不同刈割周期、留茬高度对4种柱花草属牧草产量的影响

利用正交试验研究了不同刈割周期、留茬高度对4种柱花草属牧草产草量的影响。试验表明,草种和刈割周期对草产量的影响显著,留茬高度对草产量影响不大,各因素对草产量的影响为：RA＞RC＞RB,即品系＞刈割周期＞留茬高度。极差分析得出各因素的最优水平为：A2品系,GC1581柱花草; B4留茬高度,40 cm;C2刈割周期,60 d。     

植株刈割对马铃薯块茎形成的影响

刈割是一种重要的农艺措施,不同程度的刈割对于马铃薯生长产生的影响不同。试验采用随机区组设计,探索刈割时期及频次、刈割高度对马铃薯产量、块茎大小分布的影响。在幼苗末期或块茎形成期刈割一次,刈割茎叶程度分别为植株高度1/3或1/4,对马铃薯产量无影响,在幼苗末期和块茎形成期刈割2次会造成马铃薯显著减产。刈割处理会明显增加小薯（<50 g）个数,块茎形成期刈割1/3比例与CK（常规种植）相比显著增加20～50 g单株块茎个数,除幼苗末期刈割1/4比例、幼苗末期刈割1/4+块茎形成期刈割1/4比例2个处理外,其他6个刈割处理与CK相比均显著增加小于20 g单株块茎个数。在幼苗末期或块茎形成期刈割1次,与CK相比单株地上部生物量差异不显著,说明在马铃薯生育前期进行适当刈割补偿效应明显。综上所述,马铃薯幼苗末期或块茎形成期刈割1次,对马铃薯产量无影响,但能增加小薯的数量及重量,有利于马铃薯种薯生产。     

头季稻刈割时间对饲草产量、品质和再生稻产量的影响

为研究头季水稻的刈割时间对青贮饲草产量、品质和再生稻产量的影响,以黄华占、渝香203和渝香优8133为材料开展大田试验,设置头季稻倒4叶期、倒2叶期和齐穗期3个刈割时间处理,分析各处理头季稻饲草产量、青贮饲草营养化学和饲用品质及再生季水稻产量表现。结果表明,头季全株青贮饲草产量和干饲草产量随刈割时间推迟呈显著增加趋势,至齐穗期达到最大值,各品种饲草产量由高到低分别为渝香优8133、渝香203、黄华占。推迟刈割时间,黄华占体外干物质消化率显著降低,而渝香203和渝香优8133呈增加趋势,至齐穗期达到51.3%～52.7%。推迟刈割时间,头季饲草粗蛋白含量呈降低趋势,中性洗涤纤维和酸性洗涤纤维含量先增加后降低,灰分含量呈增加趋势。再生稻产量表现为倒4叶期刈割处理最高,齐穗期刈割处理最低,各品种产量表现为渝香优8133>渝香203>黄华占。综上所述,如以收获再生稻稻谷为主,头季稻宜在倒4叶期刈割,如以提高饲草—再生稻两季总体效益为目标,头季稻宜在齐穗期刈割。     

几个决明属牧草在亚热带丘陵红壤的个体与群体生长特性

从引进的40个决明属牧草品系中选出代表性品系观测其生长表现,结果表明决明品种均表现为出苗率低、出苗时间长、种子成熟度低,营养含量差异较小。个体与群体生长研究结果表明,ATF2228品系为匍匐型、早熟品种,生物量低;ATF2217和ATF2219为直立型、中早熟品种,种子产量高、生物量大、再生能力较差,适于1年1次刈割利用;CPI92985的品种特性与CPI34721相类似,都是半匍匐型、中早熟品种,但CPI92985的生物量、种子产量、茎叶营养含量及刈割后再生能力好于CPI34721;CPI86134和CPI86172为半匍匐型、迟熟品种,冠高和生物量均大于CPI92985和CPI34721。另外,施肥可以显著提高CPI86134的生物产量和刈后再生能力,达到1年3～4次刈割利用,值得进一步研究。     

刈割高度对多花黑麦草新品种产量和品质的影响

为探讨不同刈割高度对多花黑麦草新品种饲草产量和品质的影响,以2个多花黑麦草新品种为对象,采用5个刈割高度分别测定2个品种的鲜、干草产量、粗蛋白、可溶性碳水化合物(WSC)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)和干物质体外可消化率(IVDMD)。结果表明:在65 cm时刈割,所获得的鲜、干草产量最高;随着刈割高度的增加,2个黑麦草品种的粗蛋白和可溶性碳水化合物含量呈抛物线趋势变化,在刈割高度为55 cm时达到最高值;中性和酸性洗涤纤维含量则随着刈割高度的增大逐渐增加;干物质体外消化率亦呈现抛物线的趋势,在刈割高度为65 cm时达到最高。2个品种的表现规律一致。     

