Effects of Brown Rust caused by Puccinia recondita on Wheat

Abstract

Plants of susceptible and resistant varieties were inoculated with the brown rust pathogen Puccinia recondita. Rust reduced the average plant height, weight of grain, volume of grain and yield of susceptible varieties compared with healthy controls. Two varieties, Lerma Rojo and E.871 were resistant and are recommended for use in further hybridisation work.     

Effect of Subsurface Water Level and Irrigation Intervals on Hassawi Rice (Oryza sativa L.) Production on a Sandy Loam Soil

A 2-year experiment was conducted using 84 cylindrical metal barrels, each 80 cm in diameter and 120 cm in height. Barrels were packed with sandy loam soil to evaluate the effect of three subsurface water levels (30, 70, and 100 cm) and four irrigation intervals (daily, every second day, every third day, and every fourth day) in a completely randomized design on growth and production of Hassawi rice (Oryza sativa L.) cultivar. The 30-cm subsurface water level (SW L) gave the highest grain yield. However, yield decreased as SW L increased. On the other hand, the four irrigation intervals showed significant increase in grain yield as the frequency of irrigation decreased. All yield components were positively affected by increasing irrigation frequency. The most important was found to be the 100-grain weight. The increase in grain yield was associated with the increase in plant height, plant fresh weight, plant dry weight, and weight of 100 grains. The interaction between SW L and irrigation intervals revealed that the highest grain yield was obtained at 30-cm SW L and daily irrigation. However, the grain yield obtained at 30-cm SW L and irrigation every second day showed similar yield and higher water use efficiency, with a savings of 12% irrigation water compared to that used at daily irrigation and 30-cm SW L. All other combinations of SW L and irrigation intervals either produced very low grain yields or showed low water use efficiency. Therefore irrigation of Hassawi rice in sandy loam soil may benefit from shallow SW L (30 cm) and irrigation every second day, which may prove to be an acceptable management practice for grain rice production, providing the highest water use efficiency.     

Effect of chemical and cultural methods of weed control on the yield and growth of maize

Abstract

Traditional sorghum cultivars in the tropics are generally photoperiod sensitive, flowering just as or after the rains cease, so that their grains fill and mature during dry weather. Improved cultivars have been developed which flower and mature earlier in the season, when soil moisture levels are generally more favourable for grain filling, which potentially gives higher grain yields. However, the earlier flowering often results in the exposure of developing grain to wet conditions in which it can deteriorate rapidly. Grain moulds are a major component of the sorghum grain deterioration complex, and have become a widespread problem of improved sorghums in temperate and tropical regions. Many fungi have been isolated from mouldy grain, the most commonly occurring genera being Fusarium and Curvularia, and vary from those such as F. moniliforme Sheldon which are pathogenic on young developing inflorescences, to many saprophytic fungi which develop on the mature grains. The review covers terminology, causal agents, time of infection, predisposing factors, effects on yield and quality, control measures, resistance screening procedures and progress and recommendations for further research particularly in resistance.     

Effects of Herbicides on Horticultural Characteristics,Yield and Quality of Onions

Abstract

Seven different herbicides were tested in 1967, and two of these chemicals were further evaluated in 1969 for their efficacy in onions grown in Lebanon. Chloroxuron at 6 kg a.i./ha and Sindone at 1.5 kg/ha gave a significant increase in the bulb weight and yield of onions over unweeded plots. Significant reductions in yield were observed from pre-em. applications of chlorbromuron at 3 kg/ha, propachlor at 6 kg/ha, Sindone at 0.5 kg/ha, and prometryne at 1 and 1.5 kg/ha. Good weed control was obtained as a result of pre-em. application of all herbicides tested.

With post-em. application, weed control was not effective. With the exception of prometryne at 1.5 kg/ha which injured the onions and reduced the yield, the post-em. applications of herbicides tested gave no significant effect on onion yield.

None of the treatments, in both pre-em. and post-em. applications, had any significant effect on leaf length, bulb index, bolting and splitting percentages, dry matter content, total soluble solids, or pungency of onions.     

