Performance of Rapeseed-mustard Cultivars under Various Moisture Regimes on the Gangetic Alluvial Plain of West Bengal

A Field trial was conducted during 1988–89 and 1989–90 at Water Management Research Station, Memari. Bidhan Chandra Krishi Viswavidyalaya, Burdwan, to study the effect of three different irrigation regimes, namely rainfed (I₁) (No irrigation), one irrigation (I₂) at flowering and two irrigations (I₃ at flowering and at sihqua formation stages) on the grain yield and water expenses on four different rapeseed-mustard cultivars, namely Pusa Bold, Pusa Baroni, Varuna and DIR 247. The variety DIR 247 recorded maximum grain yield (12.1 qha') followed by Pusa Baroni (11.8 q ha⁻¹). The variety Varuna showed the lowest water use efficiency (48.1 kg ha⁻¹ cm⁻¹) while DIR 247 showed the maximum value of 57.0 kg ha⁻¹ cm⁻¹. The number of irrigations significantly increased the grain yield. Two irrigations, one at flowering and at siliqua formation stage increased grain yield by 28 % over the rainfed plots. During the crop growth period the actual water expenses among the cultivars in any moisture regime were more or less similar. The interaction between varieties and irrigation levels were, however, not significant.     

Effect of Irrigation and N-Fertilization (Fertigation) Scheduling on Tomato in the Jordan Valley

Tomato ( Lycopersicon esculentum mill. cv. Petopride ) is the most important vegetable crop in Jordan; its production is characterized by inadequate irrigation and fertilization practices, especially under open field conditions. A field study was carried out to determine the effect of different irrigation intervals and different N-fertilizer doses on water use, tomato yields and residual soil nitrogen.
Results indicated significant differences in water use and tomato yields between irrigation treatments. Highest yield (51.4 ton ha⁻¹) was obtained under three irrigations per week with 504 mm total water supply, whereas under irrigation once a week 35.3 ton ha⁻¹were produced with 353 mm total water supply. There were no significant differences in yield between fertigation with ten equal time intervals and fertigations with intervals as per crop requirements, the yields were 47.1 ton ha⁻¹ and 44.5 ton ha⁻¹, respectively. However, yield was significantly lower with three fertigations at equal intervals and equal doses (35.8 ton ha⁻¹) throughout the season. There were no significant differences between mineral nitrogen forms in terms of yield effects. Significant irrigation effects were observed on total soil nitrogen. Residual soil N was 0.052% in the surface layer (0–30 cm), and 0.030% in the subsurface layer (30–60 cm).     

Water Use and Yield of Wheat under Unmulched and Mulched Conditions in Laterite Soil of the Indian Sub-continent

A held experiment was conducted during three winter seasons on West Bengal laterite soil to study the effect of irrigation and paddy straw mulch on water consumption. Water use efficiency and yield of wheat are reported. Both irrigation and mulch increased wheat yield significantly; there was also significant interaction between irrigation and straw mulch application: three irrigations combined with mulch resulted in 21.6 q ha^-1 wheat grain yield compared with 17.5 q ha^-1 for three irrigations without mulch. Mulch consistently increased irrigation response. Both irrigation and mulch increased water consumption and water use efficiency of the wheat crop. To compare the two irrigation treatments, irrigation at crown root initiation followed up by at flowering stage gave higher values of water use efficiency as well as higher grain yield than that of irrigation applied at panicle stage followed by at crown root initiation.     

Growth dynamics of winter wheat in the field with daily fertilization and irrigation

In a field experiment with fertilized and irrigated winter wheat the above-ground crop was sampled once a week. Phenological development, plant density and canopy height were recorded and the green surface areas of leaves, stems and ears were measured. Soil mineral nitrogen was sampled and the field climate monitored. There were four treatments. The daily irrigated/fertilized (IF) and daily irrigated (I) treatments were both irrigated by a drip-tube system. Liquid fertilizer was applied to IF following a logistic function according to calculated plant uptake. A total of 200 kg N ha⁻¹ was applied. Treatment I, control (C) and drought (D) were all fertilized once in spring with 200 kg N ha⁻¹. In treatment D transparent screens were used to divert rainwater. Dry matter production ranged between 1400 in D and 2352 g m⁻² in IF. The corresponding amount of nitrogen uptake ranged between 15.8 and 24.6 g m⁻². After harvest, soil mineral nitrogen was lowest in IF.
An increase in the availability of nitrogen and water enhanced total biomass production as well as grain yield and leaf area. The daily supply of nitrogen according to crop demand delayed nitrogen uptake and increased total uptake. The results suggest that when the nitrogen is supplied in accordance with crop demand, the efficiency with which the applied fertilizer is utilized increases and the risk for nitrogen leaching decreases.     

