Inheritance characteristics of F1 and F2 offsprings obtained from full diallele crosses of five cowpea cultivars (Vigna unguiculata L. Walp) against pseudocercospora leaf spot disease

The experiment was carried out at the Experimental Farm, Department of Agricultural Technology, Mahasarakham University, Mahasarakham Province in the 2005 (February to April) for F1 offsprings and also at the Experimental Farm, Khon Kaen University, Khon Kaen Province, Northeast Thailand for F2 offsprings (July to October), i.e., four experiments were carried out, each location had two experiments. The research aimed to investigate inheritance characteristics of F1 and F2 offsprings derived from full diallele crosses of five cowpea cultivars (20 pairs of crosses) against a pathogenic disease of Pseudocercospora cruenta (Sacc,) Deighton. The first two experiments were carried out under field and glasshouse conditions at Mahasarakham University for F1 offsprings and the other two experiments were carried out at Khon Kaen University for F2 offsprings. A Chi square test method was used to justify dominant genes on the infection of the disease. The results showed that the cowpea plants of F1 and F2 offsprings gave only one pair of dominant gene that had its complete dominant effect over recessive gene of the cowpea offsprings.     

The effects of uneven, patchy cultivar mixtures on disease control and yield in winter barley

Three winter barley cultivars were mixed in equal proportions but in different ways to give different patterns of spatial heterogeneity. The mixtures were sown in large field plots over three successive years and disease severity and yield were compared between the mixtures and the mean of the components grown as monocultures. Most mixtures significantly reduced disease in all years. The mixture composition, which appeared to generate a discrete pattern of small patches of the component cultivars, gave a yield advantage in 2 years, while the mixture which was pre-mixed most homogeneously gave no significant yield advantage in these trials. The cost of homogeneous mixing is therefore unlikely to be recovered in increased yields, compared with a simpler, imprecise mixing of the components in the seed hopper prior to sowing.     

Performance of oat (Avena sativa L.) sown in late summer for autumn forage production in Central Europe

Spring‐sown oat (Avena sativa L.) is well adapted for forage production in Central Europe; however, environmental conditions make this crop susceptible to crown rust disease (Puccinia coronata) when grown in summer. The objective of this study was to assess oat cultivars sown in late summer, when conditions for crown rust are less favourable, and harvest in autumn for forage with potential use for feeding lactating dairy cows. Three oat cultivars: Berdysz, Zuch and ForagePlus, the first two from Poland and the latter from United States, were sown 1 and 15 August, and 1 September, over three consecutive years, and harvested for forage in late October. The two Polish cultivars had 61% leaf area affected by rust with 1 August sowing, but ForagePlus was not affected by rust with any sowing date. Sowing 15 August significantly reduced crown rust incidence and increased DM yield of the Polish cultivars 21% relative to the 1 August sowing date, but decreased ForagePlus DM yield by 35%. Sowing 1 September resulted in best forage nutritive value, but the lowest DM yields for all cultivars. Calculated milk production per ton of forage for all cultivars was lowest with the 1 August sowing date. Calculated milk production per hectare was greatest for Berdysz sown in mid‐August. Oat can be sown 15 August and harvested in autumn for forage production, avoiding crown rust disease during summer in Poland. Nutritive value of autumn oat forage is adequate to meet forage requirements of lactating dairy cows.     

The assessment of persistence and its application to the evaluation of mid-season and late perennial ryegrass cultivars

Persistence assessments on eight mid-season and ten late cultivars of perennial ryegrass were made at the end of the second, third and fourth years after sowing. Botanical analyses were carried out on the herbage from plots cut in the fourth year and these results related lo the different persistence assessments. It was found that persistence assessments carried out at the end of the second year enabled predictions to be made about botanical composition of cuitivars in the fourth year. Little extra precision was gained by delaying assessment until the third or fourth years as the ranking order of cultivars with respect to persistence remained largely unchanged. All persistence assessments were positively correlated with yields of sown cultivars and negatively correlated with yields of unsown herbage species in the fourth year. However, only low correlation coefficients were obtained between persistence assessments and the total yield of sown cultivar and unsown species in the fourth year, due to yield substitution between these two components. In swards sown as monocultures low persistence in a cultivar is considered to be a lack of perenniality and tiller regeneration rather than poor competitive ability against volunteer species though in mixed swards competitive ability per se will have considerable influence upon the changes in botanical composition under different managements. Persistence and yield capacity are seen, however, as distinct characteristics of a cuitivar and long-term yield potential is a joint function of these characteristics.     

