Hill Spacing Research Articles

Growth and Seed Yield of Amphicarpaea edgeworthii Benth, in a Field Cropping.

Growth and reproductive yield of Yabumame (Amphicarpaea edgeworthii Benth.), a geocarpic edible wild legume, were investigated by field experiments. In experiment 1, seedlings of subterranean seeds derived from a natural habitat were transplanted to the field at a hill space of 30 cm within a row and 45 cm interrow spacing with 3 levels of support poles. A significant difference was observed in the increasing rates in the number of main-stem leaves between the plants with and without support poles since the 30th day after germination, when spiral elongation of their main stems started. The yield of subterranean seeds was approximately 20 gm-2, but the total reproductive yield including aerial seeds was 40 g m-2 The latter had a highly positive correlation with the total number of leaves. However, the plants with over 120 leaves per m2 to produce more aerial seeds than subterranean seeds. In experiment 2, the growth of seedlings of aerial seeds (SA) was compared with that of subterranean seeds (SS). SA and SS were transplanted to a level field with 1 plant per 1 m2 During the vegetative growth, the increasing rates of main-stem leaves were SA=SS, but the specific growth rates in total number of leaves were SA<SS. The yield of subterranean seeds may be increased by the increase in total leaf number through the improvement of sowing date, planting density, and support poles. It may also be increased by concentrating the seed production on the subterranean part by the breeding technology.

Improvement of Lodging Resistance in Submerged Direct Seeding Rice (Oryza sativa L.) Cultivation Using a Newly Developed 'Shooting hill-seeder'. Method of hill-seeding for the improvement and stabilization of lodging resistance.

By using a newly developed 'Shooting hill-seeder', it is easy to adjust the hill space within a row or the seeding depth, and change the hill-seeding form in the submerged direct seeding rice cultivation. In this study, the effects of these seeding conditions on the lodging resistance of hill-seeded rice were examined. It was suggested that the increased hill space within a row resulted in lower lodging resistance because of the elongation of culm and decrease in pushing resistance of the hill. These results show the importance to adopt a variety with high lodging resistance, or to control the nitrogen uptake by improvement of fertilizer application or water management, when a large hill space is necessary. On the other hand, the hill-seeding form did not seem to affect the lodging resistance. Furthermore, in hill-seeded rice, the chance of shallow seeding is rare, and the degree of lodging due to shallow seeding is extremely small as compared with broadcast-seeded rice. These characteristics are very important for the stabilization of the submerged direct seeding cultivation, in which unification of the seeding depth is difficult, and the stabilization of seedling emergence is important.

491 Intercropping of Spring-planted Sugarcane with Sweetpotato and Cowpea Under Conditions of Middle Egypt

Sugarcane, cowpea, and sweetpotato were grown in sole and intercrop systems at Experimental Station, Mallawi, Egypt (lat. 28°N) in the two spring seasons in 1996 and 1997 to determine the effects of cropping system on yield and yield components. The soil texture of the experimental site was loamy with a pH of 8.2. Results showed significant differences in yield and yield components of cane, cowpea, and sweetpotato due to intercropping treatments. Sugarcane intercropping caused signficant reduction in yield of sweetpotato and cowpea. The average yields of both sweetpotato and cowpea in the intercrop system were about 19.8 % and 29.9 %, respectively, of those of sole crop yields. Moreover, sweetpotato was more competitive than cowpea when intercropped. Furthermore, the magnitude of differences in sugarcane was low between sole and intercropped system as compared to sweet potato or cowpea. All yield attributes of cowpea and sweetpotato were better for the sole planted as compared to those for intrecrop treatments. Intercropping of one cowpea row sown at 15-cm hill spacing, between two sugarcane rows produced the maximum Land Equivalent Ratio (LER). This work suggests that the best cash return could be obtained when a single cowpea row planted at 30-cm hill spacing, is intercropped between two springplanted sugarcane rows.