刈割期对多棱饲料大麦饲草及籽粒产量与品质的影响

为探明大麦饲草与籽粒双收的适宜刈割期,以六棱皮大麦皖饲麦2号为材料,设不刈割(T0)及分蘖期(T1)、拔节期(T2)、孕穗期(T3)分别进行一次刈割4个处理,比较了两年度不同刈割期大麦饲草、籽粒产量及品质的差异。结果表明,随刈割期后移,皖饲麦2号饲草产量显著增加;饲草粗蛋白、粗灰分、钙、磷含量显著下降,粗纤维、酸性洗涤纤维、中性洗涤纤维含量显著增加,即饲草品质显著下降。籽粒产量受刈割期影响大,与T0相比,两年度T1期刈割籽粒产量无显著变化,T2、T3期刈割则籽粒产量显著下降;而品质受影响小。说明T1期刈割,可达到饲草与籽粒双收目标,且饲草品质好;在生产中要保障一定的籽粒产量,T2期后应停止刈割。     

豆科牧草绿肥圆叶决明、羽叶决明在闽东的再生性研究

通过对9个圆叶决明、羽叶决明品种(系)的再生性能进行观测，及对5个圆叶决明、羽叶决明品种(系)进行收割试验得出：9个品种(系)的再生植株处理的长势、产量和种子产量均好于种子自然落地萌发植株的处理：92985、34721品种(系)表现出较强的综合再生能力和耐割(牧)能力；刈割植株时，留茬高度应控制在20cm以上。     

基于CRISPR/Cas9技术创制木薯MeSTP7和MeSTP15双基因突变体

木薯(Manihot esculenta Crantz)是一种热带、亚热带重要的粮食与能源作物,提高木薯的产量对木薯产业发展至关重要.木薯块根的发育直接影响其产量情况,而不同逆境胁迫会影响木薯块根的发育情况.因此解析木薯块根的发育机制有助于通过分子育种手段实现木薯高产,以及获得具备一定抗逆品质的优良种质,增强木薯的适应...     

大麦茎、叶、穗对饲草产量及品质的影响

为探明大麦不同组织（茎、叶和穗）在不同刈割期对饲草产量及品质的影响,以安徽省两个主栽饲用大麦品种为材料,比较了两年度两个品种茎、叶和穗分别在齐穗期及其后14 d和28 d饲草产量及品质的差异。结果显示,不同组织、刈割期及组织×刈割期互作效应对饲草产量及品质均有显著影响(P<0.05),年度效应主要影响产量,其他互作效应因品种和性状不同而异。饲草产量随刈割期后移增加,对其贡献表现为茎﹥穗﹥叶,第2年度高于第1年度。饲草品质性状在组织间和刈割期间存在显著差异,而在年度间仅在单个品种若干性状上存在差异;粗蛋白含量表现为穗﹥叶﹥茎,且随刈割期后移下降;粗纤维、酸性洗涤纤维、中性洗涤纤维和酸性洗涤木质素含量均为茎﹥叶﹥穗,且随刈割期后移前3个性状先降后升,酸性洗涤木质素含量持续上升;粗脂肪含量为叶﹥穗﹥茎,且随刈割期后移上升。综上,在株高相当时,增加穗部比例可提高大麦饲草产量和品质;刈割期后移可提升饲草产量但降低品质。基于本研究,选育大穗、多叶型品种,适期刈割,有望同步提升大麦饲草产量和品质。     

刈割对玉米生长发育及产量的影响

2016年以郑单958和先玉335为研究对象,研究不同叶龄期刈割对玉米生长发育及产量的响应。2017年以相对耐密品种郑单958为研究对象,研究增密刈割的产量效应。结果表明,不同叶龄期刈割影响玉米生长发育,随刈割时间的延后对玉米影响越大,表现为抽雄、吐丝时间推迟,郑单958抽雄时间推迟2～8 d,吐丝期推迟3～6 d;先玉335抽雄时间推迟2～8 d,吐丝期推迟4～8 d。株高和穗位高降低,穗位高系数和茎秆长粗比降低。绿叶数目减少,叶面积下降。两个品种单穗重较对照分别降低4.6%～21.7%和1.4%～24.5%,穗粒数3叶龄期刈割最高,其他处理穗粒数较对照降低。产量降低,以3叶期刈割减产幅度最小,5叶期在1叶位刈割基本全部死亡,6叶以后刈割叶位提高至4叶以上但减产幅度较大,且较对照产量差异达显著水平。随着刈割密度的增加,产量性状呈下降趋势,产量较对照先降低后增加,密度达到1.08万株/hm~2时,产量与对照相当;密度达到1.2万株/hm~2时,产量较对照提高7.3%,增加密度可弥补刈割对产量的影响。     

