Showing papers on "Sowing published in 1978"

Effect of environment and cultivar on source limitation to grain weight in wheat

Abstract: The relative increase in final kernel weight (SR, %) with an artificial reduction of about 80% in the number of grains per spike was assumed to estimate the degree of post-anthesis assimilate or source limitation to grain weight in wheat. This assumption was supported by comparisons with other treatments designed to alter the ratio of source to grain number. SR was determined in crops grown under irrigation and high fertility in north-west Mexico over a 5 year period, in order to examine the effect of environment (year, sowing date) and cultivar on source limitation. Some old tall cultivars and many modern short cultivars of wheat (Triticum aestivum L., T. turgidum L.) and triticale (X Tritosecale Wittmack) were studied. For modern cultivars, kernel weight always appeared to be limited by source, SR averaging 21% over all years for eight such cultivars. For a given cultivar, environmental effects were considerable, being partly explained by a positive relationship between SR and mean temperature after anthesis. Each year SR was significantly affected by cultivar and, despite cultivar by year interaction, showed some consistency between years. Old bread wheats and triticales usually showed low source limitation (SR <10%), whereas most modern cultivars, regardless of species, showed higher source limitation (SR up to 50%) and higher grain yields, probably because of higher grain numbers per sq metre. Within this latter group, there was no relationship between SR and grain yield. The kernel weight attained as a result of grain number reduction, defined here as potential kernel weight, was a stable cultivar trait useful in understanding yield variation.

Straw Mulch Effects on Soil Temperatures and Sorghum Germination and Growth1

Abstract: The possibility that lower than normal temperatures in residue-covered soils may affect crops has caused concern regarding the use of conservation tillage systems in some regions. To evaluate this possibility in the Southern G::eat Plains, soil temperatures were measured at a 10- cnl depth in field plots on which 0 (check), 1, 2, 4, m 12 metric tons/ha of wheat (Triticum aestivum L.) straw were applied on the surface. The soil was Pullman clay loam, a fine, mixed, thermic Torrertic Paleustoll (order Mollisol). Objectives were to determine the effects of mulch-induced temperatures on grain sorghum [Sorghum bicolor (L.) Moench] planting dates, germination, emergence, and growth, and to obtain information concerning effects of mulch rates on soil temperatures at various seasons and under specified climatic conditions. Increasing mulch rates delayed the time that soil reached favorable temperatures for sorghum germination and growth. However, temperatures were near optimum before normal planting dates and, therefore, mulches did not affect sorghum germination and only slightly delated emergence. Since temperatures with high mulch rates rarely, if ever, reached the optimum for sorghum growth, plants on these plots grew slower early in the season than t]hose on plots with low mulch rates. Later in the season, when soil water limited growth, plants on high mulch 1ate plots grew more than on other plots because of higher water contents. Increased mulch rates decreased average soil temperature means, maximums, minimun~s, and standard deviations during all seasons of fallow front wheat harvest to sorghum planting. However, when temperature of bare soil approached or fell below 0 C, the temperature effect was reversed. The change in temperature for each metric tons/ha of mulch as compared with bare soil was greatest for the 1-metric ton/ha rate and generally decreased as mulch rates increased

Influence of irrigation and seeding rates on yield and yield components of brassica napus cv. tower

Abstract: An analysis of the yield components of rape (Brassica napus L.) was carried out under field conditions for 2 yr at Saskatoon. Plant morphology and the crop environment were altered by the use of four planting densities and three water regimes. The number of branches per plant was scarcely affected by irrigation, but was reduced by high seeding rates. Number of pods per plant was increased by irrigation and reduced by high seeding rates. The number of seeds per pod was increased by irrigation, but reduced by high seeding rates. The 1,000-seed weight was increased both by irrigation and increased seeding rate, as was seed yield. Yield was positively correlated with 1,000-seed weight in both years. Yield component compensation was evident in the relationship of 1,000-seed weight to pod number and number of seeds per pod.

Deer mouse preference for seed of commonly planted species, indigenous weed seed, and sacrifice foods.

