Potato Rows Research Articles

Growth and yield of sugarcane and potato in companion cropping system

SUMMARYTwo potato genotypes, Kufri Sindhuri (KS) and Kufri Chandramukhi (KC), were grown in association with sugarcane (cv. Co 1148) at 1:1 (SP) and 1:2 (SPP) sugarcane (S): potato (P)row arrangements. Growth behaviour and yield of both crops in companionship were compared with those of their sole cropping. Initially, KC accumulated more dry matter in tubers than KS. At harvest, the contribution of tubers to total dry matter was the same in both genotypes. However, KS produced significantly higher absolute tuber yields than KC. Potato row arrangements in sugarcane did not significantly affect the proportion of dry matter in different plant components. However, SPP gave significantly higher tuber yields than SP and was the same as with sole potatoes. Drymatter accumulation, canopy development and yield of sugarcane were not affected significantly by potato row arrangements in the companion cropping system. Sugarcane was unaffected by KC in companion cropping but KS exerted an adverse effect on all the growth characters and yield of sugarcane. Similarly, in sequential cropping, sugarcane yielded significantly less when planted after KS than after KC.

The effect of subsoiling and irrigation on potato production

Thin tillage pans restrict water movement and potato ( Solanum tuberosum L.) root penetration in fine-textured soils of the Columbia Basin in central Washington State, U.S.A. Deep chiseling beneath potato rows, with simultaneous deep incorporation of fertilizer, was used to break-up the pans, enabling deeper root development. The effects of subsoiling on soil physical conditions and on potato production were examined under varying rates of irrigation. Deep tillage decreased soil strengths and bulk densities and increased porosity to depths of 10–16 cm below the pans. These improved subsoil physical conditions resulted in deeper root penetration, but the additional rooting only amounted to a small increase to the total root system. Cubic polynomial regressions demonstrated that subsoiling significantly increased potato yields under very droughty conditions but had no significant effects at intermediate (near optimum) levels of water application. Potato quality (percentage of U.S. No. 1 grade tubers and tuber specific gravity) was generally unaffected by deep tillage. These results indicate that, for potatoes, appropriate irrigation management can be used to overcome problems of restricted root penetration and impeded water movement caused by tillage pans.

Irish Potato, Control of Potato Infesting Aphids, 1985

Abstract The foliar and systemic experiments were randomized complete block designs with 6 replicates each and were conducted at Presque Isle, ME on land that was in clover in 1984. The planting dates were 21 May ’85 for the systemic experiment and 22 May, for the foliar experiment. In each experiment the 3-m space between blocks and the 1.4-m space between columns and at the sides and ends of the experiments were sown to oats after planting. Each plot consisted of 4 rows of potatoes 0.9 m apart and 15.0 m long. The healthy Katahdin seed pieces ca. 75 g each were planted with a tractor-pulled, assisted-feed planter. Fertilizer and hilling practices were normal for the area. Late blight was controlled by 7 foliar applications of Dithane M-45 (1681 g/ha weeks of 8 and 15 Jul, 2242 g/ha weeks of 22, 29 Jul, 12, 19 and 26 Aug) and 1 application of Ridomil 2E (1.17 1/ha 31 Jul). Soil applications of insecticides were made with a modified Gandy applicator just prior to planting or as a sidedressing after emergence. Foliar insecticide applications were made with a Century boom sprayer, 3 nozzles per row at 7.0 kg/cm2 pressure and 1.2 kl/ha. Numbers of aphids (by species) were counted on top, middle, and bottom leaves of 25 plants in the middle rows of each plot. When dates of count and application were the same, aphid counts were made prior to applications of the insecticide. Analyses of variance were calculated following transformation of the data using log10(x + 1). Means of the total number of wingless aphids were compared using DMRT and then reconverted. The soil was classified as Caribou Loam, pH 5.2. Total monthly rain fall for Jun, Jul, and Aug was respectively 11.2, 13.8 and 6.1 cm. The average temperature for each of the same 3 months was 15.6, 19.5 and 17.2°C.

