October Sowing Research Articles

Factors affecting winter survival of the florally determinate white lupin cv. Lucyane

SummaryIn a series of three field experiments with factorial design, on sites that had not grown lupins previously, sowing date was the main factor affecting over‐winter survival of autumn‐sown white lupin. In 1993, the sowing dates (23 September and 20 October) were too late to prevent much plant death in autumn and early winter, with the onset of frosts. In 1994, the sowing dates (30 August and 22 September) were early enough to prevent severe frost damage, but infestations of bean seed fly (Delia platura) occurred, more in the later than in the earlier sown crops, causing wilting and plant death. Losses were decreased where furothiocarb seed treatment was applied. In 1995, losses were greater in early‐sown (12 September) than in later sown (28 September) crops; plant death was gradual, occurring into the spring, and was apparently associated with over‐development of young shoots before an unusually long, cold winter. A chlorpyrifos spray (13 or 29 September for early or late sown plots, respectively) slightly increased survival, possibly by controlling Thrips angusticeps. Fungicides applied to seed or as sprays in late autumn had little or no effect in these experiments. In another series of experiments to test fungicides, in 1992‐93 and 1993‐94, survival was poor following late sowing (in October), but was increased by application of prochloraz in December or January, or, in 1994, by seed treatment with thiram.

Establishment and persistence of palatable taxa of Eragrostis curvula complex in southern New South Wales

Summary. Spring sowings in cultivated plots at Wagga Wagga in 1980 and 1982, and Cowra and Colinroobie in 1980 and 1981 examined the establishment and persistence of Eragrostis curvula (Schrad.) Nees complex cv. Consol and accession 4660, Cenchrus ciliaris L. cv. American and Phalaris aquatica L. cv. Sirocco. Cenchrus ciliaris was short-lived and not frost-hardy. Competition and dry conditions reduced establishment of all species, nevertheless E. curvula established reliably. In 1 experiment where conditions were not immediately favourable for germination, E. curvula demonstrated a capacity to delay establishment until conditions improved. Competition from cool-season plants reduced persistence, particularly in the first year and when conditions were dry. Surviving E. curvula plants were generally long lived. At Cowra, the density of E. curvula was enhanced by regular mowing, but mowing reduced the density of P. aquatica. Presence of Trifolium subterraneum L. reduced the density of E. curvula while P. aquatica was unaffected. A second experiment at Colinroobie, sown in October 1987 examined the effects of mowing and fertiliser application on establishment and persistence of E. curvula cv. Consol and accession 4660. Fertiliser increased competition by cool-season annual species, reducing establishment and persistence of E. curvula, while regular mowing improved its persistence. In an experiment sown at Wagga Wagga in October 1989, E. curvula cv. Consol establishment was very low (<1 plant/m2) in undisturbed annual pasture and in the absence of cultivation, herbicide (glyphosate at 530 g a.i./ha) and mowing with herbage removal provided the best conditions for establishment.

ASD 19 (AS 781/1) - NEW MEDIUM DURATION HIGH YIELDING RICE VARIETY FOR SOUTHERN DISTRICTS OF TAMIL NADU

A new rice variety ASD 19 (AS 781/1) has been developed from the Rice Research Station, Tamil Nadu Agricultural University, Ambasamudram, for southern districts of TamilNadu. ASD19 recorded a mean yield of 5.81/ha in 127 days (240 trials). It outyielded IR 20 by 14.2 per cent. ADT 39 by 8.4 per cent, C043 by 11.9 per cent and Ponni by 13.2 per cent. The biological yield of ASD 19 is 16.5 t/ha (5.8 1 of grain; 10.7 Uha of straw) and its potential grain yield is 11.0 t/ha. It is semidwarf in stature with well exserted panicles. Grain is short slender white rice with 9.59 percent protein content. ASD 19 is moderately resistant to blast and moderately tolerant to carly drought. ASD 19 is suitable for October sowings in Pishanam of Southern districts in place of IR 20 and ADT 39.