Abstract: Highlight: Captive deer mice from pinyon-juniper, sagebrushbitterbrush, and Jeffrey pine-ceanothus plant associations were fed a variety of shrub, grass, forb, and tree seeds. Mice ate or destroyed an amount of seed equal to approximately one-third their body weight daily. Seed of bitterbrush, singleleaf pinyon, balsamroot, and small burnet were the most preferred food items tested while seed of Utah juniper, smooth brome, fourwing saltbush, and big saltbush were least preferred. Planting valuable forage species whose seeds are not preferred by deer mice would appear to improve seeding success on sites where seed predation by deer mice is a problem.

Germination, seedling emergence and establishment of some Plantago species under laboratory and field conditions.

Abstract: SUMMARY (a) The germination of Plantago lanceolata L., P. coronopus L., P. major L. ssp.major, P. major L. ssp. pleiosperma Pilger, P. media L., and P. maritima L. in relation to the age of dry-stored seeds was investigated under laboratory conditions. In general, higher percentages of radicle emergence were found with two- to five-year-old seed than with fresh seed. Only P. lanceolata and P. media seeds germinated in complete darkness. A feature of interest was the high germination of both subspecies of P. major in so-called green safelight. (b) The germination and early establishment were tested on various microsites, obtained with glass beads of various sizes. At increasing particle size, an increase in radicle emergence was found for large seeds (P. lanceolata and P. media). Root penetration of the surface occurred sooner on substrates of large particles than on those of small ones. The effects of size of the glass beads on germination and penetration were less in species with small seeds than in species with large seeds. (c) Sowing tests in the field resulted in relatively high numbers of established P. lanceolata and P. coronopus seedlings in open and dry habitats. P. lanceolata seedlings were able to establish themselves in tall dense vegetation layers. P. major ssp. major occurred most frequently on moist and open sites with a compact soil. On trodden paths P. major and P. coronopus seedlings showed opposite mortality curves.

The effect of fallowing on the yield of wheat. I. The effect on soil water storage and nitrate supply

Abstract: The effect of fallowing before a wheat crop was studied in South Australia in an environment with suboptimal rainfall in the growing season. A 9–10 month pre-sowing fallow increased mean water storage (0–120 cm depth) at sowing by 28 mm, compared with a non-fallow soil preparation (2 month period of cultivation). Variation in additional storage ranged from nil to 125 mm. These amounts depended on soil type and season: in coarse-textured soils, fallowing conserved little additional water, but in fine-textured soils much additional water could be stored. Storage was not related to the summer rainfall (November-March) before sowing but was related to rainfall during July and August in the previous winter—just before or at the start of the fallow period. A combination of these two factors, fine-textured soil and good July–August rainfall, gave considerable storage. Fallowing also increased the nitrate nitrogen content in the surface 60 cm at sowing; the mean additional nitrogen amounted to 19 kg/ha in the coarse-textured soils and 30 kg/ha in the fine-textured soils. The largest increases due to fallowing were recorded in soils following medic leys and with ample rains on the fallow in spring. Comparison is made between these findings and those obtained with fallowing in other parts of Australia.

Aspects of Germination, Emergency, and Seed Production of Three Ipomoea Taxa

Abstract: The influence of seed age, planting depth, and temperature on the germination and emergence of ivyleaf morningglory [Ipomoea hederacea (L.) Jacq. var. hederacea], white morningglory (Ipomoea lacunosa L.), and entireleaf morningglory (Ipomoea hederacea var. integriuscula Gray) was studied by using pure seed of each taxa that were collected in 1972, 1973, and 1974. Germination of acid-scarified white and entireleaf morningglory seed ranged from 64 to 98% at continuous 20, 25, 30, 35, and 40 C and at an alternating 20/30 C cycle. The ivyleaf morningglory germination range was 50 to 98% at these temperatures, except at 40 C germination was <25%. Germination of nonscarified seed was generally 30 to 60% lower than scarified seed for the three taxa. Germination of seed collected in 1972 for all three taxa was less than 10% with 6 days of exposure to 45 C and 100% relative humidity, and germination of seed collected in 1973 and 1974 ceased with 12 days of exposure. Maximum emergence for all taxa occurred at planting depths of 1.3 and 2.5 cm. Seed age influenced seedling emergence of white morningglory and ivyleaf morningglory but not entireleaf morningglory. Total numbers of seed produced per plant for white, entireleaf, and ivyleaf morningglory were 15,200, 14,600, and 5,800, respectively.

