2,4-滴丙酸对苹果树采前落果的控制与果实贮藏的效应

以90%2,4-DP结晶体、2,4,5-TP粉剂、10.8%2,4-DPNa,29%2,4-DPN(C_2H_2OH)_3配平平加乳化剂,稀释成所需浓度(清水对照含有相同浓度的平平加乳化剂),在果实采收前对新红星和元帅苹果进行全树喷布。结果表明,新红星在采前12、20、27天喷布20ppm2,4-DP或20ppm2,4,5-TP对控制采前落果有显著效果,都能显著的推迟采前落果时间、明显的减轻采前落果强度,对采收单果重和果实贮藏品质无不良影响,对果实贮藏中的合计损耗率有减少趋势。元帅在采前21天喷布一次20ppm2,4-DP,也显著的控制了采前落果,不影响单果重和果实品质,但同期喷布一次相同浓度的2,4-DPN(C_2H_2OH)_3或2,4-DPNa,则对控制采前落果无显著效果。2,4-DP可以用来代替2,4,5-TP作为苹果树的控制采前落果剂使用。     

Effect of 3,5,6-trichloro-2-pyridyl-oxyacetic acid on fruitlet abscission and yield of ‘Mauritius’ litchi (Litchi chinensis Sonn.)

Summary

‘Mauritius’, the main cultivar in Israel’s litchi industry, tends to suffer from massive fruitlet drop. Recently, spraying ‘Mauritius’ trees with 2,4,5-TP at the ca. 2 g fruitlet stage was shown to improve greatly productivity due to a reduction in fruitlet drop. Here we examine another synthetic auxin, 3,5,6-trichloro-2-pyridyl-oxyacetic acid (3,5,6-TPA), used in the commercial product Maxim^®. We found it to be as effective as 2,4,5-TP in reducing ‘Mauritius’ fruitlet drop. In seven commercial-scale trials, spraying with 25 or 50 ppm 3,5,6-TPA consistently and significantly increased ‘Mauritius’ yields relative to non-sprayed controls.Therefore 3,5,6-TPA is recommended for routine use in ‘Mauritius’ orchards.     

Natural fruit drop and induced abscission to facilitate mechanical harvesting of Manzanillo and Souri olives

The natural drop of olive fruit, before harvest, in relation to stages of fruit development, was studied in Manzanillo olives. The absolute amount of green and half-black fruit drop was rather constant for most of the studied period. The drop of black fruit increased constantly with the advancement of maturation on both an absolute and relative basis.In studying the effect of various halogenated acetic acids on the abscission induction of Manzanillo and Souri olives, no consecutive order of activity could be found. Dichloroacetate (DCA) and monoiodoacetate (MIA) showed the highest activity. A pretreatment of Manzanillo olives with 2,4,5-chlorophenoxypropionic acid (2,4,5-TP) and chlormequat (CCC) did not affect the efficiency of various abscission-inducing chemicals.Large-scale mechanical harvesting trials with the Souri variety showed a mean increase of fruit drop up to 26% when agents such as glycerin, MIA and 2-chloroethane phosphonic acid (CEPA) were used over a period of three seasons.     

Carbaryl as a Fruit Thinning Agent

The results are presented of fruit thinning studies carried out over several years with the apple varieties Laxton’s Superb and Worcester Pearmain.

The thinning activity of carbaryl was negligible at 0·0028% a.i. but increased rapidly over the range 0·0083% to 0·075%. Comparatively little additional thinning resulted from a further increase in concentration.

In Worcester Pearmain thinning was stimulated by applications of carbaryl over a 4–5 week period from petal fall, the cessation of thinning activity coinciding with the end of the main period of natural fruitlet shedding. The intensity of thinning was greatest at petal fall and declined with delay in application. This decline was not continuous but showed two intervals of 7 to 13 days duration during which the intensity of thinning remained relatively constant. Up to 12 days elapsed between application and the commencement of induced fruitlet shedding.

Carbaryl was found to thin within, rather than between, fruitlet clusters, and to stimulate the abscission of lateral fruitlets more than terminal ones.