Irish Potato, Control of Colorado Potato Beetle, 1985

Abstract The experiment was a randomized complete block design with 6 replicates, planted 23 May at Presque Isle, ME on land that was in clover in 1984. The 3-m space between blocks was bare soil. The 4-row plots were separated by 2 rows of untreated potatoes. All rows were machine planted 0.9 m apart and 15.0 m long and the healthy seed pieces (ca. 75g) were 30 cm apart. Fertilization and hilling practices were normal for the area. Late blight was controlled by 7 foliar applications of Dithane M-45 (1681 g/ha the weeks of 8 and 15 Jul, 2242 g/ha the weeks of 22, 29 Jul, 12, 19 and 26 Aug) and 1 application of Ridomil 2E (1.17 1/ha 31 Jul). Foliar insecticide applications were made with a Century boom sprayer, 3 nozzles per row at 7.0 kg/cm2 pressure and 1.2 kl/ha. Numbers of larvae and adults were counted on 25 whole plants in the middle rows of each plot. When dates of count and application were the same, beetle counts were made prior to application of insecticides. Analyses of variance were calculated following transformations of the data using log10 (x + 1). Means of the sum of larvae and adult beetles were compared using Duncan’s new multiple range test and then reconverted. The soil was classified as Caribou Loam, pH 5.2. Total monthly rainfall for Jun, Jul, and Aug was respectively 11.2, 13.8, and 6.1 cm. The average temperature for each of the same 3 mo was 15.6, 19.4 and 17.2°C. Approximately 40 overwintered adult beetles were added to each plot on 26 Jun to supplement the natural population.

Irish Potato, Control of Potato Infesting Aphids, 1984

Abstract The foliar and systemic experiments were randomized complete block designs with 6 replicates each and were conducted at Presque Isle, Maine on land that was in clover in 1983. The planting dates were 22 May, 1984 for the systemic experiment and 23 May, for the foliar experiment. In each experiment the 3.0-m space between blocks and the 1.4-m space between columns and at the sides and ends of the experiments were sown to oats after planting. Each plot consisted of 4 rows of potatoes 0.9 m apart and 15.0 m long. The healthy Katahdin seed pieces ca. 75 g each were planted with a tractor pulled assisted feed planter. Fertilizer and hilling practices were normal for the area. Late blight was controlled by 8 foliar applications of Diathane M-45 (1681 g/ha weeks of 9 and 16 Jul, 2242 g/ha weeks of 23, 30 Jul, 6, 13, 20 and 27 Aug). Soil applications of insecticides were made with a modified Gandy applicator just prior to planting or as a sidedressing after emergence. Foliar insecticide applications were made with a Century boom sprayer, 3 nozzles per row at 7.0 kg/cm2 pressure and 1.2 kl/ha. Numbers of aphids (by species) were counted on top, middle, and bottom leaves of 25 plants in the middle rows of each plot. When dates of count and application were the same, aphid counts were made prior to applications of the insecticide. Analyses of variance were calculated following transformation of the raw data using log10(x + 1). Means of the total number of wingless aphids were compared using DMRT and then reconverted. The soil was classified as Caribou Loam, pH 5.2. Total monthly rainfall for Jun, Jul, and Aug was respectively 15.52, 13.74 and 7.26 cm. The average temp for each of the same 3 months was 15.6, 20.0 and 19.7°C.

Irish Potato, Control of Colorado Potato Beetle, 1984

Abstract The experiment was a randomized complete block design with 6 replicates, planted 23 May at Presque Isle, ME on land that was in clover in 1983. The 3.0-m space between blocks was bare soil. The 4-row plots were separated by 2 rows of untreated potatoes. All rows were machine planted 0.9 in apart and 15.0 m long and the healthy seed pieces (ca. 75g) were 30 cm apart. Fertilization and hilling practices were normal for the area. Late blight was controlled by 8 foliar applications of Diathane M-45 (1681 g/ha the weeks of 9 and 16 Jul, 2242 g/ha the weeks of 23, 30 Jul, 6, 13, 20 and 27 Aug). Foliar insecticide applications were made with a Century boom sprayer, 3 nozzles per row at 7.0 kg/cm2 pressure and 1.2 kl/ha. Numbers of egg masses, larvae, and adults were counted on 25 whole plants in the middle rows of each plot. Analyses of variance were calculated following transformations of the raw data using log10 (x + 1). Means of the sum of each stage of the beetle were compared using Duncan’s new multiple range test and then reconverted. The soil was classified as Caribou Loam, pH 5.2. Total monthly rainfall for Jun, Jul, and Aug was respectively 15.52, 13.74, and 7.26 cm. The average temp for each of the same 3 months was 15.6, 20.0 and 19.7°C.

