Volume 2, Number 1 (April 2001)
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Shifts from sorghum and pearl millet to maize in semi-arid cropping systems of Zimbabwe have been blamed for increased food insecurity of smallholder farmers. In this study, sorghum, pearl millet and maize were compared for their fit into the farming system of the northern Sebungwe of Zimbabwe under low input conditions, the current farmer management strategy. A number of tests were used to compare the three species : modified stability analysis, confidence intervals, ability to meet household calorific requirements and economic performance. Sorghum was higher yielding than either pearl millet or maize in most environments. When mean site yield was >1300 kg/ha, maize was higher yielding than pearl millet but lower with mean site yield of <1300 kg/ha. At the 90% confidence level, sorghum offered the best stability, with a yield range of 1469 to 2171 kg/ha compared to 924 to 1626 kg/ha for pearl millet and 793 to 1541 kg/ha for maize. Marginal analysis indicated that it was cheaper to produce sorghum and pearl millet compared to maize. Sorghum was the most reliable species to supply household calorific requirements. It was concluded that the shift from sorghum and pearl millet to maize was not justified under current farmer management.
Sorghum and pearl millet are considered stable food crops in climatic risk situations, whereas maize is a high yield crop. Recent studies analysing the climatic potential of the northern Sebungwe region, Zimbabwe indicate that rainfall in some parts is high enough to ensure stable crop production. In this study, sorghum, pearl millet and maize were compared for their fit into the farming system of the region under high input conditions. A number of tests were used to compare the three species : modified stability analysis, confidence intervals, ability to meet household calorific requirements and economic performance. There was more than one recommendation domain with regards to choice of species. In environments with a mean yield >1850 kg/ha (high yielding), maize had a mean grain yield of 3269 kg/ha followed by sorghum at 2702 kg/ha and 1830 kg/ha for pearl millet. Sorghum was the highest yielding species in environments with mean yield of <1850 kg/ha (low yielding). Sorghum average yield was 1845 kg/ha compared to 1296 kg/ha and 1129 kg/ha for pearl millet and maize, respectively. In low yielding environments, the average rate of return to investment was 22% for pearl millet, 45% for maize and 61% for sorghum. In high yielding environments, the returns for maize and sorghum were high at 222 and 111%, respectively, compared to 60% for pearl millet. A shift from sorghum to maize resulted in a marginal rate of return of 198% in high yielding environments. It is concluded that the shift from sorghum and pearl millet to maize can be justified in conditions typifying the high yielding environments; less acid soil reaction, rainfall >600 mm and growing season >120 days.
A field investigation for two consecutive years (1996 and 1997) was carried out at Regional Research Station (Coastal Saline Zone), Bidhan Chandra Krishi Viswavidyalaya, West Bengal to analyse the growth pattern of rice (cv. NC 492) under different treatments in rice-prawn dual system during wet season (kharif) in rainfed intermediate deepwater situation (0-50 cm). The studies revealed that application of either organic manure (FYM) or inorganic fertilizers (Urea, SSP and MOP) to rice in rice-prawn dual culture significantly increased plant height, dry matter accumulation, leaf area index, crop growth rate, net assimilation rate and number of tillers/m2 as compared to rice grown alone (control), but there was no significant difference observed between these treatments throughout the growth period. The variations in growth attributes among the other treatments viz., rice alone (control), rice-prawn culture (without fertilization) and rice-prawn culture with fishfeed were found to be insignificant at all stages of crop growth. Further, growth attributes markedly influenced the grain yield of rice..
A field experiment was conducted at the Indian Agricultural Research Institute, New Delhi, India to examine and analyse the effect of phosphorus, zinc and biofertilizers on lentil cultivars in relation to dry matter production, grain yield and nutrient uptake. The two lentil cultivars used in the study were : JL 1 (Microsperma) and Lens 4076 (Macrosperma) and the biofertilizers were : Rhizobium and vesicular arbuscular mycorrhizal (VAM) fungi. The results showed that cultivar JL 1 produced higher grain yield than Lens 4076 in 1990-91, but both the cultivars did not differ in respect of dry matter production and nutrient uptake. Application of 17.2 kg P as single superphosphate with 5 kg Zn ha-1 produced higher dry matter and grain yield. N, P and Zn uptake was improved by P and Zn application. Dual inoculation of Rhizobium and VAM fungi resulted in increased dry matter, grain and straw yield and nutrient (N, P and Zn) uptake when compared with their individual inoculation.