Leaf retention and cassava productivity

Increased longevity of leaves, or improved leaf retention, has been suggested as a possible means to increase productivity of cassava (Manihot esculenta Crantz). This study evaluated variation in leaf retention and its relation to cassava productivity under irrigated and stressed conditions. In the first trial 1350 clones were evaluated on the North Coast of Colombia with a 5-month dry period towards the end of the growth cycle. Clones with the leaf retention trait produced more total fresh biomass and yielded 33% more root dry matter than plants without the trait. In the irrigated trial 110 clones were evaluated on the CIAT farm at about 1000 mamsl. Leaf retention was quantified using a 1–5 visual score with five corresponding to excellent leaf retention. Genetic correlations between leaf retention and fresh foliage production (0.49), root dry matter yield (0.46), fresh root production (0.43) and root dry matter content (0.25) were obtained. Increased root yield under stressed and unstressed conditions was associated with increased total biomass production and increased harvest index. These finding concur with the results of cassava growth models that include leaf longevity as a variable. The lack of any negative genetic correlations between leaf retention and useful agronomic traits coupled with the relatively high genetic correlation for root yield and the high heritability (0.55) for leaf retention indicate that it should be relatively easy and advantageous to incorporate this characteristic in breeding and selection programs directed to increasing root yield under both water stressed and unstressed conditions.     

干旱条件下不同种茎材料对木薯成活率及产量性状的影响

在干旱条件下,比较4种不同种茎材料对木薯成活率、农艺及产量性状的影响。结果表明：成活率(survival rate,SR)呈现SR1年生种茎(100.0%)＞SR2年生种茎(92.2%)＞SR60 d嫩茎(78.9%)＞SR老茎头(30.0%);鲜薯和薯干产量(root yield,RY)呈现RY1年生种茎＞RY60 d嫩茎＞RY老茎头＞RY2年生种茎;淀粉产量(starch yield,SY)呈现SY60 d嫩茎＞SY1年生种茎＞SY老茎头＞SY2年生种茎;薯干率和鲜薯淀粉含量呈现老茎头＞60 d嫩茎＞2年生种茎＞1年生种茎,且植株密度越小,则薯干率和鲜薯淀粉含量越高。     

木薯//大豆间距对间作作物农艺性状及品质的影响

木薯间作短期作物是常见的栽培模式之一,本文以木薯南植199和大豆华春8号为试验材料,在不同间距处理下,记录和测定作物的农艺性状和品质,试图了解间作距离对其的影响,为两种作物合理配置获得高产高效提供理论和技术依据。结果显示:间距处理对大豆的有效分枝数、主茎节数和木薯的株高具有显著影响,而对两种作物的其它农艺性状无显著影响。当间作间距为D30时,大豆蛋白质、粗脂肪和3种脂肪酸含量显著提高,木薯淀粉含量高于其它处理,但低于单作木薯。此外,间距处理对木薯的单株产量有影响显著,单作和D50间距处理的木薯单株产量高于其它处理,但对大豆的单株产量无显著影响。结果表明D30的间距间作模式下,木薯和大豆的品质性状具有优势,而D50的间距间作模式下,木薯和大豆的产量性状具有优势。     

Effects of Non-flooded Cultivation with Straw Mulching on Rice Agronomic Traits and Water Use Efficiency

Rice (Oryza sativa) is one of the main foodstuffs of Chinese people. More than 30% crop field is used for rice cultivation in China. It provides 45% of crop yields in our country. However, the production of irrigated rice requires considerable water, up t…     

覆草旱作对水稻主要农艺性状的影响及节水效应

为减小南方季节性干旱对水稻生长的影响,提高水分利用效率,于2003年在江西省余江县进行了水稻覆盖旱作的田间试验。大田条件下对比研究了裸地旱作、稻草覆盖旱作和常规水作下水稻大田生长期内的水分利用效率和作物主要农艺性状。结果表明,常规水作处理的灌溉水总量分别是裸地旱作和稻草覆盖旱作灌水量的2.42 和3.31倍。旱作处理下水稻的淹水时间明显减少,只有常规淹水处理的1/10左右。由于淹水时间的减少,水分渗漏量和田面蒸发损失也大大降低。旱作条件下,稻草覆盖旱作的水稻分蘖数、叶面积、根系生长明显优于裸地旱作。覆盖旱作产量最高可达6 747 kg/hm2,接近于常规水作对照的6 811.5 kg/hm2,两者无显著差异。而裸地旱作处理的水稻产量仅为4 716 kg/ hm2,显著低于常规水作和稻草覆盖旱作处理。水分利用效率和灌溉水利用效率均为稻草覆盖旱作>裸地旱作>常规水作。     