Irish Potato, Control of Potato Infesting Aphids, 1983

Abstract Experiments A, B, and C were randomized complete block design with six replicates each and were conducted at Presque Isle, Maine, on land that was in clover in 1982. The planting dates were 18 May 1983, for experiment A and 2 and 3 June for experiments B and C, respectively. In each experiment the 2.0-m space between blocks and the 1.4-m space between columns and at the sides and ends of the experiments were sown to oats after planting. Each plot consisted of four rows of potatoes 0.9 m apart and 15.0 m long. The healthy seed pieces ca 75 g each were planted with a tractor-pulled, assisted-feed planter. Fertilizer and hilling practices were normal for the area. Late blight was affected by four foliar applications of Ciba-Geigy Ridomil MZ58 (2471 g/ha weeks of 18 July and 4 Aug., 3707 g/ha weeks of 16 and 30 Aug.). Soil applications of insecticides were made with a modified Gandy applicator just prior to planting or as a sidedressing after emergence. Foliar insecticide applications were made with a Century boom sprayer, three nozzles per row at 7.0 kg/cm2 pressure and 1.2 kl/ha. Numbers of aphids (by species) were counted on top, middle, and bottom leaves of 25 plants in the middle rows of each plot. When dates of count and application were the same, aphid counts were made prior to applications of the insecticide. Analyses of variance were calculated following transformation of the raw data using log10 Duncan’s multiple range test and then reconverted. The soil was classified as Caribou Loam, pH 5.2. Total monthly rainfall for Jun., Jul., and Aug. was, respectively, 1.66, 12.99., and 8.86 cm. The average temperature for each of the same 3 months was 17.8, 18.9, and 18.9°C.

Irish Potato, Control of Potato Infesting Aphids, 1982

Abstract Experiments A and B were randomized complete block designs with 6 replicates each and were conducted at Presque Isle, ME on land that was in clover in 1981. The planting date was May 18. In each experiment the 2.0 m space between blocks and the 1.4 m space between columns and at the sides and ends of the experiments were sown to oats after planting. Each plot consisted of 4 rows of potatoes 0.9 m apart and 15.0 m long. The healthy seed pieces ca 75 g each were hand planted 30 cm apart. Fertilization and hilling practices were normal for the area. Late blight control was effected by 2 foliar applications of Ridomil (2EC) 396 g/ha wk of Aug 6 and 19) and 3 applications of M45 (1781 g/ha wk of Jul 30 and Aug 6, 2242 g/ha Aug 19). Soil applications of insecticides were made by hand with a plastic tube applying previously weighed amounts of insecticide into the furrow or fertilizer band just prior to planting or as a sidedressing after emergence. Foliar insecticide applications were made with a Century boom sprayer, 3 nozzles per row at 7.0 kg/cm2 pressure and 1.2 kl/ha. Numbers of aphids (by species) were counted on top, middle, and bottom leaves of 25 plants in the 2 middle rows of each plot. When dates of count and application are the same, aphid counts were made prior to applications of the insecticide. Analyses of variance were calculated following transformation of the raw data using log 10 (x + 1). Means of the total number of wingless aphids were compared using DMRT and then reconverted. The soil was classified as Caribou Loam, pH 5.2. Total monthly rainfall for Jun, Jul and Aug was respectively 8.79, 6.07 and 10.36 cm. The average temperature for each of the same 3 mo was 15.6, 18.9 and 15.6°C.

Irish Potato, Control of Potato Infesting Aphids, 1981

Abstract Experiments A, B, C, and D were randomized complete block designs with 6 replicates each and were conducted at Presque Isle, MA on land that was in clover in 1980. The planting dates were May 21 for experiments A, B and C and Jun 11 for experiment D. In each experiment the 2.0 m space between blocks and the 1.4 m space between columns and at the sides and ends of the experiments were sown to oats after planting. Each plot consisted of 4 rows of potatoes 0.9 m apart and 15.0 m long. The healthy seed pieces ca 75 g each were hand-planted 30 cm apart. Fertilization and hilling practices were normal, for the area. Late blight control was effected by 3 foliar applications of CIBA-Geigy Ridomil (2EC) 280 g/ha the weeks of Jul 8, 22 and 396 g/ha the week of Aug 5. Soil applications of insecticides were made by hand with a plastic tube applying previously weighed amounts of insecticide into the furrow or fertilizer band just prior to planting or as a sidedcessing after emergence.