Agronomic performance of urea briquettes containing diammonium phosphate in rainfed transplanted rice on farmers' fields

Seventy-seven adaptive research trials were conducted, with the participation of local farmers, on their fields during the 1993 and 1994 wet seasons (southwest monsoon seasons) in the warm subhumid tropical zone on the west coast of India. The objective of the trials was to compare the agronomic and economic benefits of an improved management consisting of placing urea briquettes containing diammonium phosphate (UB–DAP) by hand (56 kg N/ha and 14 kg P/ha) after controlled transplanting using a modified 20×20 cm hill spacing with two other practices: (i) the current management system, consisting of random transplanting and two split applications of prilled urea (PU) and a basal application of single superphosphate (SSP) and (ii) the farmers' traditional management practices, involving random transplanting and broadcasting of fertilizers. In spite of marked variations in rainfall distribution patterns during the 1993 and 1994 seasons, the improved management using UB–DAP increased grain yields by 2·14 t/ha (89%) in 1993 and 1·23 t/ha (45%) in 1994 over traditional management practices and by 1·56 t/ha (52%) in 1993 and 0·83 t/ha (27%) in 1994 over the current management system. These additional yields were obtained at a 28–36% lower plant population density (25 hills/m2v. 35–39 hills/m2). The use of a modified 20×20 cm spacing could reduce by up to 50% the labour normally required for the conventional placement of UB by hand about 1 week after transplanting using the standard 20×20 cm spacing (8–10 workdays/ha). The estimated value: cost ratios for the improved management ranged from 4·9 (1994) to 8·6 (1993) and increased further when the savings in seed input were considered. Stochastic dominance analysis of the yield data suggests that the improved management of UB–DAP could be risk-free and therefore would be preferred over the other two managements by rice farmers and policy makers.

Integrated rice straw–urea management for transplanted rice

SUMMARYFour field experiments were conducted over the 1992 and 1993 seasons (southwest monsoon seasons, June–October) in the warm subhumid tropical region on the west coast of the Maharashtra State, India. The objective was to investigate the effect of recycling limited amounts of rice straw (RS) (as a source of K and Si) integrated with the use of prilled urea (PU) and urea briquettes (UB) at 60 kg N/ha on the growth and yield of rainfed transplanted rice (Oryza sativa L.). The management practice, consisting of basal incorporation of RS (2 t/ha) integrated with deep placement of UB (one 2·1-g UB/4 hills) immediately after transplanting using a modified 20 × 20 cm spacing, produced a significantly higher grain yield (average increase of 1·3 t/ha) and straw yield (average increase of 1·1 t/ha) than did the RS practice integrated with two equal split applications of PU at the same N rate and hill spacing. The additional yields were attributed to the increase of total and productive tillers/m2 and panicle weight. The results indicate the potential of the integrated RS–UB management for increasing yields of rainfed transplanted rice in the warm subhumid tropical zone.

Agronomic performance of urea briquette applicator in transplanted rice

Field trials were conducted in the Philippines and India during 1989 and 1990 seasons to study comparative yield responses of transplanted rice (Oryza sativa L.) to pillow-shaped urea briquettes (UB) deep placed by an applicator (prototype developed by IFDC) and by hand immediately after transplanting. The applicator-placed UB consistently increased grain yields over the split-applied prilled urea, and the additional yields ranged from 0.23 to 1.48t ha−1 (5 to 83%) for 25 to 63 kg N ha−1. Agronomic responses of transplanted rice to the UB placed by the applicator and by hand were statistically equal. Modified rice hill spacing may be considered as a requirement for efficient use of the applicator. The results demonstrate that with the UB applicator it is possible to deep place UB mechanically and achieve the agronomic efficiency that is achieved by hand deep placement of the UB.