Effect of Weeding Regime and Plant Spacings on Weed Growth and Performance of Transplanted Rice

Abstract

Effect of weeding regime (unweeded control, hand weeding once, 4 weeks after transplanting (w.a.t.) and hand weeding twice, 4 and 7 w.a.t.) and different plant spacings (20 × 2.5 cm, 20 × 5 cm, 20 × 10 cm, 20 × 15 cm and 20 × 20 cm) on weed growth and performance of transplanted rice were tested in a split-plot design. Grain yield and number of panicles were not significantly different in both weeding treatments from the unweeded control at 20 × 2.5 to 20 × 10 cm spacings, showing that, at closer spacings weed control may not be necessary to increase grain yield. The number of weeds at harvest was significantly lower in the weeded plots than the unweeded control at all spacings used. Weed weight at harvest was significantly affected by weeding regime at all spacings except at 20 × 2.5 cm, where no significant difference was observed between the weeded and the unweeded plots. Plant spacings significantly affected the grain yield and weed weight, but did not affect the panicle number and weed counts of transplanted rice. At 20 × 2.5 cm, grain yield was significantly better than that at 20 × 15 cm or 20 × 20 cm. A simple trend of increase in grain yield along with the decrease in spacing between plants was observed in terms of actual grain yield.     

Estimation of the effect of <Emphasis Type="Italic">Tomato spotted wilt virus</Emphasis> (TSWV) infection on some yield components of tomato

The effects of Tomato spotted wilt virus (TSWV) on yield and quality of tomato fruits were studied from May through November of 2004 at the Experimental Field of the Agricultural Faculty of Ondokuz Mayis University, in Samsun province, Turkey. TSWV caused 42.1% and 95.5% reduction in yield and marketable value of tomato, respectively. TSWV infection in tomato crop caused significant (P < 0.05) reductions in weight, total number, width and length of the fruits in infected plants. Reductions in yield-contributing parameters were 26.61% in weight, 20.18% in number, 10.94% in width and 11.93% in length of fruits. It is difficult to estimate the actual yield loss and influence levels of TSWV in the field. Economic data are scarce, but in the present study it was estimated that the yield loss due to TSWV in tomatoes was approximately $0.9 million in Samsun, Turkey.     

Response of transplanted rice to nitrogen fertilization under different weed management practices

Abstract

Rice yield increased significantly and consistently up to 120 kg N/ha when weeds were not controlled. But when weeds were effectively controlled by two hand weedings (20 and 40 days after transplanting) or by use of thiobencarb at 1–0 kg a.i./ha rice yield increased significantly up to 80 kg N/ha. The optimum dose of N for transplanted rice under mid‐hill conditions of Himachal Pradesh (Palampur) was 82 kg/ha when two hand weedings were done and 86 kg/ha when weeds were managed using thiobencarb. The yield response per kg of N in the respective treatments was 20 and 24 kg of grain. The weed dry weight was significantly lower in thiobencarb and hand weeded plots compared with unweeded check though the difference in weed dry weight due to the former two treatments was not significant.     

Fourth International Conference on Spices

Abstract

The present article suggests a simple procedure for estimating yield and production losses in a given crop and region. The utility of the procedure is illustrated by an empirical application to bean production in Cauca Valley, Colombia. Using data obtained from direct field observations on a panel of farms, a production function approach is used to estimate yield and production losses caused by each of the yield constraints identified. It is expected that such estimates will be useful for establishing agricultural research priorities. In an empirical analysis of bean production in Cauca Valley, six important yield limiting factors were identified. Unfavourable rainfall conditions caused a yield loss of about 32% and a total production loss of about US $1.2 million for the region during one growing season. The production losses caused by rust and bacterial blight were slightly smaller. Other important yield constraints were Empoasca kraemeri, angular leaf spot and the use of noncertified seed. Small production increases could be obtained by increasing input use and plant population.     

