Effect of Gibberellic Acid Spray during Ontogeny of Mustard on Growth, Nutrient Uptake and Yield Characteristics

In a field trial conducted during 1993–1994, mustard ( Brassica juncea L. Czern & Coss.) cv. Varuna was sprayed with either deionised water or 10⁻⁵ M GA₃ at 40 (vegetative stage), 60 (flowering stage) or 80 (pod fill stage) days after sowing (DAS) to select the suitable growth stage for spray for augmenting productivity of the crop. Shoot length per plant, leaf number per plant, leaf area per plant, dry weight per plant and leaf area index and accumulation of N, P and K were recorded at 100 DAS. Pods per plant, seeds per pod, 1000 seed weight, seed yield, biological yield, harvest index and seed yield merit were computed at harvest. Growth, NPK accumulation and yield were maximal when spraying was done at 40 DAS. However, spraying at 40 and 60 DAS gave at par values for most of the growth and yield parameters. It was also noted that there was a significant difference in spray treatment at different growth stages only when G A, was sprayed and not when water was sprayed.     

缩节胺和矮壮素对燕麦生长发育和产量的调控效应

为研究燕麦的抗倒伏特性,提高燕麦产量,以燕麦品种冀张莜7号为试验材料,以喷等量清水为对照（CK）,拔节前选择晴朗无风天气叶面喷施不同浓度的缩节胺（2.0、2.5、3.0和3.5mL/L）和矮壮素（2.0、4.0、6.0和8.0mL/L）进行化控处理试验,探讨不同浓度的缩节胺和矮壮素对燕麦生长发育的调控作用及对产量的影响。结果表明：喷施缩节胺和矮壮素均能降低燕麦株高,增加茎粗,提高茎秆中全钾和可溶性糖含量,增强抗倒伏能力,提高产量。喷施3.5mL/L缩节胺的增产效果最好,比CK增加34.94%;喷施4.0mL/L的矮壮素增产效果最好,比CK增加20.95%,且喷施缩节胺的效果优于矮壮素。     

Growth and development of bambara groundnut (Vigna subterranea) in response to soil moisture: 1. Dry matter and yield

The effect of drought on the growth and development of bambara groundnut (Vigna subterranea (L.) Verdc.) was studied in controlled-environment glasshouses in the UK. There were three landraces (S19-3, DipC and UN from Namibia, Botswana and Swaziland, respectively) and two watering regimes; a control that was irrigated weekly to 90% field capacity and a drought treatment with no irrigation from 49 days after sowing (DAS) until final harvest (147 DAS). Bambara groundnut responded to drought by reducing the rate of leaf area expansion, final canopy size and total dry matter (TDM) during vegetative growth. Drought also caused significant reductions in pod dry matter (PDM), pod number, seed weight and harvest index (HI), leading to a decrease in final pod yield that was different between landraces. Across landraces, drought reduced mean pod yield from 298 g m⁻² to 165 g m⁻², representing 45% yield loss. Despite the reduction in all landraces, the mean pod yield across the droughted treatments that had received no water for almost 100 days indicated the resilience of the species to drought. The three landraces differed in their phenology; S19-3 exhibited a reduced phenology while UN maintained the longest life cycle. The different responses of the landraces reflect their adaptation to their local climates where mean annual rainfall ranges between 365 mm (Namibia) and 1390 mm (Swaziland). We discuss the significance of these results for future breeding programmes on bambara groundnut.     

Effect of combined indole acetic acid and mepiquat chloride on endogenous gibberellins and tuber growth in Chinese yam (Dioscorea opposita Thunb.)

The combined effect of indole-3-acetic acid and mepiquat chloride on the endogenous gibberellins of aerial and underground tubers as well as tuber yield was studied on Chinese yam plant. Two plant hormones were combined in the following concentrations: IAA 50, 100, 200, and 300 ppm, plus MC 600 ppm. Combined plant hormones were foliar-sprayed once in early July. Exogenously applied IAA combining mepiquat chloride increased fresh weight of the aerial and underground tubers affecting the increase of endogenous gibberellins. The results suggest that IAA is likely to be one of the active plant hormones responsible for aerial tuber growth and enlargement, stimulating the promotion of endogenous gibberellin when combined with mepiquat chloride.     

