 21 October took significantly more days to 50% flowering (55 and 57) and maturity (154 and 156) compared to 7 October planting. The maximum seed yield (2.98 tonnes/ha) and yield-contributing parameters (branches/plant, siliquae on main shoot and siliquae/plant) were recorded when the crop was planted on 21 October and increased the seed yield by 8.5 and 3.5 % over that planted on 7 and 14 October respectively. Overall, 'RB 9901' was found superior for seed yield (3.05 tonnes/ha), oil yield (1.26 tonnes/ha) and yield attributes, viz siliquae on main shoot (83), siliquae/plant (626) and seeds/siliqua (19), and outyielded 'RH 30' and 'Laxmi' by a margin of 14.3 and 5.2 % respectively. The crop geometry of 45 cm × 10 cm was found optimum for all the varieties. The interaction effects revealed that performance of 'RH 30' was significantly superior when planted on 21 October, whereas 'Laxmi' and 'RB 9901' were equally better under both the sowing dates of 14 and 21 October.

Response of gram (Cicer arietinum) to types and methods of microbial inoculation

Abstract: A field experiment was conducted during the winter seasons (rabi) of 1996-97 and 1997-98 at Sehore, Madhya Pradesh, to study the effect of microbial inoculation (Rhizobium and phosphorus-solubilizing bacteria) and method of inoculation on nodulation, yield, nutrient uptake, quality and economics of 'JG 315' gram (Cicer arietinum L.). Dual inoculation in gram with Rhizobium and phosphorus-solubilizing bacteria either as seed or as soil inoculation (5x : 5 times and 10x : 10 times of the doses used in seed inoculation) significantly increased the nodulation (3.1 to 3.9 times nodule number and 3.2 to 4.2 times nodule dry weight), seed yield (20.7 to 24.7%), protein content in seeds (4.9 to 5.9%), nitrogen uptake (30.5 to 37.5%), phosphorus uptake (1.9 to 2.3 times), soil rhizosphere Rhizobium (10.6 to 13.8 times) as well as phosphorus -solubilizing bacteria population (23 to 31 times) over the control. The most economical treatment with 22.9% higher yield and Rs 2 442/ha net return was the use ofRhizobium + phosphorus-solubilizing bacteria + compost @ 125 kg/ ha as seed inoculation, followed by soil inoculation as 5x Rhizobium and 5x phosphorus- solubilizing bacteria + compost @ 125 kg/ ha with 23.7 % yield increase and Rs 2 228/ ha net return over the control.

Effect of drip and surface irrigation on yield and water-production efficiency of brinjal (Solanum melongena) in saline Vertisols

Abstract: A field experiment was conducted during 2000-2001 and 2001-2002 on saline soils of Agricultural Research Station, Gangavati, Karnataka, to study the response of brinjal (Solanum melongena L.) to various levels of drip andsurface irrigation. The treatments included 4 levels of drip, viz 0.8 evapo-transpiration (ET), 1.0 ET, 1.2 ET and 1.4 ET, and 3 levels of surface irrigation, viz 1.0 ET, 1.2 ET and 1.4 ET. The canal water having electrical conductivity (EC) of 0.20 dS/ m and well water of having electrical conductivity 2.2 dS/m were used for surface and drip irrigation respectively. The irrigation methods and levels had a significant effect on crop growth and yield parameters. Plant height (59.5 cm), branches (13) and fruits/plant (28) were better under drip irrigation than under surface irrigation. The highest fruit yield (26.2 tonnes/ ha) and water-production efficiency (69.3 kg/ha-mm) were achieved with drip irrigation compared to surface irrigation. The soil salinity was less near the vicinity of the root zone in the plots irrigated through drip irrigation compared to surface irrigation. The gross benefit: cost ratio varied between 1.97 (highest) for surface irrigation at 1.2 ET to 1.42 (lowest) for drip irrigation at 0.8 ET. Though the gross benefit : cost ratios were marginally less in drip irrigation, the use of poor-quality groundwater through drip irrigation seemed feasible solution, especially in the water-scarcity areas.The net profit achieved per mm water used was higher under drip irrigation than surface irrigation.

