Simple Summary Corn ear pests, such as cotton bollworm and corn borer larvae, can infest corn ears within hours to a day, posing a significant challenge for their control. This study aimed to determine the ideal timing for pesticide application, select effective and safe pesticides, and optimize application methods. Over several years, we monitored adult sweet corn ear pests in Beijing, investigating their relationship with corn phenology and local climate to identify the best time for effective pesticide application. Through field experiments evaluating 13 different pesticides, we identified cost-effective and safe options. Ultimately, we discovered that in mid-June, approximately five days after corn silking in sweet corn fields, moth populations got the greatest growth rate. During this crucial period, applying Indoxacarb + Chlorfenapyr, Virtako + mineral oil, or the biopesticide Beauveria bassiana + oil on corn silks and ear surfaces maximized their effectiveness. Our research significantly improves corn ear pest control. Abstract Helicoverpa armigera (Hübner) and Ostrinia furnacalis (Guenée) are the most devastating insect pests at the ear stage of maize, causing significant losses to the sweet corn industry. Pesticide control primarily relies on spraying during the flowering stage, but the effectiveness is inconsistent since larvae are beneath husks within hours to a day, making pesticide treatments simpler to avoid. Insufficient understanding of pest activity patterns impedes precise and efficient pesticide control. H. armigera and O. furnacalis in corn fields were monitored in the last few years in Beijing China, and we observed a higher occurrence of both moths during the R1 stage of sweet corn. Moth captures reached the maximum during this stage, with 555–765 moths per hectare corn field daily. The control efficiency of nine synthetic insecticides and five biopesticides was assessed in the field during this period. Virtako, with mineral oil as the adjuvant, appeared to be the most effective synthetic insecticide, with the efficiencies reaching 88% and 87% on sweet and waxy corn, respectively. Pesticide residue data indicated that the corn is safe after 17 days of its use. The most effective bioinsecticide was Beauveria bassiana combined with mineral oil, with 88% and 80% control efficiency in sweet and waxy corn, respectively. These results suggested that spraying effective insecticides 5 days after corn silking could effectively control corn ear pests H. armigera and O. furnacalis. Our findings provide valuable insights for the development of ear pest management strategies in sweet corn.

Helicoverpa armigera (Hübner) and Ostrinia furnacalis (Guenée) are the most devastating insect pests at the ear stage of maize, causing significant losses to the sweet corn industry. Pesticide control primarily relies on spraying during the flowering stage, but the effectiveness is inconsistent since larvae are beneath husks within hours to a day, making pesticide treatments simpler to avoid. Insufficient understanding of pest activity patterns impedes precise and efficient pesticide control. H. armigera and O. furnacalis in corn fields were monitored in the last few years in Beijing China, and we observed a higher occurrence of both moths during the R1 stage of sweet corn. Moth captures reached the maximum during this stage, with 555–765 moths per hectare corn field daily. The control efficiency of nine synthetic insecticides and five biopesticides was assessed in the field during this period. Virtako, with mineral oil as the adjuvant, appeared to be the most effective synthetic insecticide, with the efficiencies reaching 88% and 87% on sweet and waxy corn, respectively. Pesticide residue data indicated that the corn is safe after 17 days of its use. The most effective bioinsecticide was Beauveria bassiana combined with mineral oil, with 88% and 80% control efficiency in sweet and waxy corn, respectively. These results suggested that spraying effective insecticides 5 days after corn silking could effectively control corn ear pests H. armigera and O. furnacalis. Our findings provide valuable insights for the development of ear pest management strategies in sweet corn.

为筛选出符合北京市现代农业需求、满足市民口感要求的优质高端品种,以BM380、京白甜456、墨瞳、京科甜608、中农甜414、黑甜639、中农甜419和京科甜183等8个甜玉米为试验对象进行了品种筛选试验,从植株形态、产量性状和品质口感等方面进行比较.结果表明,BM380、京白甜456、墨瞳、京科甜608、中农甜414品质较好、产量较高,可作为面向高端客户、线上销售优质农产品的新型种植主体的推荐品种,以期获得更高的效益.

为筛选出适宜在北京地区早春种植的鲜食糯玉米品种,选取10个品种开展田间筛选试验,通过综合比较生育期、农艺性状、产量和品质等指标,结果表明:农科糯336的生育期较短、鲜穗产量最高,农科玉368的生育期适中、品质最佳,特色糯玉米品种京紫糯219综合性状较好,这3个品种均适宜在北京地区早春种植.

为进一步加快优质品种及配套栽培技术的推广应用,有效促进农业增效和农民增收,笔者总结出京白甜456一年两熟优质高产栽培技术,包括地块选择、隔离种植、适期播种、田间管理、适期收获等具体内容,以期通过良种良法配合,提高鲜食玉米露地种植效益,并满足市民对本地优质鲜食玉米的需求.