Application of anhydrous ammonia or urea during the fallow period for winter cereals on the Darling Downs, Queensland .II. The recovery of 15N by wheat and sorghum in soil and plant at harvest

Three field experiments were conducted on the Darling Downs (Queensland) to evaluate fertilizer management practices such as application depth and addition of nitrification inhibitor (N-serve), for nitrogen (N) applied in the February-May fallow period for winter cereals. Anhydrous ammonia or urea was applied in February, March or May at two depths (7 or 17 cm), with or without N-serve. Soil fertilized in February generally had a lower mineral-N content at sowing than soil fertilized in May. Deeper application (17 cm) in February did not increase soil mineral-N content to 0.2 m depth in May but addition of N-serve did at one site where it appeared to slow the movement of mineral N into the subsoil (0.2-0.4 m). A companion experiment was conducted at each site in which 15N-enriched urea was applied to a small (1 m2) area at the centre of a 4 m2 fertilized plot. Effects of fertilizer placement and N-serve treatment, as were used in field experiments, were evaluated in terms of crop recovery of 15N and total 15N recovery in plant and soil at harvest. Recovery of 15N by wheat, sown at two sites in June, showed that neither fertilizer management practice, application depth nor N-serve affected 15N recovery. At only one site did wheat recover less February-applied N than May-applied N. N-serve had no effect on 15N recovery by sorghum sown in October, of N applied in February or May, but 15N recovery was increased by deeper fertilizer placement. Total recovery of 15N in soil and plant after wheat harvest was lower (-74%) for February-application than for May-application (>94%). Similarly, total 15N recovery after sorghum was lower the earlier the fertilizer was applied. Unrecovered 15N was presumed lost due to denitrification during periods of temporary waterlogging of surface soil. Use of N-serve with the fertilizer application had no effect in conserving 15N applied for wheat or sorghum. However, deeper (17 cm) placement of N than normal (7 cm) promoted higher total recoveries, and therefore reduced losses, of applied 15N at the three sites.

Influence of Seed Size and Growth Stage on Forage Sorghum‐sudangrass Hybrid cv. P988 Grown on Striga‐infested Soil

AbstractDelaying harvest of P988 from the boot stage to the maturity stage significantly reduced 1) forage greenchop yield of P988 grown on Striga‐ infested soil at 1st and 3rd harvest of July sowing and at 3rd harvest of October sowing, 2) root dry weight of P988 grown on Striga‐infested soil at 3rd harvest of July and October sowing, and 3) forage sucrose of P988 grown on Striga‐infested soil at 3rd harvest of July sowing and at 1st and 3rd harvest of October sowing. Reductions in forage greenchop yield of P988 with successive harvests were accelerated by Striga infestations. The root dry weight was significantly greater from P988 plants grown from small compared to large seed. Delaying harvest of P988 to the maturity stage was associated with significant increases in number of open Striga flowers at 1st and 2nd harvest from October planting and in Striga shoot dry weight at 1st harvest of July and 1st and 2nd harvest of October planting. These increases were positively correlated with forage sucrose of P988. Results suggest that optimal forage greenchop yield on Striga‐infested soil may be obtained from P988 plants grown from small seed and harvested at the boot stage.