Sulphur and Micronutrient Nutrition of Groundnut in a Calcareous Soil

Field experiments conducted on a calcareous soil have shown that application of elemental sulphur reduced the chlorosis of groundnut leaves and increased the dry matter, nodule biomass, pod, haulms, and oil yields, and concentration of nutrients in leaf tissue and their uptake by groundnut. The application of iron (Fe), zinc (Zn) and manganese (Mn) further helped in recovering the chlorosis of groundnut and increased the above parameters. On average, application of 20 kg S ha⁻¹ as elemental sulphur (S) increased pod yield by 8.6–9.8% and oil yield by 8.8–15%. However, application of 10, 2, and 4 kg ha⁻¹ of Fe, Zn and Mn, increased pods by 19.5, 13.6, and 11.7% and oil yield by 20.1, 13.9 and 12.2%, respectively.     

Effect of CCC on the Growth and Yield of Mung Bean (Vigna radiata [L.] Wilczek var. Guj-2)

Pot experiments were conducted on mung bean by spraying 500, 1000 and 1500 ppm CCC, 14 days after the emergence of seedlings. Results showed that:
CCC application at 1000 and 1500 ppm led to stem shortening.
Dry weight of shoot system, leaf area, leaf thickness and total chlorophyll content were significantly increased by 1000 ppm CCC.
CCC at 1000 ppm increased amylase and invertase activity in the leaf tissue.
CCC at 1000 ppm increased the pod number/plant, seed number/pod, leading to increased seed yield/plant.
CCC had no effect on the 1000 seed weight.     

Effect of GA, CCC and B-9 on Morphophysiological Characters and Yield of Kidney Beans (Phaseolus vulgaris L.)

A pot and 2 successive seasons field experiments were conducted on bean, by spraying 25,50 or 100 ppm GA, 100, 250 or 500 ppm of either CCC or B-9, one month after sowing. Results showed that:
GA induced stem elongation and thinning through cell elongation and decrease of both of ground tissue cell-size and vascular cylinder cell layers in the stem. On the other hand, CCC and B-9 led to stem shortening and thickening, as a consequence of increased number of cell layers leading to widening the vascular cylinder of the stem.
Leaf area was much more increased by CCC and B-9 than by GA.
GA increased amylase activity and had no effect on invertase, meanwhile CCC and B-9 mostly decreased the former's and increased the latter's enzyme activity, 30 days after spraying.
GA and CCC increased number of seeds/pod, while B-9 had no effect on this character.
CCC and B-9 increased pod number/plant, specific seed weight, leading to increment of seed yield/plant, while GA had no effect on these characters.     

3种植物生长调节剂对花生的光合生理及产量品质的影响

为了探明花生在化学调控作用下的产量、品质变化及与之相关的光合作用机理。比较研究了初花期喷施矮壮素、缩节胺和结荚初期喷施多效唑对花生的化学调控效应。结果表明：3种植物生长调节剂均可矮化植株,增加茎粗、有效分枝数及结果数,提高花生叶片的叶绿素含量和光合速率,并在结荚期降低叶片的蒸腾速率,最终达到提高花生产量和改善花生品质的目的。其中,多效唑对增加花生叶绿素含量、降低蒸腾速率、增加产量和粗蛋白含量的调控效果最好,其产量和蛋白质含量分别比对照增加了9.0%和7.8%;而缩节胺对提高花生的光合速率调控效果最佳,其光合速率比对照增加了25.0%;矮壮素最利于改善花生的亚油酸含量,其亚油酸含量比对照增加了6.4%。综合考虑花生的产量品质和光合生理效应,多效唑对花生的化学调控增产效应最好,其次为缩节胺处理。     

Evaluation of Genetic Traits for Improving Productivity and Adaptation of Groundnut to Climate Change in India

Anticipated climate change will alter the temperature and rainfall characteristics of crop growing seasons. This will require genetic improvement of crops for adapting to future climates for higher yields. The CROPGRO model for groundnut was used to evaluate genetic traits of Virginia and Spanish types of groundnut for various climate scenarios of India. The analysis revealed that productivity of groundnut can be increased in current and future climates by adjusting the duration of various life‐cycle phases, especially the seed‐filling to physiological maturity (SD‐PM). Increased maximum leaf photosynthesis rate (AMAX), increased partitioning to reproductive organs (XFRT) and increased individual seed‐fill duration (SFDUR) all contributed to the increase in pod yield in all climates. More determinate pod set (shorter PODUR) was beneficial only in the water deficit environments. The positive effect of increasing specific leaf area (SLA) and leaf size (SIZLF) on pod yield was greater in environments more favourable for plant growth. Increasing reproductive tolerance to high temperature by 2 °C increased pod yield of groundnut in warmer environments, especially where the crop often suffers from drought. Increased adaptive partitioning to roots (ATOP) increased drought resistance of groundnut on high water‐holding capacity soils. Combination of traits had additive effects and pod yield increased substantially. These results indicate that the CROPGRO model can be used to assess the potential of individual or combination of plant traits for guiding breeding of improved groundnut varieties for current and future climates.     