Correlation Studies on Ammonium/Nitrate Concentrations in Soil and Growth and Yield of Wheat

A field experiment was conducted at the Indian Agricultural Research Institute, New Delhi to study the growth and yield of wheat as influenced by the concentrations of ammonium-N and nitrate-N in soil. A series of ammonium and nitrate nitrogen concentrations in soil on a time frame was developed by treating prilled urea with nitrification inhibitors DCD or neem cake as well as by changing the dose and time of N application. The study revealed that number of tillers m^-1 as well as ears m^-1 row length were significantly positively correlated with ammonium-N concentration at 15 and 30 DAS and nitrate-N concentration at 30 and 45 DAS. Number of grains ear^-1 was significantly positively correlated with ammonium-N at 30, 45 and 60 DAS and nitrate-N at 45 and 60 DAS. Ultimately grain yield in wheat was significantly positively correlated with ammonium-N concentration at 15 and 30 DAS and nitrate-N concentration at 30, 45 and 60 DAS. The response between grain yield and concentrations of both ammonium and nitrate forms of N was quadratic. The optimum concentration of ammonium-N in soil for maximum grain yield gradually decreased with the age of the crop from 54.6 to 63.6 μg g^-1 at 15 DAS to 22.7 to 26 μg g^-1 at 30 DAS. In the case of nitrate-N its optimum concentration for maximum grain yield increased with age of the crop from 25.1 to 30 μg g^-1 at 15 DAS to 31.6 to 34 at 45 DAS and it decreased thereafter.     

Effects of Irrigation at Different Growth Stages and Source-Sink Manipulations on Yield and Yield Components of Mung Bean, Vigna radiata (L.) Wilczek, in Dry and Intermediate Zones of Sri Lanka

Irrigation is a management option available to farmers in the subhumid zones of Sri Lanka to increase mung bean yields during the dry Yala season. The objective of this study was to quantify the yield gain in response to irrigation at different stages of the crop and thereby determine the most suitable stage/s of irrigation. Four field experiments were conducted during Yala in 1995 and 1996 at two sites, Maha-Illuppallama (MI) and Kundasale (KS). Eight irrigation regimes consisting of all possible combinations of irrigation at three growth stages of the crop were defined. The respective growth stages were vegetative (from germination to appearance of first flower), flowering (from appearance of first flower to 75 % pod initiation) and pod-filling (from 75 % pod initiation to maturity). The treatments which received irrigation during two or more stages had significantly higher yields (793–1396 kg ha⁻¹) than those which received irrigation during only one stage (401–756 kg ha⁻¹) with the lowest yield being shown by the rain-fed treatment (227–396 kg ha⁻¹). When at least two stages can be irrigated, irrigation during the flowering and pod-filling stages was most effective. Irrigation during flowering produced the highest yield gain when only one stage could be irrigated. Seed yield showed a strong positive correlation with number of pods m^−2. Fifity per cent de-podding caused yield reductions at both sites, indicating sink limitation. In contrast, 50 % defoliation reduced the yields only at MI where the number of pods m⁻² was greater than at KS. Hence, source limitation was present only when the number of pods was higher.     

Effect of Foliar Applications of Glycinebetaine on Stress Tolerance, Growth, and Yield of Spring Cereals and Summer Turnip Rape in Finland