Seed germination ecology of poison hemlock, Conium maculatum

In north-central Kentucky, United States, seeds of Conium maculatum are dispersed from mid-September to mid to late February, with up to 95% of them being dispersed by late December. Depending on the year, 40–85% of the freshly matured seeds had morphological dormancy (MD) and thus needed only a moist substrate, 10–15 14-h photoperiod days and 12-h alternating thermoperiods of 30:15 °C for embryo growth and germination. The other seeds had morphophysiological dormancy (MPD), and embryo dormancy had to be broken before embryo growth and germination could occur. MPD was broken in some of the undispersed seeds during summer, and by September 50–85% (depending on the year) germinated at 25:15 °C in light. During late autumn and winter, 35–95% (depending on the year) of the undispersed seeds in MD in autumn entered MPD. Cold stratification at 5 °C induced about half the seeds with MD into MPD. Seeds in MD germinated to higher percentages on soil than on sand, and in light than in darkness. Most of the seeds sown on soil in a nonheated greenhouse in July, August, and September germinated in September. Seeds sown in October and November germinated in autumn, late winter, and the following autumn, and those sown in late winter germinated in spring and autumn. The later seeds were sown, the higher germination percentages were the following autumn. Key words: dispersal, dormancy, germination, morphological dormancy, poison hemlock, Conium maculatum, monocarpic perennial.

Chickpea Evaluation for Cold Tolerance under Field Conditions

Chickpea (Cicer arietinum L.) yields are higher when plantings are made in early winter in the Mediterranean region instead of during the traditional spring season, but winter killing is often a problem. Cold tolerant chickpea cultivars are needed to successfully utilize a winter sowing approach. A study was conducted at the International Center for Agricultural Research in the Dry Areas (ICARDA), Tel Hadya, Syria during 1982 to 1983 with the objective of developing a field screening technique for cold tolerance in chickpea, and to identify sources of tolerance. A set of previously identified tolerant, intermediate, and susceptible lines was sown from mid‐fall to early spring. All susceptible lines sown during October were killed from cold injury, showing that the crop was more susceptible at the late vegetative stage than at the seedling stage. Consequently, a field screening technique was proposed, with an October sowing date to allow the crop to grow to the late vegetative stage before the onset of severe winter. Susceptible checks are grown at frequent intervals and evaluation takes place after the death of the susceptible check. This is followed by confirmation of tolerance. A 1 to 9 visual score was used to evaluate germplasm for cold tolerance. A total of 3276 germplasm accessions and breeding lines were evaluated from 1981 to 1987. Twenty‐one lines were identified as tolerant. Cold tolerance was not associated with the phenotypic traits of leaflet area, seed size, time to maturity, plant height, or growth habit.

STUDIES ON GROWTH AND YIELD OF GROUNDNUT AS A POST-RAINY CROP IN NAGPUR REGION

Climatic adaption of groundnut variety SB-XI as a post-rainy crop has been investigated considering the agroclimatic data of Nagpur region and the meteorological equivalents of the crop. The crop sown on 1, 15 and 29 October fortnightly interval during post rainy seasons of 1985-86 and 1986-87 exhibited a cold tolerance indicating its suitability for the Nagpur region as a post-rainy crop. The 15 October sowing alongwith other growth attributes recorded highest dry pod yieid (21.24 g/ha) followed by 1 October sowing (18.36 q/ha) being lowest (16.85 g/ha) for the 29. October. From the various growth and yield parameters 15 October sowing was found to exhibit best performance enjoying favourable weather of the season forming optimum sowing time in the region for the post-rainy groundnut. The sub-optimal temperatures prevailed during the winter delayed maturity to 123 days in 1 October sowing, to 136 days in 15 October sowing and to 140 days in 29 October sowing. The low temperature and low evaporation reduced water demand of the crop the conserved soil moisture and post monsoom rains favoured better development and yield of groundout.

Comportamento de algumas leguminosas em distintas épocas de semeadura

Estudou-se, através do presente trabalho, o efeito de épocas de semeadura sobre o comportamento de diversas leguminosas, comumente utilizadas na prática da adubação verde. O delineamento experimental usado no campo foi o inteiramente casualizado, em esquema de parcelas subdivididas com 40 tratamentos, constituídos pela combinação de 10 leguminosas com 4 épocas de semeadura. Os resultados obtidos indicaram que para todas as leguminosas avaliadas, as épocas de semeadura influenciaram a produção de matéria seca total, sobressaindo a mucuna preta (Stizolobiun aterrimum) na semeadura de janeiro e o guandu (Cajanus cajan) cv. FAJ e cv. Paraíba na semeadura de outubro. A mucuna preta constituiu-se na melhor opção para rotação com culturas de verão de ciclo curto.

