Rambutan is a fruit tree original from Malaysia, member of the Sapindaceae family. It is currently grown in some parts of India, Thailand, Indonesia, Costa Rica, Ecuador, Australia, Guatemala, and Mexico [1] . Given its acceptance in regional and national markets, rambutan is an economic option for the diversification of fruit crops in Chiapas, Mexico, mainly in the coffee growing zones located at an altitude between 100 and 1000 m [2] , with the 28˚C temperatures, 4000 mm precipitation and 75% HR averages during the spring and summer. The growing interest in this crop has brought about an increase in new plantations in the Soconusco area in the Chiapas state. The yields reported by the SAGARPA [3] are of 9.81 t∙ha⁻¹; while the FAO [4] reports yields in Malaysia, where this crop has efficient agronomical handling of 15 t∙ha⁻¹. Despite the mentioned importance of rambutan growing in Mexico, there are several biotic and abiotic factors that limit its production. These factors are phytosanitary problems, little genetic diversity in the grown varieties, deficient agronomical handling, difficulty in vegetative propagation, and production alternancy [1] .

Alternancy is a frequent phenomenon in woody fruit species. It is characterized for having high production yields in one year followed by low yields in the next year. Guardiola [5] mentions that this phenomenon has been mainly linked to genetic and physiological factors, among which stands out insufficient floral differentiation. In some fruit species, this behavior can be regulated with some agronomical practices like girdling, pruning, and water stress which are recommended to decrease alternancy in production [6] .

The practice of girdling or striping the branches of trees interrupts phloem in the plant, which favors the accumulation of carbohydrates and decreases gibberellins in buds and leaves. This allows inducing the anticipated flowering and increases floral differentiation [7] [8] . Likewise, it causes an increase in fruit set and fruit size, partially corrects late ripening of the fruits and alternancy of the production in fruit crops like litchi and citrus fruits [9] . The pruning of terminal shoots in fruit trees is done to ensure balance in the distribution of sap, light penetration, and ventilation of neighboring branches. In mango and citrus fruit crops, however this has invigorating effects, allowing to increase the number of new terminal shoots, increase photosynthetic efficiency, and the optimum value of cytokinins-gibberellins to stimulate flowering every year [10] [11] . With regard to the practice of water stress in tropical fruit crops, it causes flower induction and increase in flowering, while at the same time helps seasonal regulation, intensity, duration, and distribution of the flowering and harvest [12] . In fruit crops like apples and peaches, this practice induces flower bud production since the trees have greater reserves in the flower differentiation stage than for vegetative growth of stem and roots. Moreover, depending on the intensity of the stress, there can be wilting of the leaves, decrease of the stoma activity, net CO₂ assimilation, and radical conductance [13] . Because of this, the objective of the present study was to evaluate the effect of the application of agronomical practices such as pruning, girdling, water stress, and their interaction on the rambutan alternancy.

The research was carried out in the “La Chinita” commercial orchard, located on km. 4.5 of the Huehuetan Station-Nueva Victoria highway, Huehuetan, Chiapas, Mexico, at 15˚00'33" North Latitude and 92˚26'17" West Longitude, an altitude of 19 m. The soil characteristics are: texture-sandy loam, with the organic matter content of 1.31%, pH 6.1, 37.2% porosity, 59.7% saturation, and field capacity of 37%. The climate is represented by the acronym Am (w') ig corresponding to the warm subhumid climate with summer rains, an annual mean precipitation of 2200 mm, an annual average isothermal temperature of 28.4˚C and an average annual relative humidity of 85%.

From the temperature and precipitation records in the study site, it was observed that flowering induction of rambutan was influenced by exogenous factors, since all the treatments showed floral differentiation in the vegetative shoots. The factors that possibly allowed floral induction were: low temperatures between 17 and 20˚C, in the mornings (5:00 h A.M.) during November and February; and the loss of soil moisture during the dry season from November to April (Figure 3). The temperature in second cycle of evaluation was low from November to February, which allowed the flowering induction of the crop (Figure 4).

According to the data obtained from the monitoring of soil moistures under water stress conditions, the temporary wilting percentage (TWP) was reached 60 days after irrigation was suspended, with a percentage of usable moisture of 13%. Moreover, it was observed that the start of flowering (SF) and start of harvest was homogeneous in the treatments with water stress (WS), water stress and pruning (WS + P), water stress and girdling (WS + G), and water stress with pruning and girdling (WS + P + G); while at the end of the harvest (EH), the same treatments showed a longer harvest period than did the treatments with permanent irrigation (Figure 5).

In the treatments with permanent irrigation, the moisture percentage recorded was greater than 25% during the dry season; also, the start of flowering occurred 15 days before the treatments with water stress. Nevertheless, the start of harvest in the treatments with irrigation and pruning (I + P) was 10 days later than the treatments with only permanent irrigation (PI), irrigation and girdling (I + G), and irrigation with pruning and girdling (I + P + G). But at the end of harvest (EH), the treatment with irrigation, pruning and girdling (I + P + G) showed a more precocious harvest period (Figure 5).

In the second evaluation cycle, soil moisture for the conditions of water stress, the temporary wilting percentage (TWP) was reached 58 days after irrigation was suspended, where the percentage of usable moisture was 13%, similar to the first cycle of evaluation. In this cycle of evaluation, the start of flowering was homogeneous; however, when compared against the second cycle, there was a shorter harvest time. In the treatments with permanent irrigation, the moisture percentage was kept above 25% during the dry season. In this case, the flowering start time was in the months of December and January; however, the time necessary to start harvest was longer given that fruit development was slower (Figure 6).

