Biomass yield and accumulations of bioactive compounds in red amaranth (Amaranthus tricolor L.) grown under different colored shade polyethylene in spring season

Biomass yield and accumulations of betacyanin, chlorophyll, total polyphenol, and antioxidant activity were evaluated growing red amaranth (Amaranthus tricolor L.) in spring season under five different shades made of white, blue, green, yellow, and black polyethylene, and non-shaded frame. Temperature and light intensity varied significantly (P < 0.05) under the different colored polyethylene shades, and these differences in microclimate are implicated for the variability in growth and accumulations of bioactive compounds. The highest temperature was obtained under the blue polyethylene shade and the plants achieved highest plant height, stem length and leaf number, fresh and dry matter biomass, betacyanins, total polyphenol, and antioxidant activity. The achieved biomass yield and accumulation of bioactive compounds were almost similar to field grown red amaranth in summer season. Blue polyethylene shade has probably ensured the optimum microclimate for growth and development of red amaranth in the studied growing period. Exceptionally the plants grown under green polyethylene shade accumulated highest chlorophyll. Although non-shaded plants received highest sunlight intensity but gave the poor biomass yield as well as accumulated less bioactive compounds than plants grown under blue polyethylene shade due to low air temperature. Thus, the results indicated that blue polyethylene has potentials to increase the yield with health beneficiary bioactive compounds betacyanins, polyphenol and antioxidant activity during the low temperature regime in spring season.     

对开蕨对遮荫处理的响应

研究了全光和遮光30%、50%、70%、90%处理对对开蕨生长及光合生理特性的影响。结果表明:随着遮光强度的增大,对开蕨叶片面积、单位叶面积鲜质量、叶绿素含量、叶片含水量增加,可溶性糖含量、可溶性蛋白含量下降;净光合速率日变化呈双峰曲线,有光合"午休"现象;日平均净光合速率以遮光50%～70%处理为最佳;光补偿点逐渐降低;光饱和点在遮光50%处理下最高,遮光70%和90%处理下较低。综合考虑,对开蕨适宜的光环境为遮光50%～70%。     

Effect of shade regime on flower development,yield and quality in lisianthus

The effects of shading on lisianthus (Eustoma grandiflorum) floral transition, plant development, flower yield and quality, and content of starch and soluble sugars were assessed in three cultivars, over two consecutive years. Shading nets affording 67% or 88% reduction in light intensity, were fitted at planting in the greenhouse for periods ranging from 3 to 8 weeks. Meristem morphology at floral transition was characterized by apical meristem widening and the appearance of two bract primordia. Floral transition time was affected by cultivars, but in general, longer and heavier shade treatments delayed floral transition; the longest delay (6 weeks) being recorded in Mariachi White under 88% shade for 7 weeks or under a combined shade treatment of 88% for 3 weeks followed by 67% for 5 weeks. Despite interactions between cultivar and shade treatment, consistent trends were discerned: the heaviest and most prolonged shading reduced yield (up to 40%), cut stem length (up to 15%), and number of flower buds/stem (up to 26%), within cultivar. Total carbohydrates levels were very low, and it is questionable whether changes observed in carbohydrate quantity following shade treatments had any effect on plant growth or flower yield. Rather, it appears that lisianthus is very dependent on current photosynthesis, so that even a brief shading interlude could reduce branching and flower quality. It may be concluded that the intensive shading usually applied is detrimental for lisianthus.     