长期施肥对木薯农艺性状、鲜薯产量和淀粉质量分数的影响

1992—2003年12a间，对2个木薯品种(华南205和华南124)，进行氮、磷、钾和火烧土等4种肥料各4个不同施肥水平组成共16个施肥配方的试验，研究了长期施肥对木薯农艺性状、鲜薯产量和淀粉质量分数的影响。结果表明：淀粉质量分数与收获指数呈显著正相关，鲜薯产量与株高、茎径及单株结薯数呈极显著正相关，单株结薯数与株高、茎径呈极显著正相关，株高与茎径呈极显著正相关。并列出它们的相关回归方程。推荐木薯最佳N，P2O5，K2O的施肥质量配比为2～4：1：2～4，其中，N，P2O5，K2O的施肥质量配比在连作初期以2：1：2为佳，而连作后期则以逐渐过度为4：1：4为佳。     

株行距和施肥量对木薯产量及生长的影响

采用裂区试验设计方法,研究株行距和施肥量对华南5号木薯产量和生长的影响.结果表明:在本试验株行距和施肥量条件下,施肥量对木薯产量和生长的影响比株行距大.密植(0.6～0.8 m)有利于提高淀粉产量、鲜薯产量和鲜薯淀粉含量,以0.8m株行距最佳,而疏植(1.2～1.4m)有利于提高单株薯数、单株鲜薯重、单株鲜茎叶重、收获指数和茎径.施肥有利于提高淀粉产量、鲜薯产量、单株鲜薯重、单株鲜茎叶重、茎径、株高和单株薯数,但降低鲜薯淀粉含量和收获指数.丰产栽培技术要兼顾单位面积株数、单株鲜薯重和鲜薯淀粉含量.建议在土壤肥力差和少施肥时,用0.6 m株行距;土壤肥力中等且较高施肥时.采用0.8 m株行距;土壤肥力中上且优越水肥管理,采用1.0 m株行距.     

Application of infrared thermography to assess cassava physiology under water deficit condition

ABSTRACT

Water deficit stress is a major factor that inhibits the overall growth and development in cassava (Manihot esculenta), leading to decreased storage root yield. We conducted a study to investigate whether thermal sensing could be used to indicate water deficit stress and the health and yield of cassava crops in field. The objective of the study was to use thermal imaging to determine relationship between crop water stress index (CWSI) and physiological changes, and to identify the critical CWSI point in fields of cassava cv. Rayong 9 under well-irrigated and water-deficit conditions. At the time of storage root initiation (85 DAP [day after planting]), thermal imagery was collected and the physiological changes and growth characters were measured prior to storage root harvesting (162 DAP). Thermal infrared imager was used to measure the canopy temperature and CWSI of cassava plants. Net photosynthetic rate (P_n), stomatal conductance (g_s) and transpiration rates (T_r) of cassava plants under water deficit conditions for 29 d (114 DAP) were significantly decreased, leading to delayed plant growth as compared to those under well-irrigated conditions. In contrast, air vapor pressure deficit (VPD_air) and CWSI in drought-stressed plants were higher than well irrigated plants. High correlations between T_r/g_s/P_n and CWSI were observed. The study concludes that CWSI is a sensitive indicator of water deficit stress caused due to stomatal function.

Abbreviations: CWSI: crop water stress index; DAP: day after planting; Pn: net photosynthetic rate; gs: stomatal conductance; Tr: transpiration rate; VPDair: air vapor pressure; RMSE: root mean square error     

Intercropping of cassava (Manihot esculenta) with maize or cowpea under different row arrangements

The effects of various intercropping arrangements of cassava (Manihot esculenta Crantz) and maize (Zea mays L.) or cowpeas (Vigna unguiculata L. Walp) on crop yields were compared over a 3-year period in Nigeria, in an attempt to improve grain yields of the maize and cowpea intercrops without substantially reducing the cassava root yield. Sole-cropped cassava produced the largest yield; this was significantly reduced by about 40% when intercropped with maize or cowpeas but only when using a 1:2 (cassava:intercrop) row arrangement, mainly because of a reduction in its population density. Cassava yield differences among different row arrangements were more marked when grown with maize than with cowpeas. Maize and cowpea grain yields were reduced by intercropping, but somewhat less so when grown with cassava in widely spaced rows. Cassava row spacing did not affect maize yield, but cowpea yield was affected significantly. Land Equivalent Ratios were always greater than 1, irrespective of the crop combinations and row arrangements. However, increased yields of intercropped cassava:maize were obtained at 1:1 or 2:2 row arrangements and of cassava:cowpea at 2:2 rows, without much reduction in cassava tuber yield.