Crop losses caused by environmental stresses might be reduced by applying osmoprotectans to crop canopies. Glycinebetaine is endogenously accumulated by some halophytes under stress conditions and represents such a compound. Glycinebetaine was applied exogenously to barley ( Hordeum vulgare L.), oat ( Avena sativa L.), spring wheat ( Triticum aestwum L.), and summer turnip rape ( Brassica rapa ssp. oleifera DC.) canopies and its optimal concentration was monitored in the greenhouse. In field experiments the response of crop plants to betaine applications was assessed by measuring accumulation of above ground biomass, leaf area index (LAI), leaf chlorophyll, and yield. The optimum betaine concentration producing advantageous effects on growth and crop physiology in turnip rape was close to 0.1 M and for wheat 0.3 M. Such concentrations promoted accumulation of betaine similar to that of halophytes under stress conditions [ca. 200 μmol (g DM)⁻¹]. In the 1993 field experiment peak LAIs were recorded in irrigated wheat and barley treated with 17.5 kg ha⁻¹ betaine applied at 300 1 ha⁻¹. Green leaf area was slightly more persistent in wheat treated twice with 1 kg ha⁻¹ betaine applied at 200 1 ha⁻¹ in 1994, although it was not associated with increased grain yield. Our results indicated that betaine has no actual potential in Finland for the principal grain crops but further studies are needed in stress prone environments to assess the potential of betaine treatments for preventing crop failures.     

Shoot and Root Production and Nitrogen Uptake in Barley, with and without Nitrogen Fertilization

Two barley crops, one fertilized with 120 kg N ha⁻¹ (B120) and the other without nitrogen fertilization (BO), were cultivated for the second year on the same plot. In 1981 the growth and nitrogen content of the whole plant, above- and below-ground parts were measured by sampling every second week. Production was calculated as the difference between annual maximum and minimum amounts of biomass found above- and below-ground. Nitrogen uptake was estimated as the sum of the peak amounts of nitrogen present in the roots and shoots. The amount and concentration of nitrogen in partly decomposed plant debris in the soil was estimated simultaneously with the biomass.
Total net production in B120 was 1004 g m⁻² of which the roots constituted 16%. The unfertilized barley produced 558 g m⁻² of which 23% were produced below-ground. The maximum amount of living roots found in B120 was 160 g ash-free dry mass m⁻² and 128 g m⁻² in BO.
In the fertilized treatment 15 g N m⁻² (21% in roots) was taken up by the plant, compared to 5.8 g N m⁻² (28% in roots) in the unfertilized crop.     

Effect of Nitrogen and Sulphur Application on Yield and Fatty acid Composition of Mustard (Brassica juncea L.) Oil

The effects of nitrogen and sulphur on the yield and fatty acid composition of mustard ( Brassica juncea L.) oil were studied in a field experiment. Significantly higher grain and oil yields were obtained with N and S application. Applications of nitrogen up to 60 kg ha⁻¹ and sulphur up to 40 kg ha⁻¹ favourably influenced the grain yield. Increasing levels of N decreased the oil content while application of sulphur improved the oil content. The contents of linoleic and linolenic acid were maximum (16.82 and 8.73%, respectively) with 60 kg N along with 40 kg S ha⁻¹. No use of fertilizers led to higher contents of undesirable fatty acids such as palmitic (hypercholesterimic) and erucic (do not have food value) acids.     

Effect of Lentil Residues on the Yield and Response of Succeeding Rice to Nitrogen

A field experiment was conducted at the Division of Agronomy, Indian Agricultural Research Institute, New Delhi during 1983-84 and 1984-85 to study the effect of lentil residues on the yield and response of succeeding rice to nitrogen. Lentil residues benefitted the succeeding rice and gave longer and heavier panicles, more grains per panicle, higher 1000-grain weight and higher grain and straw yield of rice as compared to fallow. Rice responded well to applied nitrogen both in the absence and presence of lentil residues. The effect of lentil root residues and root residues plus incorporation of lentil straw was equivalent to 11 and 33 kg N ha⁻¹ when 60 kg N ha⁻¹ was applied to rice; the corresponding values being 54 and 60 kg N ha⁻¹ when 120 kg N ha⁻¹ was applied to rice.     