二月兰耐阴性的研究

用黑色遮阴网设置四种光强(全日照、全日照的33%、全日照的11%、全日照的3%),研究二月兰的耐阴性,结果表明:二月兰具有较典型阴生植物结构特点,其叶绿素含量随着光强降低而增加,叶绿素a/b则降低。二月兰对光照适应能力较强,全日照的3%下仍具有很高的观赏价值。但最适光照为全日照的33%。     

Effect of overhead shading on yield and fruit quality of kiwifruit (Actinidia deliciosa)

Summary

Kiwifruit vines (cv. Hayward) were shaded from early spring until fruit harvest at levels of 100% (control), 70% or 45% full sun. Although shoot growth during the early part of the season was not significantly affected by the shading, the percentage bud burst was reduced and the time of full bloom appeared to be slightly delayed. The mean fresh weight of individual fruits was significantly reduced by shading, and fruit on shaded vines reached commercial harvest maturity of 6.2% soluble solids two to three days later than those on unshaded vines. During cool storage, fruit from vines grown under 45% full sun were slightly but consistently less firm and had lower soluble solids concentrations than unshaded fruit. No differences in the starch or total sugar contents were found between shaded or unshaded fruit, either at harvest or after cool storage. Shading vines did not affect either the colour (HunterLab values) or the chlorophyll concentration of fruit. Possible implications of these results for commercial orchards are discussed.     

生姜光合效率日变化的研究

生姜生长期间,午间强光使叶片光合速率（Pn)、表观量子效率（AQY）及PSⅡ的光化学效率（Fv/Fm)下降,即表现为光抑制。苗期因光照强、温度高、AQY,Fv/Fm较低,光换制较重;随季节进展及光、温等条件的改善,光抑制减轻。对生姜遮荫可提高AQY和Fv/Fm,降低光抑制,但由于遮荫降低了羧化效率（CE）,使Pn明显下降。据此,对有关遮荫理论及AQY等指标的应用进行了讨论,并提出改革当前遮荫方式的设想。     

Bulbing responses of two cultivars of red tropical onions to photoperiod,light integral and temperature under controlled growth conditions

Summary

The effects of photoperiod, light intensity and temperature on bulb formation and bulb structure of two tropical onion cultivars were investigated. From an initial experiment it was observed that the number of true scales and sheath scales differed significantly between the cultivars ‘Red Creole’ and ‘Agrifound Dark Red’. When these two cultivars were given 11, 12 and 13 h photoperiod treatments, it was found that both cultivars needed at least 12 h photoperiod for bulb formation. Modify the R/FR ratio from 1.22 to 1.16 in the final hour of the 11 h light period did not induce bulbing. The 13 h photoperiod increased the number of true scales and decreased the number of sheath scales compared with the 12 h photoperiod in both cultivars but total scale + leaf sheath numbers remained nearly constant. When onion plants were grown under 0%, 25%, 50% and 75% shading treatments, (12 h photoperiod), only plants receiving 0% and 25% shading bulbed. Low light intensity decreased the number of true scales and increased the number of sheath scales. Four temperature regimes were compared in a growth room experiment. Plants under the 29°348C treatment bulbed within two weeks and matured within six weeks. However, plants receiving the 25°308C treatment delayed bulb initiation more than those plants receiving 17°228C and 21°268C treatments. At the lowest temperature, bigger bulbs with thick necks were produced. This may be due to changes in bulb structure since at low temperature, the number of sheath scales was increased, however the number of true scales remained relatively constant in both cultivars. Dormant leaf initials decreased with decreasing temperature while the number of secondary meristems significantly increased. The results suggest that ‘Red Creole’ was more responsive to shorter photoperiods, bulbing earlier than ‘Agrifound Dark Red’. There was no significant difference in time to bulbing in response to temperature between the two cultivars if measured by bulbing ratio however there were differences in bulb structure which suggested that ‘Red Creole’ bulbed earlier. These effects may be due to the breeding histories of the two cultivars. It is suggested that studying bulb structure may provide a useful method of interpreting onion bulbing responses.     

Influence of pre-planting applications of nitro-chalk,superphosphate, sheep manure and a fertilizer mixture,in factorial combination,on the growth of one-year-old peach trees

A field experiment was carried out with one-year-old peach trees to determine the influence of applications of nitro-chalk (N), superphosphate (P), sheep manure (SM), and a fertilizer mixture (X), in factorial combination, on tree growth during the first growing season. Fertilizers were mixed into the soil at planting sites about two weeks before tree planting.