杂交水稻及其亲本抗细菌性条斑病的研究初报

水稻细菌性条斑病（以下简称细条病）在热带和中国南方已上升为一种主要病害。为探讨杂交水稻及其亲本对该病的抗性规律，笔者在国际水稻所曾用Ｘａｎｔｈｏｍｏｎａｓ ｃａｍｐｅｓｔｒｉｓＰＶ．ｏｒｙｚｉｃｏｌａ的两个菌株（９３和３３５号）喷雾接种于五个杂交组合及其亲本上。结果表明，杂交水稻对细条病表现出不同程度的抗病反应，其抗性值接近双亲平均值，且属水平抗性。杂种一 代的抗性在很大程度上决定于恢复杂的抗性水平。     

甘蓝型三系杂交油菜春播制种技术研究

在贵州生态条件下,用陕2A类型胞质不育材料进行秋播制种因其微粉较多,故产生自交结实,所制杂种不育株率高达70％一80％。改用春播,则开花延迟,而不育系无微粉发生,所制杂种不育株率仅2.4％—12％。波里玛类型质不育材料春播制种其不育株率也显著降低。春播制种适宜播种期在思南地区1356A为元月中旬,3A为元月下旬。采用直播方式。父母本行比1:3—5,密度每亩3—4万株。亩产杂种可达45—50公斤。     

A comparison of two cultivars of Holcus lanatus with Lolium perenne, under cutting

This work examined whether or not Holcus lanatus, cv. Massey Basyn, is an improvement on plants from German Commercial seed of this species and whether either could outyield Lolium perenne cv. Aberystwyth S23. The three grasses were sown in monoculture in a field near Oxford and received a total of either 250 or 500 kg N ha^-1 over two years. They were also sown with Tri-folium repens cv. Blanca. The plots were cut 11 times over the 2-year period at a height of 50 mm from ground level.
At the high rate of nitrogen Lolium perenne always gave the highest yields of DM and DOM. In the second year, both types of H. lanatus gave higher yields than L. perenne at the low level of N. The L. perenne and T. repens mixture yielded more than that with H. lanatus and T. repens. H. lanatus depressed the yield of T. repens more than did L. perenne. H. lanatus h lanatus; Massey Basyn was affected less by rust infection than was German Commercial H. lanatus. At the final harvest, plots with r. repens contained more unsown grass than did N-fertilized plots sown to grasses only.     

江苏射阳地区红皮小麦品种不同播期筛选试验

在江苏射阳县新洋农场进行16个红皮小麦品种不同播期的筛选试验,对参试品种早晚2个播期下的生育期、农艺性状、抗性及产量进行汇总分析。结果表明:早播组全生育期变幅在221~225 d,晚播组全生育期变幅在213~217 d,扬麦23全生育期均最短,华麦6号全生育期最长。早播组产量变幅为591.67~739.67 kg/667 m₂,华麦6号最高,扬麦15最低;晚播组产量变幅为637.00~707.67 kg/667 m₂,扬麦23最高,扬麦27最低。未防治条件下,锈病早播组发病明显重于晚播组,早播情况下华麦7号、扬江麦580-1、宁麦13(CK)锈病发生极重,华麦6号锈病早、晚播发生均轻,锈病抗性突出。总之,早播组平均产量水平低于晚播组,产量变幅明显高于晚播组,品种间产量差异较大。扬麦23、华麦1430表现最为突出,在早播组、晚播组产量均居于最前列,赤霉病、锈病均发生较轻。     

Crop establishment method and irrigation schedule effect on water productivity,quality, economics and energetics of aerobic direct-seeded rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.)