The growth of young fruitlets was retarded for a short period following the application of carbaryl, but as a result of thinning the size of mature fruit was increased. In the year after treatment increased blossoming and cropping was most marked with biennial trees of Laxton’s Superb. With regularly cropping trees of Worcester Pearmain, although thinning induced a moderate increase in subsequent blossoming, no residual effects on cropping were detected.     

Shedding of the upper parts of grapevine shoots

Shedding of the upper parts of unlignified grapevine (Vitis vinifera L.) canes is frequent during autumn. Stress conditions during the growing-season lead to similar shedding of shoot tips. The separation process occurs above a node in the boundary area between the distal part of the diaphragm and the pith.Ethephon (2-chloroethyl-phosphonic acid) sprays, at 750 or 1500 mg l^?1, induced separation of the shoot tips of ‘Perlette’ and ‘Queen of the Vineyards’. Ethylene (C₂H₄) 200 vpm and ethephon at 10, 100 and 1000 mg l^?1 enhanced separation in shoot explants, whereas 2,4,5-TP (2,4,5-trichlorophenoxy-propionic acid) at concentrations above 1 mg l^?1 arrested it.This phenomenon may be regarded as a shoot abscission process which may represent adaptation of self-pruning of the grapevine.     

生长抑制剂对美味猕猴桃幼树控长促花及其核酸、蛋白质代谢的影响

1983—1986年在美味猕猴桃幼树上进行了喷布生长抑制剂试验。结果表明:猕猴桃幼树在新梢生长前期(5月上旬～5月下旬)喷布2000～3000ppmB9 1—2次.1000～1500ppmCEPA 2次、2000ppmPP3332次以及2000ppmB9+500ppm CEPA 2次,2000ppmPP333+600ppmCEPA 2次,均能有效地控制营养生长.促进花芽分化.其中两个混喷处理控长促 花尤为显著.喷布生长抑制剂后,叶内总核酸、DNA、RNA、蛋白质的含量增加,表明生长抑制剂促进了核酸、蛋白质的生物合成.这样可使叶部的核酸代谢活化,影响遗传信息的表达,调节和推动生理代谢过程,促进成花基因的活化,从而显示出促进花芽的效果.     

Pre-harvest drop control of ‘Red Delicious’ and ‘Jonathan’ apple (Malus domestica) as affected by the synthetic auxin 3,5,6-TPA

Summary

‘Red Delicious’, the main apple cultivar grown in Israel, and ‘Jonathan’, grown on a smaller scale, are prone to substantial pre-harvest drop. Spraying both cultivars with the synthetic auxin 3,5,6-trichloro-2-pyridyl-oxyacetic acid (3,5,6-TPA) reduced pre-harvest fruit drop and increased yield. Application of 40 mg l^–1 3,5,6-TPA 2 weeks before anticipated harvest (WBH), or 30 mg l^–1 3,5,6-TPA at 4 and 2 WBH gave the best results, and were as effective as 2,4,5-trichloro-phenoxypropionic acid (2,4,5-TP) which was the commercial product commonly in use until being withdrawn. There were no negative effects on fruit quality at harvest, or during 8 months of storage. Therefore 3,5,6-TPA can be recommended for routine use on ‘Red Delicious’ and ‘Jonathan’ apples in Israel.     

Inter-Relations of Growth and Cropping in Apple Trees Studied by the Method of Component Analysis

Pomological records taken on Cox’s Orange Pippin and Worcester Pearmain were converted to new variates by the method of component analysis. The new variates, which were the weighted sums of the old, were expressions of physiological characteristics such as vigour, fruitfulness (or intensity of cropping) and apical dominance. A study of the new variates showed that vigour was correlated from year to year, but the correlation decayed with time ; in particular, nursery vigour was little associated with field vigour. A nursery expression of apical dominance was found to be largely associated with nursery position and did not influence later growth and cropping. Later fruitfulness, which showed a tendency to biennial behaviour, was positively correlated with early vigour and negatively related to early severity of pruning. A further variate was determined chiefly by fruit set ; it was associated with field position and with both fruitfulness and fruit set in the previous year.     