Effect of seasons and larval food plants on the quality of <Emphasis Type="Italic">Gonometa postica</Emphasis> cocoons

The effect of food plants [Acacia elatior Brenan, A. tortilis (Forssk.) and A. nilotica (L.) Del.] on the development time of Gonometa postica Walker (Lepidoptera: Lasiocampidae) larvae and the quality of their cocoons was studied in the Imba and Mumoni forests of Mwingi, Eastern Kenya, during the long (March-May) and short (October-December) rainy seasons of 2006 and 2007. Larvae were reared in semi-captivity in net sleeves attached to branches of the plants. The period between hatching of eggs and spinning of cocoons, as well as their weight, as determinants of cocoon quality were recorded. In addition, collections of cocoons from the wild were done in the two forests from the same host plants for assessment of their quality. In the cage experiment, larval development period and quality of cocoons differed according to food plants, seasons and sites, whereas quality of cocoons sampled from the wild habitat was similar for all food plants and seasons but varied according to site. Generally, there was a positive correlation between weight of cocoon, its length and width for the two seasons for both the semi-captive population and those from the wild. Larvae reared on A. elatior had a shorter development period and higher cocoon quality than those raised on A. tortilis and A. nilotica. Generally, temperature and relative humidity significantly influenced larval development time and the effect was both positive and negative. Rainfall was generally higher in Mumoni than in Imba. The implications of the above findings for the semi-captive rearing of G. postica to increase the quality of cocoons are discussed.     

施氮量对滴灌高产春大豆根系生长及产量的影响

为揭示施氮量对滴灌高产春大豆根系生长及产量的影响规律,在田间滴灌条件下采用挖掘取样法研究了0 kg·hm~(-2)(N_0)、75 kg·hm~(-2)(N_(75))、150 kg·hm~(-2)(N_(150))、225 kg·hm~(-2)(N_(225))4种施氮量对新大豆27号0~80 cm土层根系干物质量、侧根长度、表面积、根系活性、伤流量、根瘤数、根瘤质量及产量的影响。结果表明:随着施氮量的增加,0~80 cm土层根系总干物质量、侧根总长度、侧根总表面积呈现先增后降的变化趋势,均以N_(150)处理最高,在R_5(始粒期)期分别较N_0增加27.3%、49.46%、38.14%,其中,0~20 cm土层分别较N_0增加27.0%、29.02%、34.24%;R_5期N_(150)单株伤流量较N_0增加176.0%,R_2(盛花期)期0~20、20~40 cm土层根系活力N_(150)分别较N_0增加44.3%、25.1%;R_5期N_(150)单位面积根瘤数及质量分别较N_0减少8.74%、34.6%;施氮可增加产量,以N_(150)产量最高,为4 889.62kg·hm~(-2),氮肥农学利用效率3.58 kg·kg~(-1)。施氮增加产量主要是促进0~20 cm土层根系生长,提高0~40 cm根系活力的结果。     

苯肽胺酸对辣椒内源激素及果实品质和产量的影响

明确苯肽胺酸对作物内源激素和果实品质及产量的影响,对其在农业生产中合理使用具有重要意义。本研究以辣椒为供试作物,芸苔素内酯为对照药剂,在田间小区试验条件下,采用酶联免疫吸附 (ELISA) 等生理生化测定方法,研究了不同质量浓度的苯肽胺酸处理 (133.3、200.0、266.7 mg/L) 对辣椒叶片中内源激素含量、果实品质及产量的影响。结果表明:与空白对照相比,分别于辣椒蕾期、花期和果期喷施苯肽胺酸后,其叶片中生长素 (IAA) 和玉米素 (ZT) 含量分别提高了4.15%~28.54%和23.41%~163.10%,脱落酸 (ABA) 含量降低了5.47%~28.97%,而对赤霉素 (GA₃) 含量无明显影响;苯肽胺酸处理的辣椒叶片中IAA/ZT比值呈先降低后升高趋势,而IAA/ABA、ZT/ABA、GA₃/ABA的比值在各测定期均升高;对照药剂芸苔素内酯处理对辣椒叶片内源激素的含量和比例也有较明显的影响,但与苯肽胺酸处理相比存在一定的差异。苯肽胺酸处理能明显改善辣椒果实品质,与空白对照相比,单果质量、果形指数和干重 (每100 g鲜果) 最高可分别增加14.75%、49.67%和26.09%,可溶性糖、可溶性蛋白、维生素C和辣椒素含量分别提高69.75%~99.62%、29.17%~94.32%、15.86%~55.35%和1.82%~31.69%;苯肽胺酸处理具有明显增产效果,总产量比空白对照增加了20.66%~37.19%;芸苔素内酯处理也能改善果实品质和提高产量,尤其是增产效果明显,较空白对照增加了38.02%,但改善果实品质的整体效果弱于苯肽胺酸。研究表明,苯肽胺酸能够影响辣椒叶片的内源激素含量和比例,并可提高辣椒产量和改善果实品质,但与芸苔素内酯对辣椒的作用机理和效果不同,其田间推荐剂量为有效成分质量浓度133.3~200.0 mg/L。     