Rice is cultivated through transplanting of seedling in submerged field which is a cumbersome, labour intensive and water-guzzling practice. A field experiment was conducted to study the effect of crop establishment methods and irrigation schedules on water productivity, economics and energetics of aerobic direct-seeded rice at Punjab Agricultural University, Ludhiana, India, during Kharif 2012–2013. The experiment was laid out in split plot design, keeping combinations of two tillage system (no-tillage and conventional tillage) and two methods of sowing (uni-directional and bi-directional) in main plots and four irrigation schedule [(30, 45, 60 and 75 mm CPE (cumulative pan evaporation)] in sub plots. Aerobic direct-seeded rice sown after conventional tillage gave significantly higher grain yield than no-till with 15.4 % higher water expense efficiency. The energy gain and net monetary returns were 13.2 and 21.2 % higher in conventional sown crop than no-till, respectively. Bi-directional sowing resulted in 26.5 % higher grain yield than uni-directional with no effect on quality traits of grains. The net energy gain and net monetary returns were 26.5 thousands MJ/ha and 125.3 $/ha higher from bi-directional sown crop than uni-directional sown crop. Crop irrigated at 30 mm CPE schedule resulted in significantly higher grain yield than that irrigated at 45, 60 and 75 mm CPE. The energy gain, energy use efficiency and net returns were also maximum at 30 CPE schedule than at 45, 60 or 75 CPE. However, brown, milled and head rice recoveries were statistically at par between irrigation scheduling at 30 and 45 mm CPE but significantly better than 60 and 75 mm CPE. Bi-directional sowing with conventional tillage and irrigation at 30 CPE is an energy efficient and economical viable technique for direct-seeded rice.     

不同行距下两个花生品种的水分利用,生长发育和荚果产量

研究在本农艺学院开展,对每日平均气温、降水和光照均作记录。处理设六种不同株行距(0 .70×0 .12 ,0 .50×0 .12 ,0 .70×0 .06 ,0 .30×0 .12 ,0 .50×0 .06和0 .30×0 .06 m) ,对应密度是12 ,18 ,24 ,28 ,33和55株/ m2。测定0~100cm土壤样品水分含量,用于计算作物水分蒸发蒸腾量(ET)、作物光截获量(α)、土壤蒸发量(Es)、作物水分利用率( WUE)和蒸腾率(Te)。最低密度(0 .70×0 .12 m)单株生长最好,最高密度处理则导致最低的单株干物质产量,其余4个处理单株干物质产量居于二者之间。两个品种的不同间距处理同样对单株荚果饱果数、荚果和种子产量有显著影响,高密度下使其均降低,但单位面积荚果和种子产量提高,但Florman的产量要好于Colorado。种植处理显著影响作物水分蒸发蒸腾量。行距0 .30 m和0 .50 m下,两个品种都达到46和60 DAS;行距0 .70 m下,Colorado是66DAS而Florman是87DAS。两个品种的蒸腾率都受到行距的影响,两个品种的WUE都受到间距影响,0 .70 m行距下WUE最低,Colorado在0 .50 m和0 .30 m行距下,Florman在0 .30 m下WUE最高。行距对Te的影响因品种而异,Colorado在不同行距下无显著差异,而Florman的Te则随行距减少而增加。不同间距和品种对光合效率都没有很大影响(Colorado是3 .1×10-2Kcal/ha ,Florman是3 .0×10-2Kcal/ha)。     

对SMV不同抗性的大豆品种体内过氧化物酶活性变化的研究

采用ＳＭＶ－ａ析系为毒源接种３人不同抗性类型的大豆品种，在接种后８，２４，４８，７小时及在３，６，９，１２，１５，１８ １１次连续取样与相应ＣＫ一并测定过氧化物酶的活性后发现：未经接种的抗感品种体内ＰＯ酶活性差异较大，病品种中ＰＯ酶活性水平高于抗性品种２倍以上。     

Rice seedling establishment as affected by cultivar,seed coating with calcium peroxide,sowing depth,and water level

