FRUIT DEVELOPMENT guajava L.)

OF THREE

GUAVA CULTIVARS

(Psidium

Ben-Hur Mattiuz, Luiz Gonzaga Neto and José Moacir Pinheiro Lima Filho Agricullural Research Center for the Semi-Arid Tropic (CPATSA) P O. Box 23. Petrolina PE Brasil

Abstract The knowledge of guava fruiting cycle is of great interest not only due to its biological aspects but also as an important datum for the application of cultural practices. This paper was carried out in the Submédio São Francisco region on four-year old plants from the germplasm bank of EMBRAPA-CPATSA. The objective was to study the fruit growth pattem of the guava cultivars Patillo, Paluma and Red Selection of Florida. Fruit length and diameter were monitored on five occasions on twenty-day intervals, resulting on sigmoidal curves characterizing three growth phases, for alI cultivars. The results showed that, within the experimental period, the cultivars Red Selection of Florida and Paluma had about the same diameter and length growth rate with a mean value of 0.036 cmlday and 0.042 cmlday, respectively. The cv. Patillo had the lowest fruit growth rate, with an increment of 0.027 cmlday in diameter and 0.033 cmlday in length. 1. Introduction Irrigated horticulture presents today a great opportunity for agribusiness in the Northeast Brazil. This fact is mainly a function of soil and climate factors, followed by the increase of the irrigated areas, which usually maximize yield and profit. In this respect, guava is one of the fruit crops with increasing social and economic importance. It has been estimated that the planting area in the Submédio São Franciso region comprises about 600 hectares. Despite the actual and potential importance of irrigated guava, there is a luck of information that would allow the grower to improve guava yield. In this context, the knowledge of the developmental pattem of the guava fruit would decreaseyield losses. Determination of growing and developmental pattems of the guava fruit is very important for suggesting the right time for irrigation and fertilizer application (Pereira, 1987). Besides, under the biological scope, this study is of great value for evaluating varietal and interspecific traits that may define crop yield capacity (FeITi, 1979). 2. Material and methods This research was carried out in the Agricultural Research Center for the Semi-Arid Tropic (EMBRAPA-CPATSA), at Petrolina, PE. The region has a hot and dry climate, 23°C mean annual temperature and 61.7% mean annual relative humidity. Mean annual rainfall is around 450 mm. Three four-year old guava plants of the cultivars Paluma, Red Selection of Florida and Patillo were used. Initial diameter and length of the sampled fruits were measured with a sliding calliper. Five evaluations were performed on twenty-day intervalo The mean initial diameter and length were, respectively, 1.98 cm and 1.13 em. Fruit growth rate was calculated using the methodology proposed for plant growth analysis (Radford, 1967). The data collected were plotted for establishing fruit growth curves. Proc. Int. Sym. Myrtaceae Ed. L.C. Donadio Acta Hor!. 452. ISHS 1997

The mean fruit length and diameter of the cultivars Paluma, Red Selection of Florida and Patillo are presented in Figures 1,2, and 3. It was observed an accelerated growing phase occurring from day O to day 20. From this point, fruit growth slowed until day 80, when a new growth burst was observed. This tendency was also noted by Pereira (1987) for the cultivars Paluma and Rica. Weaver (1972) has defined guava fruit growth in three growing phases. The first one is a fast growing phase of the ovary and its components, except the endosperm and embryo. The growth of endosperm and embryo is observed in the second phase, together with the endocarp lignification and a small increase of the ovary wall. The third is the mesocarp growing phase, complete fruit formation and maturation. Fruit growth rate curves of the cultivars studied are presented in Figures 4, 5 and 6. The plotted data showed quadratic response for alI cultivars. From day 20 to day 60 it was observed a decrease in fruit growth rate. From then on, growth acceleration was detected until complete fruit formation that happened at day 100. These two periods are related to the second and third phases described by Weaver (1972). The cultivars Red Selection of Florida and Paluma showed identical mean growth rate values based on fruit diameter and length, reaching g 0.036 crn/day and 0.042 crn/day, respectively. However, the cultivar Patillo had the lowest growing rate, with only 0.027 crn/day in diameter and 0.033 crn/day in length.

Fruit length and diameter were characterized by sigmoidal curves, with three growth phases, for alI cultivars. The cultivars Red Selection of Florida and Paluma showed the greatest mean growth rate values, based on fruit diameter and length.

Ferri, M.G. Fisiologia vegetal. São Paulo: Ed. da Universidade de São Paulo, 1979, v. 1, 350p. Pereda, F.M; São José, A B. Estudo do desenvolvimento dos frutos da goiabeira 'Paluma' e 'Rica'. In: Congresso Brasileiro de Fruticultura, 9, 1987, Campinas, SP. Anais .. Campinas: SBF, 1987, v. 2, p. 469-474. Radford, P.J. Growth Analysis Formulae - their use and abuse. Crop Science, Madison, v. 7, n 3, p. 171-175, 1967. Weaver, RJ. Plant growth substances in agriculture. San Francisco: Freeman and Company, 1972. 594 p.

8.00

7)S{J 7110 8)S{J

v......,.

0,0423)(' + 0,434)( + 1.4487

YIolIr

0,D3X' + 0.4077)( + 0,81103 R2.

R2.

0"1117

0,t011

8,00 5,50 5.00 4,50

G

4,00 3,50 3.00 2,liO 2,00 1,liO 1.00 0,liO

1===1

0.00 20

40

Doya _lhe

10 Iht

10

8MIIIIInG

FIG. 1. Growth curves based on fruit diameter and length of cv. Paluma. EMBRAPACPATSA. Petrolina, PE, 1996. 8.00 7,liO 7.00 8,liO 8.00

YIeng. VdI8m.