Irish Potato, Control of Colorado Potato Beetle, 1981

Abstract The experiment was a 4 x 6 randomized complete block design planted May 22 at Presque Isle, ME on land that was in clover in 1980. The 2.0 m space between blocks was bare soil. The space between columns was planted with 2 rows of untreated seed (ca 75 g) 30 cm apart. Each plot consisted of 4 rows of potatoes, 0.9 m apart and 15.0 m long. The healthy seed pieces ca 75 g each were machine planted 30 cm apart. Fertilization and hilling practices were! normal for the area. Late blight control was effected by 3 foliar applications of CIBA-Geigy Ridomil (2EC) 280 g/ha the weeks of Jul 8, 22 and 396 g/ha the week of Aug 5. Foliar insecticide applications were made with a Century boom sprayer, 3 nozzles per row at 7.0 kg/cm2 pressure and 1.2 kl/ha. Numbers of egg masses, larvae, and adults were counted on 25 whole plants in the middlef 2 rows of each plot. Analyses of variance were calculated following transformations of the raw data using log10 (x + 1). Means of the sum of each stage of the beetle were compared using Duncan’s new multiple range test and then reconverted. The soil was classified as Caribou Loam, pH 5.2.

Irish Potato, Control of Potato Infesting Aphids, 1980

Abstract Experiments A and B were randomized complete block design with 6 replicates each and were conducted at Presque Isle, ME on land that was sown to oats in 1979. The planting date was May 23, 1980 for all experiments. In each experiment the 2.0 m space between blocks and the 1.4 m space between columns and at the sides and ends of the experiments were sown to oats after planting. Each plot consisted of 4 rows of potatoes 0.9 m apart and 15.0 m long. The healthy seed pieces ca. 75 g each were hand planted 30.0 cm apart. Fertilization and hilling practices were normal for the area. Late blight control was effected by weekly foliar applications of Rhom & Haas M45 (1121 g/ha weeks of Jun 30 through Jul 22, 1781 g/ha weeks of Jul 25 through Aug 15, and 2242 g/ha weeks of Aug 18 and 29). Soil applications of insecticide were made by hand with a plastic tube applying previously weighed amounts of insecticide into the furrow just prior to planting. Foliar insecticide applications were made with a Century boom sprayer, 3 nozzles per row at 7.0 kg/cm2 pressure and 1.2 kl/ha. Foliar insecticides were mixed with the fungicide. Numbers of aphids (by species) were counted on top, middle, and bottom leaves of 25 plants in the 2 middle rows of each plot. When dates of count and application are the same, aphid counts were made prior to application of the insecticide. Analyses of variance were calculated following transformation of the raw data using log10 (x + 1). Means of the total number of wingless aphids were compared using Duncan’s new multiple range test and then reconverted. The soil was classified as Caribou Loam, pH 5.2. Total monthly rainfall for Jun, Jul, and Aug was respectively 9.2, 13.3 and 7.2 cm. The average temperature for each of the same 3 months was 15, 18.3 and 18.3°C.

Irish Potato, Control of Potato Infesting Aphids, 1979

Abstract Experiments A, B, and C were randomized complete block designs with 6 replicates each and were conducted at Presque Isle, ME on land that was sown to oats In 1978. The planting date was May 21 for all experiments. In each experiment the 2.0 m space between blocks and the 1.4 m space between columns and at the sides and ends of the experiments were sown to oats after planting. Each plot consisted of 4 rows of potatoes 0.9 m apart and 15.0 m long. The healthy seed pieces ca 57g each were hand planted 30.0 cm apart. Fertilization and hilling practices were normal for the area. Late blight control was effected by weekly foliar applications of Rohm & Haas M45 (1121 g/ha weeks of Jul 1 through 22, 1781 g/ha weeks of Jul 29 through Aug 12, and 2242 g/ha weeks of Aug 19 and 26). Soil applications of insecticide were made by hand with a plastic tube applying previously weighed amounts of insecticide into the furrow just prior to planting. Foliar insecticide applications were made with a Century boom sprayer, 3 nozzles/row at 7.0 kg/cm2 pressure and 1.2 kl/ha. Foliar insecticides were mixed with the fungicide. Numbers of aphids (by species) were counted on top, middle, and bottom leaves of 25 plants in the 2 middle rows of each plot. When dates of count and application are the same, aphid counts were made prior to application of the insecticide. Analyses of variance were calculated following transformation of the raw data using log10(x + 1). Means of the total number of wingless aphids were compared using Duncan's new multiple range test and then reconverted as given in the Table. The soil was classified as Caribou loam, pH 5.2. Rainfall for June, July and August was respectively 72.7, 49.9 and 138.5 percent of normal. Temperature for the same 3 months departed +5.0°, +7.2° and +3.9°C from normal.