Maximum tree growth was achieved when 3 lb. P and 36 lb. SM were applied per tree. However, all fertilizers depressed leaf bud development and early shoot growth and, in a few cases, application of 3 lb. N per tree resulted in tree death. It is concluded that heavy rates of these fertilizers should not be applied to planting sites prior to planting young peach trees. Rather, it appears from seasonal growth measurements that fertilizers should not be applied to newly planted trees until late spring (November).

The only consistent and significant interaction occurred between N and SM. Application of SM increased tree growth more in the absence of N than in its presence; i.e. the SM acted as a nitrogen source. SM depressed tree growth early in the growing season, probably because some of its components are readily soluble. However, later in the season it promoted growth and partly alleviated the detrimental effect on tree growth induced by 3 lb. N per tree. It is evident from calculated concentrations of elements per planting site that the SM treatment supplied larger quantities and a wider range of elements than the inorganic fertilizers.

In the absence of an N × SM interaction trees grew better if given nil or 1 lb. N than if they were given 3 lb. N. For some growth parameters, trees also grew significantly better if given 1 lb. N rather than nil.

Application of a fertilizer mixture containing potassium sulphate, magnesium carbonate, lime, ammonium molybdate, zinc sulphate, borax, Chel-138 iron chelate, and manganese sulphate to planting sites significantly depressed tree growth throughout the growing season, but this may have been due to molybdenum toxicity, although no visual symptoms were present.     

不同光照条件下两种卷柏光合特征日变化研究

以卷柏和圆枝卷柏为试材,研究其叶片在不同光照强度下(不遮光(对照CK:透光率100%)、单层遮光(透光率70%)、双层遮光(透光率50%)、三层遮光(透光率20%))的光合特性。结果表明:2种卷柏在不遮光与单层遮光条件下,净光合速率高于其它2种处理;卷柏净光合速率日变化为双峰曲线,具有明显的午休现象,而圆枝卷柏的午休现象不明显。从午休恢复程度看,卷柏对光照的适应性要广于圆枝卷柏。叶片叶绿素总含量及比叶质量的变化进一步证明了此论点。     

不同生育期弱光胁迫对番茄生长及产量的影响

于番茄的开花期、果实膨大期和果实绿熟期进行持续5周的50%自然光强的弱光处理。试验结果表明:果实绿熟期的弱光胁迫对植株干物重、各器官的物质分配率和果重影响程度最小,果实膨大期的弱光胁迫使番茄果重显著降低,而开花期弱光胁迫使坐果率和单果重显著下降,导致产量显著降低。因此,番茄对弱光的敏感程度依次为开花期>果实膨大期>果实绿熟期。     

The Effect of Rooting Date on Fruit Production in the Strawberry

The crops harvested from maiden plants of Redgauntlet, Cambridge Vigour and Cambridge Favourite, rooted at intervals from April to November, have been examined in detail. Total crop decreased with later rooting dates, but average berry weight increased. This is attributed to the initiation of potentially larger receptacles on the flowers, to a higher proportion of primary flowers and to better berry development on the later-rooted plants. Usually the heavier total yield of early-rooted runners was due to the production of greater numbers of smaller berries, which adversely affected the profitability of the crop.

The actual yield of the plants examined was only one half to two-thirds of the possible yield had all the flowers initiated produced full-sized berries. The shortfall has been examined and attributed to a serious failure of some flowers to produce berries of any sort, coupled with poor berry development resulting in the formation of fruits that were only two-thirds to four-fifths of their possible size. Fields for study are indicated that offer the prospect of substantial increases in yields.     