An experiment was conducted for two consecutive years to evaluate the impact of different sources and levels of sulphur on the productivity, chemical composition and uptake of nutrients by rainfed soybean grown on black clay soils. The results led to conclude that application of 75 kg S ha-1 through single super phosphate proved to be better in increasing the seed yield of soybean and also in improving the quality of soybean seed. Thus, it is concluded that single super phosphate be used as sulphur source looking to the easy availability and feasibility without taking care of any special management practices during application.
A field experiment was conducted at the Main Research Station, Hebbal, Bangalore during summer season of 1999 to determine the response of sunflower to drip irrigation levels and methods of planting. The prediction models indicated that sunflower showed a marked response to irrigation water upto drip at 0.6 Epan amounting to 457.68 mm of crop ET with positive regression coefficient. Cubic and three halves models were the best fit for prediction purposes with higher R2 values (0.8598 each). Also, predicted yields were in close agreement with the experimentally obtained, indicating the suitability of these models. With respect to planting geometry, normal spacing of 60 x 30 cm was the most suitable method of planting for realising the higher seed yield of sunflower as evident from positive regression coefficient in cubic (3.4925), three halves (3.4925) and also quadratic functions (3.4925). However, cubic and three halves models underestimated the yield of sunflower under normal planting while overestimating with paired row planting at 45-90-45 x 30 cm.
A field experiment was conducted during the summer seasons of 1996-97 and 1997-98 to study the suitability, effect and economics of intercropping blackgram at different populations in snakegourd field. The cropping systems were sole snakegourd and blackgram intercropped @ 3, 6, 9 and 12 plants per pit of snakegourd. The results indicated that snakegourd yield was not affected due to intercrop. The nitrogen addition, land equivalent ratio, snakegourd equivalent yield and net return were the highest under intercropping blackgram in snakegourd at the rate of nine blackgram plants per pit of snakegourd.
An experiment was conducted to know the influence of plant growth regulators and colour of wrappers on air-layering in mango varieties. The results revealed that mango variety Dusehri had better ability for success and survival of air-layers as compared to Chowsa and Langra. Plant growth regulators were important components of air-layering. IBA was found most effective in promoting the success, rooting, survival and growth attributes as compared to NAA and IBA+NAA. Among the wrappers, black polythene was found most appropriate for better success of air-layering and survival of air-layers in mango.
The experiment was conducted to study the biochemical changes during growth and development of litchi cvs. Muzaffarpur Early, Nafarpal, Deshi, Purbi, China, Seedless Late, Bedana, Bombai, Rose Scented and Early Large Red and their correlation with pericarp anthocyanin content. Both total soluble solids and total sugar content increased considerably after 45 days of fruit set until maturity. The total sugar content was recorded highest in Bedana/Bombai (16.54%) followed by China (15.55%) and Muzaffarpur Early (14.75%). The cultivar Bedana also registered highest reducing and non-reducing sugar content of pulp followed by Bombai. The acidity content of fruit pulp sharply declined (by 40-90%) after 45 days of fruit set until maturity. Anthocyanin content of fruit pericarp was negatively correlated with pH and acidity content of fruit pulp. In general, TSS and total sugar content exhibited negative correlation with peel anthocyanin content except Bombai.
Studies on 11 turmeric germplasms under rainfed condition in the New Alluvial Zone of West Bengal revealed that among the different germplasms, Kasturi produced the highest fresh yield (49.63 t/ha) and dry yield (10.67 t/ha) but curcumin content was very much low (2.1% i. e. lower than appreciable level as spice). Roma produced second highest dry yield (9.77 t/ha) and gave the highest level of dry recovery (29.89%) and curcumin content (9.12%). Investigation also revealed that germplasms Roma, Armoor, PTS-8 and PTS-62 can be made popular for their higher yield and curcumin content instead of local cultivar.
Leaf area estimation in brinjal was ascertained through indirect linear leaf measurement. The results indicated that the regression model y= -77.39+14.47 l for leaf length, y= -6.47+13.50 w for leaf width, y=47.18+0.56 for leaf length x width and y=67.40+117.23 dw for dry weight fairly estimated the mean leaf area on par with the actual leaf area determined by the automatic electronic leaf area meter. The simplest approach was to multiply the leaf length with the factor 9.87, leaf width with 13.21 and leaf length x width with 0.78 for rapid, accurate and in situ leaf area estimation on par with the actual leaf area. The indirect method of brinjal leaf area estimation in destructive sampling studies was to multiplying the leaf dry weight with the factor 196.97 with equal accuracy as the actual leaf area.