Correlation Studies on Ammonium/Nitrate Concentrations in Soil and Growth and Yield of Wheat

A field experiment was conducted at the Indian Agricultural Research Institute, New Delhi to study the growth and yield of wheat as influenced by the concentrations of ammonium-N and nitrate-N in soil. A series of ammonium and nitrate nitrogen concentrations in soil on a time frame was developed by treating prilled urea with nitrification inhibitors DCD or neem cake as well as by changing the dose and time of N application. The study revealed that number of tillers m^-1 as well as ears m^-1 row length were significantly positively correlated with ammonium-N concentration at 15 and 30 DAS and nitrate-N concentration at 30 and 45 DAS. Number of grains ear^-1 was significantly positively correlated with ammonium-N at 30, 45 and 60 DAS and nitrate-N at 45 and 60 DAS. Ultimately grain yield in wheat was significantly positively correlated with ammonium-N concentration at 15 and 30 DAS and nitrate-N concentration at 30, 45 and 60 DAS. The response between grain yield and concentrations of both ammonium and nitrate forms of N was quadratic. The optimum concentration of ammonium-N in soil for maximum grain yield gradually decreased with the age of the crop from 54.6 to 63.6 μg g^-1 at 15 DAS to 22.7 to 26 μg g^-1 at 30 DAS. In the case of nitrate-N its optimum concentration for maximum grain yield increased with age of the crop from 25.1 to 30 μg g^-1 at 15 DAS to 31.6 to 34 at 45 DAS and it decreased thereafter.     

Response of Mustard to Ethrel Spray and Basal and Foliar Application of Nitrogen

In a field trial conducted during 1992–93 and 1993–94, the effect of basal (B) nitrogen (N) (45 and 60 kg N ha⁻¹) and foliar application (F) of water (W) or 10 kg N ha⁻¹ and 400 or 600 ppm ethrel (E) (2-Chloro ethyl phosphonic acid) at 70 days after sowing was studied on leaf area index and dry mass at 90 days and pod number per plant, seeds per pod, 1000 seed weight, seed yield, oil content and oil vield at harvest of mustard ( Brassica juncea L. Czern & Coss.) cv. T-59. Recommended basal (B) application of 90 kg N ha (BN₉₀) was used as control. On the basis of 2 year data it was found that basal application of 60 kg N and foliar spray of 10 kg N ha ⁻¹ and 600 ppm ethrel gave higher values for growth and yield characteristics and enhanced seed yield and oil yield by 12.5 and 14.8%, respectively over control BN_90.     

Effect of Concentration of Seed Hardening Chemicals on Physiological Characters of Pearl Millet (Pennisetum typhoides Stapf and Hubb)

A laboratory study was taken up in the Department of Agronomy, Tamil Nadu Agricultural University, Coimbatore in the year 1986 to fix optimum concentration and to evaluate the efficiency of CCC (2-chloroethyl trimethyl ammonium chloride), succinic acid and sodium chloride as seed hardening chemicals for pearl millet. The study revealed that CCC 100 ppm, succinic acid 0.15 per cent and sodium chloride 1 per cent concentrations were better in improving the germination per cent, root : shoot ratio and vigour index of pearl millet.     

N-Dimethylamino Succinamic Acid (B-Nine) as a Potential Aid in Improvement of Medicago sativa L.

The influence of N-dimethylamino succinamic acid (B-nine) on lucerne plants cv. IGFRI-244 was investigated. B-nine (a growth regulant) was sprayed as a foliar sprays, employing 10, 100, 250, 500, 1000 and 5000 ppm alongwith water spray as control, and the effects were observed on plant growth, flowering, nutritive constituents and seed yield of the crop. Plant height was reduced from 6.19 to 26.85 % in various concentrations of B-nine being highest retardation in 5000 ppm, whereas 250 ppm produced more branches and leaves with dense foliage in comparison to control and other treatments. Delayed flowering by 2–15 days with significant increase in seed yield and 1000 seed weight B-nine bein maximum seed yield in 250 ppm. However, total seed yield was increased by 4.16 to 24.76 per cent over unsprayed control plants. Among the treated levels of B-nine, 250 ppm also gave higher values for Carbohydrate, IVTDMD in shoot of lucerne plants with considerable decreased in 5000 ppm. NDF condent decreased progressively with increased concentration of B-nine but always lesser than the value of IVTDMD.     