The relationship between different spray combinations of certain fungicides with calcium nitrate and the incidence of bitter pit and fungal diseases of apple

Two apple cultivars, Cox’s Orange Pippin and Worcester Pearmain, were sprayed at high volume for scab control in two seasons with either captan or thiram, with dinocap to control mildew. On Worcester, it was confirmed that thiram reduced crop and increased fruit russet and bitter pit incidence; the proportion of misshapen fruits was also increased. On Cox, thiram reduced crop number, without any compensatory increase in weight, and provided inferior scab control as well as increasing fruit russet.

The application of commercial calcium nitrate (C.C.N.) four times between mid-June and mid-August led to a considerable reduction in the incidence of bitter pit and storage rots in fruits from trees sprayed with captan and dinocap; it also partially offset the greater incidence of bitter pit associated with thiram treatments. In contrast to this, the application of a similar total amount of calcium, either in the form of a standard lime sulphur programme or by adding C.C.N, to the organic fungicide programmes for scab control, i.e. from April to mid-July, failed to reduce the incidence of bitter pit on either cultivar. Neither C.C.N, programme affected cropping, fruit russeting or scab control on either cultivar.

The ratio of potassium to calcium was higher in leaves and fruits from Worcester trees receiving thiram than in those from trees receiving captan; the application of C.C.N, in the summer reduced this ratio in fruits from trees receiving captan but not in those from trees receiving thiram, although it reduced the incidence of bitter pit associated with both fungicide programmes.

Results on Cox show that fungicide deposition and control of scab were independent of fungicide formulation and of the presence or absence of C.C.N. ; mildew control was not affected when C.C.N, was applied as the recommended summer programme.     

Investigations on the use of (2-chloroethyl) phosphonic acid (ethephon,CEPA) for the control of biennial bearing in mango

Biennial bearing is a serious economic problem facing mango growers. In the past it has been attributed to the lack of new growth and insufficient carbohydrate and nitrogenous reserves following a year of heavy cropping. The results of our studies conducted over a period of 4 years have shown that ethephon (200 ppm) could be used to induce heavy flowering and fruiting during the “off year” in the notedly biennial bearing cv. ‘Langra’. The spray applications of ethephon should be started during September and continued four to five times at 15–20 days interval. Higher concentrations of ethephon, viz. 500, 1000 and 2000 ppm, induced moderate to heavy leaf abscission in the experimental trees. Consecutive applications of 200 ppm ethephon for a period of 3 years did not show any decline in the vigour and yielding ability of the treated ‘Langra’ mango trees.     

Pruning Trials With Worcester Pearmain Apple

Three pruning treatments were compared on Worcester Pearmain on M.IV rootstock, viz.: open-centre tree, established-spur pruned; delayed open-centre tree, established-spur pruned; regulated pruned tree. In the fifteenth year secondary treatments were begun, the trees being pruned either annually or in alternate years, with and without fruit thinning by hand. The trees were grubbed after 21 years and scion weights were obtained.

There were no important differences in growth and cropping between open-centre and delayed open-centre trees. Regulated trees had an 11% smaller area of branch spread than established-spur pruned trees at 21 years. At 15 years there was no significant difference between treatments in total weight of prunings, but three times as much old wood as new had been removed from regulated trees compared with two and a half times as much new wood as old from established-spur pruned trees. During a 6-year period, the same weight of wood was removed from alternate-year pruned trees as from those pruned annually.

During the first 10 years regulated trees yielded twice as much fruit as did established-spur pruned ones, and 49% more during the second 10-year period. In many years, in the absence of fruit thinning, regulated trees bore smaller fruits than did established-spur pruned trees. Regulated trees had more red colour on the fruits than established-spur pruned trees, and alternate-year pruning, whether regulated or established-spur, gave more red colour on the fruits than did annual pruning, especially in seasons following no pruning. Alternate-year pruning had no harmful effect upon fruit size. Fruit thinning had no important effect upon red colour but it increased the percentage crop weight in the larger size grades, especially on established-spur pruned trees. The regulated method is well suited to the growth habit of Worcester provided that the fruit is thinned by hand or chemical spray in years of heavy setting.

The relative ratios between total crop : scion weight and crop 15–21 years : scion weight, were similar; scion weights were twice as heavy as weights of prunings.     