Granular systemic insecticides for control of green peach aphid (Myzus persicae) and their effect on yield and quality of tobacco grown in riverside lankas

Abstract

Flue‐cured Virginia (f.c.v.) tobacco grown on deltaic islands or lankas in the Godavari river in Andhra Pradesh, India is subject to heavy infestations of green peach aphid, Myzus persicae Sulz. The relative efficacy of granular formulations of the systemic insecticides phorate, disulfoton, carbofuran, aldicarb and terbufos in controlling the aphid, and their effect on the yield and quality of lanka tobacco have been studied. Aldicarb granules at 1 g/plant and disulfoton at 2 g/plant were found to be the most effective in controlling the aphid, and also resulted in higher yields of green leaf, cured leaf and total bright leaf equivalent (an index of visual quality). Terbufos at 2 g/plant also gave good yields, but was slightly less effective in controlling aphid infestations. Carbofuran at 3 g/plant was the least effective. The chemical quality of f.c.v. tobacco was not affected by the application of granular insecticides to the soil.     

不同钾肥品种对甘肃中部地区马铃薯产量及品质的影响

为了确定甘肃中部马铃薯主产区马铃薯生产过程合理施用钾肥品种及其用量,于2009年在甘肃省漳县进行了硫酸钾和氯化钾两种钾肥的不同用量试验,测定了马铃薯植株地上部分株高、分枝数以及经济性状和薯块产量,分析了不同用量下马铃薯品质和经济效益。结果表明,施用钾肥能有效提高马铃薯地上部分株高、分枝以及薯块产量和品质;同一钾肥下K₂O施用量105 kg·hm^-2时单株薯块、大中薯率、产量以及干物质、粗淀粉、Vc最高,而烂薯率和薯块还原糖含量最低,K₂O 60 kg·hm^-2时马铃薯粗蛋白含量最高;同一钾水平下施用硫酸钾马铃薯植株分枝数以及烂薯率明显低于施用氯化钾,单株结薯个数、大中薯鲜重、大中薯率及产量明显高于氯化钾,同时薯块干物质、粗淀粉、Vc、粗蛋白含量高于氯化钾,还原糖含量低于氯化钾,而株高差异不明显。研究得知,甘肃中部马铃薯主产区马铃薯生产过程中施用硫酸钾优于氯化钾,在施纯N120 kg·hm^-2、P₂O₅ 60 kg·hm_-2条件下,K₂O施用量105 kg·hm_-2时可有效提高马铃薯产量和品质,且纯收益最高。     

不同氮肥处理对糜子产量及品质的影响

以晋黍9号为材料,研究了普通尿素和缓释尿素对糜子产量和品质的影响。结果表明:施氮处理的糜子蛋白质含量都显著大于对照,而淀粉含量都显著小于对照;产量以PN2(普通尿素150 kg·hm-2)最高,增产幅度为28.48%;产量与穗数和单株粒重达到极显著正相关,相关系数分别为0.81和0.62;糜子产量与籽粒蛋白质含量呈极显著正相关,相关系数为0.83,与籽粒淀粉含量呈显著负相关,相关系数为-0.44。本试验条件下,糜子产量的增加主要是通过增加穗数和单株粒重来实现的。以普通肥料N150 kg·hm-2为最适施氮量。研究表明不是所有土壤类型都适合施用缓释尿素,研究区为砂质土,保水保肥能力差,通气性好,施用普通尿素比缓释尿素效果好。     