SUPERCONDUCTIVITY IN URANIUM MATERIALS

Metallic uranium materials occupy an interesting niche that is intermediate between transition and f-electron materials. Uranium in different environments is able to span this entire range, with narrow d-bands replaced by f-bands when the U-U distances are close enough for direct f-orbital overlap (closer than the Hill spacing), and with localized f-electrons forming magnetically ordered materials in the other extreme of large U-U spacing. As the U-U spacing and, in compounds, the ligand atoms, change, an interesting continuum of physics develops connected with the changing f-character of the materials. Corresponding to changing U-U separation are large, but non-monotonic, changes of more than two orders of magnitude in the low-temperature electronic specific heat parameter /gamma/. This parameter is a measure of the electronic density of states at the Fermi level, and in the free-electron theory of metals as well as the Landau Fermi liquid, the magnetic susceptibility chi due to the conduction electrons is also proportional to the density of states at the Fermi level. It is useful to plot for various materials the measured /gamma/ versus the T /yields/ O K limiting chi to see how much the measured chi is present, so to speak, in /gamma/. The authors domore » this for most of the known uranium superconductors. The solid line plotted there is the free-electron expression relating /gamma/ and chi. For materials with anisotropic susceptibility, the horizontal span of values corresponds to the range of chi values.« less

The Occupational Use of Hill Space in the Tucson Basin: Evidence from Linda Vista Hill

Recent investigations at the Tucson Basin “trincheras” site of Linda Vista Hill, located adjacent to the large floodplain village site of Los Morteros (AZ AA: 12:57 ASM), have revealed that a substantial number of the rock features there may represent the foundations of habitation structures. Evidence is presented that more than 80 of the Linda Vista trincheras were used as houses, and a mixed residential-agricultural use of the hill is proposed. Clustering of the proposed house foundations is apparent, and it is suggested that the Linda Vista trincheras may represent a restructuring of the Los Morteros community during the transition from the early to late Classic periods. It is suggested that other trincheras sites in the Tucson Basin were also used for residential purposes during the Classic period.

Studies on analysis and application of intensive planting techniques in small land agriculture. I. Effect of plant type, sowing time and planting density on growth and yield in maize-kidney bean intercropping.

The field experiment based on the results of field surveys (1978-1979) was made to determine the effect of plant type, sowing time and planting density on growth and yield in maize-kidney bean intercropping in 1979, from a viewpoint of analysis and application of conventional intensive culture in small land. Applied planting pattern was hill space intercropping of in-row planting and the obtained results were as follows: 1. Growth: The overlapping period of growth duration of maize and kidney bean in intercropping was longer in the planting with pole type bean than with the dwarf type bean, and also it was longer in late sowing than in early sowing of beans. Maize showed a tendency of increasing plant height at high planting density after tasseling irresepective of planting patterns. Plant height of pole type bean was shorter at intercropping than single cropping and this tendency was remarkable at later sowing with high planting density (Table 2). The dwarf type tended to be taller in plant height at intercropping in later sowing, especially in high planting density, but no difference in plant height was observed at early sowing (Fig. 2) Weed prostration was remarkably surpressed at high planting density of intercropping. The weed growth was coincident with the patterns of light transmission (relative light intensity) in the plant community (Fig. 3). 2. Yield: Grain yield per plant of maize was low at higher planting density irrespective of planting patterns. This higher yield in intercropping could be obtained at the planting with dwarf type bean than the planting with pole type bean. On the other hand, yield per area was higher at high planting density of any planting patterns but this incremental rate by intercropping was small (Fig. 4, Fig. 5, Fig. 6). The intercropping bean yield was particularly low at early sowing of pole type bean and also at late sowing of dwarf type bean. 3. Evaluation of land utlization in intercropping culture by relative yield totals (RYT) showed higher effect compared with single cropping, and maximum of RYT was found at late sowing with pole type in high planting density and early sowing with dwarf type bean in low planting density (Fig. 10).

Relative susceptibility of some rice varieties to the stalk-eyed fly Diopsis thoracica West

Ten rice varieties were studied for their relative susceptibility to the stalk-eyed fly, Diopsis thoracica West. Preference for oviposition was observed and some of the factors which appeared to pre-dispose the plants for oviposition were number of tillers per hill, leaf angle, plant height, stem diameter, leaf colour, plant age and plant spacing. The relative developments of Diopsis thoracica in the different varieties are given. Varietal susceptibility to infestation by the insect seemed to be different from varietal suitability for its growth. Insect damage affected the yield components and total yields, but the extent was varietal. The level of infestation, the production and time of production of compensatory tillers seem to be important factors in yield reductions. Implications of some of these results in a pest management programme are highlighted.