Observations on the control of the stem nematode Ditylenchus dipsaci of tulips with hot-water or thionazin treatment

Stem nematode (Ditylenchus dipsaci (Kühn) Filipjev) was controlled by either hot-water or thionazin treatment of lifted tulip bulbs, but some nematodes survived all the treatments. Hot-water treatment at 115 °F (46.1 °C) for one hour was less damaging to the bulbs than treatment at lower temperatures for longer periods of time, and treatment in July was less harmful than treatment in September; but the growth, of all except the most tolerant cultivars was checked so severely that the method would have only a limited use in commercial tulip production. Dipping the bulbs in the normal strength of thionazin, 2300 ppm, or in double this strength (4600 ppm), had no adverse effect on growth and flowering during the year after treatment, and the performance of bulbs treated in July or September was similar.     

Collection time,cutting age,IBA and putrescine effects on root formation in Corylus avellana L. cuttings

The effects of collection time, cutting age, indole-3-butyric acid (IBA) and putrescine application on the rooting of cuttings of Italian hazelnut cultivars ‘Tonda Gentile Romana’, ‘Tonda di Giffoni’ and ‘Nocchione’ were investigated. Samples collected during late June, late July and early September from newly formed and 1-year old part of twigs to be utilized to produce leafy cuttings, after being treated with 1000 and 2000 ppm IBA, respectively. In addition, the September cuttings were also treated, respectively, with 1000 and 2000 ppm IBA and 1600 ppm putrescine. Rooting ability was evaluated 2 months after planting for each treatment and collection time. Satisfactory rooting of hazelnut leafy cuttings was observed when collection time occurred in June and September, whereas leafy cuttings collected in July showed a limited capacity of rooting in all cultivars tested. On average, the rooting of the newly formed leafy cuttings was more than the 1-year old cuttings. Rooting was also promoted by IBA treatments, mainly in ‘Nocchione’ and ‘Tonda di Giffoni’. In contrast, young cuttings collected from ‘Tonda Gentile Romana’ in early September rooted poorly when treated with IBA alone, but showed the best rooting (∼80%) after the application of a combination of 1000 ppm IBA and 1600 ppm putrescine. The current findings confirm that putrescine can be a useful substance for increasing rooting percentage and root quality in cuttings of some hazelnut cultivars as obtained from ‘Tonda Gentile Romana’ cultivar.     

Bitter Rot of Apples: II. Seasonal Variations in The Development and Sporulation of Cankers of Gloeosporium SPP. Inoculated into Apple Branches

Two-year-old potted trees of Cox’s Orange Pippin, Laxton’s Superb and Worcester Pearmain were grown in controlled environment chambers at Long Ashton during 1960 and 1961, and subjected to four types of winter temperatures : 1, a long, cold winter ; 2, a severe autumn and mild spring ; 3, a mild autumn and severe spring ; 4, a short, mild winter ; 5, natural winter.

The order of bud break was treatment 2 followed by 4, then I and lastly 3. The time of bud break was more strongly influenced by the date of winter chilling than by its intensity, but the intensity influenced the temperature at which bud break became possible. On I-year-old wood the number of leafy rosettes developing increased with the length of the chilling period.

Because of limitation of space and the consequent small number of trees used, no firm conclusions could be drawn, but flower bud production and rate of spur development from bud break to full bloom appeared to be favoured by a mild autumn. An early and severe autumn apparently increased flower bud abscission at green cluster, but no effect of treatments could be determined in the final yields of fruit.     

Effects of NAA and Carbaryl on Fruit Set and Return Bloom for Some Apple (Malus domestica Borkh.) Cultivars

Abstract

This research was conducted in 1997 and 1998 to investigate the effects of naphthalene acetic acid (NAA) (5, 10, and 15 ppm), Carbaryl (1-naphthyl N-methylcarbamate) (750, 1000, and 1250 ppm), and NAA + Carbaryl (5 + 750, 7.5 + 750, and 10 + 750 ppm) applications on the return bloom of some standard apple (Malus domestica Borkh.) cultivars grafted on MM106 rootstock. Of these applications, 750 ppm Carbaryl for ‘Starkspur Golden Delicious’, 1250 ppm Carbaryl for ‘Granny Smith’ and ‘Starkrimson Delicious’, and 5 ppm NAA for ‘Jonagold’ increased the mean number of flower buds significantly, compared with the control treatments. The other treatments of Carbaryl, NAA, and NAA + Carbaryl also increased the mean number of flower buds in a nonsignificant sense with a few exception. A negative correlation between the final fruit set and the mean number of next year's flower buds was found for three cultivars. The correlation coefficients were r = ?0.5150 (P< 0.05), r = ? 0.6999 (P< 0.05), r = ?0.0335 for ‘Starkspur Golden Delicious’, ‘Granny Smith’, and ‘Jonagold’ cultivars, respectively. However, this relationship was positive and nonsignificant for ‘Starkrimson Delicious’ (r = 0.1980).     