Performance of Agricultural Systems under Contrasting Growing Season Conditions in South-western Quebec

Climate change will alter temperature and rainfall patterns over North American agricultural regions and there will be a need to adapt crop production systems to the altered conditions. A set of field experiments were conducted in south-western Quebec, Canada, with soybean ( Glycine max L.), corn ( Zea mays L.), sorghum ( Sorghum bicolor L.) × sudangrass ( Sorghum sudanense Piper) hybrid and switchgrass ( Panicum virgatum L.) under two tillage and three nitrogen fertility regimes, to study their performance in three successive growing seasons (2001–2003), two of them with unusually warm and dry conditions. The annual crops were established in two tillage systems: conventional and no-till (NT). All crops except soybean were fertilized with three levels of nitrogen: corn – 0, 90 and 180 kg N ha⁻¹, sorghum-sudangrass – 0, 75 and 150 kg N ha⁻¹, switchgrass – 0, 30 and 60 kg N ha⁻¹. The 2001 and 2002 seasons were hotter and drier than the 2003 season, which was the most favourable for crop growth. The capacity of the crops to yield in dry seasons was as follow: switchgrass > sorghum-sudangrass > corn > soybean. The corn and sorghum-sudangrass responses to nitrogen fertilizer were low in 2001 due to the combined effect of dry growing season and coarse soil texture. Soybean did not perform well under NT. Corn yielded better at the highest nitrogen fertilizer rate under NT when the early season was warmer than the normal. Our results show that switchgrass and sorghum-sudangrass could be an option in south-western Quebec if the frequency of hot and dry seasons increase in the future, because of climate change.     

Nitrogen Level and Seeding Rate Effects on the Performance of Hulled Wheats (Triticum monococcum L., T. dicoccum Schubler and T. spelta L.) Evaluated in Contrasting Agronomic Environments

Effects of the nitrogen level and of the seeding rate on the performance of Triticum monococcum L., T. dicoccum Schübler and T. spelta L. (hulled wheats, together referred as 'farro') in comparison with bread wheat (variety Eridano) were evaluated. Field trials were conducted in five contrasting environments located in the north and central areas of Italy. Eridano mean grain yield was 3.86 t ha⁻¹, resulting the highest in all the field trials. T. spelta, T. dicoccum and T. monococcum net grain yield was 2.71 t ha⁻¹, 2.371 ha⁻¹ and 1.06 t ha⁻¹, respectively. Significant differences in all the evaluated parameters were observed among the species as well as among the environments. Biomass yield, grain protein and SDS sedimentation values of the hulled wheats were significantly influenced by nitrogen, which had no effect on grain yield. The results show the necessity to breed hulled wheat varieties adapted to the Italian environments and competitive with the bread wheat productivity in the marginal areas.     

Effect of Depth and Method of Irrigation and Nitrogen Application on Herb and Oil Yields of Java Citronella (Cymbopogon winterianus Jowitt.) under Semi-arid Tropical Conditions

A field expenment was conducted during 1992–94 at CIMAP, Field Station, Bangalore, India to study the effect of depth (25, 37.5 and 50 mm) and methods (Ridge and furrow and Broad Bed and furrow method) of irrigation and nitrogen levels (0, 200 and 400 kg N ha⁻¹ year⁻¹) on herb and oil yields of Java citronella. At the highest level of N application (400 kg N ha⁻¹ year⁻¹) ridge and furrow method was better suited for irrigating citronella. However, under lower N levels (0 and 200 kgN ha⁻¹ year⁻¹), as much as 30 % water can be saved by the broad bed and furrow method. The results have shown that highest herb and oil yields of citronella were achieved with the application of 400 kg N and maintaining 25 mm depth of irrigation. Content and quality of oil were not affected either by irrigation or nitrogen.     

Interactive Effect of Nitrogen and Sulphur on Growth and Yield of Rape-seed-Mustard (Brassica juncea L. Czern. and Coss. and Brassica campestris L.) Genotypes

A simple randomized field experiment was conducted to assess the growth and yield of rape-seed-mustard in relation to sulphur and nitrogen interaction. Three levels of sulphur (0, 40 and 60 kg ha⁻¹) in combination with three levels of nitrogen (60, 100 and 150 kg ha⁻¹) were tested as treatments, T₁, T₂, T₃, T₄, and T₅. Results indicated significant favourable effects of sulphur and nitrogen, when applied together, on yield components, seed and oil yield. Maximum response was observed with treatment T₃ (having S and N of 40 and 100 kg ha¹, respectively). Percentage oil content of seed was maximal at T₄ (having S and N of 60 and 100 kg ha¹) in both cultivars. The increase in N dose from 100 to 150 kg ha⁻¹ without any change in applied S, i.e. 60 kg ha¹ (T₅), decreased the percentage oil content. The seed and oil yield, however, were similar to T₃. Favourable responses of S and N interaction on leaf area index, rate of photosynthesis and biomass production were also observed.     

