Fruit Set Moisture & Carbohydrates. HOS 6546 Spring 2012

Transcription

1 Fruit Set Moisture & Carbohydrates HOS 6546 Spring 2012

2 Koo, R.C.J Weather conditions, irrigation practices, and Valencia orange production. Cit. and Vegetable Mag. July;8-10, Study to look at nutrition in 150 groves, but found moisture an issue Further evaluated data for rainfall and irrigation effects

3 No strong N effect, particularly in Group B

4 Best yields in 60 inch rainfall years

5 Basis of soil moisture evaluation very low capacity

6 Relationship between water used per day and temperature

7 Gain in yield by irrigating groves could have other factors different

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9 Summary Detailed comparisons of benefit from spring irrigation on yield Little statistics No fruit numbers Not original intent

10 Koo, R.C.J. and D.P.H. Tucker Soil moisture distribution in citrus groves under drip irrigation. Proc. Fla. State Hort. Soc. 87:61-65 Introduction of drip irrigation raised issues about adequate coverage in sandy soils Worked well on other crops Tests to determine water spread and tree response

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12 Broader spread

13 Drip got good set but more was late bloom. A = 1 gal/hr, B = 1.2 g/h

14 Summary Emitter wet soil 2 to 5 ft from emitter depending on volume rate and soil Fruit set near that of microjets but more in late bloom Weak because of no statistics

15 Koo, R.C.J Response of densely planted Hamlin oranges on two rootstocks to low volume irrigation. Proc. Fla. State Hort. Soc. 91:8-10 Earlier work raised issues about low volume irrigation Questions about how much area needs to be watered Experiments set up to cover 0 to 80 % of area under canopy of Hamlin on rough lemon or sour orange rootstocks

16 Best trunk growth at % coverage

17 Increased lb solids/box and solids

18 Best yields in 2 or 3 years and % moisture coverage

19 Solids increased with more ground area irrigated

20 Summary Less than % ground irrigated resulted in less yield (and soluble solids) No statistics for per acre data

21 Barbera, G. and F. Carimi Effects of different levels of water stress on yield and quality of lemon trees. Proc. Internl. Soc. Citricuture 6 th Cong.; Growing lemons with Forzatura method resulted in some adverse problems with current crop loss Drought in early summer followed by irrigation stimulates second crop Heavy fruit drop of current crop observed Needed to adjust the drought period better Tested 7, 9, and 10 week periods of drought Measured leaf water potentials and crop responses

22 Leaf water potentials reached 2 MPa in 7 weeks, heavier soil and cooler (?) than Florida

23 Ten week period caused excessive drop of summer crop

24 Nine week drought improved yield in one year and 10 weeks decreased yields in 2 years

25 Ten week drought produced smaller fruit

26 Ten week drought increased drop in all 3 years, 9 weeks in two years over 7 weeks

27 Winter crop quality not affected

28 Summary Seven or 9 weeks provided adequate new crop with less adverse effects (drop and fruit quality) on current crop when compared to 10 weeks of drought Winter crop quality not as affected As Koo, did not consider partial replacement of ET with drip irrigation.

29 Abdel-Messih, M.N. and M.A. Elham Ghaly El-Nokrashy Effect of different soil moisture levels on growth, yield and quality of Washington Navel orange. Agr. Res. Rev. 55: Many reports of benefits from irrigation of citrus in other countries Set of levels to see what is best program for Egypt.

30 Control was near the most frequent irrigation frequency

31 Two frequent irrigation levels gave more growth for shoot length and veg. circumference.

32 B and C gave best % set and yield (LSD). Low irrigation (A) resulted in poor set

33 C gave best numerical fruit size and D next, but no stats

34 C best, but no statistics

35 C larger fruit, maybe diluted SS and acidity?

36 Similar to 1974 incorrect statistical method

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38 C best yield in 74, higher in 75

39 Summary Most frequent irrigation schedule (C) usually gave best results Two years not enough as 1 in 2 not different. May be using too much water Low irrigation resulted in poor set

40 Davies, F.S. and J. Bower Water stress, gas exchange and fruit set of Olinda valencia orange trees in eastern Transvaal area of South Africa. Acta Hort. 365: High temperatures can occur in this area of South Africa Irrigation rates tried to compensate for high deficits Expected that gas exchange might be adversely affected