Growth analysis of brassica napus cv. tower

Abstract: Growth analysis of field-grown rape (Brassica napus L.) was carried out during 1975 and 1976 at Saskatoon. Plant morphology was altered by the use of four planting densities under three water regimes. High seeding rates and non-irrigated conditions caused a greater proportion of dry matter production to occur before flowering than after flowering, while the reverse occurred at low seeding rates and under irrigated conditions. Leaf area index reached a maximum near the start of flowering, and then declined rapidly. Pod surface area was increased by irrigation and was higher at the high seeding rates than at the low seeding rates. Maximum leaf area index was correlated with seed yield. Correlations between pod area and seed yield were poor, particularly in 1976. The growth functions mean net assimilation rate and mean crop growth rate were influenced by both seeding rates and irrigation. There was an increase in during the ripening phase, suggesting increased photosynthetic efficiency. No evidence of a dist...

The effect of fallowing on the yield of wheat. II. The effect on grain yield

Abstract: The effect of fallowing on wheat yields is reported for a South Australian environment where 62 % of the variation in yield is ascribed to water supply and where water use efiiciency in grain production ranges from 1 to 11 kg/ha/mm. The mean yield response from a fallow (initial tillage 9 months before sowing) compared with a non-fallow (tillage 2 months before sowing) in 28 seasonal, site and fertility situations was 335 kg/ha and the maximum 875 kg/ha. Each additional millimetre of water stored through fallowing gave on average 8 kg grain per ha. Only fine-textured soils stored considerable water through fallowing. The additional nitrate in fallow gave yield responses when the non-fallow soil contained less than 70 kg nitrate nitrogen per ha, but only when water use by the crop exceeded 230 mm. The results are related to responses to fallowing obtained in other wheat-growing districts in Australia.

Effect of grazed lucerne on the moisture status of wheat-growing soils

Abstract: The effects of varying durations of lucerne ley and subsequent wheat cropping on the moisture status of contrasting wheat growing soils are reported from two experiments in northern New South Wales. Lucerne leys of 5 1/2, 3 1/2 and 1 1/2 years on a red brown earth and 3 1/2, 2 1/2, and 1 1/2 years on a black earth were compared with a wheat-cowpea rotation, long fallow and continuous wheat. Lucerne extracted available soil water within eight months of sowing to a depth of 100 cm, with partial extraction of water to 150 cm. Within 18 months available water to a depth of 200 cm had been extracted. Subsequent growth of lucerne was dependent on incident rainfall and water extraction from depths greater than 200 cm. Wheat extracted water from the soil only to a depth of 150 cm, and extracted less water to this depth than did lucerne. Lucerne extracted water beyond the -1 5 bar suction level. On the black earth, soil moisture at 150 cm had not been recharged before time for sowing the third wheat crop, 28 months after lucerne plough-out. On the red brown earth, after a drought enforced long fallow immediately following lucerne plough-out, soil water at 200 cm was recharged within 18 months. Available soil moisture after three to five months fallow following plough-out of the lucerne leys was much less than for a wheat cropping system, with a consequent severe reduction in the grain yield of the following wheat crop. On the black earth grain yield was reduced by 7.7 kg ha-1 for each reduction of 1 mm in available moisture in the first crop after lucerne plough-out. Data indicate that lucerne must be ploughed out before January if a severe reduction in yield of the following wheat crop is to be minimized.

The effects of sowing density, salinity and substrate upon the germination of seeds of plantago coronopus l.

Abstract: SUMMARY The influence of number of seeds per clump upon germination of Plantago coronopus L. was investigated at different salinity levels on filter paper, sand and soil. These substrates provide both artificial and semi-natural microenvironments for seed germination. On all substrates, germination was positively dependent on clump density and seeds in clumps had a higher tolerance of salinity as reflected in higher germination percentages. Final percentage germination for a given clump size and salinity level depended upon substrate, being far higher on filter paper and sand than on soil, whilst the time required to reach final germination also increased in that order. The possible ecological significance of density-dependent seed germination is discussed.