The variance analysis showed significant differences for all the variables (P ≤ 0.05), except for the skin thickness variable. During to the cycles evaluated, the relevant effects were in four of the main variables: flowering percentage, fruit diameter and weight, and bunch weight. The treatment with water stress had effects on yield components like flowering percentage, number of fruits in the inflorescence, fruit diameter, aril thickness, fruit weight, bunch weight, and kilograms per tree in both harvest cycles. The treatments with pruning and girdling showed effect on flowering percentage, fruit diameter, shelf-life, and kilograms per tree variables. The treatments interactions showed significant differences (P ≤ 0.05) in fruit diameter, aril thickness, fruit weight, bunch weight, and postharvest shelf-life variables (Table 2).

In the mean comparison, the variables in both evaluation cycles showed significant differences (P ≤ 0.05) in the rambutan production. The trees with permanent irrigation (PI), flowering percentages of 52% were obtained, as well as fruits with 3.6 cm diameter, 0.6 cm thick arils, individual fruit weight of 31 g and a yield of 178 kg for tree. The trees with water stress were the flowering

VS = Variation source, Y = years, WS = Water stress, P = Pruning, G = Girdling, Y + WS = Years and Water stress, Y + P = Years and Pruning, Y + G = Years and Girdling, WS + P = Water stress and Pruning, WS + G = Water stress and Girdling, P + A = Pruning and Girdling, C + E + P = Years with Water stress and Pruning, C + E + A = Years with Water stress and girdling, Y + P + G = Years with Pruning and Girdling, Y + WS + P + G = Years with Water stress, Pruning, and Girdling, * = Significant alpha = 0.05 and ** = Highly significant alpha = 0.01; FP = Flowering percentage, NF = Number of fruits, FD = Fruit diameter, AT = Aril thickness (mm), ST = Skin thickness (mm), FW = Fruit weight (g), BW = Bunch weight (g), SL = Shelf-life (days), KPT = Kilograms per tree (kg).

percentage reached 96.8%, fruits with 3.9 cm diameter, 0.7 cm thick arils, individual fruit weight of 38.3 g and a yield of 296 kg for tree. In “Fortune” mandarin trees, Dell’Amico et al. [14] observed that plants subjected to water stress increased 21.35% more fruits per plant than the plants managed with sufficient irrigation; however, in other studies with citrus fruits, it has been observed that limited irrigation conditions are responsible for a greater number of smaller fruits given their lower average weight and lower final diameter [15] . The trees with girdling, the variables no showed effect, although there was an effect on flower percentage, fruit diameter, shelf-life, and kilograms per tree. In the first cycle of evaluation, the expressed variables were: fruit diameter, fruit weight, and bunch weight. In the second cycle of evaluation, the variable that showed significant difference (P ≤ 0.05) was flowering percentage (Table 3). In works with apples, similar behaviors were observed, agreeing with previous evaluation from other authors. Thus, it is important to cut down the number of fruits in commercial production of apple, mostly to obtain greater girths and avoid alternancy in cultivars with genetic problems. Late water deficit does not affect fruit quality. The production, fruit weight, and production efficiency are in function the fruit loads. The applied water deficit affects tree growth, but favors flowering density [16] .

In the global analysis of the two production cycles, the trees had an effect on

Same letter in a column shows no significant statistical difference alpha = 0.05, WS = Water stress, IR = Irrigation, P = Pruning, WP = Without pruning, G = Girdling, WG = Without girdling; Y1 = 1^st year, Y2 = 2^nd year, FP = Flowering percentage, NF = Number of fruits, FD = Fruit diameter, AT = Aril thickness (mm), ST = Skin thickness (mm), FW = Fruit weight (g), BW = Bunch weight (g), SL = Shelf-life (days), KPT = Kilograms per tree (kg).

the phenomenon of production alternancy were those kept though management the water deficits. The trees have the stress and pruning and girdling, stress and pruning, stress and girdling, and water stress no showed effect on the flowering percentage, fruit weight, and kilograms per tree. With regard the trees were haven constant irrigation combined with pruning and girdling, pruning, girdling, and irrigation, the same variables mentioned shown significant effects (Table 4).

According to the results of this study, agronomical management like pruning, girdling, and water stress has effects on the yield components in rambutan fruit crops. Thus, the impact of the alternancy phenomenon on the yield components of fruit crop can be decreased through some for the studied agronomical practices.

The pruning and girdling practices in rambutan were very unstable when paired with constant irrigation, but when interacting with water stress they showed the effects favorable in yield. Furthermore, the water stress is a practice suggesting that for the rambutan fruit crops, it gives the benefits in the fruit quality, uniformity of flowering differentiation, yield, and the decrease in alternancy.

Joo-Pérez, R., Avendaño-Arrazate, C.H., Sandoval-Esqui- vez, A., Espinoza-Zaragoza, S., Alonso-Báez, M., Moreno-Martínez, J.L., Ariza-Flores, R. and Morales-Nieto, C.R. (2017) Alternancy Study on Rambutan (Nephelium lappaceum L.) Tree in Mexico. American Journal of Plant Sciences, 8, 40-52. http://dx.doi.org/10.4236/ajps.2017.81004