Techniques to explore the reliable estimation of leaf area in ridge gourd were attempted through indirect methods of measuring the leaf variables. The linear regression models as well as the simple constants were equally accurate. The linear regression models were : y= -66.20+22.24 l, y= -98.54+18.12 w, y=10.02+1.00 lw and 57.48+161.45 dw through leaf length, maximum width, product of leaf length and width, and leaf dry weight, respectively. The estimation of leaf area by multiplying the leaf length with the factor 16.37 or leaf width with 10.90 or the product of length and width with 1.09 were more simple techniques for in situ and accurate leaf area estimation of ridge gourd on par with actual leaf area. The factor 248.71 multiplied with leaf dry weight was also simple and accurate for leaf area estimation in destructive sampling.
Heterosis for six important physiological attributes was studied using Line x Tester mating design comprising 36 crosses from four lines and nine testers in cowpea revealed considerable amount of variability among the parents and hybrids for all the characters studied. High magnitude of heterosis was observed for all the characters. TVX-944/APC-714 was the top ranking hybrid for WUE and its related attributes followed by KBC-1/APC-761 and C-152/APC-761. The high magnitude of heterosis for WUE might be due to increased NAR, LAD, TDM and decreased CWT and RWL. The parents APC-761, APC-714, KBC-1 and KBC-2 contributed significantly towards WUE, LAD and TDM.
The potential of in vitro culture for rapid propagation of a medicinal plant Hyoscymus muticus L. was investigated by trying the embryo, leaf segment and petiole as explants on MS media and its three modifications using various concentrations and combinations of growth hormones and vitamins, B5 and White’s media. The embryo explant on M4 medium (MS+2 mg IAA+0.5 mg Kn+0.5 mg BAP+2 mg GA/I) gave the shoot regeneration. The regenerated shoots rooted prolifically on MS medium containing half strength MS with 2 mg/l of IBA and 40 g/l sucrose. Rooting was also obtained on White’s medium supplemented with 2 mg/l IBA, 1.0 mg/l Kn and 40 g/l sucrose.
The bioefficacy of Lantana camara and Adhatoda vasica with aqueous, chloroform, petroleum ether and methanol solvent was found to be promising against tea mosquito bug in the field during 1996-97. The efficacy of L. camara was superior over A. vasica. The L. camara aqueous extracts reduced the percentage of infestation to 27.63-38.90 as against 0.54-1.64% in control treatment which were significantly different from each other (P=0.01). Likewise, A. vasica aqueous extract also reduced the percentage of infestation to 25.41-37.78 as against 1.08-2.73% in control treatment. Similar observations were also made in case of solvent extracts. However, chloroform extracts of L. camara gave the highest significant reduction (36.74-46.93%) followed by petroleum ether of L. camara. Again A. vasica with all the solvents also gave significant reduction (30.00-44.68%) over control. All the concentrations of extracts gave significant reduction of infestation but higher concentration of extracts gave better results. However, commercial product Neem Gold gave the highest significant reduction of infestation than all the plant extracts.
The studies on extent of damage and estimation of loss in yield of tomato caused by different insect-pests species in winter and spring-summer crop on two varieties_one open pollinated (Pusa Ruby) and another hybrid (Abinash-II) showed that the composition of insect-pests species in both the varieties over seasons followed almost similar pattern but variation in the level of population over seasons, varieties and treatments was much prominent. A relatively low level of population of all the pest species was observed during winter as compared to spring-summer crop and again in insecticidal and combined insecticidal and fungicidal treated plots over untreated ones. The open pollinated variety always witnessed less pest attack than hybrid; however, loss in yield of tomato can be avoided from protective use of insecticides to an extent of 10.63 and 11.09% in winter and 23.69 and 26.66% in spring-summer crop from open pollinated (Pusa Ruby) and hybrid (Abinash-II), respectively.
Three application rates of dry powder of Dennettia tripetala and Eugenia aromatica for the control of Callosobruchus maculatus F were used. The various dry powders at 2.5, 5.0 and 7.5 g per 250 g of seed were effective in reducing oviposition and damage to cowpea seeds. E. aromatica was the most effective in discouraging oviposition and minimizing damage to the seed, as indicated by the significantly lowering the number of emergency holes on the seed. The seed viability and quality were not affected by the dry powder of D. tripetala and E. aromatica treatment. The result is indicative of the potential for the use of dry powder of these common spices in protecting stored cowpea seed against C. maculatus.