Colorado Potato Beetle Control, 1979

Abstract Potato beetle larvae collected Jul 18 from potatoes in Grand Forks, North Dakota were used in laboratory tests of Gulf Products numbered insecticides. Insecticides were applied Jul 19 to 50-ft rows of potatoes at the Rosemount Agricultural Experiment Station, Rosemount, MN by using a hand-operated compressed air sprayer delivering 50 gal water/acre at ca 50 psi. Foliage was collected immediately after treatment and every second day thereafter to be fed to the larvae. Survival was checked every 24 hr. and only if there were no signs of life was a larva considered dead.

Irish Potato, Control of Potato Infesting Aphids, 1978

Abstract Experiments A and B were randomized complete block designs with 6 replicates and were conducted at Presque Isle, Maine on land that was sown to oats in 1977. The planting date was May 23‘78 for all experiments. In each experiment the 2.0 m space between blocks and the 1.4 m space between columns and at the sides and ends of the experiments were sown to oats two weeks after planting. Each plot consisted of 4 rows of potatoes 0.9 m apart and 15.0 m long. The 57 g healthy seed pieces were hand planted 30.0 cm apart. Fertilization and hilling practices were normal for the area. Late blight control was effected by weekly foliar applications of Rohm & Haas M45 (1121 g/ha week of Jul 7, 1781 g/ha weeks of Jul 10 through 24, and 2242 g/ha weeks of Jul 31 through Aug 28). Soil applications of insecticides were made by hand with a plastic tube applying previously weighed amounts of insecticide into the furrow just prior to planting. Foliar insecticide applications were made with a Century boom sprayer, 3 nozzles per row at 7.0 kg/cm2 and 1.2 kl/ha. Foliar insecticides were mixed with the fungicide. Numbers of aphids (by species) were counted on top, middle, and bottom leaves of 25 plants in the 2 middle rows of each plot. When date of count and application are the same, aphid counts were made prior to application of the insecticide. Analyses of variance were calculated following transformation of the raw data using log10(x + 1). Means of the total number of wingless aphids were compared using Duncan’s new multiple range test and then reconverted as given in the Table. The soil was classified as Caribou Loam, pH 5.2. Rainfall for Jun, Jul, and Aug was respectively 103.7, 124.2, and 57.6 percent of normal. Temperature for the same 3 months departed + 0.6°, + 4.4°, and + 5.0°C from normal.

Irish Potato, Control of Potato Infesting Aphids, 1977

Abstract Experiments A, B, C, D, and E were 7x6, 7x6, 8x6, 7x6, and 6x6 randomized complete block designs respectively and were conducted at Presque Isle, Maine, on land that was sown to oats in 1976. The planting date was May 25, 1977, for all experiments. In each experiment the 9.1-m space between blocks and the 1.4-m space between columns and at the sides and ends of the experiments were sown to oats at planting. Each plot consisted of 4 rows of potatoes 0.9 m apart and 15.2 m long. The 57-g healthy seed pieces were hand planted 30.5 cm apart. Fertilization and hilling practices were normal for the area. Late blight control was effected by weekly foliar applications of Rohm & Haas M45 (1121 g/ha week of July 17 and 1781 g/ha weeks of July 24 through August 28, 1977). Soil applications of insecticides were made by hand with a plastic tube applying previously weighed amounts of insecticide into the furrow fust prior to planting. Foliar insecticide applications were made with a Slosser sprayer (14.1 kg/cm2 and 1.2 kl/ha). Foliar insecticides were mixed with the fungicide.