Relations between summer crops and ground cover legumes in a subtropical environment 2. Effects of sorghum and sunflower on the growth of Vigna trilobata and Medicago scutellata

Vigna trilobata (L.) Verdc. is a low growing legume with potential as a ground cover for controlling soil erosion in cropping lands of the subhumid/semi-arid subtropics of northern Australia. When it was grown beneath sorghum ( Sorghum bicolor (L.) Moench) and sunflower ( Helianthus annuus L.) crops under well-watered conditions on a vertisol in southern Queensland it decreased their yields by about 20% in the first season. This paper reports the effects of competition from crops sown at a normal dryland density or at half the normal density on its growth. V. trilobata sown in pure stand in October produced 531 g m −2 of above-ground dry matter, and sown in January produced 323 g m −2, by the time the grain crops sown at the same time were mature. Yields under mature sorghum sown at the normal density (10 plants m −2) in October and January were 38% and 35% respectively of those from pure stands of ground cover sown at the same time. Under sunflower at the normal density (5 plants m −2), corresponding values were 42% and 22%. The decrease in dry matter yield attributable to competition for water, nutrients and/or radiation from the main crops was proportional to the decrease in intercepted radiation. V. trilobata responded to shade in several ways, but a substantial increase in specific leaf area, together with some additional partitioning of dry matter to leaf, was sufficient to ensure that its leaf area index under crops was similar to that in pure stands. Seed yields of 116 and 84 g m −2 were obtained from pure stands of V. trilobata sown in October and January respectively. However, seed yields under crops sown at the normal density were only 4–18% of those measured in pure stands. Seed size was not affected by treatment. We conclude that, under well-watered conditions in southern Queensland, V. trilobata grown as a ground cover under crops of sorghum and sunflower should be able to produce sufficient biomass to decrease soil erosion, and also produce sufficient seed for regeneration in successive seasons. Its growth and suitability are also briefly compared with those of an alternative ground cover legume, Medicago scutellata (L.) Mill. (snail medic).

Relations between summer crops and ground cover legumes in a subtropical environment 1. Effects of a Vigna trilobata ground cover on growth and yield of sorghum and sunflower

An annual form of Vigna trilobata (L.) Verdc., a semi-domesticated herbaceous legume, was used to provide additional ground cover under rainfed crops in a subtropical environment. This study reports effects of V. trilobata on growth and yield of sorghum ( Sorghum bicolor (L.) Moench) and sunflower ( Helianthus annuus L.). Crops were sown on a vertisol in south-east Queensland in October and January at densities of 10 and 5 plants m −2 for sorghum and 5 and 2.5 plants m −2 for sunflower, and with or without ground cover legume. Crop rows were 0.8 m apart. V. trilobata seed was broadcast at 150 seeds m −2 when the crops were sown. While a full profile of soil water at sowing, and 330 to 424 mm rainfall during crop growth, led to vigorous growth of both crops and ground cover, crops from both sowings experienced water stress from about anthesis to the middle of grain fill. At the higher crop density, yields of sorghum grain were 453 and 355 g m −2 and yields of sunflower seed were 161 and 227 g m −2 after sowing in October and January, respectively. Yields were decreased to 87%, 70%, 76% and 90% respectively in the presence of up to 330 g m −2 of dry matter of V. trilobata. Sorghum yields were marginally lower at the lower density and decreased relatively more in the presence of ground cover. Neither the yield of sunflower seed, nor the effect of ground cover on it, was affected by density. Competition from ground cover decreased radiation interception by crops through decreasing their leaf area index. It did not appear to affect the efficiency of conversion of intercepted radiation to dry matter. Tiller number in sorghum was decreased by ground cover, except in the low density stand sown in October. Effects of ground cover on the contribution of tiller heads to yield were more severe, leading to a halving of their contribution at the lower density. Lower grain yields in the presence of ground cover were due to lower numbers of seeds m −2 in both crops. Seed size was also smaller in sunflower, but the percentage of oil was not affected. We conclude that under well-watered conditions in south-east Queensland the decreases in yields of summer crops in competition with V. trilobata are likely to be outweighed by the anticipated long-term benefits from using ground cover to decrease soil erosion. The need for information on the processes and consequences of competition under drier conditions is emphasized, so that we can evaluate the broader potential for ground cover legumes in the subhumid subtropics.