Inconsistent seedling establishment is a constraint to the adoption of direct seeding of lowland rice (Oryza sativa L.) in the tropics. Rice cultivars with superior seedling establishment in flooded soil have been recently identified. The establishment of these tolerant cultivars was compared with a control cultivar with and without calcium peroxide-coated seed under various combinations of water level and sowing depth. Water level had little effect on seedling establishment when seed were sown on the soil surface, but establishment was reduced by raising the water level when seed were sown below the soil surface. Calcium peroxide-coated seed established better than the tolerant cultivars at 13- and 25-mm sowing depths, but their seedlings were shorter and less vigorous than those of tolerant cultivars. Tolerant cultivars and coated seed had longer mesocotyls than controls. Sowing tolerant cultivars beneath a flooded soil surface at less than 13 mm assists achievement of consistent seedling establishment in lowland rice production.     

Nutritional quality of some improved cultivars of cowpea

The seeds of 13 improved cowpea cultivars were analysed for proximate composition, methionine, tryptophan and polyphenols. Considerable genetic variations were observed for the contents of protein, nonprotein nitrogen, limiting amino acids and polyphenols. The globulins contributed about 50% of the total seed proteins. A significant proportion of proteins of high protein cultivars was found to be insoluble. The proteins of most of the cultivars were found deficient in methionine and tryptophan. Methionine and tryptophan levels were negatively correlated with protein and positively correlated with carbohydrate contents. The cultivars with colored seed coats contained higher amounts of polyphenols. The difference in polyphenol content between various cultivars were due to seed coat polyphenols.     

Leaf development of spring wheat cultivars in an irrigated heat-stressed environment

Wheat (Triticum aestivum L.) is expanding into lower latitudes of the Nile Valley Region, where maximum air temperature can reach 38–40°C during the short growing season. Genotype and environment, particularly temperature, affect the rate of leaf appearance. Field experiments were conducted at the Gezira Research Station, Wad Medani, Sudan in 1992–94. The study aimed to determine the effect of high temperature (by manipulating sowing dates) on leaf and tiller appearance and growth of nine spring wheat cultivars. Linear response was found between rate of leaf appearance and thermal time and it was faster before double-ridge stage than after double ridge. Phyllochron ranged between 99°C d and 122°C d. Differences in phyllochron interval (PI) were pronounced among cultivars and early-maturing cultivars had faster leaf appearance compared with late-maturing ones. Mean final leaf number on the main stem ranged from 8.1 to 12.2 and it was highly correlated with thermal time from sowing to double ridge stage (r=0.71**). Genetic constitution of cultivars had larger effect on number of leaves per main-stem than temperature. Tillers were initiated at leaf stage 2.9 and cultivars differed in their tillering capacity and only 1.5–2.0 reproductive tillers per plant were produced. About 810°C d were needed to produce tillers 1 and 2 and about 1140°C d for tillers 3 and 4. Leaf senescence started at leaf stage 6.1 for cv. Wadi El Neil and 4.2 for Debeira. Cultivars sown late exhibited delayed senescence of their leaves. High temperature accelerated maturity and the cultivars suited for the irrigated tropical environment were found to be early-sown late-maturing types.     

The effect of time of sowing and sowing method on production of white clover in mixed swards