灌溉和施肥方式对红麻生长和产量的影响

本研究旨在通过大田小区试验,研究灌溉和施肥方式对红麻生长和产量的影响,为确定红麻合理的灌溉和施肥方式提供依据。试验选择福红992(常规栽培种)和红优2号(杂交种)2种红麻品种,沟灌和滴灌2种灌溉方式,3种施肥方式:1 T1,60%N和K肥作基肥,余下40%N和K肥用作追肥;2 T2,40%N和K肥作基肥,余下60%N和K肥用作追肥;3 T3,20%N和K肥作基肥,其余作为追肥。结果表明:1沟灌时,福红992的产量明显高于红优2号,且60%NK肥作追肥时产量最高。2与沟灌相比,滴灌明显改善了株高等农艺性状,显著提高了红优2号的生麻产量;但灌溉方式对福红992的产量影响不显著。结论为在滴灌施肥状态下,60%NK肥作追肥时,红麻杂交种"红优2号"的生麻产量和地上部干质量均最高。     

不同灌水量及频率对番茄品质及糖分累积影响的研究

采用两因素随机区组试验设计,设置4个灌水量(L1,L2,L3,L4)及2个灌水频率(P1,P2),通过对冬春茬和夏秋茬番茄营养品质、糖组分、糖代谢酶及产量的研究,以期探讨灌水量及频率对番茄品质形成机理的影响及综合品质产量最优的合理灌水量及频率。研究结果表明:适当减少灌水量可提高番茄各营养指标含量、糖组分含量、SS和SPS活性以及WUE,但抑制AI和NI活性且降低了产量,而灌水频率对各指标无显著影响;冬春茬可溶性酸、可溶性糖含量、糖酸比、SS和SPS活性、果糖和葡萄糖含量均在L2处理达到了最大,而产量以L4最大,其中Vc、葡萄糖、SS活性等对其品质及产量形成影响较大;夏秋茬L1处理番茄营养品质指标、糖组分含量(淀粉除外)、SS活性显著高于L3、L4,产量仍以L4最大,果糖含量L1处理甚至显著高于L3与L4 1.02倍和1.25倍,其中Vc、蔗糖、NI活性等对其品质及产量形成影响较显著;根据主成分综合品质及产量得出,冬春茬与夏秋茬温室番茄苗期、开花坐果期、盛果期至拉秧分别灌水150、200、400 ml·株~(-1)·d~(-1)与300、600、900 ml·株~(-1)·d~(-1),每天灌水1次或者2次时品质及产量综合得分最佳。     

Tolerence of Wheat and Barley at Different Stages of Growth to 2, 4-D Sprays

Abstract

The tolerance of wheat and barley to 2, 4-D sprayed at six stages of growth, ranging from the 3-leaf stage up to the ripe grain stage, was studied. Five concentrations ranging from 500 to 8000 ppm (a.e.) of 2, 4-D were tested.

All the concentrations sprayed at the 3-leaf stage were phytotoxic to wheat and barley, whereas at the 5-leaf, jointing, and booting-to-heading stages, only 4000 and 8000 ppm were phytotoxic and caused lodging in the two crops. Reductions in plant height were significant at all concentrations used in the case of barley, and at 1000 ppm and above in the case of wheat.

The 8000 ppm treatment, applied at the jointing and anthesis stages, caused significant reductions in the grain yield of wheat; in the case of barley, significant reductions in the grain yield were observed at concentrations ranging from 2000 to 8000 ppm, sprayed at the 3-leaf, booting-to-heading, arid anthesis stages. At the 5-leaf stage, the 1000 ppm treatment gave a highly significant increase of 18.7% in the grain yield over the unweeded check. Significant reductions in the 1000-kernel weight and test weight of the two crops were observed only at the higher concentrations used.

The protein percentages of wheat and barley seeds were significantly increased as a result of the application of 2, 4-D at 2000 to 8000 ppm, sprayed at the 3-leaf, jointing, booting-to-heading, and anthesis stages of growth. However, significant reductions in the protein yield of the two crops were observed at these treatments. No significant effects were observed on the straw yield and germination percentages of wheat and barley as a result of 2, 4-D applications at the various stages of growth.     