41 Better set for leafy at low soil moisture tension Not for leafless, no statistics

42 CO2 higher at lower tension in morning and at fruit set period

43 Summary Drought increased fruit drop and CO2 assimilation tended to be lower also Stress of low water or low CO2 Data erratic and no statistics

44 Ginestar, C. and J.R. Castel Responses of young clementine citrus trees to water stress during different phenological periods. J. Hort. Sci. 71: Clementines do not set well (seedless production) Effects of low water availability on fruit development and yield at different periods of the year of interest where water is limited Various periods (early, mid or late) subjected to low water levels

45 Treatments

46 Water Stress Integral

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53 R-R - gave good fruit set

54 Acidity levels higher

55 Yield down with more integrated stress, But increased with ET increase? Also, temp up??

56 Summary Good irrigation in spring (bloom + fruit set) resulted in best set Very complex set of data Not all of data seemed logically

57 Brewer, R.F., K. Ortiz, F. Aljibury and K. Hench The effects of cooling by overhead sprinkling on June Drop of navel oranges in California. Proc. Intnl. Citriculture 1977, Vol 3: Washington Navel sheds excessive fruitlets under California conditions, particularly in San Joaquin Temperature or moisture stress effect Set up sprinkler system to apply fine mist of water intermittently into the canopy Evaluate fruit set

58 In 1971 fruit/tree and wt/tree increased by sprinkling, but in 1972 only the larger nozzles provided an increase, maybe since no statistics.

59 Reverse logic, if not significant from control it was labeled

60 Maybe soluble solids increased

61 Salts in water did cause rise in leaf content of Na and Cl, but not above critical level

62 Summary Intermittent sprinkling increased fruit set without any obvious adverse side effects Was it cooling or stopping excessive water loss? Poor use of statistics Attempts to repeat in Florida not too successful salt and disease problems

63 Jones, W.W., T.W. Embleton, M.L. Steinacker and C.B. Cree The effect of time of fruit harvest on fruiting and carbohydrate supply in the Valencia orange. Proc. Amer. Soc. Hort. Sci. 84: In California, bloom and fruit set of next crop occurs while current crop still on tree Crop remaining on tree with late harvest has adverse effect presumably by continuing to compete for carbohydrates and water Study to evaluate carbohydrate supply with later versus earlier harvest

64 Current crop = weight-size larger with later harvest although fruit numbers/carton decreased the remaining fruit were larger in 1961 harvests of current crop

65 Following year harvest was less if previous crop harvested late. Fruit were larger for later harvest previous year even if harvested later.

66 Total carbohydrates per leaf less if harvest was later, but not starch

67 Again less yield next year from late harvest because of reduced fruit numbers with slight reduction in fruit size.

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69 Summary Yield loss confirmed with major effect on next crop fruit numbers Presumed effect on set, but no flowers to set measured (reduced flowering Moss) Adequate statistics Carbohydrates, mostly soluble, were lower in leaves with later harvest

70 Hilgeman, R.H., J.A. Dunlap and F.O. Sharp Effect of time of harvest of Valencia oranges in Arizona on fruit grade and size and yield the following year. Proc. Amer. Soc. Hort. Sci. 90: Even though Valencia fruit in Arizona are harvested earlier than in California, there is still overlap of current crop and next crops flowering and young fruit development. Study repeats work in California Harvest dates examined for current and next crop effects

71 Alternate bearing with late (May) harvest greater and reversed if harvest dates reversed. Alternate bearing for both, line higher Feb.

72 Numerically, yields higher for February harvest. No statistics. Temperature effect hot period versus max. temperatures?

73 Fruit wt. per tree less for May harvest 4 of 8 yrs, twice reversed (1 sign.)

74 Only one of these 3 years with fewer fruit for late harvest, following high yield year. Fruit size less, soluble solids higher with late harvest (still accumulating as sink)

75 Summary Similar effect to California, but not as strong, maybe because harvest not as late Yield not reduced every year by late harvest Warmer winters resulting in better photosynthesis?

76 Hilgeman, R.H., J.A. Dunlap and G.C. Sharples Effect of time of harvest of Valencia oranges on leaf carbohydrate content and subsequent set of fruit. Proc. Amer. Soc. Hort. Sci. 90: Again following lead of California studies, determining if carbohydrate levels are primary reason for reduced set of next crop if current crop is harvested late Probably couldn t get published today

77 Late harvest did not reduce next years crop (# fruit) in 1963, but did in 1964 after heavier crop in 63 Weight of fruit per tree increased in 1963 (weight/fruit) with late harvest, but not in 1964

78 Soluble solids down, peak March-April; juice weight up; soluble solids per tree up with later harvest: Therefore fruit a continuing sink.