Two field trials were carried out in successive years in which (1) perennial ryegrass and white clover seeds were drilled together, or (2) clover was broadcast and grass drilled, or (3) both clover and grass were broadcast. The last two treatments were followed by harrowing or not of the seed bed. Sowing took place in early May or August. Four harvests were taken in each full harvest year. In establishment years, sowing in May resulted in a total dry matter (DM) production at least ten times higher than that resulting from sowing in August. No sowing method treatment effects on total DM or clover yield were significant in the establishment year (measured only in spring-sown plots). In the first harvest year the August-sown treatments produced 15% less DM than those sown in May and clover yield was, on average, 40% lower than the earlier sown treatments; clover proportion followed a similar pattern to yield. Drilling of both grass and clover without harrowing produced swards with a significantly lower proportion of clover in the first harvest year in the first trial than in treatments in which clover was broadcast but not harrowed. In the second trial at harvest 1, clover proportion just failed to be significantly lower in the treatment in which grass and clover were drilled than in the treatment when clover was broadcast and the seed bed harrowed. In the second harvest year (first trial only), annual clover yield and proportion were not affected but drilled grass and clover had lower DM yield than when grass was drilled and clover broadcast without harrowing and when both were broadcast, without harrowing. At one harvest, the yield of clover in treatments sown in May was actually lower than that in the later-sown plots. In a subsidiary controlled environment experiment to investigate the effect of stage of clover development on cold hardiness (a factor in autumn-sown swards), plants which were about to initiate stolons (58 days old) had an LD₅₀ of ?5·1° compared with ?9·3°C for plants 60 days older. It is concluded that autumn sowing delays the time at which optimum clover production is achieved (late in the first full harvest year) and method of sowing does not compensate for this. However, sowing in August under Northern Ireland conditions does not seem to jeopardize the chances of a successful establishment of white clover, and plants should be sufficiently winter hardy to withstand relatively hard freezing conditions.     

Performance of double cropping and relay intercropping for black soybean production in small-scale farms

We investigated the soybean productivity of double cropping and relay intercropping in farmer’s fields for three years using two black soybean cultivars of Kurozukin and Tanbaguro, which are used for the first and second crop, respectively. Kurozukin is the early maturing cultivar for vegetable soybean harvest and Tanbaguro is the late-maturing cultivar for the harvest of vegetable soybean and seeds. The yield of the first crop (Kurozukin) was similar to the mono cropping regardless of cropping patterns. However, the yield of the second crop (Tanbaguro) was affected by cropping patterns. The yield of Tanbaguro in double cropping was prone to decrease by late sowing. The late sowing was induced by the late sowing and late harvesting of Kurozukin because of the low temperature in April and the large amount of precipitation in rainy season, respectively. In relay intercropping that Tanbaguro was sown between the rows of Kurozukin at about one month before the harvest of Kurozukin, the yield of Tanbaguro was similar to the mono cropping and the competition with Kurozukin was not observed. Thus, the land equivalent ratio value of double cropping was lower than that of relay intercropping. These results suggest that relay intercropping is more useful cultivation system than double cropping to increase the annual soybean production.     

Wound-healing and the effect of soil temperature,cultivars and protective chemicals on wound-healed potato seed pieces inoculated with seed piece decay fungi and bacteria

The effect ofFusarium solani (Fsc),F. sambucinum (Fs),Erwinia carotovora subsp.atroseptica (Eca), andE. carotovora subsp.carotovora (Ecc) inoculated singly and in combination (FscFs, FscEca, FscEcc, FsEca, FsEcc, and EcaEcc) on wound-healed potato seed pieces of the cultivar Kennebec was studied. Potato seed pieces wound-healed for 5 days at 13 C and approximately 100% relative humidity, inoculated with Fsc, Fs, Eca, Ecc and their combinations, and incubated for 10 days at 9 C were protected from Eca, Ecc, and EcaEcc. When wound-healed potato seed pieces were inoculated with Fsc, Fs, Eca, Ecc, and their combinations and planted in soil maintained at 7, 10, 15, 20 and 25 C, wound-healing protected seed pieces from all pathogens and their combinations in seed pieces held for 10 days at 10 and 15 C. When seed pieces of cultivars Atlantic, Kennebec, Norchip, Russet Burbank and Superior were inoculated with Fsc, Fs, Eca, Ecc, and their combinations, different levels of protection were observed: Russet Burbank had the highest level of protection, Atlantic and Kennebec were intermediate, and Norchip and Superior were slightly protected. Dusting mancozeb on wound-healed seed pieces before inoculation with Fsc, Fs, Eca, Ecc, and their combinations increased protection against all pathogens and their combinations by 39% or more compared to the nonchemical control.     