Irish Potato, Control of Potato Infesting Aphids, 1976

Abstract Experiments A, B, C, D, E, and F were 7 × 6, 4 × 6, 6 × 6, 5 × 6, 7 × 6 , and 6 × 6 randomized complete block designs respectively and were conducted at Presque Isle, Maine on land that was sown to oats in 1975. The planting date was June 4, 1976 for all experiments. In each experiment the 9.1 m space between blocks and the 1.4 m space between columns and at the sides and ends of the experiments were sown to oats at planting. Each plot consisted of 4 rows of potatoes 0.9 m apart and 15.2 m long. The 57 g healthy seed pieces were hand planted 30.5 cm apart. Fertilization and hilling practices were normal for the area. Late blight control was effected by weekly foliar applications of Rohm & Haas M 45 (2242 g ai/ha July 10 through August 31, 1976). Soil applications of insecticides were made by hand with a plastic tube applying previously weighed amounts of insecticide into the furrow just prior to planting. Foliar insecticide treatments were made with a Slosser sprayer (14.1 kg/cm2 and 1.2kl/ha) in combination with the fungicide. Numbers of aphids (by species) were counted on a top, middle, and bottom leaf of 25 plants in the 2 middle rows of each plot. When date of count and application are the same, aphid counts were made prior to application of the insecticide. Analyses of variance were calculated following transformation of the raw data using log10,(x + 1)- Means of the total number of wingless aphids were compared using Duncan's new multiple range test and then reconverted as given in the Table. The soil was classified as Caribou Loam, pH 5.2. Rainfall for June, July, and August was 112, 140, and 174 percent of normal. Temperature for the same 3 months departed + 3.5°, + 1.0°, and 0.0°C from normal.

Irish Potato: Control of Colorado Potato Beetle, 1976

Abstract The experiment was a 13 × 6 randomized complete block design planted May 18, 1976 at Presque Isle, Maine on land which was fallow in 1975. The 7.62 m space between blocks was bare soil. The space between columns was machine planted with 2 rows of untreated seed (57 g average), 30.5 cm apart. Each plot consisted of 4 rows of potatoes, 0.86 m apart and 12.19 m long. The 57 g average seed pieces were hand planted 30.5 cm apart. Fertilization and hilling were normal for the area. Late blight control was effected by weekly foliar applications of Rohm & Haas M 45 (2242 g ai/ha July 10 through August 3 1 , 1976). Soil treatments in the experiment were made in the furrow just prior to planting with a plastic tube containing previously weighed amount of insecticide. Foliar applications were made with a Slosser sprayer (14.1 kg/cm2 and 1.2 kl/ha). Numbers of egg masses, larvae, and adults were counted on 25 whole plants in the 2 middle rows of each plot. Analyses of variance were calculated following transformation of the raw data using logjQ (x + 1). Means of sum of all stages of the beetle were compared using Duncan's new multiple range test and then reconverted as given in the Table. The soil was classified as Caribou loam, pH 5.2. For the growing season, rainfall for June, July, and August was 112, 140, and 174 percent of normal. Temperatures for the same 3 months departed + 3.5°C, + 1.0°C, and 0.0°C from normal.

Studies on the Seed Potato Growing in Warmer District in Japan : I. Seasonal variation in the parasitic activity and the flight of potato aphids in relation to the transmission of virus disease in potato fields grown twice in a year in spring and autumn.