The Effect of Summer Nitrogen Applications on The Quality of Apple Blossom

A summer application of nitrogen was used to induce the production of “ strong ” flowers for comparison with the " normal ” flowers produced on trees of Worcester Pearmain given only a spring application of nitrogen.

The flowers were given various pollination treatments to provide material for an assessment of flower quality. These included the following : auto and alio self-pollination and cross-pollination with diploid apple or pear at anthesis, cross-pollinations and self-pollinations at additional daily intervals subsequent to anthesis.

The stigmas of strong flowers remained receptive for a longer period than those of normal flowers.

After cross-pollination with a diploid apple, fertilization took place in 6-7 days. After self-pollination a typical incompatibility reaction was apparent. Pear pollen tubes showed an intermediate response.

Egg sacs in strong flowers continued to enlarge after those of corresponding normal flowers had ceased to grow. The fertilized ovules and embryo sacs of strong flowers showed a more rapid acceleration in growth rate than those of normal flowers.

Cell division in unfertilized ovules also continued for a longer period in strong flowers and appeared to be correlated with the behaviour of the egg sac.

Ovule longevity provided the most striking difference between the two flower types. The ovules of strong flowers remained capable of fertilization for almost twice as long as those of normal flowers.

Abnormalities of several types were seen in ovules. The most common was the production of secondary egg sacs, a feature of strong flowers which had been self-pollinated. Three types of secondary sac, micropylar, lateral and chalazal are described and illustrated.

The effects of rate of pollen tube growth, ovule longevity and the period of stigma receptivity in limiting the effective pollination period, are discussed. It is suggested that some variations in fruit set may be due to differences in flower quality. The use of summer or early autumn nitrogen is advocated as a method of improving blossom quality in certain varieties.     

Vegetative and floral bud abortion in cucumber plants: Hormonal and environmental effects

The acropetal, zonal pattern of axillary buds along the main shoot of the cucumber plant, which includes bare nodes (no appreciable development), staminate, mixed and, lastly, pistillate (or hermaphrodite) ones, is described in monoecious, gynoecious, andromonoecious and hermaphrodite genotypic lines grown at various seasons and treated with gibberellin (GA_{4 + 7}) or with an ethylene-releasing compound (CEPA, 2-chloroethyl phosphonic acid).Under optimal growing-conditions, GA given to gynoecious and hermaphrodite plants mimicked summer conditions by increasing the number of basal bare nodes and the proportion of abortive female buds and staminate buds. CEPA given to monoecious and andromonoecious plants generally imitated winter conditions by decreasing the proportion of bare and abortive nodes, and increasing female tendency.Bud abortion was also noticed under sub-optimal growing-conditions (low light intensities and relatively low temperatures) during the winter. This seems to be physiologically unrelated to the above mentioned phenomena.     

Chemical Defoliation of Nursery Stock. I. Initial Experiments with Fruit Tree Material

Both 50 000 ppm FeEDTA and 1000 ppm N252 (2, 3-dihydro-5,6-dimethyl-l,4-dithiin-1,1,4,4-tetroxide) effectively defoliated Cox’s Orange Pippin and Golden Delicious maiden apple trees on M.9 rootstock when applied in mid-September. Defoliation of MM. 104 apple rootstocks by 30 000 ppm FeEDTA was enhanced by pretreatment with 3000 ppm MH, and defoliation of Quince A rootstocks by 30 000 ppm FeEDTA, 250 ppm N252 or 750 ppm ethephon with 13 500 ppm urea was enhanced by prior treatment with 3 000 ppm butralin.