A COMPARISON OF BROADCAST AND WIDE-ROW SPACED GRASSES WHEN MANAGED FOR FOGGAGE PRODUCTION

A small-plot trial comparing perennial ryegrass, cocksfoot, timothy and meadow fescue sown broadcast and also in 21 inch rows was conducted at Auchincruive from 1954 to 1957. The cutting treatments were arranged so that measurement could be made of both summer and winter production.
Of the four species, cocksfoot was the most suitable for foggage production. Perennial ryegrass suffered severely from winter killing. Timothy and meadow fescue, although persistent, did not yield as much as cocksfoot.
Total dry-matter production over three years was higher from the cocksfoot rows than from the broadcast stand. For ryegrass and meadow fescue, broadcasting gave higher yields than row sowing while timothy showed no significant difference between sowing methods.
During the winter, all species showed a loss of dry matter. Losses for ryegrass, cocksfoot, timothy and meadow fescue were respectively 34%, 17%, 18% and 24%. Broadcast stands averaged 11% greater loss than the rows.     

播期对花生农艺性状、产量和品质的影响

以普通花生品种（冀花9号、冀花10号、冀花12号）、高油酸花生品种（冀花11号、冀花13号、冀花16号）为材料,通过田间小区试验,设置7个播种时期（4/25、5/6、5/16、5/26、6/6、6/15、6/26）,研究不同播期对花生生长发育、产量指标和品质的影响,以期确定花生最佳播种时期,为集成优质高效栽培技术奠定基础。结果表明,冀花10号、冀花12号、冀花13号、冀花16号的农艺性状表现为主茎高、侧枝长、分枝数多;而冀花9号和冀花11号则表现为主茎矮、侧枝短、分枝少。6个花生品种荚果平均产量为4716.22 kg/hm2,籽仁平均产量为3469.52 kg/hm2。以籽仁产量最高的冀花12号（3541.99 kg/hm2）为对照,普通花生品种冀花9号、冀花10号减产0.35%~1.91%;高油酸花生品种冀花11号、冀花13号、冀花16号减产2.11%~5.54%。随播期的延后,各个播期的花生农艺性状及产量指标基本遵循5/6-5/16 > 4/25 > 5/26-6/26的变化趋势。5/6-5/16播期的平均荚果产量和籽仁产量分别5547.16 kg/hm2、4204.24 kg/hm2,油酸/亚油酸比值平均12.90。4/25播种,荚果和籽仁减产约5.16%,油亚比为14.61;5/26日播种,荚果和籽仁减产约9.05%,油亚比降低35.56%。晚于5/26播种,主茎高变矮7.40%～22.89%、侧枝长变短7.07%～24.89%、单株分枝数减少3.74%～9.70%、单株结果数降低4.59%～21.78%、百果重减少6.59%～27.94%、百仁重减少10.35%～32.33%、荚果减产17.97%～45.78%、籽仁减产21.80%～52.50%、油亚比降低50.57%～73.30%。综合考虑农艺性状、产量指标及品质优劣,河北省中南部地区露地平播花生的最适播期为5/6至5/16之间,最晚不应晚于5/26。     

不同播期对华南夏大豆品种产量和品质的影响

采用3个国审夏大豆新品种,在广州分5个播期种植,研究了不同播期对华南夏大豆农艺性状、产量、蛋白质及脂肪含量的影响。结果表明:播期对大豆的农艺性状、产量和品质都有明显的影响。播期对产量、粗蛋白、粗脂肪及蛋脂总和的影响达显著或极显著水平;对不同品种的产量构成因素也有显著的影响,随着播期的延迟,单株产量、主茎荚数、分枝荚数、主茎粒数和分枝粒数呈显著下降趋势。在6月中旬至7月上旬播种,大豆产量和品质表现较好,是最佳播种期。在7月下旬之后播种,大豆植株矮小,分枝数少且分枝粒数比主茎粒数少,需要增加播种密度来提高产量;同时应适当灌溉,以防晚熟或晚播品种在开花至鼓粒期受干旱影响。华夏3号在最佳时期播种,分枝产量起主要贡献,所以该品种在6月中旬至7月上旬播种应合理密植,以保证通过提高分枝产量而获得高产。