Soil impedance as a factor reducing crop seedling emergence, and its relation to soil conditions at sowing, and to applied water

Abstract: SUMMARY (1) Seeds of calabrese, carrot, onion and sugar beet were sown in the field on successive occasions. Soil integral impedance (work done in penetrating the soil to 15 mm depth) was measured at the time of seedling emergence. (2) There were negative linear relationships between seedling emergence and soil integral impedance, which accounted for over 80% of the variation in percentage emergence of carrot, onion and sugar beet, and 67% of the variation in calabrese. (3) In a laboratory experiment there was a marked interaction between temperature and soil integral impedance in the case of calabrese, but not the other crops. (4) Pre-emergence losses of onion and calabrese were due largely to the failure of seedlings to emerge through the soil after germination, rather than failure of seeds to germinate, and it seems likely that this was also true of carrot and sugar beet. (5) A multiple regression equation was derived relating soil integral impedance to soil compaction and soil surface moisture content at sowing, and to water applied after sowing.

Apparatus for sowing seeds in suspension

Abstract: The invention provides an apparatus for sowing seeds in a liquid suspension in which a peristaltic pump supplies the suspension to the ground at a position behind and above the lower part of a drill coulter.

Superphosphate and stocking rate effects on a native pasture oversown with Stylosanthes humilis in central coastal Queensland. 1. Pasture production

Abstract: Changes in the yield, botanical composition and chemical composition of a native pasture (Heteropogon contortus dominant) oversown with S. humilis (T.S.) were measured in a grazing experiment from 1966 to 1973. The 24 treatments were factorial combinations of two sowing methods for T.S. (ground sowing into spaced cultivated strips, or aerial sowing), three levels of molybdenized superphosphate (F0 = nil ; F1 = 125 kg ha-1 annually; F2 = 250 kg ha-1 annually plus an extra 250 kg ha-1 initially) and four stocking rates. Stocking rates were gradually increased during the experiment and for the last three years overlapping ranges were used for the three fertilizer levels; the overall range was then from 0.55 to 1.65 beasts ha 1 T.S. establishment by ground sowing was much more reliable than from aerial sowing, giving twice the average percentage frequency, and this proportion was maintained over years. High fertilizer improved establishment and the best legume stands were in the high fertilizer high stocking rate treatments. Total presentation yield of pasture was increased by fertilizer and reduced by high stocking rates. Over the last two years the means for March, adjusted by regression to the overall average stocking rate of 0.98 beasts ha-1, were 31 20,4020 and 5370 kg ha-1 for F0, F1 and F2 respectively, but these yields were reduced by ca 25 per cent for an increase of 0.5 beasts ha-1. H. contortus remained dominant and its mean contribution to total yield increased from 48 per cent in 1969 to 67 per cent in 1973. This proportion was reduced by 12.8 per cent over the range from 0.55 to 1.65 beasts ha-1, but high fertilizer had the opposite effect so that differences between the extremes low stocked F0 and high stocked F2 were small. The DM percentage yield of T.S. was strongly increased by fertilizer, and, most importantly, also by high stocking rates in the presence of fertilizer. Values for F0 treatments remained below 10 per cent, but in the final year values for F1 and F2 at the highest stocking rates were 36 and 27 per cent, respectively. Despite these large changes in T.S., there was overall stability of botanical composition. Phosphorus and nitrogen concentrations in T.S. and H. contortus were increased by superphosphate but there was an overall decline in potassium concentration. Soil phosphorus levels were greatly increased