Assessment of Groundnut under Combined Heat and Drought Stress

In semi‐arid regions, particularly in the Sahel, water and high‐temperature stress are serious constraints for groundnut production. Understanding of combined effects of heat and drought on physiological traits, yield and its attributes is of special significance for improving groundnut productivity. Two hundred and sixty‐eight groundnut genotypes were evaluated in four trials under both intermittent drought and fully irrigated conditions, two of the trial being exposed to moderate temperature, while the two other trials were exposed to high temperature. The objectives were to analyse the component of the genetic variance and their interactions with water treatment, year and environment (temperature) for agronomic characteristics, to select genotypes with high pod yield under hot‐ and moderate‐temperature conditions, or both, and to identify traits conferring heat and/or drought tolerance. Strong effects of water treatment (Trt), genotype (G) and genotype‐by‐treatment (GxTrt) interaction were observed for pod yield (Py), haulm yield (Hy) and harvest index (HI). The pod yield decrease caused by drought stress was 72 % at high temperature and 55 % at moderate temperature. Pod yield under well‐watered (WW) conditions did not decrease under high‐temperature conditions. Haulm yield decrease caused by water stress (WS) was 34 % at high temperature and 42 % under moderate temperature. Haulm yield tended to increase under high temperature, especially in one season. A significant year effect and genotype‐by‐environment interaction (GxE) effect were also observed for the three traits under WW and WS treatments. The GGE biplots confirmed these large interactions and indicated that high yielding genotypes under moderate temperature were different to those at high temperature. However, several genotypes with relatively high yield across years and temperature environments could be identified under both WW and WS conditions. Correlation analysis between pod weight and traits measured during plant growth showed that the partition rate, that is, the proportion of dry matter partitioned into pods, was contributing in heat and drought tolerance and could be a reliable selection criterion for groundnut breeding programme. Groundnut sensitivity to high‐temperature stress was in part related to the sensitivity of reproduction.     

甲哌鎓化控对南疆杂交棉功能叶生理指标及产量性状的影响

在南疆气候生态条件下,设置6组不同甲哌鎓喷施次数,以兆丰1号和鲁棉研30号2个杂交棉品种为材料,研究植物生长调节剂甲哌鎓对杂交棉功能叶生理特性及产量性状的影响。结果表明:喷施甲哌鎓并未改变杂交棉主要生理指标的变化规律,但较对照明显提高了同期各指标值及峰值持续时间。系统喷施甲哌鎓3~4次使得棉花株型紧凑,成铃率高;LAI前期上升快,峰值高且持续期长,后期下降缓慢;功能叶SPAD值增大且后期下降缓慢,净光合速率(Pn)峰值高且持续时间长;可溶性糖含量(SS)与可溶性蛋白质含量(SP)明显增加;皮棉产量增产显著。     

Patterns of osmotic adjustment in pigeonpea — its importance as a mechanism of drought resistance

Osmotic adjustment (OA) is considered as an important physiological mechanism of drought adaptation in many crop plants. The present investigation was aimed at assessing the importance of OA in improving productivity under drought. Using two automated rain-out shelters, 26 extra-short-duration pigeonpea [Cajanus cajan (L.) Millsp.] genotypes were grown with irrigation during the growth period or with water deficit imposed from flowering until maturity. Mean leaf Ψs₁₀₀ (60–92 DAS) under drought correlated significantly (r²=0.72**; n=26) to the mean OA (60–92 DAS) and contributed 72% of the genotypic variation in OA. Significant genotypic variation was observed in the initiation of OA, the duration of OA and the degree of OA. Based on the measured OA at 72, 82, and 92 days after sowing (DAS), genotypes were grouped into five different clusters. Genotypic differences in total dry matter production under drought were positively associated with OA at 72 DAS (r²=0.36**, n=26). Significant positive relationship between OA at 72 DAS and grain yield under drought was found (r²=0.16*; n=26). However, OA towards the end of pod filling phase, i.e. at 92 DAS, had a significant negative relationship with grain yield under drought (r²=0.21*; n=26). Genotypic differences in grain yield under drought was best explained using stepwise multiple regression to account for differences in OA at 72, 82, and 92 DAS (r²=0.41**; n=78). The degree of OA at 72 and 82 DAS contributed positively to the grain yield, whereas OA at 92 DAS contributed negatively to this relationship.     