Integrated nutrient management practices in soybean (Glycine max) and sorghum (Sorghum bicolor) in sole and intercropping systems in a Vertisol

Abstract: A field experiment was conducted in a deep Vertisol during the rainy season of 2000 and 2001 at Bhopal, to study the root growth, seasonal evapo-transpiration and productivity of soybean [Glycine max (L.) Merr.] and sorghum [Sorghum bicolor (L.) Moench] as sole and intercrop in 6 nutrient combinations. Integrated use of farmyard manure @ 5 tonnes/ha or phosphocompost @ 5 tonnes/ha or poultry manure @ 1.5 tonnes/ha along with 75% NPK improved the root length density (42.4%), root mass density (95.9%) and root volume density (80.8%) and registered higher seasonal evapo-transpiration (4.4%), total dry-matter yield (12.9%) and seed yield (12.7%) over application of 100% NPK irrespective of the cropping systems. Also there was an improvement in the root-length density of intercrop sorghum (111.5%) over its sole crop in the 0-15 cm soil layer. The seasonal evapo-transpiration showed a quadratic relationship with the total dry-matter yield in sole soybean, sole sorghum and soybean+sorghum intercropping system. The optimum seasonal evapo-transpiration for maximum dry-matter yield of sole soybean, sole sorghum and soybean + sorghum intercropping system was 605.5 mm, 529.7 mm and 576.2 mm respectively. The seed yield of intercrop soybean decreased by 8% and that of intercrop sorghum increased by 7% over the corresponding sole crops. Among the organic sources the effect of farmyard manure was more prominent in soybean, while poultry manure was more effective in sorghum for seed yield, seasonal evapo-transpiration and root growth.

Effect of tillage on root growth, crop performance and economics of rice (Oryza sativa)-wheat (Triticum aestivum) system

Abstract: A field study was conducted during 1999-2000 at Pantnagar, Uttaranchal, to evaluate tillage effects on performance of the rice (Oryza satva. L.)-wheat (Triticum aestivum. L. emend. Fiori & Paol.) system. Tillage treatments for rice were puddling by 4 passes of rotary puddler, reduced puddling by 2 passes of rotary puddler, conventional puddling by 4 passes of cultivator with cage wheel, and direct seeding without puddling in 4 replications, and for wheat were zero-tillage and conventional tillage superimposed over the rice tillage treatments. Soil cracking greatly increased by puddling intensity. Among the puddled plots, crack volume was 1.17 times and 1.36 times higher in the conventional puddling and puddling by rotavator plots, respectively, compared to the reduced puddling plots. The root length density of rice in 0-0.1 m layer was maximum (2.33 cm/cm 3 ) in the plot puddled by rotavator, while the total root length density in the 0-0.6 m soil profile was maximum (3.68 cm/cm 3 ) in the direct seeding without puddling plot and minimum (3.52 cm/cm 3 ) in the plot puddled by rotavator. The total root length density of wheat in the 0 - 0.6 m profile was maximum (2.83 cm/cm 3 ) under conventional tillage, in the direct seeding without puddling plot of rice, and minimum (2.21 cm/cm 3 ) under zero tillage, in the plot puddled by rotavator for rice. Rice yield was highest (5 714 kg/ha) in the puddling by rotavator plot, followed by that in the conventional puddling and direct seeding without puddling plots and was statistically equal to that in the reduced puddling plot. The increase in rice yield in the plot puddled by rotavator was 9.3 % from that in the direct seeding without puddling plot, but the wheat yield was maximum (4 029 kg/ha) under zero tillage condition of the direct seeding without puddling plot. The maximum net return (Rs 18 560/ha) from rice crop was under reduced puddling treatment, followed by that under direct seeding without puddling, puddling by rotavator and conventional puddling treatments. Net return from wheat was maximum (Rs 11 820/ha) under zero tillage condition of the direct seeding without puddling plot and minimum (Rs 7 090/ha) under conventional tillage condition of the puddling by rotavator plot.