Nitrogen Fertilization in Establishing Forage Legumes1

Abstract: Forage legumes play a special role in agriculture in that they fix N and serve as feedstuffs for livestock and poultry. Researchers do not agree, however, concerning need for fertilizer N in legume establishment. We studied the effects of N applied at and shortly after planting of legumes on growth and N fixation and compiled information on current recommendations of agricultural experiment stations in the United States on use of N with forage legumes. Two greenhouse experiments were conducted. In the first, seed of red clover (Trifolium pratense L.) and bigflower vetch (Vicia grandiflora var. kitalbeliana W. Koch) were planted in sand and given Hoagland's solution at planting or 3 or 6 weeks post-planting to. furnish 28, 56, or 112 ppm N (N₁, N₂, N₃). A comparable N-free solution (No) was included. In the second, red clover, vetch, and alfalfa (Medicago sativa L.) were seeded into three soils and fertilized with NaNO₃ at rates to supply 30 or 60 kg N/ha, and a no-N check. Plants were harvested at 8 or 9 weeks post-planting, roots and tops separated, and N fixation estimated by C₂H₂ reduction. After drying, plant parts were weighed, ground, and analyzed for N. Published recommendations for fertilizing legumes were requested from Agronomy Departments in the United States, and these were summarized. In trial 1 N₁, N₂, and N₃ plants were larger than No plants but, at harvest, fertilized clover plants were fixing only 63, 33, and 6% as much N/pot/hour, respectively, as the latter. Interactions among treatment variables were common. In contrast, level of N applied in experiment 2 did not affect N fixation. Growth was increased equally by 80 and 60 kg N/ha. Current recommendations concerning N usage on forage legumes vary widely, especially with grass-legume mixtures. The findings in these greenhouse experiments and the disparities in state recommendations indicate need for further research to more clearly define the conditions, if any, under which use of N with forage legumes is justified.

Studies on a barley-oats mixture

Abstract: In three experiments with mixtures of barley and oats, a combination of Midas barley and Karin oats gave consistently higher yields than the mean of the components and slightly higher yields than the better component. The performance of this mixture was maintained over different sowing patterns and seed rates, but where sowing was arranged to give an advantage to one component of the mixture at the expense of the other, mixture yields were less than where both components were closely mixed.The increased yield of the mixture was attributed to the greater tillering of barley in mixture than in pure stand, brought about by less competition before heading, and to a higher weight per grain of Karin in mixture than in pure stand, a result of its greater height after heading and the favourable disposition of its panicles and upper leaves in the canopy.

The effect of sowing pre-germinated seeds of lettuce (Lactuca sativa) on seedling emergence

Abstract: SUMMARY Glasshouse and field experiments were conducted to investigate the effects of sowing both untreated and pre-germinated seeds, with or without a gel carrier, and also pelleted seeds into soils of different moisture contents and at different temperatures on seedling emergence of lettuce cvs Cobham Green and Avondefiance. Pre-germinated seeds with radicles 1–2 mm long gave, on average, 15 and 4% higher final percentage emergence than untreated and pelleted seeds respectively. Sowing pre-germinated seeds having radicles longer than 2 mm gave more variable levels of emergence and often reduced emergence, particularly when they were sown into dry or drying seedbeds. Increasing the rate of gel carrier from 0 to 30 ml m_1 of row reduced emergence progressively from 67 to 30%. Pre-germinated seeds emerged 2–5 and 3-0 days earlier than untreated and pelleted seeds, respectively, at a soil temperature of 10 oC; at 15 oC the corresponding figures were 0–5 and 3–5 days. Sowing pre-germinated seeds reduced the spread (i.e. variability) of emergence by an average of 37 and 47% compared with untreated and pelleted seeds, respectively.

Effect of clove size, spacing, fertilisers, and lime on yield and nutrient content of garlic (Allium sativum)

Abstract: The effect of clove size, spacing, fertilisers, and lime on garlic (Allium sativum) was studied in a field experiment on Levin silt loam. Treatments were: large or small cloves at 40 or 27/m2; with and without N and K; with low or high P, and lime. Best crop yield (33.9 t/ha fresh weight) resulted from large cloves at close spacing, with N and K, high P, but low lime. Fertiliser and lime need was related to Advisory soil test levels for pH and available Ca, K, P, and Mg. The range of nutrient levels, in youngest mature leaves, associated with maximum crop yield, 6.5 months after planting, was (as % dry matter): N 3.9-4.7, P 0.26-0.36, Mg 0.12-0.20, Ca 0.7-1.1, Na Nil-0.03, K 3.4-4.6, and (in ppm) Mn 50-100. Compared with 6.5 months, at 8 months leaf nutrients were lower for N, higher for Mg, Ca, Na, and Mn, with little change for P and K. From nutrient content of bulbs at harvest, crop removal was calculated to be (in kg/ha): N 201–244, S 49–64, P 28–36, Mg 5–7, Ca 17–32, Na 0.7–1.6, K 106–127, a...