79 Starch down, dry matter down, total carbs down in leaves collected later and with later harvest. Two way difficult to follow, leaves change

80 June-July increases mature leaves and warmer temperatures?

81 Summary Generally carbohydrates were reduced with later harvest to a point but individual forms were not reduced as dramatically as in California Change in sampled leaves, net sinks to source leaves Higher temperatures increased Pn to overcome fruit sink Data in Figure very clear Last table hard to follow

82 Monselise, S.P., R. Goren and I. Wallerstein Girdling effects on orange fruit set and young fruit abscission. HortScience 7: Girdling at bloom time increased set Shamouti orange on sour orange in a heavy soil was tested and girdling helped This is a report of that work

83 Fruit number effect, not fruit weight

84 Early drop reduced, but later drop greater than control. Needed cumulative data that is presented in next table

85 Difficult to make a comparison since girdled trees averaged 6,000 less units. There were 4 trees of each treatment and SE look small, but no test of % of total data. As stands, small buds, fruitlets and fruit were conserved by girdling, but not pea-sized buds

86 Summary Girdling helped conserve flowers to fruit if applied at bloom Mechanism not provided From previous work suggest GA higher and causing response Girdling known to enhance carbohydrate levels but timing probably important to effect fruit set Not a balanced discussion

87 F. RIVAS,Y. ERNER, E.ALÓS2 M. JUAN,V.ALMELA and M.AGUSTÍ Girdling increases carbohydrate availability and fruit-set in citrus cultivars irrespective of parthenocarpic ability. Journal of Horticultural Science & Biotechnology (2006) 81 (2) Carbohydrate status plays a pivotal role in determining the fruit-setting capability of a tree by modulating its abscisic acid, 1-amino-cyclopropane-1-carboxylate and ethylene levels, thereby adjusting the fruit load to match the carbohydrate supply (Talón et al., 2000) Girdling has also been shown to alter the partitioning of photosynthates, mineral nutrients and plant growth regulators in the tree (Furr and Amstrong, 1956; Fishler et al., 1983; Mataa et al., 1998; Wallerstain et al., 1973; 1974; 1978ab)

88 Purpose Most girdling experiments have been applied to low bearing cultivars, and have not included comparisons with high-bearing cultivars. There is a lack of information about the most appropriate time for girdling, and the reasons for its effects The aim of the present study was to examine the effects of time of girdling on fruit-set, abscission pattern and yield. Starch, sucrose and reducing sugars contents in developing fruitlets of Fortune and Satsuma, two mandarin cultivars that differ in their productivity, provided information about the effects of girdling

89 Materials and Methods Orchards of Fortune mandarin differing in yields were selected for Expt. 1 Girdling was applied 15 d before anthesis (15 DBA), at anthesis (A), 10 d after anthesis (10 DAA), 35 DAA, 60 DAA and 90 DAA. Ungirdled controls The last girdling coincided with the end of fruitlet drop.

90 Materials and Methods Expt. 2-Ten-year-old Satsuma mandarin cv. Clausellina were girdled on main scaffold branches at 10 and 40 DAA w/ ungirdled Controls Abscission, carbohydrate analysis and harvest data obtained.

91 Results

92 Percentage remaining fruitlets of Fortune-pattern and final set

93 Accumulated abscission (Panel A) and on daily fruit drop (Panel B) in Satsuma cv. Clausellina from girdling 10 and 40 DAA

94 Note values in fruitlets

95 Effect of girdling date before, at or after anthesis (A) on fruit number at harvest in Fortune mandarin (Experiment 1). Values correspond to low-yield trees.

96 Effect of girdling at 40 DAA on the accumulation time-course of soluble carbohydrates [sucrose (Panel A); fructose (Panel B) glucose (Panel C)] in ovaries of Satsuma cv. Clausellina mandarin

97 Effect of girdling date before, at or after anthesis (A) on yields in low (Panel A) and high (Panel B) yielding orchards of Fortune mandarin in two consecutive years (Experiment 1).

98 Effect of girdling date (DAA, days after anthesis) or no girdling (control) on fruit harvested per tree in Satsuma cv. Clausellina mandarin (Experiment 2).