I. Fluctuations in population of the alatae and the apterae of Myzus persicae (SULZER), Aphis gossypii GLOVER and Aulacorthum solani (KALTENBACH) were Surveyed, sticky traps of BROADBENT style being used with regard to their flight, in experimental potato-field-blocks which were planted at nine different times successively throughout from spring to autumn in Himeji from 1955 to 1958. The results are as follows: (1) The appearance of those aphids has three seasons, marked off by the disappearance and the diminution periods on host and flight, which are relatively stable but without connection with plant growth. (2) M. persicae appears most abundantly in the early and middle part of the first season (from April to June), and also in the middle and late part of the third season (from Octover to December), but scarcely in the second season (from July to mid September); A. gossypii exceedingly in the second season, and also in the middle and late part of the first season, and in the early and middle of the third season; the counts of A. solani is always the smallest. (3) Though the aphid population varies markedly with dats of potato sprouting, the seasonal fluctuation curve of parasitic activity in each species is obtainable by the line connecting the highest value of the aphid population among blocks of each planting date. Such fluctuation curves in different years and aphid species were discussed with regard to flight fluctuation. II. On a virus free potato row planted in a victoria lawn tunnel, adjacent to an alternate open row of diseased poatoes infected with virus Y and leafroll virus, was allowed natural inoculation by opening the tunnel for one week at definite time, in Himeji from 1955 to 1957. The results are: (1) the fluctuation observed in virus transmission in years, seasons and with the dates of sprouting revealed close connection with activities, especially with flight, of the aphids which inoculated the diseases, i.e. virus Y being associated with A. gossypii or plus M. persicae, and leafroll virus with M. persicae or plus A. solani. However, in un-caged blocks, transmission of leafrall and virus Y were rather correlated with the index-value for the whole season infestation of alate aphids, with the relation of M. parsicae plus A. solani to leafroll and A. gossypii plus A. solani to virus Y, the index-value being obtainable by summing up all countings made on every tenth day by the line of parasitic activity. The reason for the affecting of A. solani to the transmission of virus Y must be owing to the abnormal appearance of the species in autumn 1956. (2) The number of days for virus diseases to flow down from inoculated leaves to tubers varied in connection with the aphid population; in relatively shorter period of time the tubers seemed to be infected, if much of inoculations have been occured by many aphids.

The Influence of Certain Fertilizing Materials on the Soil Reaction and Nutrient Level in the Potato Row during the Growing Season

AbstractThis is a continuation of an experiment conducted at the Virginia Truck Experiment Station in 19483 to determine the influence of acid and neutral fertilizers on the soil reaction in the potato row during the growing season. Results from the 1948 study indicate that fertilizers applied in bands in the potato row had a marked influence on lowering the soil reaction, and that the degree of this influence was dependent upon where the sample was taken with respect to the fertilizer bands. The purpose of this study was to determine whether fertilizer materials might differ in their influence on the soil reaction, with some possibly being more effective than others in reducing the pH of soils where there was danger of scab.A commercial 5‐10‐5 fertilizer was used for treatment 1, and hand mixed materials were used for the other five treatments. In treatment 2, all the nitrogen was derived from NH4NO3, while in treatment 3, it was derived from (NH4)2SO4. In treatments 4 and 5 the nitrogen was derived from NH4NO3, and 50 and 100 pounds of sulfur, respectively, were added per ton of fertilizer. All of the treatments were applied at the rate of 2,000 pounds per acre except treatment 6 where the fertilizer mixture was applied at the rate of 3,000 pounds per acre.Soil samples were taken 2, 4, 8, and 12 weeks after planting at certain locations around the band. Phosphorus, potassium, pH, nitrate and conductivity tests were run on all samples.The six fertilizer mixtures markedly lowered the soil reaction in the potato row during the 1949 and 1950 growing seasons. This influence varied with the sampling location or position of the soil sample with respect to the fertilizer bands, with the greatest influence being exerted above the bands. The lowering of the pH was associated with increases in salt concentration in nitrates and in potassium. There was no important differences in the influence of the six different mixtures on the soil acidity except where the soil samples were taken from the fertilizer bands.

The Influence of Acid‐forming and Neutralized Fertilizers on the Soil Reaction and Nutrient Level in the Irish Potato Row During the Growing Season1

Agronomy JournalVolume 42, Issue 10 p. 512-515 Article The Influence of Acid-forming and Neutralized Fertilizers on the Soil Reaction and Nutrient Level in the Irish Potato Row During the Growing Season1 E. M. Dunton Jr., E. M. Dunton Jr.Search for more papers by this authorF. W. Bell, F. W. BellSearch for more papers by this authorM. E. Taylor, M. E. Taylor Soils Technologist, Soils Assistant and Analyst, respectively.Search for more papers by this author E. M. Dunton Jr., E. M. Dunton Jr.Search for more papers by this authorF. W. Bell, F. W. BellSearch for more papers by this authorM. E. Taylor, M. E. Taylor Soils Technologist, Soils Assistant and Analyst, respectively.Search for more papers by this author First published: 01 October 1950 https://doi.org/10.2134/agronj1950.00021962004200100011xCitations: 1 1 Contribution from the Soils Department, Virginia Truck Experiment Station, Norfolk. Paper No. 101, Journal Series. Approved for publication December 7, 1948. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume42, Issue10October 1950Pages 512-515 RelatedInformation