Date of Sowing and Nursery Growth of Provenances of Pseudotsuga menziesii Given Two Fertilizer Regimes

Abstract: (1) Seed was collected from natural stands of Pseudotsuga menziesii growing at 250, 520 and 880 m elevation in Oregon, U.S.A. Seed was also obtained from a cross between trees at 250 and 520 m. The seed was sown on five dates between 23 April and 8 July 1974. Half the plots were left unfertilized in 1974; all plots were fertilized in 1975. (2) Early sowing significantly increased stem height and diameter, advanced the date of budset and altered the period of stem elongation, extending it in the first year and shortening it in the second. (3) Fertilizer increased seedling height and diameter and the elongation period if seeds were sown early but not if they were sown late. (4) There were significant differences among provenances from different elevations for stem diameter, date of budset and date of budflush. (5) Interactions between provenances and dates of sowing were significant for dates of budset and budflush, and for stem height, diameter and form. Comparisons of young material of different provenances must take into account the effect of cultural conditions, particularly conditions altering the length of the elongation period.

Seedling growth characteristics of Stylosanthes

Abstract: Twenty-four lines of annual (S. humilis, S. subsericea, S. sundaica and S. hamata) and perennial (S. viscosa, S. scabra and S. fruticosa) species of Stylosanthes were grown for a 6 week period after sowing, and sampled weekly to determine whether differences in seedling dry weight, earlier exhibited by single members of each species in the field, were (1) representative of each species, and (2) attributable to differences in seed size, relative growth rate (RGR) or distribution of dry matter between tops and roots. Seedlings of all lines of the perennial species had much lower dry weights than the annual species. This was due largely to the low RGR values of the perennials, and to low initial photosynthetic areas of the extremely small-seeded (< 1.3 mg) lines of S. viscosa and S. scabra. Seedling weight at the first harvest was highly correlated with seed weight, embryo weight and cotyledon area regardless of species. With each successive harvest, this correlation was reduced owing to differences in RGR which were independent of seed weight. The poor top growth of the perennial species could not be attributed to increased root growth. In fact, between harvests 1 and 3, the small plants of the perennial species allocated a greater proportion of dry matter to the tops than did the annuals. The perennial species did, however, develop deeper and less-branched root systems than the annuals when both had similar root weights. The results suggest that the perennial species of Stylosanthes may present more problems than the annual species both in establishment and in competition with the vigorous tropical grasses.

The growth of maize: IV. Dry-matter yields and quality components for silage

Abstract: Total dry-matter yield of maize silage rose asymptotically as density was increased up to 17 plants/m2. Over the range 11–17 plants/m2, which is generally higher than is used in the U.K., the increase in yield was 1–1·6 t dry matter/ha which can justify the higher seed cost and although there was no adverse affect on time of maturity the risk of lodging increased at the highest density. During the harvest period whilst whole crop dry-matter percentage was rising from 23 to 28%, the ear dry-matter content rose steadily from 29 to 35%, whereas the leaf and stem dry-matter content remained essentially constant and only dried out at a later stage after a frost.Caldera 535 had a higher leaf area index and net assimilation rate than the earlier variety Julia which it outyielded by 15%. The additional yield was mainly stem tissue and the greater vegetative production caused an 11-day delay in reaching the silage stage of maturity (25% crop D.M.). NO differences occurred between density treatments and varieties in the forage quality components considered, namely percentage drymatter digestibility, modified acid-detergent fibre, crude protein and ash. Thus in U.K. conditions, total dry-matter yield exerts an overriding influence on the yields per unit area of these quality constituents. This contrasts with reports from the U.S.A. in which a reduced grain/stover ratio adversely influences silage quality.Removal of the whole ear (including husk and rachis) at an early stage in ear development resulted in a 50% reduction in the final dry-matter yield. In the earless plants, leaf area and net assimilation rate was lower, but the dry-matter content of the leaves and stem was considerably higher, and a marked purple coloration developed indicative of excess starch concentration. These results emphasize the need in maize silage not only for an adequate leaf canopy, best obtained early in the growing season by using high planting density and subsequently by using late maturing varieties, but also for sufficient sink capacity in the ear as well as in the stem fraction.