99 Conclusions Girdling branches increased fruit-set in citrus. Girdling performed close to anthesis facilitated the setting process in a cultivar less prone to set. When it was performed in full fruitlet abscission (35 40 DAA), girdling facilitated the setting process in cultivars, irrespective of their ability to set. The increased availability of carbohydrates to the fruitlets appears to be the most plausible explanation for the increased fruit-set that resulted from girdling.

100 F. RIVAS, A. GRAVINA and M. AGUSTÍ Girdling effects on fruit set and quantum yield efficiency of PSII in two Citrus cultivars. Tree Physiology 27, Fruit set in citrus requires large amounts of carbon compounds that are provided by current photosynthesis and reserves accumulated by the tree during winter Goldschmidt & Koch 1996, Bustan & Goldschmidt 1998 Carbohydrate reserves are mainly used during the early stages of fruitlet development (Shimizu et al. 1978) As a consequence of sink competition, a decline in the amount of stored photoassimilates leads to fruitlet abscission (Goldschmidt & Monselise 1978, Rivas et al. 2006) Fruit survival at this stage depends mainly on carbohydrates supplied by current photosynthesis (Iglesias et al. 2003)

101 Objectives Objectives were to determine the effects of trunk girdling on fruit set of leafless and leafy flowering shoots, and to examine how mature (8 to 12 months old) and young leaves (current spring flush) respond to the carbohydrate demands of developing fruitlets. The extent to which source leaves are able to modify the quantum yield efficiency of PSII (ΦPSII) during fruit set in response to girdling was also determined.

102 Materials and Methods Container-grown trees were 2-year-old Loretina mandarin (Spain) and 7-year old Nova (Uruguay) used. Half the trees/cultivar were trunk girdled at anthesis (60% of flowers opened), 10 cm above budunion 15 days before anthesis, four branches with at least 800 nodes each were selected (Nova) or all nodes counted (Loretina). At the end of natural fruitlet drop, persisting fruitlets were counted, and final fruit set was calculated. Citrus leaf SPAD readings provide a nondestructive method for determining leaf chlorophyll (Chl) and extracted Chl also determined

103 M and M (cont) The value of quantum yield efficiency of PSII of light adapted leaves (ΦPSII) was calculated according to the formula ΦPSII = (Fm Fs)Fm, where Fm and Fs are the maximum and steady-state fluorescence yield of light adapted leaves. Appropriate light absorption measurements taken. Appropriate carbohydrate values obtained 30 days after girdling

104 Results

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106 Figure 1. Fruit set pattern of the flowering shoots in 2-year-old Loretina mandarin trees trunk girdled at anthesis ( ) or ungirdled ().

107 Figure 2. Effects of girdling at anthesis on fruit set (bars) and fruit growth (lines) patterns of multiple-flowering and single-flowering leafy shoots in Nova mandarin.

108 Figure 3. Diameter of persisting fruitlets (A) and dry weight of abscised fruitlets (B) of trunk girdled (O) or ungirdled (O) trees in Loretina mandarin.

109 Figure 4. Quantum yield efficiency of photosystem II (ΦPSII,, ) and chlorophyll concentration (,) of mature leaves of trunk girdled (filled symbols) and ungirdled (open symbols) Loretina mandarin trees.

110 Figure 5. Quantum yield efficiency of photosystem II (ΦPSII, O ) and chlorophyll concentration (^) of young leaves of multiple-flowering leafy shoots of trunk girdled (filled symbols) and ungirdled (open symbols) Loretina mandarin.

111 Figure 6. Quantum yield efficiency of photosystem II (ΦPSII, O ) and chlorophyll concentration (^) of young leaves of vegetative shoots of trunk girdled (filled symbols) and ungirdled (open symbols) Loretina mandarin.

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113 Conclusions Girdling increased final fruit set only in leafy shoots. The delay in fruitlet abscission and the increase in ΦPSII in girdled leafy flowering shoots were the mechanisms underlying the enhancement of fruit set by girdling. Mature leaves did not adjust ΦPSII and vegetative shoots reduced ΦPSII in response to girdling

114 Mature leaves and vegetative shoots support the fruit set process, but are not implicated in the improvement in fruit set that results from girdling. Girdling reduces vegetative Pn Photoinhibition due to starch loading? Other papers

115 Overall Summary Fruit set characteristics last week Water availability effects Carbohydrate effects Girdling Carbohydrates elevated, GA elevated? timing Next week Effects of nutrition Hormonal or PGR effects