0,0081)(' + 0,5558)( + 1,3023 R2. 0,D173x' + 0,3433)( + 0,8424 R2.

5.50 8.00 4,liO

G

4.00 3,liO 3.00 2,liO

0'O,l78ll

-----~

..

/

/

2.00 1,liO 1.00 0,50 0,00

1==::1 20

40

Doya _lhe

10

10

Iht umpI!lllI

FIG. 2. Growth curves based on fruit diameter and length of cv. Patillo. EMBRAPACPATSA. Petrolina, PE, 1996.

8.00

7)S{J 7.00 8,liO

YIeng.

0,ll327X' + O.~

VdI8m.O,0727x'

+ l.oa711 R2.

+0.1113X+

0,11I15

1,247 R2.0.8m

8.00 5,liO 5.00 4,liO

G

4.00 3.50

3.00 2,liO 2,00 1,50

1===1

1,00 0,liO 0.00 20

40

10

ao

Doya ZIIlerlhelIrst umpIllllI

FIG. 3. Growth curves based on fruit diameter and length of cv. Red Selection of Florida. EMBRAPA-CPATSA. Petrolina, PE. 1996.

0,10 0,08

YIeng• O,0142X2- 0.1148X+ 0,248 R2. 0,ll329 VdI8m- 0,0138)(2. O,11ll8X+ 0,233 R2 - 0,11II28

0,08 0,07

i:' 0,08

I

0,05 0,04 0,03 0,02 0,01 0,00 20

40 DlIys-

80

80

lhe_

100

UIIIpIIng

FIG, 4, Fruit diameter and length growth rate of the cv. Paluma. EMBRAPA-CPATSA. Petrolina PE, 1996.

f

0,08 0,05 0,04 0,03 0,02 0.01 0,00 DlIys -lhe

_.-..pIIng

FIG, 5. Fruit diameter and length growth rate of the cv, Patillo. EMBRAPA-CPATSA. Petrolina, PE, 1996. 0,10 0,08 0,08

YIeng• O,01l18X2O,13048X • + 0,2818 R2 - 0,8ll3ll V-.-0,017x"·0.1338X+0,284

R2-0,ll8ll1

0,07

f ::

0,04

0,03 0,02

1===1

0,01 0.00 40 DlIys -

80

80

lhen•• Ampltng

FIG. 6. Fruit diameter and length growth rate of the cv. Red Selection of Florida. EMBRAPA-CPATSA. Petrolina, PE, 1996.

STEM AND FRUIT GROWTH OF SIX GUAVA TREE (Psidium guajava L.) CULTIVARS UNDER SOIL WATER STRESS CONDITIONS Walter Esfrain Pereira and Flávio Alencar D'Araujo Couto Departamento de Fitotecnia, Universidade Federal de Viçosa 36571-000, Viçosa, MG Brasil.

The objective of this research was to study guava tree stem and fruit development of the 'Pirassununga Branca', 'Pirassununga Vermelha', 'Industrial de Montes Claros', 'Brune Branca', 'Tetraploide de Limeira' and 'IAC-4' cultivars under soil water stress conditions. After pruning on February 1995 it was evaluated the stem length and fresh and dry matter weight of fruits at each two week. For alI cultivars, the stem initial growth was high up to 56 or 84 days after pruning, depending from the cultivar, after that growth decreased due to soil water stress measured. The cultivars presenting the longest stem at 224 days after pruning were 'Pirassununga Branca' (521 mm) and 'Tetraploide de Limeira' (482 mm), while the smallest stem length was observed for the IAC-4 variety (258 mm). In relation to fruit growth, it is expected an increase of the productive cycle from 28 to 56 days according to cultivar, as a consequence of soil water stress. At the harvest time the cultivar presenting the heaviest fruit fresh matter was the 'Industrial de Montes Claros' (78,5 g), while the lowest value was for the 'Tetraploide de Limeira', with 26,3 g. 1. Introduction Guava tree is an important tropical and subtropical region fruit tree because of its high nutritive value. In addition to annual total rainfall, the rainfall distribution is a major factor. For its growth and development, guavatree requires a well distributed rainfall since lacking or excessive soil water conditions during growing stages may cause fruit quantitative and qualitative losses (Pereira and Martinez Jr 1986). Fruit growth is largely dependent on plant water potential. In addition it may be used as an adequate index for irrigation schedule (Assaf et.al., 1982). According to Rathore (1976), guava fruit growth curve has a double sigmoid shape presenting three different growing phases. The first growing phase corresponds to an accelerated growth, beginning a few days after anthesis and goes on for 45 or 60 days during the rainy season or winter and during spring, respectively. The second one is relatively slow and last about 30 days, except during spring when it extends up to 60 days; seed ripening and hardening occur at this growing phase. In the third one it is observed an exponential increase of fruit growing rate resulting in increased fruit diameter and length; this period last for 30, 60 and 90 days in raining season, winter and spring respectively. After fruit growth its external colour changes until its complete maturation. For in natura consumption it is very important to know guava growing curve mainly when commercial exploration is concerned. From the fruit growing curve and time interval it requires for reaching development, the farrner may plan his activities mainly those involving fruit thinning, packing as well as to decide about the best moment for harvesting under the commercial view point (Gonzaga Neto and Soares. 1994). The objective of this research was to study fruit and stem development from six guava tree varieties under soil water stress conditions.

Proc. Int. Sym. Myrtaceae Ed. L.C. Donadio Acta Hor!. 452. ISHS 1997