Management of Irrigated Soybeans on a Moderately Coarse‐textured Soil in the Upper Midwest1

Abstract: Increased availability of water for supplemental irrigation in the upper Midwest has enhanced an interest in growing soybeans [Glycine max (L.) Merr.] on moderately coarse-textured soils where they have not previously been introduced. The objectives of this study were to determine the yield potential of supplementally irrigated soybeans on these soils and to develop an irrigation schedule for efficient water management. The study, conducted on Maddock sandy loam from 1972 to 1974, employed a splitsplit plot design with water level as the main block and N fertility rates (0, 56, 112, and 224 kg/ha) as sub-plots. Water levels were Wl (dryland), W2 (under-irrigation), W3 (optimum) and W4 (over-irrigation). Sub-sub plots were planting dates in 1972 and cultivars in 1973 and 1974. Soil samples were collected from 15 to 30 cm intervals to depths of 90, 150, or 270 cm throughout the study and analyzed for NO:,-N in the soil profile under irrigated conditions. Grain yields were significantly different for water levels during each of the 3 years. Threeyear yield means were 543, 1,823, 2,428, and 2,164 kg/ha for Wl, W2, W3 and W4, respectively. The application of 24 kg/ha N fertilizer in 1972 increased grain yield at the 0.95 probability level. The seed was not inoculated that year but was inoculated in 1973 and 1974. Soybeans planted 10 May 1972, outyielded soybeans planted 6 June by 356 kg/ha. ‘Anoka’ outyielded the ‘SRF-100’ cultivar by 137 kg/ha in both 1973 and 1974. An irrigation schedule based upon tensiometers placed at the 30 cm depth until 15 July (growth stage R2) and at the 45 cm depth after 15 July proved effective in applying irrigation water. Analysis of NO3-N in the soil profile at different dates during the 3-year period showed that under heavy fertilizer NO₃ N applications, the NO₃-N moved below the crop rooting zone when excess water was applied. Based upon results of this study, soybeans can be seriously considered as a crop to be included in cropping systems for irrigated, moderately coarse-textured soils in the Upper Midwest.

Sulphur, phosphate, and molybdenum coating of legume seed

Abstract: The development of additional S, P, and Mo coating on rhizobia-coated legume seed for sowing in tussock grassland is described. The main response was to additional S, as elemental S, which approximately doubled establishment in coatings of 50–100% increase relative to bare seed weight. The effect was greater when seed was sown into existing vegetation than into cultivated soil, and on brown-grey soils. Response to phosphates was smaller and less consistent with coatings of 50–100%, and Calciphos and reverted superphosphate were better than Gafsa phosphate. Responses to types or levels of Mo were generally not significant. Manufacturing problems are discussed.

Flower initiation in relation to maturity in crop plants. IV.* Sowing time and maturity type in pea (Pisum sativum L.) in Australia

Abstract: Seven varieties of pea (Pisum sativum L) sown monthly through the year in the temperate climate at Melbourne (38° S), varied in their pattern of reproductive development according to their maturity type The pattern was simple in the five early to mid-season varieties (Alaska, Collegian, Canner's Perfection, Dun, Partridge) in which rate was controlled directly by temperature, whereby the growing period after spring sowing was half that after winter sowing The pattern was complex in the late varieties (Mackay, Austrian Winter) in which the slowest development followed sowing in late summer and early autumn At each sowing, the range in time of flowering of early to late varieties resulted from a decreasing tendency to reach flower initiation from fast (Alaska) to very slow (Dun, Partridge, Mackay and Austrian Winter), together with an increasing positive sensitivity to photoperiod and a negative sensitivity to temperature Both responses ranged from absent in Alaska to weak in Canners, Collegian and Dun, slightly more in Partridge and to strong in the two latest varieties In Partridge, the sensitivity to photoperiod continued after flower initiation, causing abscission of flower buds in winter-sown plants Three relationships can be used to forecast the ability of a variety to fit its seed maturity to a given growing season: the correlation between (1) early and later stages of development; (2) leaf stage at flower initiation and at first flower; (3) rate of development and temperature Thus a sound basis for planning yield improvement is provided _______________ *Part III, Aust J Agric Res, 17: 1 (1966)