Varietal performance of transplant &lt;i&gt;aman&lt;/i&gt; rice under different hill densities

An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh from July to December 2004 to evaluate the effect of hill spacing on the performance of BRRI dhan40 and BRRI dhan41 as Transplant aman crop. The experiment consisted of five hill spacings viz., 5cm. 10cm, 15 cm, and 25 cm where row to row spacing of 25 cm was kept constant for all treatments. The experiment was laid out in randomized complete block design with four replications. The 25 cm x 5 cm hill spacing produced the tallest plant, highest total number of tillers/hill, bearing tillers/hill lowest number of non-hearing tillers/hill, grain yield and harvest index, while 25 cm x 5 cm hill spacing produced the highest number of sterile spikelets/panicle, straw yield and biological yield. BRRI dhan41 produced higher grain yield (4.7 t/ha) which was the contribution of higher number of grains/panicle and heavier grain weight. Lower yield (4.51 t/ha) was recorded in BRRI dhan40.Key Words: Varietal performance; T. aman rice; hill density.DOI: 10.3329/bjar.v34i1.5750Bangladesh J. Agril. Res. 34(1) : 33-39, March 2009

Effects of Hill Spacing, Number of Plants Per Hill and Nitrogen Supply on Growth and Yield of Rice

SummaryIn a factorial experiment with two spacings, four numbers of seedlings per hill, and two levels of nitrogen the highest numbers of shoots were produced in high nitrogen and high plant density plots. Increasing the number of seedlings per hill led to a rise in the number of shoots per plot and this was more pronounced in high than in low plant densities. Significant differences in shoot number between high and low nitrogen plots occurred only at the higher plant density, but high nitrogen and wide spacing led to an increase in the number of shoots per hill and per plant. Increasing the number of seedlings per hill resulted in an increase in the number of shoots per hill but a decrease in the number of shoots per plant. The effects of treatments on leaf blade area at ear emergence and on grain yields were similar to those on shoot number. The percentage increase in the yield of grain per unit area due to increasing the number of seedlings to three and four were 12 and 9 respectively. The percentage shoot mortality was greater in plots with low than with high plant density. Plants were higher in high nitrogen plots, especially at high plant density, while high nitrogen supply and four seedlings per hill increased the number of days from seeding to ear emergence. The former treatment also increased ear length. Low plant density and three seedlings per hill increased the ear to shoot dry weight ratio. The best combination of treatments for high grain yield was high nitrogen, 15 cm x 15 cm spacing, and four seedlings per hill.

Studies on the Spacing Density of Rice Plants : Part 3. Interrelationships between the spacing density and the mode of hill arrandement (2)

In the previous paper, the influences of the mode of hill arrangement on the density effect for yield and various characters of rice plants was examined, in respect to the continuous changes from the square hill arrangement with a-plant-planting per hill to the square hill arrangement with four-plant-planting per hill, through the nest arrangement of hill. In this paper interrelationships between spacing density and the mode of hill arrangement in respect to the continuous changes from the square hill arrangement to the row arrangement pass through the rectangular hill arrangement is reported. The experiment was conducted at Kashimadai Farm, Institute for Agricultural Research, Tohoku University, in 1957. Fixing the distance between rows constant and increasing the density by reducing the hill spacing in the row, yield-density relationship coincided also with the low of C-D effect as was stated in the previous papers. In regard to the relative situations among square, rectangular and row arrangement of hill in the same density, the maximum grain yield per unit area obtained at the point which the retio of row distance to hill djstance in a row is 2 : 1 or 3 : 1.