The effects of infection by barley yellow mosaic virus on the yield and components of yield of barley

Infection by barley yellow mosaic virus (BaYMV) was greater in a crop sown in October than in November and in cv. Maris Otter than in cv. Sonja. However, a greater proportion of plants of Sonja than of Maris Otter were infected, and more severely, with the soil‐borne fungus vector of BaYMV. Polymyxagraminis. Indifferent years the yield of individual plants of Maris Otter was decreased by 15% and of Sonja by 40%. The spring barley cultivars Athos. Porthos. Georgie and Ark Royal were all infected with BaYMV when sown in autumn in infected soil. Infected winter barley cv. Igri lost up to 50% of yield when this was measured across a naturally infected patch of crop.

Control of cereal aphids on wheat in People's Democratic Republic of Yemen

AbstractLoss estimates for wheat insects in Africa and Asia have not received adequate attention. However, in PDR of Yemen, pests including insects, diseases, weeds and birds can cause 10™70% loss of wheat crop. Aphids are considered to be the major insect pests of wheat in the country. A survey of indigenous natural enemies has shown that they may contribute to overall aphid control. Sowing date experiments have shown that sowing in November led to higher yields and lower insect infestation than sowing in October and December. The insecticides tested achieved a significant control of aphids and higher yields when compared with unsprayed plots. A single application of malathion or dimethoate before mid-January was recommended for chemical control.

Ciclo de vida, estruturas reprodutivas e dispersão de populações experimentais de capim-carrapicho (Cenchrus echinatus L.)

A partir de semeaduras mensais de 500 cariopses em áreas de 5,00 x 3,80 m em sulcos distanciados de um metro e com profundidade de 3 cm foram obtidas 12 populações experimentais. Após 20 dias foram feitos desbastes nos canteiros restando 120 plantas distanciadas de 20 cm nas linhas. A cada mês foram coletadas ao acaso, 10 plantas para a contagem das estruturas reprodutivas. Considerando-se as quantidades de racemos, de fascículos e de cariopses, épocas de florescimento, tempo de dispersão e duração do ciclo de vida foi possível distinguir quatro periodos de semeadura. O primeiro de novembro a janeiro caracterizado pela quantidade de racemos e de fascículos bem maior que a dos outros períodos, cerca de 70% do total geral e também pela maior quantidade de cariopses. O início do florescimento foi o mais precoce (2.° mês) a dispersão de fascículos durante 120 dias com os maiores ID (72%) e 210 dias de duração do ciclo de vida. O segundo de fevereiro a março caracterizado pela menor quantidade de race-mos, de fascículos e de cariopses (2% do total geral). O início do florescimento foi tardio (4.° mês); dispersão de fascículos durante 60 dias e o menor ID (44%); 180 e 150 dias, respectivamente, de duração do ciclo de vida. O 3.° período de abril a julho, caracterizado por quantidade pequena de racemos (19% do total geral) e quantidade intermediária de fascículos e cariopses (cerca de 21% do total geral). O início do florescimento foi tardio (4.° mês); dispersão de fascículos durante 60 dias (para as de abril) e 90 dias (para as de maio, junho e julho), ID (70%) e 210 dias de duração do ciclo de vida. 0 4.° período de agosto a outubro, caracterizado por quantidade muito pequena de race-mos, de fascículos e de cariopses (7% do total geral). 0 início do florescimento ocorreu no 3.° mês; dispersão de fascículos durante 60 dias, ID (47%) e 150 dias (agosto) e 120 dias (setembro e outubro) de duração do ciclo.