Preliminary experiments on the growth of kenaf (Hibiscus cannabinus) for paper pulp production in the Ord Irrigation Area, Western Australia

Abstract: The results of agronomic studies with kenaf (Hibiscus cannabinus) grown for paper pulp production in the Ord Irrigation Area, Western Australia, are described. There were two experiments: one with cv. C2032 in which growth of the crop was studied at four seeding rates, two row spacings and four times of sowing, and a second in which the growth of cv. Guatemala -4 was followed at two times of sowing. It was demonstrated that year-round growth could be sustained with irrigation. A peak dry-matter yield of 25.6 tonnes ha-1 was achieved after 240 days from a July sowing of Guatemala -4. The yields of stem material from cv. C2032 increased as seeding rate was increased from 5 to 20 kg ha-1. Dry matter yields were higher with a narrow row spacing than with a wide row spacing; total dry matter production from crops sown on 1.5 m beds grown with 5 rows spaced 20 cm apart was 17 per cent higher than from single rows sown on 1 m ridges. The effect of row spacing was mainly in the yield of tops and foliage and there was no significant effect on stem yields. Data are given of the uptake of essential nutrients by kenaf crops. which illustrate the large quantities of nutrients removed by the crop. Ratooning of kenaf is shown to be possible provided it is cut at least 10 cm above ground level. The percentage of plants recovering after cutting increased as the height of cut was increased from 10 cm to 30 cm above ground level.

Effects of Drying on Sunflower Seed Oil Quality and Germination

Abstract: Sunflower seed (SunGro 380) were harvested 101 to 121 days after planting, and their moisture levels were between 43 and 15%. The seed were dried at 35, 53, 72, and 88 C to a final moisture level of 10% or below. Drying air flow was 2000 m3/hr./m3 seed. Temperature had no effect on peroxide values, total oil, or fatty acid composition. Free fatty acids increased as initial moisture decreased. For a given drying temperature, germination increased with decreasing initial moisture, and for a given initial moisture, germination increased with decreasing drying temperature. This study indicates that a drying temperature greater than 53 C should not be used if seed viability is to be maintained.

Growth and yield of seed potatoes after application of gibberellic acid to the tubers before planting.

Abstract: The influence of GA on growth and yield of potato seed tubers (size 28-45 mm) was studied in field experiments on sandy soil in the late cv Alpha Different GA conc were applied to seed tubers with or without sprouts by both dipping and spraying The main purpose was to find a more suitable method of preparing seed tubers than the laborious presprouting in light method This other method would allow mechanical planting, should not be laborious and should give a high yield of seed tubers The application of GA accelerated emergence GA also significantly increased the yield of the seed tuber fraction, probably by increasing the number of stems and thus the number of tubers/plant GA accelerated tuberization, decreased the total tuber yields in one experiment, whereas in the other experiment an increase occurred The best results were obtained if sprouted tubers were treated and under favourable growing conditions Spraying was equally effective as dipping also in the 'spraying just before planting' treatment after heat shock This means that application during mechanical planting seems to be possible, on the understanding that the GA conc is not too high to prevent the occurrence of phytotoxic effects (45 mg GA/l caused small leaflets with yellow discolouration) The application of GA to seed tubers seems to be attractive especially in slowly emerging cv or in cv with a high proportion of large tubers (Abstract retrieved from CAB Abstracts by CABI’s permission)

Frost-hardy Eucalyptus grow well in the southeast

Abstract: Seedlings of Eucalyptus spp. were planted in a sandy loam soil in Georgia, in 1972, 1973 and 1975. The species planted and seed sources, including southern Brazil, south Africa and Australia, varied with each planting. In 1977, measurements of height and diameter were compared with fastgrowing native species planted in the same test. E. novanglica was the most cold-hardy species that also had reasonable growth and form. Local volume tables constructed from standing and felled trees, and wood and pulping properties were compared. E. nova-anglica, E. viminalis, E. camphora and E. parvifolia were the most promising species for breeding trees that are both cold-hardy and capable of a high yield.