Effect of Sowing Season and Seeding Rate on the Morphological Traits and Yields in Pea Cultivars of Differing Leaf Types

Determination of optimal N-fertilization rates, N_OR , for crop production that minimize risk of environmental degradation require accurate application of a response model. Several models are available to describe crop yield response to N fertilization. The objective of this work was to compare the relative accuracy of a quadratic, f(N _Q), a modified Mitscherlich, and tanh( N ) models on 48 data sets. Data were collected from a Tara silt loam (fine-silty, mixed, frigid Pachic Udic Haploboroll) over a 6-year period using two maize ( Zea mays L.) hybrids and four tillage treatments, mouldboard plough, chisel plough, ridge tillage and no-tillage. In about one-third of the cases, all models performed about equally well. Generally, the tanh( N ) and modified Mitscherlich models gave better fit between N rate and grain yield data. The N_OR, ranged from about 140 to 170 kg ha⁻¹ for the modified Mitscherlich model, 136 to 184 kg ha⁻¹ for the tanh( N) function, and 124 to 173 kg ha⁻¹ using the f(N _Q) model. Estimated grain yields at these rates ranged between 6.58 ± 1.30 to 7.59 ± 1.69 Mg ha⁻¹ for the 90-day Minnesota maturity rated (MR) hybrid and between 7.52 ± 2.40 to 8.72 ± 1.70 Mg ha⁻¹ for the 95-day MR hybrid.     

Optimum Seed Rate and Nitrogen Fertilizer Requirement of Rice Under Semi-deepwater Ecosystem

The effect of varying seed rates (100–1000 seeds m⁻²) and nitrogen fertilizer (0–60 kg N ha_-1) applied either in a single basal dose or in splits was investigated on a tall elongating, photosensitive rice variety, Nalini, under semi-deepwater conditions (0–100cm) during 1993 and 1994 at Cuttack, India. Seedling emergence was higher in 1993 (53.9 %) than in 1994 (44.1 %) and it increased proportionately with increasing seed rate, Increase in the number of tillers and panicles m⁻² at higher seed rates was associated with a corresponding decrease in panicle weight. Regression analysis indicated a decrease of 0.91–1.28g in panicle weight for an increase of 100 panicles m⁻². The grain yield of rice was significantly higher at 400 seeds m⁻² in 1993 and at 600 seeds m⁻² in 1994 than at low seed rates but further increase in seed rate did not increase the yield. Application of N fertilizer increased the panicle number and thereby grain yield significantly. The effect of basal and split applied N at active or maximum tillering stages as well as between 30 and 60 kg N ha⁻¹ was not significant on the grain yield. The results suggest that a basal dose of 30kg N ha⁻¹ and seeding density of 400–600 seeds m⁻², resulting in 40–50 % seedling emergence and 150–200 panicles m⁻², each with 2.0–2.5 g weight, may be adequate for optimum productivity of rice under semideepwater conditions.     

Effect of Integration of Fertilizer and Green Manure Nitrogen on Yield Attributes, Nitrogen Uptake and Yield of Lowland Rice (Oryza sativa L.)

Field experiments were conducted at Tamil Nadu Rice Research Institute, Aduthurai, India, during the wet seasons of 1992 and 1993 to study the effect of full and partial substitution of fertiliser N with green manure N (Sesbania rostrata) on nitrogen uptake, yield attributes and yield of rice. The experiment consisted of eight treatments with two levels of N (100 and 200 kg ha⁻¹) and three sources of N application viz., fertilizer, integrated (1:1 fertilizer and green manure N) and green manure N compared to the recommended practice (150 kg fertilizer plus 6.25 t ha⁻¹ (72 kg N) green manure) and a no N control. Nitrogen application markedly increased the N uptake. Combined use of the two N sources at 200 and 222 kg N ha⁻¹ and of single fertilizer N at 200 kg N ha⁻¹ recorded the maximum N uptake, increased the yield attributes such as number of panicles per unit area, weight per panicle, number of total and filled grains per panicle and test weight. At 200 kg N ha⁻¹ full substitution of N by green manure reduced the grain yield but only partial substitution of N by green manure resulted in almost similar yield as single fertilizer N. Thus 200 kg N ha⁻¹ applied in equal proportions of fertilizer and green manure N can be recommended for medium duration rice cultivars.     