INFLUENCE OF DATES OF SOWING OF THE PARENTAL LINES OF KM. 2 BAJRA HYBRID ON SEED YIELD AND QUALITY

Sowings of the parental lines of KM 2 hybrid bajra at monthly intervals from October 1980 to March 1981, revealed that (i) the lines flowered seven days ahead when sown in October than in other months: tii) number of productive tillers and hybrid seed yield were high from the November sown crop; and (4) hybrid seed obtained from October, Novembor and December sowings exhibited significantly better vigour than from other months.

Effect of cultivar, sowing date, and harvest date on yields and sugar contents of beet on a dry land site in Canterbury

Abstract Vytomo sugar beet and Yellow Daeno and Monoblanc fodder beets were sown on 23 September, 19 October, and 23 November 1979, and harvested at 4-weekly intervals from December 1979 to September 1980. The September sowing gave higher sugar yields than the October sowing, until April. The November sowing gave sugar yields about 2.5 t/ha less than the October sowing for all harvest dates. Sugar yields increased until July, initially because of increases in root fresh-weight and, to a lesser extent, root dry matter (DM)%. However, after May, increases mainly resulted from higher sugar content of root DM. Sugar in the roots was practically all sucrose until the September harvest, when total sugar yields fell but the proportion of reducing sugars increased. Monoblanc fodder beet gave the highest sugar yields, particularly later in the season. Top fresh-weights declined throughout the autumn and winter, but increased again in late August-September. Maximum leaf area indices (LAI) were low, and were achieve...

The management of Brassica for winter forage in the sub‐tropics

AbstractIn subtropical latitudes temperate crops can be grown during the cool months but the growing season is restricted by the termination and beginning of hot weather. Postponing sowing date in south Florida from October to November to January resulted in 150, 130 and 110‐d growing seasons respectively. Dry matter (DM) yields of turnip, swede, rape and kale were lowered by each later sowing date and shorter growing season, and crude protein (CP) concentration was the same as for, or was increased by late sowing. In vitro organic matter digestibility (IVOMD) of turnip, swede and rape leaves was not affected by sowing date, but roots of turnip and swede from the earlier sowings and longer growing seasons were more digestible. Yield of the four species depended on harvest management as well as date of sowing and length of growing season. Total yield of turnip and swede were unaffected by harvest management but multiple cutting resulted in greater leaf yields and smaller root yields, whereas stockpiling resulted in smaller leaf yields and larger root yields. Kale produced more DM when harvested once at the end of the winter growing season but rape produced the greatest DM yield when sown in October and harvested

The effect of time of sowing on yield of mungbean (Vigna radiata) varieties in coastal New South Wales

The effect of time of sowing on the growth and yield of mungbean varieties (Vigna radiata var. aureus) was examined during summer in a warm humid coastal climate at Camden, New South Wales (latitude 34�s). Four varieties, Pusa Baisakhi, Berken, S8, and M4 were grown in a split-plot randomized complete block experiment with six replicates. Main plot treatments were three times of sowing (October 28, December 8 and January 19); varieties were on sub-plots. Berken, a current commercial cultivar, attained the highest grain yield, at the October sowing, of 1.5 t ha-1 in 97 days from sowing. S8 attained a yield of 1.4 t ha-1 at the October sowing in 103 days, but was susceptible to lodging, disease and pest attack. Pusa reached its highest grain yield (1.1 t ha-1) at the December sowing in 91 days. Although the grain yield of M4 was the lowest, its top dry matter yield of 5.1 t ha-1 at the December sowing indicates its promise as a forage crop.