稳定性肥料配施微生物菌剂对莴笋生长及品质的影响研究

通过以蔬菜硫基稳定性复合肥替代普通化肥作为微生物菌剂的增效载体,研究了蔬菜硫基稳定性复合肥减量对灌漠土地区露地莴笋生长及品质的影响。采用田间试验方法,设置6个处理:不施肥料(CK)、当地习惯施肥处理(CF)、100%稳定性复合肥化肥(T_(100))、 80%稳定性复合肥化肥+菌剂(T_(80))、60%稳定性复合肥化肥+菌剂(T_(60))和40%稳定性复合肥化肥+菌剂(T_(40)),测定莴笋莲座期和成熟期植物学特征指标及品质指标,并计算肥料贡献率和可塑性指数。结果表明:在添加60 kg·hm~(-2)微生物菌剂的基础上,稳定性复合肥减量40%以下不会对莴笋的生长形成抑制作用,反而可促进单株质量增加9.94%～11.57%、产量增长2.77%～10.27%,并且可有效提高莴笋Vc含量2.29%～10.23%,提高可溶性蛋白质含量1.11%～1.38%,降低硝酸盐含量14.13%～17.05%。其中,T_(60)处理表现最好,较CF处理根、茎、叶干物质积累量分别增加了17.38%、5.77%和31.24%,单株重增加11.57%,产量增加10.27%,肥料贡献率提高了7.16%,Vc提高2.29%,可溶性蛋白质含量提高1.38%,硝酸盐含量降低17.05%。基于本试验条件下荒漠土露地莴笋生产中适宜的减肥措施为720 kg·hm~(-2)稳定性长效复合肥添加60 kg·hm~(-2)微生物肥。     

Quality changes in successive generations of the millet stem borer,Coniesta ignefusalis (Hampson) (Lepidoptera : Pyralidae), in northern Ghana

Studies were conducted in northern Ghana in 1996 and 1997 to assess any changes in the quality of insects in different generations of the millet stem borer, Coniesta ignefusalis (Hampson), over the growing season. The goal was to determine if, and to what extent, such changes are responsible for observed differences in the sizes of populations of successive generations of the insect. Pupae from diapause larvae gave rise to adults that were significantly smaller and had lower reproductive rates than those derived from non-diapause larvae. There were, however, no significant differences between the non-diapause generations for all the quality indicators studied. The results suggest that observed differences in the sizes of generations developing fromnon-diapause anddiapause larvae of C. ignefusalis are, at least, partly due to differences in the inherent quality of individuals of these generations.     

Biofumigation with Fresh Manure or Brassicaceae Residuals could be a Promising Methyl Bromide Alternative in Head Lettuce Production

The current study investigates the natural alternatives of methyl bromide on head lettuce plants grown in greenhouse. Lettuce (Lactuca sativa L.) seedlings (cv. “Big Bell”) were treated with six different MBr alternatives which are, Biofumigation with fresh cow manure, fresh chicken manure, or Brassicaceae residuals plus Bio-Compost application (using disease suppressive compost) in comparison with chemical control with one of MBr chemical alternatives (Basamid) and finally negative control (which is the standard farmer treatment). Despite that chemical control with Basamid recorded the highest survival rate, biofumigation with fresh chicken manure gave the best head length, diameter, fresh weight, dry weight, total and marketable yield. Also, highest head quality characteristics such as TSS, SPAD reading, and nitrogen content were recorded with biofumigation with fresh chicken manure. Regardless of the superiority of Biofumigation with fresh chicken manure, Biofumigation with fresh cow manure or Brassicaceae residuals showed a better vegetative growth and quality parameters than farmer treatment (control), and they had significantly less effect than chemical control treatment. Bio-Compost fortified with Trichoderma harzianum and Bacillus subtilis (disease suppressive compost) recorded survival rate similar to biofumigation treatments but were significantly lower than chemical control treatment. Bio-Compost treatment did not result in a good result regarding total and marketable yield head fresh and dry weight. There was no detected significant effect of the studied treatments on stem diameter, L?ascorbic acid (vitamin C), phosphorus and potassium content