Phosphate solubilising Streptomyces spp obtained from the rhizosphere of Ceriops decandra of Corangi mangroves

Abstract: Phosphate-solubilizing potential of Streptomyces spp isolated from the rhizosphere soil of Ceriops decandra (Griffth) Ding Hou mangrove plant was studied using culture media supplemented with insoluble tricalcium phosphate which became transparent after few days of incubation. Fifteen phosphate-solubilizing strains of Streptomyces St-1 to St-15 were isolated from the rhizosphere of mangroves during 2010-11. Phosphate-solubilizing activity of these isolates was evaluated by the formation of halos (clear zones) around the colonies growing on solid medium containing tribasic calcium phosphate as a sole phosphorus source. St-3 was the most active phosphate solubilizing strain among the isolates followed by St-11. Studies on the biomass production of St-3 and St-11 showed an increase in growth at pH 7.2 after 7, 15 and 21 days of incubation at temperature 30°C and 37°C. Culture filtrate of St-3 alone showed the production of IAA. Present study reveals that the production of organic acids by the mangrove rhizosphere microorganisms may be a possible mechanism involved in the solubilization of insoluble calcium phosphate.

Nutrient depletion by weeds, weed-control efficiency and productivity of pearlmillet (Pennisetum glaucum) as influenced by intercropping systems and integrated weed management

Abstract: An experiment was conducted at Jobner, Rajasthan, during the rainy season ot 1999 and 2000 on loamy sand soil, to work out nutrient depletion by weeds, weed-control efficiency and productivity of pearlmillet [Pennisetum glaucum (L.) R. Br. emend. Stuntz.] as influenced by intercropping systems and integrated weed-management. Intercropping systems significantly reduced weed population and dry matter at all the stages compared to sole pearlmillet with lowest values under pearlmillet + cowpea [Vigna ungtiiculata (L.) Walp.] followed by pearlmillet + greengram (Phaseolus radiatus L.. However, intercropping systems were at par each other 30 days after sowing and at harvest. Pearlmillet intercropped with cowpea (28.09 %) and greengram (27.81 %) showed higher weed-smothering efficiency compared to 25.76% of pearlmillet + clusterbean [Cyamopsis tetragonoloba (L.) Taubert]. Higher weed-control efficiency (63.98 to 66.34%) and least weed-competition index (15.79 to 16.42%) were recorded under intercropping systems than sole pearlmillet. Sole pearlmillet gave significantly high grain yield, while intercropping systems fetched significantly higher net returns compared to sole pearlmillet. Maximum nutrients depletion by weeds was recorded to the extent of 26.2 kg N, 2.4 kg P and 24.8 kg K/ha at 60 days after sowing under sole pearlmillet, whereas minimum under pearlmillet intercropped with cowpea and greengram. Hand-weeding twice (30 and 45 days after sowing) remained at par with pendimethalin and oxadiazon each at 1.0 kg/ha + hand-weeding once significantly reduced the weed population (91 and 78/m 2 ) and dry-matter (616 and 625 kg/ha) at 60 days after sowing and at harvest, respectively, compared to rest of the weed-management practices. All the weed-control measures significantly increased the weed-control efficiency and weed-smothering efficiency 69.6 to 79.5% and 18.4 to 25.5 % compared with the unweeded control. Least weed-competition index (3.1 to 20.7%) was recorded under weed-control measures compared with unweeded control (55.9%). Hand-weeding twice gave maximum yield of pearlmillet and intercrops as well as net returns. Maximum nutrients depletion of 61.8 kg N, 5.6 kg P and 57.6 kg K/ha by weeds recorded under unweeded plots 60 days after sowing was significantly higher compared to rest of the weed-control measures with least under hand-weeding twice.

Simulation and validation of CERES-rice (DSSAT) model in north-western Himalayas

Abstract: A field experiment was conducted during the rainy seasons of 1998 and 1999 using CERES- Rice model to simulate growth, development and yield of 4 varieties of rice (Oryza sativa L.) in relation to dates of transplanting. The model predicted phenology of all varieties reasonably well and the association between observed and simulated days to flowering (R 2 =0.9405) and physiological maturity (R 2 =0.9540) was significant. The model failed to simulate panicles /m 2 . However, grains/m 2 and single grain weight were satisfactorily simulated and the association between simulated and observed parameters was significant. Significant association between simulated and observed grain yield were supported by the tests of significance for intercept and slope of the regression line (R 2 =0.6523). Likewise , straw yield and harvest index were also simulated fairly well by the model. However, the model did not correctly predict biomass yield at maturity. The CERES-Rice model was validated for grain yield over 5 years using data from other experiments conducted in different locations with different managements. The model simulated the grain yields very closely to the observed data. The goodness of fit (R 2 =0.8216) between simulated and observed data was significant.