Espaçamento da batata doce em São Paulo

SUMMARY AND CONCLUSIONS The effect of spacing on the total yield and on the size of sweet potatoes was studied in seventeen experiments comprising three series of tests with several treatments, carried out at five experiment stations in the State of Sao Paulo, from 1939/40 to 1948/49. Several combinations of spacing from 60 to 100 cm between rows and 20 to 50 cm between hills in the rows were tried out. Randomized blocks with four replications were used in all experiments. Observation were made on development of the vines, occurrence of failures and types of roots produced. These roots were classified according to weight in three types as follows : small (less than 80 grams) ; medium (from 80 to 800 grams) and large (more than 800 grams). The average weight of roots (total yield divided by number of roots) was calculated for each treatment The results obtained in these experiments indicated that in the rows 60 to 100 cm apart, the reduction of spacing between plants in the rows from 50 to 30 cm and from 30 to 20 cm resulted in an increase in total root yield and also in the amount of roots of average size, that is the type which is more valuable for the large consuming market. The smaller spacing in the rows favored also the production of small and medium sized roots and reduced considerably the amount of large-sized sweet potatoes. The average root weight was also increased. Total root yield was not affected by variations in the spacing between rows. Ho­wever, when spacing between rows was reduced from 100 to 75 cm, an increase was noted in the average root weight and also in the quantity of small and medium sized roots. The amount of large sized sweet potatoes was reduced. When the same area per plant was maintained, the variable spacing used has not influenced the size and average weight of the roots but highest total root yield was obtai­ned when plants were set 30 cm apart in rows spaced 100 cm apart. Based on the results of these experiments the following recommendations can be made for planting sweet potatoes in the State of Sao Paulo : a) When small sized sweet potatoes are desirable, the spacing of 70 to 80 cm bet­ween rows and 20 cm in the lines can be adopted. For intensive cultivation in small-areas, as is usual near the city of Sao Paulo, where the market prefers the small sized type, this spacing can be recommended. b) For more extensive plantings and when the small-sized type is not particularly required a larger spacing might be used, as at closer spacing an additional quantity of vines and more labor are necessary. The recommended spacing at this case is 90 to 100 cm between rows and 30 cm in the rows. c) When the roots are to be used for feeding livestock or for industrial purposes where there is no restriction to size and weight of roots, wider spacing between plants may be used. The recommended is 90 to 100 cm between rows and 40 cm within the row. LITERATURA CITADA 1. Anderson, W. S., E. A. Currey, E. B. Ferris e J. C. Robert. Sweetpotato plant spacing. Bull. Miss, agric. Exp. Sta. 358 : 1-19. 1941. 2. Anderson, W. S., H. L. Cochran, J. B. Edmond, O. B. Garrison, R. E. Wright e Victor R. Boswell. Regional studies of time of planting and hill spacing of sweetpotatoes. Circ. U.S. Dep. Agric. 725 : 1-20. 1945. 3. Anderson, W. S. e John W. Randolf. Sweetpotato production. Time of planting and hill spacing studies. Bull. Miss, agric. Exp. Sta. 378 : 1-22. 1943. 4. Beattie, J. H., Victor R. Boswell e E. E. Hall. Influence of spacing and time of planting on the yield and size of the Porto Rico sweetpotato. Circ. U.S. Dep. Agric. 327 : 1-10. 1934.

The Effect of the Spacing of Cotton Upon the form and Height of the Plant

This paper reports results of cotton growth on Mississippi River Bottom soil at the Louisiana Experiment Station, Baton Rouge, Louisiana. In 1924, with total rainfall of 7.15 inches during June, July and August, Salisbury cotton averaged 1588 pounds seed cotton per acre. The same variety on similar soil in 1925, with a normal rainfall amounting to 14.48 inches during June, July and August, produced an exceedingly rank weed growth with abundant blooming but practically complete shedding of small bolls and no crop was picked. Spacing tests were conducted in 1926 with Lone Star No. 65 cotton on similar soil, planted June 25 and records completed by September 25. Rainfall during June, July and August amounted to 25.51 inches and a severe tropical storm occurred on August 25, when over 10 inches of rain fell. The widest spacing, single plants 24 inches apart, produced invariably the lowest and broadest growth with thickened bases to the stalks, heavy vegetative branches and delayed setting of bolls. The unthinned cotton was extremely slender and whip-like with no vegetative branches and very few bolls. In all spacings varying from single stalks at 8 inches to 3 to 5 stalks per hill, there developed a practically full stand of from 16,000 to 18,000 stalks per acre having “normal growth” and fruiting. These stalks were, as a rule, moderately slender, with few if any vegetative branches and reaching a rather uniform height of 38 to 42 inches at three months of age. Hill spacing with 3 to 5 stalks at 12 to 15 inches apart appeared to give the most practicable and desirable spacing.