为筛选出适宜在北京市房山区早春茬口种植的鲜食糯玉米品种,选取10个糯玉米新品种开展田间筛选鉴定试验.结果表明,在综合比较生育期、产量和果穗性状等指标的基础上,早春茬口鲜食玉米品种可选择京科糯336、万糯198、农科玉257和斯达糯41种植,综合表现较好.生产中应根据各品种特征特性进行栽培管理、抢早播种,以获得较高的产量和效益.

京双甜467是北京市农业技术推广站和北京保民种业有限公司以自交系BMO110101为母本、BMB100101为父本杂交选育的优质、高产甜玉米新品种,该品种丰产性好、生育期适宜、鲜食品质优、综合抗性好,2019年通过北京市审定.适宜在北京及周边地区推广种植.

玉米是对干旱比较敏感的粮食作物,不同品种应对干旱胁迫的能力存在差异.以6个普通玉米品种为材料,在北京市郊区大田条件下,采用裂区设计,以灌溉处理为对照,分析干旱处理对不同玉米品种叶片光合速率(Pn)和抗氧化特性及产量的影响.结果 表明,与对照相比,干旱处理下不同品种玉米Pn降低幅度为京农科728(15.63％) ＜MC703 (15.84％)＜农华101 (16.34％)＜登海618 (16.92％)＜郑单958 (19.15％)＜联创808(21.74％).干旱处理后,不同品种玉米叶片的抗氧化酶(SOD、POD和CAT)活性均显著降低,丙二醛(MDA)含量均显著提高;表现为京农科728和MC703的SOD活性显著高于其余品种,而POD活性、CAT活性及MDA含量在品种间无显著差异.与对照相比,干旱处理对产量的影响在品种间差异显著,最终产量降低幅度为京农科728 (15.47％)＜登海618 (17.62％)＜农华101 (21.83％) ＜MC703 (26.20％)＜郑单958 (27.41％)＜联创808(27.30％).

Background Limited research on waxy maize yield and commercial value in response to water-limited (WL) stress and its interactions with plant density (PD) in the field. Methods: in this study, we examined the effects on two water treatments the water-limited group, and the well-watered (WW) group at one location (Fangshan, China) for fresh waxy maize hybrid URN 2000), and three plant densities (3.75, 5.25, and 6.75 plants m(-2)) in 2017 and 2018 using a block design split randomly in the field. Results: fresh waxy maize ear yield, grain yield, and yield components were affected for all treatments after WL stress lasted more than 9 d at the jointing stage. Compared with the WW treatment, WL treatment significantly decreased the fresh ear yield by 4.95%, due to decreasing ear length in waxy maize. In contrast, fresh grain yield significantly reduced by 3.75%, largely because of decreasing kernel weight and numbers per ear. The optimal PD of fresh ear yield was 6.75 plants m(-2). Conclusions: across all plant densities, WW treatment significantly increased the ear length distribution percentage by 19.19%, which effectively expand the commercial value of fresh ears of waxy maize. We concluded that waxy maize yield and commercial value of single-ear could be enhanced by the application of WW treatment at the jointing stage under field conditions.

对北京产的4种甜玉米BMB 380、昊白甜452、京白甜456、京双甜461的蛋白质、氨基酸、脂肪酸、维生素C、叶酸、矿物元素及重金属含量进行分析,并对其营养价值进行评价.4种甜玉米每100g干物质含蛋白质12.08％、脂肪酸6.40％、可溶性糖68.4％、维生素C 73.2mg、叶酸385.1 μg、钙39.9 mg、硒112.5 μg,显著高于普通玉米、大米、面粉;含有人体必需的8种氨基酸以及婴儿必需的组氨酸和精氨酸,AAS值非常接近婴儿标准模式,与成人模式比大于1;不饱和脂肪酸占77.1％,ω-3脂肪酸占1.67％,比例合理,属于优质脂肪酸;每天吃200～400g鲜玉米粒可以满足成人对叶酸的需要,有助预防胎儿神经管缺陷.这4种甜玉米每百克铅、砷最高含量分别为3.10、1.45μg,远低于国家限量.鲜食甜玉米中色氨酸含量低,与一些色氨酸含量高的食物搭配食用更益于健康.

鲜食玉米是指具有甜、糯品质和独特风味的一类专用鲜嫩玉米,在乳熟末期或蜡熟初期进行采收.与普通籽粒玉米相比,鲜食玉米具有甜、糯、嫩、香等特点.鲜食玉米根据食用特点划分为甜玉米和糯玉米.高品质甜玉米色泽光鲜靓丽,口感甜爽脆嫩,皮薄且无渣,可生食.糯玉米口感香粘软滑,风味俱佳,商品性好.甜加糯玉米既有甜玉米的清新甜脆,又有糯玉米的香粘软滑.

京白甜452是北京市农业技术推广站和北京保民种业有限公司培育出的甜玉米新品种,于2019年通过北京审定,审定编号为京审玉20190012.通过对该品种的特征特性及主要栽培技术进行介绍,为其在北京及周边地区的大面积推广及生产应用提供技术支持.