Effect of Gibberellic Acid Spray and Basal Nitrogen and Phosphorus on Productivity and Fatty Acid Composition of Rapeseed-Mustard

Two field experiments were conducted during] 994-95 to study the effect of spray of 10⁻⁵ M GA3 at 40 days after sowing on mustard ( Brassica juncea (L.) Czern & Coss.) cv. Varuna grown with basally applied 0, 40, 80 and 120 kg N ha⁻¹ (Expt. 1) and 0,15, 30 and 45 kg P ha⁻¹ (Expt. 2) on pod number per plant, seeds per pod, 1000 seed weight, seed yield, biological yield, harvest index and fatty acid composition of oil. No significant difference between water and GA3 spray was found when basally applied nitrogen was 0 or 40 kg N ha⁻¹. N₈₀ proved to be the best for yield characteristics. In another experiment on phosphorus, GA₃ and 30 kg P ha⁻¹ individually enhanced the yield, but interaction of GA₃ and P remained non-significant. The fatty acid composition of oil in both experiments was significantly affected only by nitrogen and phosphorus treatments for oleic acid and erucic acid. It was found that return in the form of yield was more for every kg applied fertilizer under GA, spray treatment. The response was more for N fertilizer in comparison to P. GA₃ at a low level of fertilization significantly increased the return from fertilization.     

Effects of Fungicide on Grain Yield of Barley Grown in Different Cropping Systems

The effect of fungicides and their combination on yield of barley under different nitrogen, slurry and tillage treatments was investigated at Hohenschulen Experimental Station near Kiel, Germany in 1991–97. Various fungicide treatments (no fungicide, and treatment with stem, leaf and ear fungicides and combinations of these), two nitrogen levels (120 and 240 kg N ha⁻¹), two tillage systems (minimum and conventional tillage) and four slurry applications (no application, and autumn, spring and autumn plus spring applications) were used. On average, fungicide application increased barley yield by 1.1 t ha⁻¹. The fungicide treatments could be classified into four types: (1) fungicides against stem diseases, which slightly increased yield by 0.25 t ha⁻¹, very similar to the results for the untreated control; (2) leaf fungicides and ear fungicides applied separately, and fungicides against a combination of stem and leaf diseases, which increased yield by 1.0 t ha⁻¹ on average; (3) fungicides against a combination of ear and stem diseases, which increased the yield by 1.22 t ha⁻¹, and (4) fungicides against a combination of leaf and ear diseases and a combination of stem, leaf and ear diseases, which increased yield by 1.59 t ha⁻¹ on average. The effects of fungicide on the yield were modified by crop husbandry. It can be concluded that application of fungicides against a combination of leaf and ear diseases could increase barley yield and reduce yield variation.     

Potential Yields and On-Farm Ethanol Production Cost of Corn, Sweet Sorghum, Fodderbeet, and Sugarbeet

Field experiments were conducted during 1980-82 at the Agronomy Farm of the University of California, Davis, to compare fermentable carbohydrate production and cost of potential ethanol from fodderbeet, sweet sorghum, sugarbeet, and corn in relation to the requirements of these crops for fertilizer nitrogen and irrigation. The response of hexose yields of these crops to fertilizer N varied in the two experiments. When all crops responded, sweet sorghum and sugarbeet required 36 % and fodderbeet 68 % of the fertilizer N needed for corn. Twelve weeks following a mid-season irrigation cut off, hexose yield of sugarbeet was decreased by 18 % as compared to an adequately watered crop. Water stressed sweet sorghum extracted higher amounts of soil moisture, increased in hexose concentration and produced 29 % higher hexose yield than when adequately watered. Stressed sugarbeet, however, had a higher hexose yield due to its higher sugar concentration.
When fertilized and irrigated adequately, fodderbeet produced 13.4, sugarbeet 11.9, sweet sorghum 10.0, and corn 8.15 Mg hexose ha⁻¹. Comparative on-farm ethanol production costs of these four crops were very close ($0.38 to 0.40 L⁻¹). Thus, growing established crops like corn and sugarbeet for which processing facilities and alternative markets already exist would be preferred.