Berry yields of two Finnish sea buckthorn cultivars under organic farming methods

Summary

The effects of different organic farming methods on berry production by two Finnish sea buckthorn (Hippophae rhamnoides L. ssp. rhamnoides) cultivars, ‘Terhi’ and ‘Tytti’, were studied in field experiments over 4 years at Merikarvia, western Finland. Four organic fertilisers, five mulches, and two land contours were used. Two experiments were conducted. In the first, fertilisation experiment, the fully-crossed effects of four different fertilisers and two land contours were tested for both cultivars. In the second, mulch experiment, the fully-crossed effects of five different mulches and two land contours were tested for the cultivar ‘Tytti’. Some sea buckthorn bushes produced a small number of berries in the second growing season. According to the three-way interactions, the effect of fertiliser on yield depended on the land contour in ‘Terhi’, but not in ‘Tytti’. Apatite increased yields in bushes grown on flat land. Yields increased in the third and fourth growing seasons, when ‘Terhi’ produced larger berries and yields than ‘Tytti’. ‘Terhi’ had a higher yield on ridged beds than on flat land. Berry size was larger on ridged beds compared to flat land in both cultivars. The effect of mulch depended on the land contour in the second and fourth growing seasons. In the second growing season, straw mulch increased berry production on the flat land compared to the other mulches. In the fourth growing season, a plastic mulch increased yields compared to organic mulches. The results of this experiment provide information on ways to improve sea buckthorn berry yields when organic farming methods are used.     

Changes in anthocyanin synthesis as an index of maturity in red apple varieties

Changes in the regulation of anthocyanin accumulation may be useful for predicting maturity in Jonathan and other early to mid-season, red apple varieties. While the level of anthocyanin at a particular stage of maturity may be related to environmental factors, the capacity to accumulate anthocyanin is a function of maturity and independent of environmental influence.

Anthocyanin is degraded in immature fruit skin as rapidly as it is formed, giving an equilibrium level that is a function of the light intensity. When light intensity is reduced (by shading), the anthocyanin level falls in immature fruit skin but continues to rise in mature fruit skin. The transition from the immature to mature stages with respect to anthocyanin accumulation occurs rapidly and precedes the normal harvest date by about two to three weeks, suggesting that this attribute might be used in the prediction of maturity in suitable red apple varieties.     

The Effects of Light Intensity,Day Temperature and Water Supply on the Fruit-Ripening Disorders and Yield of two Varieties of Tomato

A study was made of the effects on fruit-ripening disorders and crop yield of shaded and unshaded glasshouses maintained at both high and low daytime temperatures (80° F. (26 ? 5° C.) and 65° F. (18 ? 3° C.)), in which were grown two varieties of tomatoes (Potentate and Ware Cross) at two levels of watering.

Shading the glasshouses reduced the proportion of non-uniformly coloured fruit at the high temperature. At the low temperature, shading reduced the proportion in i960 but there was no effect in 1959. Light watering reduced the proportion of non-uniformly coloured fruit in the first year but it had little effect in the second year. The variety Ware Cross bore approximately 10% fewer non-uniformly coloured fruit than did Potentate in both years.

Shading the glasshouses reduced yield in both years, the decrease being greater (62%) in the very dull year of i960 than it was (40%) in the very sunny year of 1959. The house at the low day temperature yielded a 30% greater weight of crop than the warmer house. In both years the heavily watered plants yielded more than the lightly watered plants because of an increase in mean fruit size. Potentate and Ware Cross yielded similar weights of crop in both years but Ware Cross bore more fruits and had a smaller mean fruit size.

The gross cash return obtained in 1960 was reduced by shading the glasshouses, by maintaining a high day temperature and by growing the variety Potentate as opposed to Ware Cross. The differences in the watering regimes employed had little effect on the cash return obtained.

By assuming that yield and quality have simple mathematical relations with degree of shading, the profitability of shading is discussed. It is shown that shading is not likely to be profitable.     