北京市农业技术推广站联合北京保民种业有限公司以自交系BMC90102为母本、自交系BMA000102为父本杂交选育的甜玉米新品种京白甜456,于2019年通过北京市农作物品种审定委员会审定(京审玉20190010).京白甜456是为鲜穗鲜食和真空鲜穗加工市场选育的兼用型纯白色品种,具有品质较好、含糖高、种皮薄、残渣少、果穗均匀、鲜穗产量高、稳产性和商品性好等优点.适宜在北京及周边地区种植生产,具有较好的应用前景,可给种植户带来较好的经济效益.

以6个普通玉米品种为材料,在京郊大田条件下,采用裂区区组设计,分析干旱胁迫对不同基因型玉米产量及其构成因素的影响.结果 表明,干旱胁迫显著影响了玉米产量(P＜0.01)、穗数(P＜0.05)、穗粒数(P＜0.05)和千粒重(P＜0.05),干旱胁迫对6个参试玉米品种产量影响存在显著差异(P＜0.05),其最终产量降低幅度为京农科728＜郑单958＜农华101＜MC703＜联创808＜登海618,其相应基因型穗数、穗粒数、千粒重等穗部性状与产量降低的趋势一致.

2014～ 2016年在北京密云区和延庆区开展4个点次7组机械粒收试验.结果表明,破碎率均值为8.81％,高于《玉米收获机械技术条件(GB/T 21962-2008)》中规定子粒破碎率应≤5％的标准;杂质率均值为1.25％,总损失率为1.10％,分别低于≤3％和≤5％的国标标准.延迟10d收获,供试6个品种玉米子粒含水率均值由25.9％降低到20.9％,下降了5个百分点,玉米收获质量得到显著改善,其中破碎率由5.71％下降到3.68％,降低了2.03个百分点.按双向平均作图法筛选出宁玉524,MC703,真金8号,登海9号和联创808等5个适宜机械粒收候选品种,其子粒含水率平均为23.27％,较对照郑单958低4.71个百分点;平均单产1 4921.7 kg/hm2,较郑单958对照高出14.87％.

通过在北京设置3点重复试验,对春播10个甜玉米新品种的形态产量和品质指标开展试验研究,结果表明:甜玉米产量与株高呈极显著正相关性,与子粒可溶性糖含量呈显著负相关性.子粒含水量与除皮的薄厚外其他品鉴指标均呈正相关关系,可溶性糖含量与除色泽外其他品鉴指标均呈正相关关系,种皮穿刺强度与除色泽外其他品鉴指标均呈显著正相关关系.筛选品种中万甜2015、双甜316鲜穗产量较高,京双甜461、美珍208、美珍206、京科甜608、京白甜456、斯达甜221品质较好.

随着人民生活水平的不断提高,鲜食玉米越来越受到城乡居民的青睐.但是鲜食玉米品质独特,易受多种害虫的危害.该文介绍了北京地区鲜食玉米主要害虫的发生特点,并提出了其防治技术.

一、北京市鲜食玉米现状 玉米是北京市第一大粮食作物,常年种植面积超过6.67万公顷.其中,2003-2007年鲜食玉米播种面积增长最快,从1300公顷发展到了8000公顷.2008年以后,因种植业结构调整的需要,鲜食玉米随着玉米播种面积减少也逐年减少,近几年基本维持在大约2000公顷.

出苗期为玉米在生产中第一个水分需求的关键时期,该时期缺水将直接导致种子发芽率降低、出苗率下降,造成缺苗、断垄,甚至绝产.根据本试验研究结果,模拟干旱胁迫下,玉米的芽期抗旱性与多种指标的关系,通过建立灰色关联度体系,10个测定指标与综合抗旱指数的关联度从大到小的顺序为胚根长、发芽指数、发芽势、胚根/胚芽比、发芽率、胚根干重、生物量、活力指数、胚芽干重、胚芽长;而通过计算各品种抗旱度量值可知,6个品种抗旱性排序依次为京农科728、MC703、郑单958、登海618、农华101和联创808.

本试验以植株繁茂性较好的联科96和中单28号为试料,设3个密度处理,分别为3 000株/亩、4 500株/亩和6 000株/亩.化学调控采用6叶期叶面喷施膦酸胆碱合剂处理(设清水为对照),研究化学调控对不同密度下春玉米抗倒伏性的影响及产量变化.试验结果表明,6叶期叶面喷施膦酸胆碱合剂可以缩短穗下部节间的长度,有效增加密植群体下春玉米的穗长,降低秃尖长,增加穗粒数,显著增加高密度条件下春玉米千粒重,改善春玉米穗部性状.同时通过降低玉米株高和稳位高,极显著增加茎秆单位长度干物重,增大截面积,改善玉米茎秆性状,显著增加春玉米田间致倒伏推力,从而降低倒伏发生的几率,实现密植群体丰产性和抗倒伏性的协同表达.