Effects of plant population and season on kenaf (Hibiscus cannabinus L.) grown under irrigation in tropical Australia I. Influence on the components of yield

Abstract The relationships between plant population and the yield components of kenaf ( Hibiscus cannabinus ) cv. Guatemala-4 grown under irrigation in tropical Australia were examined. Plant arrangement and plant density were varied independently. The responses in both a wet season crop (sown in October), sampled at three ages until flowering, and a dry season crop (sown in May), sampled at flowering, are reported. Flowering occurred at 203 days in the wet season crop and at 105 days in the dry season crop. At all samplings, all measured components of yield (bark yield, core yield, and tops and foliage yield) were unaffected by plant arrangement for inter-row spacings between 0.28 m and 0.75 m. The response to plant density within the range of 132,000 to 923, 000 plants per hectare was modified by both season and age. At flowering in the dry season crop, all the components of yield increased as density increased, with complete plant survival at all densities. In contrast, at flowering in the wet season crop, variation in the components of yield was independent of density and there was a marked reduction in plant survival of up to 50% at high densities. The yield of total dry matter at the highest density at flowering was 7.7 t ha −1 in the dry season crop compared with 19.2 t ha −1 in the wet season crop. The Shinozaki-Kira relationship in which the reciprocal of plant weight is linearly related to density was fitted to the data for each sampling. This relationship, using plant density at establishment, was obtained only where there was minimum reduction in plant survival. Due to the ability of kenaf to compensate, an excellent fit was obtained in response to plant density at sampling irrespective of season or crop age.

トマトの1段密植栽培に関する研究

Our reseach on the single truss tomato culture was begun in an attempt to find out some means to increase the efficiency of tomato production. The results are summarized as follows1. Seeds of tomato cultivars FTVNR-3 and Dantobi-Yozu (self-topping variety) were sown nine times monthly on the 10th of each month from July 1974 to March 1975.The planting density was approximately 11, 000 plants per 10 a and the plants were all pinched at three leaves above the first inflorescence.2. Days from sowing to harvesting were about 170-188 in September, October, November and December sowings, about 140-155 in August, January and Feburuary sowings, and about 120 in March and July sowings respectively.Days after planting to harvesting were about 120 in September and October sowings, 85-100 in August, November and December sowings and about 65-75 in July, January, February and March sowings.3. The length and width of the uppermost leaf varied with sowing dates and these were affected principally by temperature. The stem length below the first inflorescence was determined by the temperature during propagation. Thus, it was much shorter in November, December and January sowings than in the other sowings.4. Total yields from each sowing over the year were in excess of 7 tons per 10 a, except for cultivar FTVNR-3 sown in October and cultivar Dantobi-Yozu sown in September.Percentage marketable fruits was, in both cultivars, as high as 85%, except for cultivar FTVNR-3 sown in October. Cultivar Dantobi-Yozu proved to be more suitable for single truss culture than cultivar FTVNR-3 since it produced stable yield throughout the year.5. The daily mean of solar radiation during the growth period and especially that during 30 days after anthesis were found to be highly correlated with the yield; the correlation coefficients being 0.758 (p<0.05) and 0.906 (p<0.001) to total yield and 0.774 (p<0.02) and 0.923 (p<0.001) to yield of marketable fruits, respectively.6. For a year-round cropping system of single truss tomatoes, however, seedlings should be planted at the stage just before the first anthesis to shorten the growing period of each crop, which is difficult to practice.Performance of three crops over the year is rather feasible by planting seedlings at five or six leaf stage and yet annual yield about 25 tons per 10 a can be obtained.7. Year-round culture of single truss tomatoes may increase the efficiency of tomato production and may bring profits to commercial growers, because 1) these plants give an annual yield higher than multi truss plants and their fruit quality is good, 2) the optimal environments are necessary to be kept only for the period of growth and development of the first inflorescence, which will simplify the cultivation and 3) the plants are supported by bar, thus the labour requirement for training is avoided.Furthermore, this cropping system makes it possible to make a planting programme over the year with flexibility from a viewpoint of the distribution of labor, and to regulate the production or shipping of tomato fruits taking aim at high price.