Flower greening in phytoplasma-infected Hydrangea macrophylla grown under different shading conditions

To determine the effect of light intensity on flower greening, the Japanese hydrangea phyllody (JHP) phytoplasma-infected hydrangea cultivars ‘Midori’, ‘Libelle’, ‘Rosea’ and ‘Madame E. Mouillere’ plants were grown under different shade conditions. In the first-year experiment, the results indicate that the flowers of the JHP-phytoplasma-infected hydrangea become green under shaded conditions (70% and 49% sunlight intensities). On the other hand, under full sunlight intensity (100% sunlight intensity), the flowers of ‘Midori’, ‘Rosea’, and ‘Libelle’ plants were blue, pink or white. To calculate the percentage of flower greening, inflorescences of these plants were separated and divided into individual flowers, and classified into four types by green-area ratio, calculated using Adobe Photoshop. Under shading with one sheet of cheesecloth (70% sunlight intensity), the inflorescences of ‘Midori’, ‘Libelle’ and ‘Madame E. Mouillere’ plants were composed of more than 40% completely green flowers (0.8 ≦ green-area ratio), whereas those of ‘Rosea’ plant had 0% completely green flowers. Under shading with two sheets of cheesecloth (49% sunlight intensity), the inflorescences of ‘Midori’, ‘Libelle’ and ‘Madame E. Mouillere’ plants had more than 75% completely green flowers; ‘Rosea’ plants had 28%. In the second-year experiment, under full sunlight intensity, ‘Midori’ plants had four types of flower depending on their green-area ratio, namely, completely blue or pink, pink-green, greenish and completely green flowers. Under shading with two sheets of cheesecloth, ‘Midori’ plants had more than 90% completely green flowers. The JHP-phytoplasma could not be identified by PCR analysis in flowers with a green-area ratio = 0 (completely blue/pink/white flowers). On the other hand, in flowers with a green-area ratio > 0, the JHP-phytoplasma was detected by PCR analysis. Thus, we conclude that shading enhances flower greening in hydrangea by increasing the JHP-phytoplasma concentration in the flowers.     

不同品种辣椒幼苗光合特性及弱光耐受性的差异

 在不同弱光处理条件下, 利用L I26400型便携式光合仪研究了弱光对4个辣椒品种幼苗光响应曲线、CO₂ 响应曲线等光合特性的影响, 结果表明弱光下辣椒的光补偿点(LCP) 、光饱和点(LSP) 、光饱和光合速率、CO₂ 补偿点(CCP) 、CO₂ 饱和点(CSP) 、暗呼吸速率(Rd ) 、羧化效率(CE) 、RuBP羧化酶活性、RuBP最大再生速率均下降, 表观量子效率(AQY) 上升, 并且弱光下辣椒净光合速率( Pn)的下降是RuBP羧化限制和再生限制的共同结果。另外随光照的减弱, 辣椒叶片叶绿素(Chl. ) 含量上升,叶绿素a /b比值(Chl. a /b) 和比叶重( SLM) 下降。弱光下LCP和Rd 相对较低、AQY和CE较高的辣椒品种可能具有耐弱光的优势。     

地面覆草对姜田小气候及生姜生长的影响

姜田地面覆草可显著增加土壤含水量,降低地温,提高空气相对湿度,但使气温稍升。尽管地面覆草未改变光强,但生姜长势与传统插草相似,因而最终产量未表现显著差异。地面覆草与插草的生姜长势及产量均极显著高于裸地     

The impact of changing light levels and fruit load on the pattern of tomato yields

Summary

Experiments in glasshouse and controlled environment facilities investigated the effect of different fruit removal and lighting/shading treatments on the pattern of tomato yields. While the removal of flowering trusses resulted in a yield loss about eight weeks later, there was little loss in cumulative yield as assimilates were distributed to neighbouring trusses. In the growth room experiment, increased photosynthetic photon flux density (PPFD) for one week resulted in a period of increased yield from 4–6 weeks after the start of the treatment, followed by suppressed yields due to smaller fruits on subsequent trusses. However, neither fruit load nor assimilate availability appeared to be responsible for the fluctuations in yield recorded within the glasshouse crop. In this experiment fruit size remained fairly consistent (except when fruit removal treatments were applied), whereas the number of fruits picked per week exhibited much greater variability. This was the case even when all trusses were pruned to leave five fruits, and so was not due to a cycle in the number of fruits set per truss. The flushes in yield were found to be a consequence of a hastening of fruit maturation.     