Growth and Yield of Peanut as Influenced by Degree and Duration of Shading

Peanuts ( Arachis hypogaea L.) which are commonly grown in intercropping systems often suffer from shading caused by the associated crop. Through this study an attempt has been made to estimate the effect of different levels of shade at different growth stages on crop yield. Field experiments were laid out during monsoon and winter seasons of 1985 and 1986 by creating artificial shading up to 25 and 50 per cent of the day/natural light at flowering-pegging, pod filling and maturity stages of a Spanish bunch type peanut. Dry matter production has shown linear response to light intensity and due to 50 per cent shading it was reduced by 55 per cent. Vegetative growth rate during pod filling stage was very poor as a result of increase in shading at this stage. In shaded plants the nodulation was less and some reduction in chlorophyll content was also observed. However, oil content in kernel was not affected by shading. Shading caused significant reduction in pod number and kernel weight and thus there was decrease in pod yield. Flowering to pegging and pod filling stages seemed to be sensitive to shading while increase in shading at maturity stage did not cause any reduction in yield. It could be possible to obtain about 90 per cent pod yield by avoiding shading during flowering to pegging stage (45 DAS).     

2种植物生长调节剂对马铃薯生长的影响

为了探讨马铃薯喷施生长调节剂的作用与使用方法,以马铃薯品种‘冀张薯8号’为材料,选用生长调节剂多效唑和矮壮素,在马铃薯现蕾期、开花期、淀粉积累期喷施,对叶绿素含量、株高、产量及大小薯等指标进行分析。结果表明,在马铃薯植株生长期内喷施多效唑和矮壮素都可有效降低株高、提高叶绿素含量和产量,开花期喷施株型合理,鲜薯总产量和大薯产量最高。所有处理和对照相比株高降幅在16.1%~43.4%之间,叶绿素含量SPAD值提高1.8%~36.5%,产量提高1.7%~35.57%。以50%矮壮素400倍液,多效唑675 g/hm2,在马铃薯开花期喷施,较不喷施的处理分别增产28.0%和35.57%。     

Physiological responses of chickpea genotypes to terminal drought in a Mediterranean-type environment

Two field experiments were carried out to investigate the effects of terminal drought on chickpea grown under water-limited conditions in the Mediterranean-climatic region of Western Australia. In the first experiment, five desi (small angular seeds) chickpeas and one kabuli (large round seeds) chickpea were grown in the field with and without irrigation after flowering. In the second experiment, two desi and two kabuli cultivars were grown in the field with either irrigation or under a rainout shelter during pod filling. Leaf water potential (Ψ_l), dry matter partitioning after pod set and yield components were measured in both experiments while growth before pod set, photosynthesis, pod water potential and leaf osmotic adjustment were measured in the first experiment only.

In the first experiment, total dry matter accumulation, water use, both in the pre- and post-podding phases, Ψ_l and photosynthesis did not vary among genotypes. In the rainfed plants, Ψ_l decreased below −3 MPa while photosynthesis decreased to about a tenth of its maximum at the start of seed filling. Osmotic adjustment varied significantly among genotypes. Although flowering commenced from about 100 days after sowing (DAS) in both experiments, pod set was delayed until 130–135 DAS in the first experiment, but started at 107 DAS in the second experiment. Water shortage reduced seed yield by 50 to 80%, due to a reduction in seed number and seed size. Apparent redistribution of stem and leaf dry matter during pod filling varied from 0 to 60% among genotypes, and suggests that this characteristic may be important for a high harvest index and seed yield in chickpea.     

黄瓜穴盘育苗株型化学调控技术及作用机理研究

采用基质表面喷施（即1次）、基质表面喷施+子叶展平时刚露心时叶面喷施（2次）及浸种3种处理方式,研究缩节胺、矮壮素、多效唑、乙烯利等4种植物生长调节剂不同浓度处理对夏季黄瓜幼苗生物学性状、生理指标及产量的影响。结果表明：DPC 400 mg/kg（2次）、PP333 20 mg/kg（1次）、CCC 400 mg/kg（2次）、浸种CEPA 5000 mg/kg 4种处理组合下胚轴相对对照明显缩短,有效控制了夏季黄瓜秧苗徒长。壮苗指数增加,根系活力提高,增加了干物质向根系的分配率,提高了秧苗质量。黄瓜叶片叶绿素含量及抗病相关酶PPO、POD、CAT活性增强,脯氨酸含量增加,增强了黄瓜的抗逆（病）性。