Water losses need to be minimized to obtain more water use efficiency. Water loss through seepage and percolation is a serious problem in the command area where water is conveyed through the network of canal system. Water losses can be minimized if the canals are lined with suitable material. The lining materials like bitumen, polythene, vinyl, etc. are costly. Artificial addition of less previous material to the surface and sides of the channel reduces considerably the amount of seepage and percolation. An experiment was conducted to study the seepage and percolation losses through trapezoidal channels of 1 : 1, 1.5 : 1 and 2 : 1 side slopes to evolve the relationship between seepage and percolation losses and channel cross section and to determine the effect of slow permeable layer on reduction of these losses. Three depths (3, 5 and 7 cm) of water were provided for each slope to study their effect separately on seepage and percolation losses. The total seepage and percolation losses were found increased with increase in cross section area of the channel. However, the seepage and percolation losses per unit area were found reduced with increase in cross section area of the channel. The reduction in seepage and percolation was maximum (75.80%) for 2 : 1 side slope and 7 cm water depth and minimum (60.50%) for 1 : 1 side slope and 3 cm water depth.
There is worldwide concern to reduce the number of tillage operations required to prepare seedbed with suitable tilth for various crops to reduce the cost of production, structural deterioration and yield losses. A field experiment was conducted during 1994 and 1995 to evaluate the effect of different seedbed tilth (coarse, medium and fine) on seedling emergence of cotton on a sandy loam (Typic Camborthid) soil. Different tilths were created by varying the number of disc harrowing after pre-sowing irrigation and cotton was planted. Mean weight, clod diameter, soil moisture content and seedling emergence were monitored during both the years. Soil temperature was also measured during the emergence in 1994. Repeated disc harrowing required for preparing fine seedbed tilth during the summer month of May resulted in decreased seed-zone soil moisture compared to coarse and medium tilth and reduced ultimate emergence (about one third of the coarse tilth) during 1994. When the seed-zone soil moisture content at sowing was kept almost uniform (1995), no appreciable difference among the tilth in the number of seedlings emerged was observed. A slight increase in soil temperature was recorded with the increase in the fineness of the tilth. The study suggested that when seed-zone soil moisture was not limiting, the coarse tilth was as good as the fine one for adequate emergence of cotton and superior when soil moisture was limiting, thus reducing the expenses on seedbed preparation considerably.
A field experiment was conducted to assess the production and land use efficiency of different crop sequences under rainfed upland condition during 1992-93 and 1993-94 in Indo-Gangetic alluvial soils of West Bengal. The results revealed that maximum production efficiency of 17.34 kg/ha per day was obtained with maize-wheat-moong sequence followed by 16.41 kg/ha per day with maize-yellow sarson-moong sequence. The land use efficiency value was 0.89 with maize-safflower-moong sequence and lowest value of 0.65 with til-yellow sarson-moong sequence.
In a 15 years of Leucaena plantation, soil samples were drawn under the tree canopy at 0-20, 20-40, 40-60 and 60-80 cm depths to study the nutrient build-up in the soil profile. Fertility status of the soil was significantly improved by the plantation. The highest amount of organic carbon, available micro- and macro- nutrients were observed in surface layer. Concentration of nutrients decreased with increase in soil depths.
22. R. K. MATHUR, M. Y. SAMDUR AND P. MANIVEL [Genetics of pod size in groundnut (Arachis hypogaea L.)]. Res. on Crops 2 (1) : 97-98 (2001). National Research Centre for Groundnut (ICAR), PO Box-5, Ivnagar Road, Junagadh-362 001 (Gujarat), India
Breeding for large seeded groundnut cultivars is one of the important objectives in any groundnut improvement programme focused on the development of confectionery types and large-seeded groundnut cultivars. Two fastigiata cultivars_GG 2 (as female parent) and NRCG 1339 (as male parent) were crossed and the F1 and F2 generations were studied for pod size. Large size of pod was dominant to small size. In F2, the ratio 170 large size pods : 24 small size pods has given a good fit of 225 : 31 (~7.25 : 1), thus, indicating control of two sets of duplicate loci interacting together with epistasis between loci. Two sets of duplicate genes P1/p1, P2/p2 and Q1/q1, Q2/q2 were proposed for pod size.
One hundred and eighty-three wheat genotypes were used for studying the genotypic correlation among grain yield and its related characters. The results showed that number of seeds/spike had the highest positive correlation with grain yield followed by 1000-grain weight and spike length. Days to 50% flowering showed highly significant negative correlation with seed yield. Hence, for improving grain yield in wheat, selection should largely depend upon early maturity, number of seeds/spike and spike length.