Screening of genotypes of menthol mint Mentha arvensis for high yields of herbage and essential oil under late cropping conditions of the sub-tropical Indo-Gangetic plains

Summary

The essential oil yields and expression of related characters were compared for seven cultivar genotypes of menthol mint Mentha arvensis using two methods of planting in the winter rabi – summer season (October to July) in a sub-tropical agroclimatic environment. The crops of all the cultivars were planted in the field by (1) sowing of suckers on 2 January and (2) transplanting germinated pieces of sucker at different times between 17 March to 14 April. Staggering of transplanting time up to 7 April did not affect oil yields and the related plant growth properties of mint crops. The oil yields of the crops planted on 14 April were lower by about 30%. In the early sucker planted crops, the oil yields were about 30% higher than those obtained from the transplanted crops of 17 March to 7 April and about double that obtained from crops transplanted on 14 April. The oil yields from the crops of the superior genotype Kosi were equal to or higher than the corresponding means of all genotypes under both planting methods. The oil yield from the crops of Kosi genotype obtained by sucker sowing method was estimated as 333 kg ha^–1. The corresponding average yield from the crops of this genotype obtained by transplanting of germinated suckers between 17 March and 7 April was about 293 kg ha^–1 and that from the crop transplanted on 14 April was 218 kg ha^–1. With the Kosi genotype, the latter two types of transplanted mint crops gave oil yields lower only by about 12% and 33% compared with the long-duration sucker-sown crop. It is concluded that a crop of mustard (brassica), Bengalgram (chickpea) or wheat sown between October and November and harvested between early March to middle of April could be taken before cropping of the Kosi genotype of M. arvensis by plantlet transplanting. These results demonstrate the potential of the following rotation of crops in the sub-tropical environments: from June/July/August to October/November (kharif cropping season), rice, maize, sorghum or pigeonpea; from November/December to February/March, mustard and Bengalgram or from November/December to April (rabi cropping season), wheat; from March/April to June/July (zaid cropping season), transplanted menthol mint.     

Optimum leaf area index in T-bar trained kiwifruit vines

Summary

The effect of leaf area index (LAI) on canopy growth, light interception, yield, fruit growth and quality and return bloom of kiwifruit were examined in 1990 and 1991. Different LAIs were obtained in the 1990 season with defoliation treatment made precociously at different intensities, in a diffuse way, uniformly in the whole canopy. At the end of canopy development LAIs of 3.6,3.3,3.1,2.6 and 1.8 were obtained and evaluated. The kiwifruit vines with a bud load of 680?700 and LAIs of 3.3 and 3.6 in 1990, showed an optimum and constant yield (>90 kg per vine), good average fruit weight (>100 g) and high fruit quality in both years, and also good return bloom the following season. The reduction of LAI to 2.6 and 1.8 drastically reduced, in the year of LAI imposition, both yield (?18.5% and ?30%, respectively) and mean fruit weight (?18.6% and ?29.1%, respectively) compared with vines with an LAI higher than 3.1. In the same treatments, the soluble solids concentration in the fruit was significantly decreased and a great reduction in numbers of fruiting shoots and numbers of fruits per fruiting shoot were observed in the year following the LAI imposition. In vines with the same bud load, fruit number and an LAI of 3.1, small variations in yield and fruit weight in the year of defoliation treatments were recorded, but in the following season the yield was significantly reduced (?14 kg per vine) due mainly to a decrease in the number of fruiting shoots (?14%). In kiwifruit vines with low LAI (2.6 and 1.8) nearly all fruits present in the canopy ripen, with no significant fruit drop. At low LAI, the sink strength of the fruit was greater and more extended so that vine growth and the plants reserves were restricted. Under the conditions of this experiment, an LAI higher than 3.3, corresponding to a leaf area-fruit ratio higher than 600 cm² per fruit, is necessary to obtain regular vine growth and yield, optimum fruit size and quality and return bloom the following season.